File indexing completed on 2024-04-28 09:38:54

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 #include "ktlq3scrollview.h"
 
 #include <QCursor>
 #include <QPainter>
 #include <QPixmap>
 #include <QScrollBar>
 #include <QWidget>
 // #include "q3ptrdict.h"
 #include <QApplication>
 #include <QHash>
 #include <QStyle>
 #include <QTimer>
 // #include "q3ptrlist.h"
 #include <QContextMenuEvent>
 #include <QDragEnterEvent>
 #include <QDragLeaveEvent>
 //#include "q3listview.h"
 // #ifdef Q_WS_MAC      // 2018.10.18 - do not depend on internal headers
 // # include "private/qt_mac_p.h"
 // #endif
 
 // QT_BEGIN_NAMESPACE
 
 // using namespace Qt;
 
 static const int coord_limit = 4000;
 static const int autoscroll_margin = 16;
 static const int initialScrollTime = 30;
 static const int initialScrollAccel = 5;
 
 struct QSVChildRec {
     QSVChildRec(QWidget *c, int xx, int yy)
         : child(c)
         , x(xx)
         , y(yy)
     {
     }
 
     void hideOrShow(KtlQ3ScrollView *sv, QWidget *clipped_viewport);
     void moveTo(KtlQ3ScrollView *sv, int xx, int yy, QWidget *clipped_viewport)
     {
         if (x != xx || y != yy) {
             x = xx;
             y = yy;
             hideOrShow(sv, clipped_viewport);
         }
     }
     QWidget *child;
     int x, y;
 };
 
 void QSVChildRec::hideOrShow(KtlQ3ScrollView *sv, QWidget *clipped_viewport)
 {
     if (clipped_viewport) {
         if (x + child->width() < sv->contentsX() + clipped_viewport->x() || x > sv->contentsX() + clipped_viewport->width() || y + child->height() < sv->contentsY() + clipped_viewport->y() ||
             y > sv->contentsY() + clipped_viewport->height()) {
             child->move(clipped_viewport->width(), clipped_viewport->height());
         } else {
             child->move(x - sv->contentsX() - clipped_viewport->x(), y - sv->contentsY() - clipped_viewport->y());
         }
     } else {
         child->move(x - sv->contentsX(), y - sv->contentsY());
     }
 }
 
 // QT_BEGIN_INCLUDE_NAMESPACE
 
 // QT_END_INCLUDE_NAMESPACE
 
 class KtlQ3ScrollViewData
 {
 public:
     KtlQ3ScrollViewData(KtlQ3ScrollView *parent, int vpwflags)
         : hbar(new QScrollBar(Qt::Horizontal, parent /*, "qt_hbar"*/))
         , vbar(new QScrollBar(Qt::Vertical, parent /*, "qt_vbar" */))
         , viewport(new KtlQAbstractScrollAreaWidget(parent, "qt_viewport", QFlag(vpwflags)))
         , clipped_viewport(nullptr)
         , flags(vpwflags)
         , vx(0)
         , vy(0)
         , vwidth(1)
         , vheight(1)
         ,
 #ifndef QT_NO_DRAGANDDROP
         autoscroll_timer(parent /* , "scrollview autoscroll timer" */)
         , drag_autoscroll(true)
         ,
 #endif
         scrollbar_timer(parent /*, "scrollview scrollbar timer" */)
         , inresize(false)
         , use_cached_size_hint(true)
     {
         hbar->setObjectName("qt_hbar");
         vbar->setObjectName("qt_vbar");
 #ifndef QT_NO_DRAGANDDROP
         autoscroll_timer.setObjectName("scrollview autoscroll timer");
 #endif
         scrollbar_timer.setObjectName("scrollview scrollbar timer");
         l_marg = r_marg = t_marg = b_marg = 0;
         viewport->ensurePolished();
         vMode = KtlQ3ScrollView::Auto;
         hMode = KtlQ3ScrollView::Auto;
         corner = nullptr;
         // vbar->setSteps(20, 1/*set later*/);
         vbar->setSingleStep(20);
         vbar->setPageStep(1);
         // hbar->setSteps(20, 1/*set later*/);
         hbar->setSingleStep(20);
         hbar->setPageStep(1);
         policy = KtlQ3ScrollView::Default;
         signal_choke = false;
         static_bg = false;
         fake_scroll = false;
         hbarPressed = false;
         vbarPressed = false;
         hbar->setLayoutDirection(Qt::LeftToRight);
     }
     ~KtlQ3ScrollViewData();
 
     QSVChildRec *rec(QWidget *w)
     {
         return /* childDict.find(w); */ childDict.value(w);
     }
     QSVChildRec *ancestorRec(QWidget *w);
     QSVChildRec *addChildRec(QWidget *w, int x, int y)
     {
         QSVChildRec *r = new QSVChildRec(w, x, y);
         children.append(r);
         childDict.insert(w, r);
         return r;
     }
     void deleteChildRec(QSVChildRec *r)
     {
         childDict.remove(r->child);
         // children.removeRef(r);
         children.removeAll(r);
         delete r;
     }
 
     void hideOrShowAll(KtlQ3ScrollView *sv, bool isScroll = false);
     void moveAllBy(int dx, int dy);
     bool anyVisibleChildren();
     void autoMove(KtlQ3ScrollView *sv);
     void autoResize(KtlQ3ScrollView *sv);
     void autoResizeHint(KtlQ3ScrollView *sv);
     void viewportResized(int w, int h);
 
     QScrollBar *hbar;
     QScrollBar *vbar;
     bool hbarPressed;
     bool vbarPressed;
     KtlQAbstractScrollAreaWidget *viewport;
     KtlQClipperWidget *clipped_viewport;
     int flags;
     // Q3PtrList<QSVChildRec>       children;
     QList<QSVChildRec *> children;
     // Q3PtrDict<QSVChildRec>       childDict; // 2018.10.07
     QHash<QWidget *, QSVChildRec *> childDict;
     QWidget *corner;
     int vx, vy, vwidth, vheight; // for drawContents-style usage
     int l_marg, r_marg, t_marg, b_marg;
     KtlQ3ScrollView::ResizePolicy policy;
     KtlQ3ScrollView::ScrollBarMode vMode;
     KtlQ3ScrollView::ScrollBarMode hMode;
 #ifndef QT_NO_DRAGANDDROP
     QPoint cpDragStart;
     QTimer autoscroll_timer;
     int autoscroll_time;
     int autoscroll_accel;
     bool drag_autoscroll;
 #endif
     QTimer scrollbar_timer;
 
     uint static_bg : 1;
     uint fake_scroll : 1;
 
     // This variable allows ensureVisible to move the contents then
     // update both the sliders.  Otherwise, updating the sliders would
     // cause two image scrolls, creating ugly flashing.
     //
     uint signal_choke : 1;
 
     // This variables indicates in updateScrollBars() that we are
     // in a resizeEvent() and thus don't want to flash scroll bars
     uint inresize : 1;
     uint use_cached_size_hint : 1;
     QSize cachedSizeHint;
 
     inline int contentsX() const
     {
         return -vx;
     }
     inline int contentsY() const
     {
         return -vy;
     }
     inline int contentsWidth() const
     {
         return vwidth;
     }
 };
 
 inline KtlQ3ScrollViewData::~KtlQ3ScrollViewData()
 {
     // children.setAutoDelete(true); // 2018.12.08
     for (QList<QSVChildRec *>::iterator it = children.begin(); it != children.end(); ++it) {
         QSVChildRec *r = *it;
         delete r;
     }
     children.removeAll(nullptr);
 }
 
 QSVChildRec *KtlQ3ScrollViewData::ancestorRec(QWidget *w)
 {
     if (clipped_viewport) {
         while (w->parentWidget() != clipped_viewport) {
             w = w->parentWidget();
             if (!w)
                 return nullptr;
         }
     } else {
         while (w->parentWidget() != viewport) {
             w = w->parentWidget();
             if (!w)
                 return nullptr;
         }
     }
     return rec(w);
 }
 
 void KtlQ3ScrollViewData::hideOrShowAll(KtlQ3ScrollView *sv, bool isScroll)
 {
     if (!clipped_viewport)
         return;
     if (clipped_viewport->x() <= 0 && clipped_viewport->y() <= 0 && clipped_viewport->width() + clipped_viewport->x() >= viewport->width() && clipped_viewport->height() + clipped_viewport->y() >= viewport->height()) {
         // clipped_viewport still covers viewport
         if (static_bg) {
             // clipped_viewport->repaint(true); // 2018.11.30
             clipped_viewport->repaint();
         } else if ((!isScroll && !clipped_viewport->testAttribute(Qt::WA_StaticContents)) || static_bg)
             clipped_viewport->update();
     } else {
         // Re-center
         int nx = (viewport->width() - clipped_viewport->width()) / 2;
         int ny = (viewport->height() - clipped_viewport->height()) / 2;
         clipped_viewport->move(nx, ny);
         clipped_viewport->update();
     }
     // for (QSVChildRec *r = children.first(); r; r=children.next()) {   // 2018.12.08
     //    r->hideOrShow(sv, clipped_viewport);
     //}
     for (QList<QSVChildRec *>::iterator it = children.begin(); it != children.end(); ++it) {
         QSVChildRec *r = *it;
         r->hideOrShow(sv, clipped_viewport);
     }
 }
 
 void KtlQ3ScrollViewData::moveAllBy(int dx, int dy)
 {
     if (clipped_viewport && !static_bg) {
         clipped_viewport->move(clipped_viewport->x() + dx, clipped_viewport->y() + dy);
     } else {
         // for (QSVChildRec *r = children.first(); r; r=children.next()) { // 2018.12.07
         //    r->child->move(r->child->x()+dx,r->child->y()+dy);
         //}
         for (QList<QSVChildRec *>::iterator it = children.begin(); it != children.end(); ++it) {
             QSVChildRec *r = *it;
             r->child->move(r->child->x() + dx, r->child->y() + dy);
         }
 
         if (static_bg) {
             // viewport->repaint(true); // 2018.11.30
             viewport->repaint();
         }
     }
 }
 
 bool KtlQ3ScrollViewData::anyVisibleChildren()
 {
     // for (QSVChildRec *r = children.first(); r; r=children.next()) {   // 2018.12.08
     //    if (r->child->isVisible()) return true;
     //}
     for (QList<QSVChildRec *>::iterator it = children.begin(); it != children.end(); ++it) {
         QSVChildRec *r = *it;
         if (r->child->isVisible())
             return true;
     }
     return false;
 }
 
 void KtlQ3ScrollViewData::autoMove(KtlQ3ScrollView *sv)
 {
     if (policy == KtlQ3ScrollView::AutoOne) {
         QSVChildRec *r = children.first();
         if (r)
             sv->setContentsPos(-r->child->x(), -r->child->y());
     }
 }
 
 void KtlQ3ScrollViewData::autoResize(KtlQ3ScrollView *sv)
 {
     if (policy == KtlQ3ScrollView::AutoOne) {
         QSVChildRec *r = children.first();
         if (r)
             sv->resizeContents(r->child->width(), r->child->height());
     }
 }
 
 void KtlQ3ScrollViewData::autoResizeHint(KtlQ3ScrollView *sv)
 {
     if (policy == KtlQ3ScrollView::AutoOne) {
         QSVChildRec *r = children.first();
         if (r) {
             QSize s = r->child->sizeHint();
             if (s.isValid())
                 r->child->resize(s);
         }
     } else if (policy == KtlQ3ScrollView::AutoOneFit) {
         QSVChildRec *r = children.first();
         if (r) {
             QSize sh = r->child->sizeHint();
             sh = sh.boundedTo(r->child->maximumSize());
             sv->resizeContents(sh.width(), sh.height());
         }
     }
 }
 
 void KtlQ3ScrollViewData::viewportResized(int w, int h)
 {
     if (policy == KtlQ3ScrollView::AutoOneFit) {
         QSVChildRec *r = children.first();
         if (r) {
             QSize sh = r->child->sizeHint();
             sh = sh.boundedTo(r->child->maximumSize());
             r->child->resize(qMax(w, sh.width()), qMax(h, sh.height()));
         }
     }
 }
 
 /*!
     \class KtlQ3ScrollView
     \brief The KtlQ3ScrollView widget provides a scrolling area with on-demand scroll bars.
 
     \compat
 
     The KtlQ3ScrollView is a large canvas - potentially larger than the
     coordinate system normally supported by the underlying window
     system. This is important because it is quite easy to go beyond
     these limitations (e.g. many web pages are more than 32000 pixels
     high). Additionally, the KtlQ3ScrollView can have QWidgets positioned
     on it that scroll around with the drawn content. These sub-widgets
     can also have positions outside the normal coordinate range (but
     they are still limited in size).
 
     To provide content for the widget, inherit from KtlQ3ScrollView,
     reimplement drawContents() and use resizeContents() to set the
     size of the viewed area. Use addChild() and moveChild() to
     position widgets on the view.
 
     To use KtlQ3ScrollView effectively it is important to understand its
     widget structure in the three styles of use: a single large child
     widget, a large panning area with some widgets and a large panning
     area with many widgets.
 
     \section1 Using One Big Widget
 
     \img qscrollview-vp2.png
 
     The first, simplest usage of KtlQ3ScrollView (depicted above), is
     appropriate for scrolling areas that are never more than about
     4000 pixels in either dimension (this is about the maximum
     reliable size on X11 servers). In this usage, you just make one
     large child in the KtlQ3ScrollView. The child should be a child of the
     viewport() of the scrollview and be added with addChild():
     \snippet doc/src/snippets/code/src_qt3support_widgets_q3scrollview.cpp 0
     You can go on to add arbitrary child widgets to the single child
     in the scrollview as you would with any widget:
     \snippet doc/src/snippets/code/src_qt3support_widgets_q3scrollview.cpp 1
 
     Here the KtlQ3ScrollView has four children: the viewport(), the
     verticalScrollBar(), the horizontalScrollBar() and a small
     cornerWidget(). The viewport() has one child: the QWidget. The
     QWidget has the three QLabel objects as child widgets. When the view
     is scrolled, the QWidget is moved; its children move with it as
     child widgets normally do.
 
     \section1 Using a Very Big View with Some Widgets
 
     \img qscrollview-vp.png
 
     The second usage of KtlQ3ScrollView (depicted above) is appropriate
     when few, if any, widgets are on a very large scrolling area that
     is potentially larger than 4000 pixels in either dimension. In
     this usage you call resizeContents() to set the size of the area
     and reimplement drawContents() to paint the contents. You may also
     add some widgets by making them children of the viewport() and
     adding them with addChild() (this is the same as the process for
     the single large widget in the previous example):
     \snippet doc/src/snippets/code/src_qt3support_widgets_q3scrollview.cpp 2
     Here, the KtlQ3ScrollView has the same four children: the viewport(),
     the verticalScrollBar(), the horizontalScrollBar() and a small
     cornerWidget(). The viewport() has the three QLabel objects as
     child widgets. When the view is scrolled, the scrollview moves the
     child widgets individually.
 
     \section1 Using a Very Big View with Many Widgets
 
     \img qscrollview-cl.png
 
     The final usage of KtlQ3ScrollView (depicted above) is appropriate
     when many widgets are on a very large scrolling area that is
     potentially larger than 4000 pixels in either dimension. In this
     usage you call resizeContents() to set the size of the area and
     reimplement drawContents() to paint the contents. You then call
     enableClipper(true) and add widgets, again by making them children
     of the viewport(), and adding them with addChild():
     \snippet doc/src/snippets/code/src_qt3support_widgets_q3scrollview.cpp 3
 
     Here, the KtlQ3ScrollView has four children:  the clipper() (not the
     viewport() this time), the verticalScrollBar(), the
     horizontalScrollBar() and a small cornerWidget(). The clipper()
     has one child: the viewport(). The viewport() has the same three
     labels as child widgets. When the view is scrolled the viewport()
     is moved; its children move with it as child widgets normally do.
 
     \target allviews
     \section1 Details Relevant for All Views
 
     Normally you will use the first or third method if you want any
     child widgets in the view.
 
     Note that the widget you see in the scrolled area is the
     viewport() widget, not the KtlQ3ScrollView itself. So to turn mouse
     tracking on, for example, use viewport()->setMouseTracking(true).
 
     To enable drag-and-drop, you would setAcceptDrops(true) on the
     KtlQ3ScrollView (because drag-and-drop events propagate to the
     parent). But to work out the logical position in the view, you
     would need to map the drop co-ordinate from being relative to the
     KtlQ3ScrollView to being relative to the contents; use the function
     viewportToContents() for this.
 
     To handle mouse events on the scrolling area, subclass scrollview
     as you would subclass other widgets, but rather than
     reimplementing mousePressEvent(), reimplement
     contentsMousePressEvent() instead. The contents specific event
     handlers provide translated events in the coordinate system of the
     scrollview. If you reimplement mousePressEvent(), you'll get
     called only when part of the KtlQ3ScrollView is clicked: and the only
     such part is the "corner" (if you don't set a cornerWidget()) and
     the frame; everything else is covered up by the viewport, clipper
     or scroll bars.
 
     When you construct a KtlQ3ScrollView, some of the window flags apply
     to the viewport() instead of being sent to the QWidget constructor
     for the KtlQ3ScrollView.
 
     \list
 
     \i An image-manipulation widget would use \c
     WNoAutoErase|WStaticContents because the widget draws all pixels
     itself, and when its size increases, it only needs a paint event
     for the new part because the old part remains unchanged.
 
     \i A scrolling game widget in which the background scrolls as the
     characters move might use \c WNoAutoErase (in addition to \c
     WStaticContents) so that the window system background does not
     flash in and out during scrolling.
 
     \i A word processing widget might use \c WNoAutoErase and repaint
     itself line by line to get a less-flickery resizing. If the widget
     is in a mode in which no text justification can take place, it
     might use \c WStaticContents too, so that it would only get a
     repaint for the newly visible parts.
 
     \endlist
 
     Child widgets may be moved using addChild() or moveChild(). Use
     childX() and childY() to get the position of a child widget.
 
     A widget may be placed in the corner between the vertical and
     horizontal scroll bars with setCornerWidget(). You can get access
     to the scroll bars using horizontalScrollBar() and
     verticalScrollBar(), and to the viewport with viewport(). The
     scroll view can be scrolled using scrollBy(), ensureVisible(),
     setContentsPos() or center().
 
     The visible area is given by visibleWidth() and visibleHeight(),
     and the contents area by contentsWidth() and contentsHeight(). The
     contents may be repainted using one of the repaintContents() or
     updateContents() functions.
 
     Coordinate conversion is provided by contentsToViewport() and
     viewportToContents().
 
     The contentsMoving() signal is emitted just before the contents
     are moved to a new position.
 
     \warning KtlQ3ScrollView currently does not erase the background when
     resized, i.e. you must always clear the background manually in
     scrollview subclasses. This will change in a future version of Qt
     and we recommend specifying the \c WNoAutoErase flag explicitly.
 */
 
 /*!
     \enum KtlQ3ScrollView::ResizePolicy
 
     This enum type is used to control a KtlQ3ScrollView's reaction to
     resize events.
 
     \value Default  the KtlQ3ScrollView selects one of the other settings
     automatically when it has to. In this version of Qt, KtlQ3ScrollView
     changes to \c Manual if you resize the contents with
     resizeContents() and to \c AutoOne if a child is added.
 
     \value Manual  the contents stays the size set by resizeContents().
 
     \value AutoOne  if there is only one child widget the contents stays
     the size of that widget. Otherwise the behavior is undefined.
 
     \value AutoOneFit if there is only one child widget the contents stays
     the size of that widget's sizeHint(). If the scrollview is resized
     larger than the child's sizeHint(), the child will be resized to
     fit. If there is more than one child, the behavior is undefined.
 
 */
 //####  The widget will be resized to its sizeHint() when a LayoutHint event
 //#### is received
 
 /*!
     Constructs a KtlQ3ScrollView called \a name with parent \a parent and
     widget flags \a f.
 
     The widget flags \c WStaticContents, \c WNoAutoErase and \c
     WPaintClever are propagated to the viewport() widget. The other
     widget flags are propagated to the parent constructor as usual.
 */
 
 KtlQ3ScrollView::KtlQ3ScrollView(QWidget *parent, const char *name, Qt::WindowFlags f)
     : KtlQ3Frame(parent, name, f & (~Qt::WA_StaticContents) /*& (~Qt::WNoAutoErase) & (~Qt::WResizeNoErase) */)
 {
     Qt::WindowFlags flags = /* Qt::WResizeNoErase |  (f&Qt::WPaintClever)
         | (f&Qt::WRepaintNoErase) | */
         (f & Qt::WA_StaticContents);
     d = new KtlQ3ScrollViewData(this, flags);
 
 #ifndef QT_NO_DRAGANDDROP
     connect(&d->autoscroll_timer, SIGNAL(timeout()), this, SLOT(doDragAutoScroll()));
 #endif
 
     connect(d->hbar, SIGNAL(valueChanged(int)), this, SLOT(hslide(int)));
     connect(d->vbar, SIGNAL(valueChanged(int)), this, SLOT(vslide(int)));
 
     connect(d->hbar, SIGNAL(sliderPressed()), this, SLOT(hbarIsPressed()));
     connect(d->hbar, SIGNAL(sliderReleased()), this, SLOT(hbarIsReleased()));
     connect(d->vbar, SIGNAL(sliderPressed()), this, SLOT(vbarIsPressed()));
     connect(d->vbar, SIGNAL(sliderReleased()), this, SLOT(vbarIsReleased()));
 
     d->viewport->installEventFilter(this);
 
     connect(&d->scrollbar_timer, SIGNAL(timeout()), this, SLOT(updateScrollBars()));
 
     setFrameStyle(KtlQ3Frame::StyledPanel | KtlQ3Frame::Sunken);
     setLineWidth(style()->pixelMetric(QStyle::PM_DefaultFrameWidth));
     setSizePolicy(QSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding));
 }
 
 /*!
     Destroys the KtlQ3ScrollView. Any children added with addChild() will
     be deleted.
 */
 KtlQ3ScrollView::~KtlQ3ScrollView()
 {
     // Be careful not to get all those useless events...
     if (d->clipped_viewport)
         d->clipped_viewport->removeEventFilter(this);
     else
         d->viewport->removeEventFilter(this);
 
     // order is important
     // ~QWidget may cause a WM_ERASEBKGND on Windows
     delete d->vbar;
     d->vbar = nullptr;
     delete d->hbar;
     d->hbar = nullptr;
     delete d->viewport;
     d->viewport = nullptr;
     delete d;
     d = nullptr;
 }
 
 /*!
     \fn void KtlQ3ScrollView::horizontalSliderPressed()
 
     This signal is emitted whenever the user presses the horizontal slider.
 */
 /*!
     \fn void KtlQ3ScrollView::horizontalSliderReleased()
 
     This signal is emitted whenever the user releases the horizontal slider.
 */
 /*!
     \fn void KtlQ3ScrollView::verticalSliderPressed()
 
     This signal is emitted whenever the user presses the vertical slider.
 */
 /*!
     \fn void KtlQ3ScrollView::verticalSliderReleased()
 
     This signal is emitted whenever the user releases the vertical slider.
 */
 void KtlQ3ScrollView::hbarIsPressed()
 {
     d->hbarPressed = true;
     emit(horizontalSliderPressed());
 }
 
 void KtlQ3ScrollView::hbarIsReleased()
 {
     d->hbarPressed = false;
     emit(horizontalSliderReleased());
 }
 
 /*!
     Returns true if horizontal slider is pressed by user; otherwise returns false.
 */
 bool KtlQ3ScrollView::isHorizontalSliderPressed()
 {
     return d->hbarPressed;
 }
 
 void KtlQ3ScrollView::vbarIsPressed()
 {
     d->vbarPressed = true;
     emit(verticalSliderPressed());
 }
 
 void KtlQ3ScrollView::vbarIsReleased()
 {
     d->vbarPressed = false;
     emit(verticalSliderReleased());
 }
 
 /*!
     Returns true if vertical slider is pressed by user; otherwise returns false.
 */
 bool KtlQ3ScrollView::isVerticalSliderPressed()
 {
     return d->vbarPressed;
 }
 
 /*!
     \internal
 */
 void KtlQ3ScrollView::styleChange(QStyle &/*old*/)
 {
     // QWidget::styleChange(old); // 2019.04.14
     updateScrollBars();
     d->cachedSizeHint = QSize();
 }
 
 /*!
     \internal
 */
 void KtlQ3ScrollView::fontChange(const QFont &/*old*/)
 {
     // QWidget::fontChange(old); // 2019.04.14
     updateScrollBars();
     d->cachedSizeHint = QSize();
 }
 
 void KtlQ3ScrollView::hslide(int pos)
 {
     if (!d->signal_choke) {
         moveContents(-pos, -d->contentsY());
         QGuiApplication::sync();
     }
 }
 
 void KtlQ3ScrollView::vslide(int pos)
 {
     if (!d->signal_choke) {
         moveContents(-d->contentsX(), -pos);
         QGuiApplication::sync();
     }
 }
 
 /*!
     Called when the horizontal scroll bar geometry changes. This is
     provided as a protected function so that subclasses can do
     interesting things such as providing extra buttons in some of the
     space normally used by the scroll bars.
 
     The default implementation simply gives all the space to \a hbar.
     The new geometry is given by \a x, \a y, \a w and \a h.
 
     \sa setVBarGeometry()
 */
 void KtlQ3ScrollView::setHBarGeometry(QScrollBar &hbar, int x, int y, int w, int h)
 {
     hbar.setGeometry(x, y, w, h);
 }
 
 /*!
     Called when the vertical scroll bar geometry changes. This is
     provided as a protected function so that subclasses can do
     interesting things such as providing extra buttons in some of the
     space normally used by the scroll bars.
 
     The default implementation simply gives all the space to \a vbar.
     The new geometry is given by \a x, \a y, \a w and \a h.
 
     \sa setHBarGeometry()
 */
 void KtlQ3ScrollView::setVBarGeometry(QScrollBar &vbar, int x, int y, int w, int h)
 {
     vbar.setGeometry(x, y, w, h);
 }
 
 /*!
     Returns the viewport size for size (\a x, \a y).
 
     The viewport size depends on (\a x, \a y) (the size of the contents),
     the size of this widget and the modes of the horizontal and
     vertical scroll bars.
 
     This function permits widgets that can trade vertical and
     horizontal space for each other to control scroll bar appearance
     better. For example, a word processor or web browser can control
     the width of the right margin accurately, whether or not there
     needs to be a vertical scroll bar.
 */
 
 QSize KtlQ3ScrollView::viewportSize(int x, int y) const
 {
     int fw = frameWidth();
     int lmarg = fw + d->l_marg;
     int rmarg = fw + d->r_marg;
     int tmarg = fw + d->t_marg;
     int bmarg = fw + d->b_marg;
 
     int w = width();
     int h = height();
 
     bool needh, needv;
     bool showh, showv;
     int hsbExt = horizontalScrollBar()->sizeHint().height();
     int vsbExt = verticalScrollBar()->sizeHint().width();
 
     if (d->policy != AutoOne || d->anyVisibleChildren()) {
         // Do we definitely need the scroll bar?
         needh = w - lmarg - rmarg < x;
         needv = h - tmarg - bmarg < y;
 
         // Do we intend to show the scroll bar?
         if (d->hMode == AlwaysOn)
             showh = true;
         else if (d->hMode == AlwaysOff)
             showh = false;
         else
             showh = needh;
 
         if (d->vMode == AlwaysOn)
             showv = true;
         else if (d->vMode == AlwaysOff)
             showv = false;
         else
             showv = needv;
 
         // Given other scroll bar will be shown, NOW do we need one?
         if (showh && h - vsbExt - tmarg - bmarg < y) {
             if (d->vMode == Auto)
                 showv = true;
         }
         if (showv && w - hsbExt - lmarg - rmarg < x) {
             if (d->hMode == Auto)
                 showh = true;
         }
     } else {
         // Scroll bars not needed, only show scroll bar that are always on.
         showh = d->hMode == AlwaysOn;
         showv = d->vMode == AlwaysOn;
     }
 
     return QSize(w - lmarg - rmarg - (showv ? vsbExt : 0), h - tmarg - bmarg - (showh ? hsbExt : 0));
 }
 
 /*!
     Updates scroll bars: all possibilities are considered. You should
     never need to call this in your code.
 */
 void KtlQ3ScrollView::updateScrollBars()
 {
     if (!horizontalScrollBar() && !verticalScrollBar())
         return;
 
     // I support this should use viewportSize()... but it needs
     // so many of the temporary variables from viewportSize.  hm.
     int fw = frameWidth();
     int lmarg = fw + d->l_marg;
     int rmarg = fw + d->r_marg;
     int tmarg = fw + d->t_marg;
     int bmarg = fw + d->b_marg;
 
     int w = width();
     int h = height();
 
     int portw, porth;
 
     bool needh;
     bool needv;
     bool showh;
     bool showv;
     bool showc = false;
 
     int hsbExt = horizontalScrollBar()->sizeHint().height();
     int vsbExt = verticalScrollBar()->sizeHint().width();
 
     QSize oldVisibleSize(visibleWidth(), visibleHeight());
 
     if (d->policy != AutoOne || d->anyVisibleChildren()) {
         // Do we definitely need the scroll bar?
         needh = w - lmarg - rmarg < d->contentsWidth();
         if (d->inresize)
             needh = !horizontalScrollBar()->isHidden();
         needv = h - tmarg - bmarg < contentsHeight();
 
         // Do we intend to show the scroll bar?
         if (d->hMode == AlwaysOn)
             showh = true;
         else if (d->hMode == AlwaysOff)
             showh = false;
         else
             showh = needh;
 
         if (d->vMode == AlwaysOn)
             showv = true;
         else if (d->vMode == AlwaysOff)
             showv = false;
         else
             showv = needv;
 
 #ifdef Q_WS_MAC
         bool mac_need_scroll = false;
         if (!parentWidget()) {
             mac_need_scroll = true;
         } else {
             QWidget *tlw = window();
             // #ifndef QT_MAC_USE_COCOA           // 2018.10.18 - do not depend on internal headers
             //             QPoint tlw_br = QPoint(tlw->width(), tlw->height()),
             //                     my_br = qt_mac_posInWindow(this) + QPoint(w, h);
             //             if(my_br.x() >= tlw_br.x() - 3 && my_br.y() >= tlw_br.y() - 3)
             // #endif
             mac_need_scroll = true;
         }
         if (mac_need_scroll) {
             // #ifndef QT_MAC_USE_COCOA           // 2018.10.18 - do not depend on internal headers
             //             WindowAttributes attr;
             //             GetWindowAttributes((WindowPtr)handle(), &attr);
             //             mac_need_scroll = (attr & kWindowResizableAttribute);
             // #endif
         }
         if (mac_need_scroll) {
             showc = true;
             if (d->vMode == Auto)
                 showv = true;
             if (d->hMode == Auto)
                 showh = true;
         }
 #endif
 
         // Given other scroll bar will be shown, NOW do we need one?
         if (showh && h - vsbExt - tmarg - bmarg < contentsHeight()) {
             needv = true;
             if (d->vMode == Auto)
                 showv = true;
         }
         if (showv && !d->inresize && w - hsbExt - lmarg - rmarg < d->contentsWidth()) {
             needh = true;
             if (d->hMode == Auto)
                 showh = true;
         }
     } else {
         // Scrollbars not needed, only show scroll bar that are always on.
         needh = needv = false;
         showh = d->hMode == AlwaysOn;
         showv = d->vMode == AlwaysOn;
     }
 
     bool sc = d->signal_choke;
     d->signal_choke = true;
 
     // Hide unneeded scroll bar, calculate viewport size
     if (showh) {
         porth = h - hsbExt - tmarg - bmarg;
     } else {
         if (!needh)
             d->hbar->setValue(0);
         d->hbar->hide();
         porth = h - tmarg - bmarg;
     }
     if (showv) {
         portw = w - vsbExt - lmarg - rmarg;
     } else {
         if (!needv)
             d->vbar->setValue(0);
         d->vbar->hide();
         portw = w - lmarg - rmarg;
     }
 
     // Configure scroll bars that we will show
     if (needv) {
         d->vbar->setRange(0, contentsHeight() - porth);
         // d->vbar->setSteps(KtlQ3ScrollView::d->vbar->lineStep(), porth); // 2018.11.30
         d->vbar->setSingleStep(KtlQ3ScrollView::d->vbar->singleStep());
         d->vbar->setPageStep(porth);
     } else {
         d->vbar->setRange(0, 0);
     }
     if (needh) {
         d->hbar->setRange(0, qMax(0, d->contentsWidth() - portw));
         // d->hbar->setSteps(KtlQ3ScrollView::d->hbar->lineStep(), portw); // 2018.11.30
         d->hbar->setSingleStep(KtlQ3ScrollView::d->hbar->singleStep());
         d->hbar->setPageStep(portw);
     } else {
         d->hbar->setRange(0, 0);
     }
 
     // Position the scroll bars, viewport and corner widget.
     int bottom;
     bool reverse = QApplication::layoutDirection() == Qt::RightToLeft;
     int xoffset = (reverse && (showv || cornerWidget())) ? vsbExt : 0;
     int xpos = reverse ? 0 : w - vsbExt;
     bool frameContentsOnly = style()->styleHint(QStyle::SH_ScrollView_FrameOnlyAroundContents);
 
     if (!frameContentsOnly) {
         if (reverse)
             xpos += fw;
         else
             xpos -= fw;
     }
     if (showh) {
         int right = (showc || showv || cornerWidget()) ? w - vsbExt : w;
         if (!frameContentsOnly)
             setHBarGeometry(*d->hbar, fw + xoffset, h - hsbExt - fw, right - fw - fw, hsbExt);
         else
             setHBarGeometry(*d->hbar, 0 + xoffset, h - hsbExt, right, hsbExt);
         bottom = h - hsbExt;
     } else {
         bottom = h;
     }
     if (showv) {
         clipper()->setGeometry(lmarg + xoffset, tmarg, w - vsbExt - lmarg - rmarg, bottom - tmarg - bmarg);
         d->viewportResized(w - vsbExt - lmarg - rmarg, bottom - tmarg - bmarg);
         if (!frameContentsOnly)
             changeFrameRect(QRect(0, 0, w, h));
         else
             changeFrameRect(QRect(xoffset, 0, w - vsbExt, bottom));
         if (showc || cornerWidget()) {
             if (!frameContentsOnly)
                 setVBarGeometry(*d->vbar, xpos, fw, vsbExt, h - hsbExt - fw - fw);
             else
                 setVBarGeometry(*d->vbar, xpos, 0, vsbExt, h - hsbExt);
         } else {
             if (!frameContentsOnly)
                 setVBarGeometry(*d->vbar, xpos, fw, vsbExt, bottom - fw - fw);
             else
                 setVBarGeometry(*d->vbar, xpos, 0, vsbExt, bottom);
         }
     } else {
         if (!frameContentsOnly)
             changeFrameRect(QRect(0, 0, w, h));
         else
             changeFrameRect(QRect(0, 0, w, bottom));
         clipper()->setGeometry(lmarg, tmarg, w - lmarg - rmarg, bottom - tmarg - bmarg);
         d->viewportResized(w - lmarg - rmarg, bottom - tmarg - bmarg);
     }
 
     QWidget *corner = d->corner;
     if (d->corner) {
         if (!frameContentsOnly)
             corner->setGeometry(xpos, h - hsbExt - fw, vsbExt, hsbExt);
         else
             corner->setGeometry(xpos, h - hsbExt, vsbExt, hsbExt);
     }
 
     d->signal_choke = sc;
 
     if (d->contentsX() + visibleWidth() > d->contentsWidth()) {
         int x;
 #if 0
         if (reverse)
             x =qMin(0,d->contentsWidth()-visibleWidth());
         else
 #endif
         x = qMax(0, d->contentsWidth() - visibleWidth());
         d->hbar->setValue(x);
         // Do it even if it is recursive
         moveContents(-x, -d->contentsY());
     }
     if (d->contentsY() + visibleHeight() > contentsHeight()) {
         int y = qMax(0, contentsHeight() - visibleHeight());
         d->vbar->setValue(y);
         // Do it even if it is recursive
         moveContents(-d->contentsX(), -y);
     }
 
     // Finally, show the scroll bars
     if (showh && (d->hbar->isHidden() || !d->hbar->isVisible()))
         d->hbar->show();
     if (showv && (d->vbar->isHidden() || !d->vbar->isVisible()))
         d->vbar->show();
 
     d->signal_choke = true;
     d->vbar->setValue(d->contentsY());
     d->hbar->setValue(d->contentsX());
     d->signal_choke = false;
 
     QSize newVisibleSize(visibleWidth(), visibleHeight());
     if (d->clipped_viewport && oldVisibleSize != newVisibleSize) {
         QResizeEvent e(newVisibleSize, oldVisibleSize);
         viewportResizeEvent(&e);
     }
 }
 
 /*!
     \reimp
 */
 void KtlQ3ScrollView::setVisible(bool visible)
 {
     if (visible && !isVisible()) {
         QWidget::setVisible(visible);
         updateScrollBars();
         d->hideOrShowAll(this);
     } else {
         QWidget::setVisible(visible);
     }
 }
 
 /*!
     \internal
  */
 void KtlQ3ScrollView::resize(int w, int h)
 {
     QWidget::resize(w, h);
 }
 
 /*!
     \internal
 */
 void KtlQ3ScrollView::resize(const QSize &s)
 {
     resize(s.width(), s.height());
 }
 
 /*!
     \reimp
 */
 void KtlQ3ScrollView::resizeEvent(QResizeEvent */*event*/)
 {
     // KtlQ3Frame::resizeEvent();
 
 #if 0
     if (QApplication::reverseLayout()) {
         d->fake_scroll = true;
         scrollBy(-event->size().width() + event->oldSize().width(), 0);
         d->fake_scroll = false;
     }
 #endif
 
     bool inresize = d->inresize;
     d->inresize = true;
     updateScrollBars();
     d->inresize = inresize;
     // d->scrollbar_timer.start(0, true); // 2018.11.30
     d->scrollbar_timer.setSingleShot(true);
     d->scrollbar_timer.start(0);
 
     d->hideOrShowAll(this);
 }
 
 /*!
     \reimp
 */
 void KtlQ3ScrollView::mousePressEvent(QMouseEvent *e)
 {
     e->ignore();
 }
 
 /*!
     \reimp
 */
 void KtlQ3ScrollView::mouseReleaseEvent(QMouseEvent *e)
 {
     e->ignore();
 }
 
 /*!
     \reimp
 */
 void KtlQ3ScrollView::mouseDoubleClickEvent(QMouseEvent *e)
 {
     e->ignore();
 }
 
 /*!
     \reimp
 */
 void KtlQ3ScrollView::mouseMoveEvent(QMouseEvent *e)
 {
     e->ignore();
 }
 
 /*!
     \reimp
 */
 #ifndef QT_NO_WHEELEVENT
 void KtlQ3ScrollView::wheelEvent(QWheelEvent *e)
 {
     /* QWheelEvent ce(viewport()->mapFromGlobal(e->globalPos()),
                     e->globalPos(), e->delta(), e->state());  - 2018.11.30*/
     /* QWheelEvent ce(viewport()->mapFromGlobal(e->globalPos()), e->globalPos(), e->delta(), e->buttons(), e->modifiers());  - 2023.04.10 */
     QWheelEvent ce(viewport()->mapFromGlobal(e->globalPosition().toPoint()),
                 e->globalPosition(),
                 e->pixelDelta(),
                 e->angleDelta(),
                 e->buttons(),
                 e->modifiers(),
                 e->phase(),
                 e->inverted());
     viewportWheelEvent(&ce);
     if (!ce.isAccepted()) {
         if ((e->angleDelta().x() != 0) && horizontalScrollBar())
             horizontalScrollBar()->event(e);
         else if ((e->angleDelta().y() != 0) && verticalScrollBar())
             verticalScrollBar()->event(e);
     } else {
         e->accept();
     }
 }
 #endif
 
 /*!
     \reimp
 */
 void KtlQ3ScrollView::contextMenuEvent(QContextMenuEvent *e)
 {
     if (e->reason() != QContextMenuEvent::Keyboard) {
         e->ignore();
         return;
     }
 
     /* QContextMenuEvent ce(e->reason(), viewport()->mapFromGlobal(e->globalPos()),
                           e->globalPos(), e->state()); - 2018.11.30 */
     QContextMenuEvent ce(e->reason(), viewport()->mapFromGlobal(e->globalPos()), e->globalPos(), e->modifiers());
     viewportContextMenuEvent(&ce);
     if (ce.isAccepted())
         e->accept();
     else
         e->ignore();
 }
 
 KtlQ3ScrollView::ScrollBarMode KtlQ3ScrollView::vScrollBarMode() const
 {
     return d->vMode;
 }
 
 /*!
     \enum KtlQ3ScrollView::ScrollBarMode
 
     This enum type describes the various modes of KtlQ3ScrollView's scroll
     bars.
 
     \value Auto  KtlQ3ScrollView shows a scroll bar when the content is
     too large to fit and not otherwise. This is the default.
 
     \value AlwaysOff  KtlQ3ScrollView never shows a scroll bar.
 
     \value AlwaysOn  KtlQ3ScrollView always shows a scroll bar.
 
     (The modes for the horizontal and vertical scroll bars are
     independent.)
 */
 
 /*!
     \property KtlQ3ScrollView::vScrollBarMode
     \brief the mode for the vertical scroll bar
 
     The default mode is KtlQ3ScrollView::Auto.
 
     \sa hScrollBarMode
 */
 void KtlQ3ScrollView::setVScrollBarMode(ScrollBarMode mode)
 {
     if (d->vMode != mode) {
         d->vMode = mode;
         updateScrollBars();
     }
 }
 
 /*!
     \property KtlQ3ScrollView::hScrollBarMode
     \brief the mode for the horizontal scroll bar
 
     The default mode is KtlQ3ScrollView::Auto.
 
     \sa vScrollBarMode
 */
 KtlQ3ScrollView::ScrollBarMode KtlQ3ScrollView::hScrollBarMode() const
 {
     return d->hMode;
 }
 
 void KtlQ3ScrollView::setHScrollBarMode(ScrollBarMode mode)
 {
     if (d->hMode != mode) {
         d->hMode = mode;
         updateScrollBars();
     }
 }
 
 /*!
     Returns the widget in the corner between the two scroll bars.
 
     By default, no corner widget is present.
 */
 QWidget *KtlQ3ScrollView::cornerWidget() const
 {
     return d->corner;
 }
 
 /*!
     Sets the widget in the \a corner between the two scroll bars.
 
     You will probably also want to set at least one of the scroll bar
     modes to \c AlwaysOn.
 
     Passing 0 shows no widget in the corner.
 
     Any previous \a corner widget is hidden.
 
     You may call setCornerWidget() with the same widget at different
     times.
 
     All widgets set here will be deleted by the KtlQ3ScrollView when it is
     destroyed unless you separately reparent the widget after setting
     some other corner widget (or 0).
 
     Any \e newly set widget should have no current parent.
 
     By default, no corner widget is present.
 
     \sa setVScrollBarMode(), setHScrollBarMode()
 */
 void KtlQ3ScrollView::setCornerWidget(QWidget *corner)
 {
     QWidget *oldcorner = d->corner;
     if (oldcorner != corner) {
         if (oldcorner)
             oldcorner->hide();
         d->corner = corner;
         if (corner)
             corner->setParent(this);
         updateScrollBars();
         if (corner)
             corner->show();
     }
 }
 
 void KtlQ3ScrollView::setResizePolicy(ResizePolicy r)
 {
     d->policy = r;
 }
 
 /*!
     \property KtlQ3ScrollView::resizePolicy
     \brief the resize policy
 
     The default is \c Default.
 
     \sa ResizePolicy
 */
 KtlQ3ScrollView::ResizePolicy KtlQ3ScrollView::resizePolicy() const
 {
     return d->policy;
 }
 
 /*!
     \internal
 */
 void KtlQ3ScrollView::setEnabled(bool enable)
 {
     KtlQ3Frame::setEnabled(enable);
 }
 
 /*!
     Removes the \a child widget from the scrolled area. Note that this
     happens automatically if the \a child is deleted.
 */
 void KtlQ3ScrollView::removeChild(QWidget *child)
 {
     if (!d || !child) // First check in case we are destructing
         return;
 
     QSVChildRec *r = d->rec(child);
     if (r)
         d->deleteChildRec(r);
 }
 
 /*!
     \internal
 */
 void KtlQ3ScrollView::removeChild(QObject *child)
 {
     // KtlQ3Frame::removeChild(child); // 2018.11.30
     if (child) {
         child->setParent(nullptr);
     }
 }
 
 /*!
     Inserts the widget, \a child, into the scrolled area positioned at
     (\a x, \a y). The position defaults to (0, 0). If the child is
     already in the view, it is just moved.
 
     You may want to call enableClipper(true) if you add a large number
     of widgets.
 */
 void KtlQ3ScrollView::addChild(QWidget *child, int x, int y)
 {
     if (!child) {
 #if defined(QT_CHECK_NULL)
         qWarning("KtlQ3ScrollView::addChild(): Cannot add null child");
 #endif
         return;
     }
     child->ensurePolished();
     // child->setBackgroundOrigin(WidgetOrigin); // 2018.11.30 - does nothing in qt4
 
     if (child->parentWidget() == viewport()) {
         // May already be there
         QSVChildRec *r = d->rec(child);
         if (r) {
             r->moveTo(this, x, y, d->clipped_viewport);
             if (d->policy > Manual) {
                 d->autoResizeHint(this);
                 d->autoResize(this); // #### better to just deal with this one widget!
             }
             return;
         }
     }
 
     if (d->children.isEmpty() && d->policy != Manual) {
         if (d->policy == Default)
             setResizePolicy(AutoOne);
         child->installEventFilter(this);
     } else if (d->policy == AutoOne) {
         child->removeEventFilter(this); //#### ?????
         setResizePolicy(Manual);
     }
     if (child->parentWidget() != viewport()) {
         // child->reparent(viewport(), 0, QPoint(0,0), false); // 2018.11.30
         child->setParent(viewport());
         child->setGeometry(0, 0, child->width(), child->height());
     }
     d->addChildRec(child, x, y)->hideOrShow(this, d->clipped_viewport);
 
     if (d->policy > Manual) {
         d->autoResizeHint(this);
         d->autoResize(this); // #### better to just deal with this one widget!
     }
 }
 
 /*!
     Repositions the \a child widget to (\a x, \a y). This function is
     the same as addChild().
 */
 void KtlQ3ScrollView::moveChild(QWidget *child, int x, int y)
 {
     addChild(child, x, y);
 }
 
 /*!
     Returns the X position of the given \a child widget. Use this
     rather than QWidget::x() for widgets added to the view.
 
     This function returns 0 if \a child has not been added to the view.
 */
 int KtlQ3ScrollView::childX(QWidget *child)
 {
     QSVChildRec *r = d->rec(child);
     return r ? r->x : 0;
 }
 
 /*!
     Returns the Y position of the given \a child widget. Use this
     rather than QWidget::y() for widgets added to the view.
 
     This function returns 0 if \a child has not been added to the view.
 */
 int KtlQ3ScrollView::childY(QWidget *child)
 {
     QSVChildRec *r = d->rec(child);
     return r ? r->y : 0;
 }
 
 /*! \fn bool KtlQ3ScrollView::childIsVisible(QWidget*)
   \obsolete
 
   Returns true if \a child is visible. This is equivalent
   to child->isVisible().
 */
 
 /*! \fn void KtlQ3ScrollView::showChild(QWidget* child, bool y)
   \obsolete
 
   Sets the visibility of \a child. Equivalent to
   QWidget::show() or QWidget::hide().
 */
 
 /*!
     This event filter ensures the scroll bars are updated when a
     single contents widget is resized, shown, hidden or destroyed; it
     passes mouse events to the KtlQ3ScrollView. The event is in \a e and
     the object is in \a obj.
 */
 
 bool KtlQ3ScrollView::eventFilter(QObject *obj, QEvent *e)
 {
     bool disabled = !(qobject_cast<QWidget *>(obj)->isEnabled());
     if (!d)
         return false; // we are destructing
     if (obj == d->viewport || obj == d->clipped_viewport) {
         switch (e->type()) {
             /* Forward many events to viewport...() functions */
         case QEvent::Paint:
             viewportPaintEvent(static_cast<QPaintEvent *>(e));
             break;
         case QEvent::Resize:
             if (!d->clipped_viewport)
                 viewportResizeEvent(static_cast<QResizeEvent *>(e));
             break;
         case QEvent::MouseButtonPress:
             if (disabled)
                 return false;
             viewportMousePressEvent(static_cast<QMouseEvent *>(e));
             if ((static_cast<QMouseEvent *>(e))->isAccepted())
                 return true;
             break;
         case QEvent::MouseButtonRelease:
             if (disabled)
                 return false;
             viewportMouseReleaseEvent(static_cast<QMouseEvent *>(e));
             if ((static_cast<QMouseEvent *>(e))->isAccepted())
                 return true;
             break;
         case QEvent::MouseButtonDblClick:
             if (disabled)
                 return false;
             viewportMouseDoubleClickEvent(static_cast<QMouseEvent *>(e));
             if ((static_cast<QMouseEvent *>(e))->isAccepted())
                 return true;
             break;
         case QEvent::MouseMove:
             if (disabled)
                 return false;
             viewportMouseMoveEvent(static_cast<QMouseEvent *>(e));
             if ((static_cast<QMouseEvent *>(e))->isAccepted())
                 return true;
             break;
 #ifndef QT_NO_DRAGANDDROP
         case QEvent::DragEnter:
             if (disabled)
                 return false;
             viewportDragEnterEvent(static_cast<QDragEnterEvent *>(e));
             break;
         case QEvent::DragMove: {
             if (disabled)
                 return false;
             if (d->drag_autoscroll) {
                 QPoint vp = (static_cast<QDragMoveEvent *>(e))->pos();
                 QRect inside_margin(autoscroll_margin, autoscroll_margin, visibleWidth() - autoscroll_margin * 2, visibleHeight() - autoscroll_margin * 2);
                 if (!inside_margin.contains(vp)) {
                     startDragAutoScroll();
                     // Keep sending move events
                     (static_cast<QDragMoveEvent *>(e))->accept(QRect(0, 0, 0, 0));
                 }
             }
             viewportDragMoveEvent(static_cast<QDragMoveEvent *>(e));
         } break;
         case QEvent::DragLeave:
             if (disabled)
                 return false;
             stopDragAutoScroll();
             viewportDragLeaveEvent(static_cast<QDragLeaveEvent *>(e));
             break;
         case QEvent::Drop:
             if (disabled)
                 return false;
             stopDragAutoScroll();
             viewportDropEvent(static_cast<QDropEvent *>(e));
             break;
 #endif // QT_NO_DRAGANDDROP
 #ifndef QT_NO_WHEELEVENT
         case QEvent::Wheel:
             if (disabled)
                 return false;
             break;
 #endif
         case QEvent::ContextMenu:
             if (disabled)
                 return false;
             viewportContextMenuEvent(static_cast<QContextMenuEvent *>(e));
             if ((static_cast<QContextMenuEvent *>(e))->isAccepted())
                 return true;
             break;
         case QEvent::ChildRemoved:
             removeChild(static_cast<QWidget *>((static_cast<QChildEvent *>(e))->child()));
             break;
         // case QEvent::LayoutHint:  // 2018.12.08 - deprecated
         //    d->autoResizeHint(this);
         //    break;
         default:
             break;
         }
     } else if (d && d->rec(static_cast<QWidget *>(obj))) { // must be a child
         if (e->type() == QEvent::Resize)
             d->autoResize(this);
         else if (e->type() == QEvent::Move)
             d->autoMove(this);
     }
     return KtlQ3Frame::eventFilter(obj, e); // always continue with standard event processing
 }
 
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     mousePressEvent(): the press position in \a e is translated to be a point
     on the contents.
 */
 void KtlQ3ScrollView::contentsMousePressEvent(QMouseEvent *e)
 {
     e->ignore();
 }
 
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     mouseReleaseEvent(): the release position in \a e is translated to be a
     point on the contents.
 */
 void KtlQ3ScrollView::contentsMouseReleaseEvent(QMouseEvent *e)
 {
     e->ignore();
 }
 
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     mouseDoubleClickEvent(): the click position in \a e is translated to be a
     point on the contents.
 
     The default implementation generates a normal mouse press event.
 */
 void KtlQ3ScrollView::contentsMouseDoubleClickEvent(QMouseEvent *e)
 {
     contentsMousePressEvent(e); // try mouse press event
 }
 
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     mouseMoveEvent(): the mouse position in \a e is translated to be a point
     on the contents.
 */
 void KtlQ3ScrollView::contentsMouseMoveEvent(QMouseEvent *e)
 {
     e->ignore();
 }
 
 #ifndef QT_NO_DRAGANDDROP
 
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     dragEnterEvent(): the drag position is translated to be a point
     on the contents.
 
     The default implementation does nothing. The \a event parameter is
     ignored.
 */
 void KtlQ3ScrollView::contentsDragEnterEvent(QDragEnterEvent * /* event */)
 {
 }
 
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     dragMoveEvent(): the drag position is translated to be a point on
     the contents.
 
     The default implementation does nothing. The \a event parameter is
     ignored.
 */
 void KtlQ3ScrollView::contentsDragMoveEvent(QDragMoveEvent * /* event */)
 {
 }
 
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     dragLeaveEvent(): the drag position is translated to be a point
     on the contents.
 
     The default implementation does nothing. The \a event parameter is
     ignored.
 */
 void KtlQ3ScrollView::contentsDragLeaveEvent(QDragLeaveEvent * /* event */)
 {
 }
 
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     dropEvent(): the drop position is translated to be a point on the
     contents.
 
     The default implementation does nothing. The \a event parameter is
     ignored.
 */
 
 void KtlQ3ScrollView::contentsDropEvent(QDropEvent * /* event */)
 {
 }
 
 #endif // QT_NO_DRAGANDDROP
 
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     wheelEvent() in \a{e}: the mouse position is translated to be a
     point on the contents.
 */
 #ifndef QT_NO_WHEELEVENT
 void KtlQ3ScrollView::contentsWheelEvent(QWheelEvent *e)
 {
     e->ignore();
 }
 #endif
 /*!
     This event handler is called whenever the KtlQ3ScrollView receives a
     contextMenuEvent() in \a{e}: the mouse position is translated to
     be a point on the contents.
 */
 void KtlQ3ScrollView::contentsContextMenuEvent(QContextMenuEvent *e)
 {
     e->ignore();
 }
 
 /*!
     This is a low-level painting routine that draws the viewport
     contents. Reimplement this if drawContents() is too high-level
     (for example, if you don't want to open a QPainter on the
     viewport). The paint event is passed in \a pe.
 */
 void KtlQ3ScrollView::viewportPaintEvent(QPaintEvent *pe)
 {
     QWidget *vp = viewport();
 
     QPainter p(vp);
     QRect r = pe->rect();
 
     if (d->clipped_viewport) {
         QRect rr(-d->clipped_viewport->x(), -d->clipped_viewport->y(), d->viewport->width(), d->viewport->height());
         r &= rr;
         if (r.isValid()) {
             int ex = r.x() + d->clipped_viewport->x() + d->contentsX();
             int ey = r.y() + d->clipped_viewport->y() + d->contentsY();
             int ew = r.width();
             int eh = r.height();
             drawContentsOffset(&p, d->contentsX() + d->clipped_viewport->x(), d->contentsY() + d->clipped_viewport->y(), ex, ey, ew, eh);
         }
     } else {
         r &= d->viewport->rect();
         int ex = r.x() + d->contentsX();
         int ey = r.y() + d->contentsY();
         int ew = r.width();
         int eh = r.height();
         drawContentsOffset(&p, d->contentsX(), d->contentsY(), ex, ey, ew, eh);
     }
 }
 
 /*!
     To provide simple processing of events on the contents, this
     function receives all resize events sent to the viewport.
 
     The default implementation does nothing. The \a event parameter is
     ignored.
 
     \sa QWidget::resizeEvent()
 */
 void KtlQ3ScrollView::viewportResizeEvent(QResizeEvent * /* event */)
 {
 }
 
 /*! \internal
 
   To provide simple processing of events on the contents, this
   function receives all mouse press events sent to the viewport,
   translates the event and calls contentsMousePressEvent().
 
   \sa contentsMousePressEvent(), QWidget::mousePressEvent()
 */
 void KtlQ3ScrollView::viewportMousePressEvent(QMouseEvent *e)
 {
     /* QMouseEvent ce(e->type(), viewportToContents(e->pos()),
         e->globalPos(), e->button(), e->state()); - 2018.11.30 */
     QMouseEvent ce(e->type(), viewportToContents(e->pos()), e->globalPos(), e->button(), e->buttons(), e->modifiers());
     contentsMousePressEvent(&ce);
     if (!ce.isAccepted())
         e->ignore();
 }
 
 /*!\internal
 
   To provide simple processing of events on the contents, this function
   receives all mouse release events sent to the viewport, translates
   the event and calls contentsMouseReleaseEvent().
 
   \sa QWidget::mouseReleaseEvent()
 */
 void KtlQ3ScrollView::viewportMouseReleaseEvent(QMouseEvent *e)
 {
     /* QMouseEvent ce(e->type(), viewportToContents(e->pos()),
         e->globalPos(), e->button(), e->state()); -- 2018.11.30 */
     QMouseEvent ce(e->type(), viewportToContents(e->pos()), e->globalPos(), e->button(), e->buttons(), e->modifiers());
     contentsMouseReleaseEvent(&ce);
     if (!ce.isAccepted())
         e->ignore();
 }
 
 /*!\internal
 
   To provide simple processing of events on the contents, this function
   receives all mouse double click events sent to the viewport,
   translates the event and calls contentsMouseDoubleClickEvent().
 
   \sa QWidget::mouseDoubleClickEvent()
 */
 void KtlQ3ScrollView::viewportMouseDoubleClickEvent(QMouseEvent *e)
 {
     /* QMouseEvent ce(e->type(), viewportToContents(e->pos()),
         e->globalPos(), e->button(), e->state());  - 2018.11.30 */
     QMouseEvent ce(e->type(), viewportToContents(e->pos()), e->globalPos(), e->button(), e->buttons(), e->modifiers());
     contentsMouseDoubleClickEvent(&ce);
     if (!ce.isAccepted())
         e->ignore();
 }
 
 /*!\internal
 
   To provide simple processing of events on the contents, this function
   receives all mouse move events sent to the viewport, translates the
   event and calls contentsMouseMoveEvent().
 
   \sa QWidget::mouseMoveEvent()
 */
 void KtlQ3ScrollView::viewportMouseMoveEvent(QMouseEvent *e)
 {
     QMouseEvent ce(e->type(), viewportToContents(e->pos()), e->globalPos(), e->button(), e->buttons(), e->modifiers());
     contentsMouseMoveEvent(&ce);
     if (!ce.isAccepted())
         e->ignore();
 }
 
 #ifndef QT_NO_DRAGANDDROP
 
 /*!\internal
 
   To provide simple processing of events on the contents, this function
   receives all drag enter events sent to the viewport, translates the
   event and calls contentsDragEnterEvent().
 
   \sa QWidget::dragEnterEvent()
 */
 void KtlQ3ScrollView::viewportDragEnterEvent(QDragEnterEvent *e)
 {
     // e->setPoint(viewportToContents(e->pos())); // 2018.11.30
     QDragEnterEvent ev(viewportToContents(e->pos()), e->possibleActions(), e->mimeData(), e->mouseButtons(), e->keyboardModifiers());
     contentsDragEnterEvent(&ev);
     // e->setPoint(contentsToViewport(e->pos())); // 2018.11.30
 }
 
 /*!\internal
 
   To provide simple processing of events on the contents, this function
   receives all drag move events sent to the viewport, translates the
   event and calls contentsDragMoveEvent().
 
   \sa QWidget::dragMoveEvent()
 */
 void KtlQ3ScrollView::viewportDragMoveEvent(QDragMoveEvent *e)
 {
     // e->setPoint(viewportToContents(e->pos())); // 2018.11.30
     QDragMoveEvent ev(viewportToContents(e->pos()), e->possibleActions(), e->mimeData(), e->mouseButtons(), e->keyboardModifiers());
     contentsDragMoveEvent(&ev);
     // e->setPoint(contentsToViewport(e->pos())); // 2018.11.30
 }
 
 /*!\internal
 
   To provide simple processing of events on the contents, this function
   receives all drag leave events sent to the viewport and calls
   contentsDragLeaveEvent().
 
   \sa QWidget::dragLeaveEvent()
 */
 void KtlQ3ScrollView::viewportDragLeaveEvent(QDragLeaveEvent *e)
 {
     contentsDragLeaveEvent(e);
 }
 
 /*!\internal
 
   To provide simple processing of events on the contents, this function
   receives all drop events sent to the viewport, translates the event
   and calls contentsDropEvent().
 
   \sa QWidget::dropEvent()
 */
 void KtlQ3ScrollView::viewportDropEvent(QDropEvent *e)
 {
     // e->setPoint(viewportToContents(e->pos())); // 2018.11.30
     QDropEvent ev(viewportToContents(e->pos()), e->possibleActions(), e->mimeData(), e->mouseButtons(), e->keyboardModifiers());
     contentsDropEvent(&ev);
     // e->setPoint(contentsToViewport(e->pos())); // 2018.11.30
 }
 
 #endif // QT_NO_DRAGANDDROP
 
 /*!\internal
 
   To provide simple processing of events on the contents, this function
   receives all wheel events sent to the viewport, translates the
   event and calls contentsWheelEvent().
 
   \sa QWidget::wheelEvent()
 */
 #ifndef QT_NO_WHEELEVENT
 void KtlQ3ScrollView::viewportWheelEvent(QWheelEvent *e)
 {
     /*
        Different than standard mouse events, because wheel events might
        be sent to the focus widget if the widget-under-mouse doesn't want
        the event itself.
     */
     /* QWheelEvent ce(viewportToContents(e->pos()),
         e->globalPos(), e->delta(), e->state()); */
     QWheelEvent ce(viewportToContents(e->position().toPoint()), e->globalPosition(), e->pixelDelta(), e->angleDelta(),
                    e->buttons(), e->modifiers(), e->phase(), e->inverted());
     contentsWheelEvent(&ce);
     if (ce.isAccepted())
         e->accept();
     else
         e->ignore();
 }
 #endif
 
 /*! \internal
 
   To provide simple processing of events on the contents, this function
   receives all context menu events sent to the viewport, translates the
   event and calls contentsContextMenuEvent().
 */
 void KtlQ3ScrollView::viewportContextMenuEvent(QContextMenuEvent *e)
 {
     // QContextMenuEvent ce(e->reason(), viewportToContents(e->pos()), e->globalPos(), e->state());
     QContextMenuEvent ce(e->reason(), viewportToContents(e->pos()), e->globalPos(), e->modifiers());
     contentsContextMenuEvent(&ce);
     if (ce.isAccepted())
         e->accept();
     else
         e->ignore();
 }
 
 /*!
     Returns the component horizontal scroll bar. It is made available
     to allow accelerators, autoscrolling, etc.
 
     It should not be used for other purposes.
 
     This function never returns 0.
 */
 QScrollBar *KtlQ3ScrollView::horizontalScrollBar() const
 {
     return d->hbar;
 }
 
 /*!
     Returns the component vertical scroll bar. It is made available to
     allow accelerators, autoscrolling, etc.
 
     It should not be used for other purposes.
 
     This function never returns 0.
 */
 QScrollBar *KtlQ3ScrollView::verticalScrollBar() const
 {
     return d->vbar;
 }
 
 /*!
     Scrolls the content so that the point (\a x, \a y) is visible with at
     least 50-pixel margins (if possible, otherwise centered).
 */
 void KtlQ3ScrollView::ensureVisible(int x, int y)
 {
     ensureVisible(x, y, 50, 50);
 }
 
 /*!
     \overload
 
     Scrolls the content so that the point (\a x, \a y) is visible with at
     least the \a xmargin and \a ymargin margins (if possible,
     otherwise centered).
 */
 void KtlQ3ScrollView::ensureVisible(int x, int y, int xmargin, int ymargin)
 {
     int pw = visibleWidth();
     int ph = visibleHeight();
 
     int cx = -d->contentsX();
     int cy = -d->contentsY();
     int cw = d->contentsWidth();
     int ch = contentsHeight();
 
     if (pw < xmargin * 2)
         xmargin = pw / 2;
     if (ph < ymargin * 2)
         ymargin = ph / 2;
 
     if (cw <= pw) {
         xmargin = 0;
         cx = 0;
     }
     if (ch <= ph) {
         ymargin = 0;
         cy = 0;
     }
 
     if (x < -cx + xmargin)
         cx = -x + xmargin;
     else if (x >= -cx + pw - xmargin)
         cx = -x + pw - xmargin;
 
     if (y < -cy + ymargin)
         cy = -y + ymargin;
     else if (y >= -cy + ph - ymargin)
         cy = -y + ph - ymargin;
 
     if (cx > 0)
         cx = 0;
     else if (cx < pw - cw && cw > pw)
         cx = pw - cw;
 
     if (cy > 0)
         cy = 0;
     else if (cy < ph - ch && ch > ph)
         cy = ph - ch;
 
     setContentsPos(-cx, -cy);
 }
 
 /*!
     Scrolls the content so that the point (\a x, \a y) is in the top-left
     corner.
 */
 void KtlQ3ScrollView::setContentsPos(int x, int y)
 {
 #if 0
     // bounds checking...
     if (QApplication::reverseLayout())
         if (x > d->contentsWidth() - visibleWidth()) x = d->contentsWidth() - visibleWidth();
     else
 #endif
     if (x < 0)
         x = 0;
     if (y < 0)
         y = 0;
     // Choke signal handling while we update BOTH sliders.
     d->signal_choke = true;
     moveContents(-x, -y);
     d->vbar->setValue(y);
     d->hbar->setValue(x);
     d->signal_choke = false;
 }
 
 /*!
     Scrolls the content by \a dx to the left and \a dy upwards.
 */
 void KtlQ3ScrollView::scrollBy(int dx, int dy)
 {
     setContentsPos(qMax(d->contentsX() + dx, 0), qMax(d->contentsY() + dy, 0));
 }
 
 /*!
     Scrolls the content so that the point (\a x, \a y) is in the center
     of visible area.
 */
 void KtlQ3ScrollView::center(int x, int y)
 {
     ensureVisible(x, y, 32000, 32000);
 }
 
 /*!
     \overload
 
     Scrolls the content so that the point (\a x, \a y) is visible with
     the \a xmargin and \a ymargin margins (as fractions of visible
     the area).
 
     For example:
     \list
     \i Margin 0.0 allows (x, y) to be on the edge of the visible area.
     \i Margin 0.5 ensures that (x, y) is in middle 50% of the visible area.
     \i Margin 1.0 ensures that (x, y) is in the center of the visible area.
     \endlist
 */
 void KtlQ3ScrollView::center(int x, int y, float xmargin, float ymargin)
 {
     int pw = visibleWidth();
     int ph = visibleHeight();
     ensureVisible(x, y, int(xmargin / 2.0 * pw + 0.5), int(ymargin / 2.0 * ph + 0.5));
 }
 
 /*!
     \fn void KtlQ3ScrollView::contentsMoving(int x, int y)
 
     This signal is emitted just before the contents are moved to
     position (\a x, \a y).
 
     \sa contentsX(), contentsY()
 */
 
 /*!
     Moves the contents by (\a x, \a y).
 */
 void KtlQ3ScrollView::moveContents(int x, int y)
 {
     if (-x + visibleWidth() > d->contentsWidth())
 #if 0
         if(QApplication::reverseLayout())
             x=qMax(0,-d->contentsWidth()+visibleWidth());
         else
 #endif
         x = qMin(0, -d->contentsWidth() + visibleWidth());
     if (-y + visibleHeight() > contentsHeight())
         y = qMin(0, -contentsHeight() + visibleHeight());
 
     int dx = x - d->vx;
     int dy = y - d->vy;
 
     if (!dx && !dy)
         return; // Nothing to do
 
     emit contentsMoving(-x, -y);
 
     d->vx = x;
     d->vy = y;
 
     if (d->clipped_viewport || d->static_bg) {
         // Cheap move (usually)
         d->moveAllBy(dx, dy);
     } else if (/*dx && dy ||*/
                (qAbs(dy) * 5 > visibleHeight() * 4) || (qAbs(dx) * 5 > visibleWidth() * 4)) {
         // Big move
         if (viewport()->updatesEnabled())
             viewport()->update();
         d->moveAllBy(dx, dy);
     } else if (!d->fake_scroll || d->contentsWidth() > visibleWidth()) {
         // Small move
         clipper()->scroll(dx, dy);
     }
     d->hideOrShowAll(this, true);
 }
 
 /*!
     \property KtlQ3ScrollView::contentsX
     \brief the X coordinate of the contents that are at the left edge of
     the viewport.
 */
 int KtlQ3ScrollView::contentsX() const
 {
     return d->contentsX();
 }
 
 /*!
     \property KtlQ3ScrollView::contentsY
     \brief the Y coordinate of the contents that are at the top edge of
     the viewport.
 */
 int KtlQ3ScrollView::contentsY() const
 {
     return d->contentsY();
 }
 
 /*!
     \property KtlQ3ScrollView::contentsWidth
     \brief the width of the contents area
 */
 int KtlQ3ScrollView::contentsWidth() const
 {
     return d->contentsWidth();
 }
 
 /*!
     \property KtlQ3ScrollView::contentsHeight
     \brief the height of the contents area
 */
 int KtlQ3ScrollView::contentsHeight() const
 {
     return d->vheight;
 }
 
 /*!
     Sets the size of the contents area to \a w pixels wide and \a h
     pixels high and updates the viewport accordingly.
 */
 void KtlQ3ScrollView::resizeContents(int w, int h)
 {
     int ow = d->vwidth;
     int oh = d->vheight;
     d->vwidth = w;
     d->vheight = h;
 
     d->scrollbar_timer.setSingleShot(true);
     d->scrollbar_timer.start(0 /*, true */);
 
     if (d->children.isEmpty() && d->policy == Default)
         setResizePolicy(Manual);
 
     if (ow > w) {
         // Swap
         int t = w;
         w = ow;
         ow = t;
     }
     // Refresh area ow..w
     if (ow < visibleWidth() && w >= 0) {
         if (ow < 0)
             ow = 0;
         if (w > visibleWidth())
             w = visibleWidth();
         clipper()->update(d->contentsX() + ow, 0, w - ow, visibleHeight());
     }
 
     if (oh > h) {
         // Swap
         int t = h;
         h = oh;
         oh = t;
     }
     // Refresh area oh..h
     if (oh < visibleHeight() && h >= 0) {
         if (oh < 0)
             oh = 0;
         if (h > visibleHeight())
             h = visibleHeight();
         clipper()->update(0, d->contentsY() + oh, visibleWidth(), h - oh);
     }
 }
 
 /*!
     Calls update() on a rectangle defined by \a x, \a y, \a w, \a h,
     translated appropriately. If the rectangle is not visible, nothing
     is repainted.
 
     \sa repaintContents()
 */
 void KtlQ3ScrollView::updateContents(int x, int y, int w, int h)
 {
     if (!isVisible() || !updatesEnabled())
         return;
 
     QWidget *vp = viewport();
 
     // Translate
     x -= d->contentsX();
     y -= d->contentsY();
 
     if (x < 0) {
         w += x;
         x = 0;
     }
     if (y < 0) {
         h += y;
         y = 0;
     }
 
     if (w < 0 || h < 0)
         return;
     if (x > visibleWidth() || y > visibleHeight())
         return;
 
     if (w > visibleWidth())
         w = visibleWidth();
     if (h > visibleHeight())
         h = visibleHeight();
 
     if (d->clipped_viewport) {
         // Translate clipper() to viewport()
         x -= d->clipped_viewport->x();
         y -= d->clipped_viewport->y();
     }
 
     vp->update(x, y, w, h);
 }
 
 /*!
     \overload
 
     Updates the contents in rectangle \a r
 */
 void KtlQ3ScrollView::updateContents(const QRect &r)
 {
     updateContents(r.x(), r.y(), r.width(), r.height());
 }
 
 /*!
     \overload
 */
 void KtlQ3ScrollView::updateContents()
 {
     updateContents(d->contentsX(), d->contentsY(), visibleWidth(), visibleHeight());
 }
 
 /*!
     \overload
 
     Repaints the contents of rectangle \a r. If \a erase is true the
     background is cleared using the background color.
 */
 void KtlQ3ScrollView::repaintContents(const QRect &r, bool erase)
 {
     repaintContents(r.x(), r.y(), r.width(), r.height(), erase);
 }
 
 /*!
     \overload
 
     Repaints the contents. If \a erase is true the background is
     cleared using the background color.
 */
 void KtlQ3ScrollView::repaintContents(bool erase)
 {
     repaintContents(d->contentsX(), d->contentsY(), visibleWidth(), visibleHeight(), erase);
 }
 
 /*!
     Calls repaint() on a rectangle defined by \a x, \a y, \a w, \a h,
     translated appropriately. If the rectangle is not visible, nothing
     is repainted. If \a erase is true the background is cleared using
     the background color.
 
     \sa updateContents()
 */
 void KtlQ3ScrollView::repaintContents(int x, int y, int w, int h, bool /*erase*/)
 {
     if (!isVisible() || !updatesEnabled())
         return;
 
     QWidget *vp = viewport();
 
     // Translate logical to clipper()
     x -= d->contentsX();
     y -= d->contentsY();
 
     if (x < 0) {
         w += x;
         x = 0;
     }
     if (y < 0) {
         h += y;
         y = 0;
     }
 
     if (w < 0 || h < 0)
         return;
     if (w > visibleWidth())
         w = visibleWidth();
     if (h > visibleHeight())
         h = visibleHeight();
 
     if (d->clipped_viewport) {
         // Translate clipper() to viewport()
         x -= d->clipped_viewport->x();
         y -= d->clipped_viewport->y();
     }
 
     vp->update(x, y, w, h);
 }
 
 /*!
     For backward-compatibility only. It is easier to use
     drawContents(QPainter*,int,int,int,int).
 
     The default implementation translates the painter appropriately
     and calls drawContents(QPainter*,int,int,int,int). See
     drawContents() for an explanation of the parameters \a p, \a
     offsetx, \a offsety, \a clipx, \a clipy, \a clipw and \a cliph.
 */
 void KtlQ3ScrollView::drawContentsOffset(QPainter *p, int offsetx, int offsety, int clipx, int clipy, int clipw, int cliph)
 {
     p->translate(-offsetx, -offsety);
     drawContents(p, clipx, clipy, clipw, cliph);
 }
 
 /*!
     \fn void KtlQ3ScrollView::drawContents(QPainter* p, int clipx, int clipy, int clipw, int cliph)
 
     Reimplement this function if you are viewing a drawing area rather
     than a widget.
 
     The function should draw the rectangle (\a clipx, \a clipy, \a
     clipw, \a cliph) of the contents using painter \a p. The clip
     rectangle is in the scrollview's coordinates.
 
     For example:
     \snippet doc/src/snippets/code/src_qt3support_widgets_q3scrollview.cpp 4
 
     The clip rectangle and translation of the painter \a p is already
     set appropriately.
 */
 void KtlQ3ScrollView::drawContents(QPainter *, int, int, int, int)
 {
 }
 
 /*!
     \reimp
 */
 void KtlQ3ScrollView::frameChanged()
 {
     //     // slight ugle-hack - the listview header needs readjusting when
     //     // changing the frame
     //     if (Q3ListView *lv = qobject_cast<Q3ListView *>(this))
     //         lv->triggerUpdate();
     KtlQ3Frame::frameChanged();
     updateScrollBars();
 }
 
 /*!
     Returns the viewport widget of the scrollview. This is the widget
     containing the contents widget or which is the drawing area.
 */
 QWidget *KtlQ3ScrollView::viewport() const
 {
     if (d->clipped_viewport)
         return d->clipped_viewport;
     return d->viewport;
 }
 
 /*!
     Returns the clipper widget. Contents in the scrollview are
     ultimately clipped to be inside the clipper widget.
 
     You should not need to use this function.
 
     \sa visibleWidth(), visibleHeight()
 */
 QWidget *KtlQ3ScrollView::clipper() const
 {
     return d->viewport;
 }
 
 /*!
     \property KtlQ3ScrollView::visibleWidth
     \brief the horizontal amount of the content that is visible
 */
 int KtlQ3ScrollView::visibleWidth() const
 {
     return clipper()->width();
 }
 
 /*!
     \property KtlQ3ScrollView::visibleHeight
     \brief the vertical amount of the content that is visible
 */
 int KtlQ3ScrollView::visibleHeight() const
 {
     return clipper()->height();
 }
 
 void KtlQ3ScrollView::changeFrameRect(const QRect &r)
 {
     QRect oldr = frameRect();
     if (oldr != r) {
         QRect cr = contentsRect();
         QRegion fr(frameRect());
         fr = fr.subtracted(contentsRect());
         setFrameRect(r);
         if (isVisible()) {
             cr = cr.intersected(contentsRect());
             fr = fr.united(frameRect());
             fr = fr.subtracted(cr);
             if (!fr.isEmpty())
                 update(fr);
         }
     }
 }
 
 /*!
     Sets the margins around the scrolling area to \a left, \a top, \a
     right and \a bottom. This is useful for applications such as
     spreadsheets with "locked" rows and columns. The marginal space is
     \e inside the frameRect() and is left blank; reimplement
     drawFrame() or put widgets in the unused area.
 
     By default all margins are zero.
 
     \sa frameChanged()
 */
 void KtlQ3ScrollView::setMargins(int left, int top, int right, int bottom)
 {
     if (left == d->l_marg && top == d->t_marg && right == d->r_marg && bottom == d->b_marg)
         return;
 
     d->l_marg = left;
     d->t_marg = top;
     d->r_marg = right;
     d->b_marg = bottom;
     updateScrollBars();
 }
 
 /*!
     Returns the left margin.
 
     \sa setMargins()
 */
 int KtlQ3ScrollView::leftMargin() const
 {
     return d->l_marg;
 }
 
 /*!
     Returns the top margin.
 
     \sa setMargins()
 */
 int KtlQ3ScrollView::topMargin() const
 {
     return d->t_marg;
 }
 
 /*!
     Returns the right margin.
 
     \sa setMargins()
 */
 int KtlQ3ScrollView::rightMargin() const
 {
     return d->r_marg;
 }
 
 /*!
     Returns the bottom margin.
 
     \sa setMargins()
 */
 int KtlQ3ScrollView::bottomMargin() const
 {
     return d->b_marg;
 }
 
 /*!
     \reimp
 */
 bool KtlQ3ScrollView::focusNextPrevChild(bool next)
 {
     //  Makes sure that the new focus widget is on-screen, if
     //  necessary by scrolling the scroll view.
     bool retval = KtlQ3Frame::focusNextPrevChild(next);
     if (retval) {
         QWidget *w = window()->focusWidget();
         if (isAncestorOf(w)) {
             QSVChildRec *r = d->ancestorRec(w);
             if (r && (r->child == w || w->isVisibleTo(r->child))) {
                 QPoint cp = r->child->mapToGlobal(QPoint(0, 0));
                 QPoint cr = w->mapToGlobal(QPoint(0, 0)) - cp;
                 ensureVisible(r->x + cr.x() + w->width() / 2, r->y + cr.y() + w->height() / 2, w->width() / 2, w->height() / 2);
             }
         }
     }
     return retval;
 }
 
 /*!
     When a large numbers of child widgets are in a scrollview,
     especially if they are close together, the scrolling performance
     can suffer greatly. If \a y is true the scrollview will use an
     extra widget to group child widgets.
 
     Note that you may only call enableClipper() prior to adding
     widgets.
 */
 void KtlQ3ScrollView::enableClipper(bool y) // note: this method as of 2018.11.30 is unused
 {
     if (!d->clipped_viewport == !y)
         return;
     if (d->children.count())
         qFatal("May only call KtlQ3ScrollView::enableClipper() before adding widgets");
     if (y) {
         d->clipped_viewport = new KtlQClipperWidget(clipper(), "qt_clipped_viewport", QFlag(d->flags));
         d->clipped_viewport->setGeometry(-coord_limit / 2, -coord_limit / 2, coord_limit, coord_limit);
         // d->clipped_viewport->setBackgroundMode(d->viewport->backgroundMode());
         d->clipped_viewport->setBackgroundRole(d->viewport->backgroundRole());
         // d->viewport->setBackgroundMode(NoBackground); // no exposures for this // 2018.11.30
         d->viewport->setAttribute(Qt::WA_NoSystemBackground); // hope this is the correct replacement for above
         d->viewport->removeEventFilter(this);
         d->clipped_viewport->installEventFilter(this);
         d->clipped_viewport->show();
     } else {
         delete d->clipped_viewport;
         d->clipped_viewport = nullptr;
     }
 }
 
 /*!
     Sets the scrollview to have a static background if \a y is true,
     or a scrolling background if \a y is false. By default, the
     background is scrolling.
 
     Be aware that this mode is quite slow, as a full repaint of the
     visible area has to be triggered on every contents move.
 
     \sa hasStaticBackground()
 */
 void KtlQ3ScrollView::setStaticBackground(bool y)
 {
     d->static_bg = y;
 }
 
 /*!
     Returns true if KtlQ3ScrollView uses a static background; otherwise
     returns false.
 
     \sa setStaticBackground()
 */
 bool KtlQ3ScrollView::hasStaticBackground() const
 {
     return d->static_bg;
 }
 
 /*!
     \overload
 
     Returns the point \a p translated to a point on the viewport()
     widget.
 */
 QPoint KtlQ3ScrollView::contentsToViewport(const QPoint &p) const
 {
     if (d->clipped_viewport) {
         return QPoint(p.x() - d->contentsX() - d->clipped_viewport->x(), p.y() - d->contentsY() - d->clipped_viewport->y());
     } else {
         return QPoint(p.x() - d->contentsX(), p.y() - d->contentsY());
     }
 }
 
 /*!
     \overload
 
     Returns the point on the viewport \a vp translated to a point in
     the contents.
 */
 QPoint KtlQ3ScrollView::viewportToContents(const QPoint &vp) const
 {
     if (d->clipped_viewport) {
         return QPoint(vp.x() + d->contentsX() + d->clipped_viewport->x(), vp.y() + d->contentsY() + d->clipped_viewport->y());
     } else {
         return QPoint(vp.x() + d->contentsX(), vp.y() + d->contentsY());
     }
 }
 
 /*!
     Translates a point (\a x, \a y) in the contents to a point (\a vx,
     \a vy) on the viewport() widget.
 */
 void KtlQ3ScrollView::contentsToViewport(int x, int y, int &vx, int &vy) const
 {
     const QPoint v = contentsToViewport(QPoint(x, y));
     vx = v.x();
     vy = v.y();
 }
 
 /*!
     Translates a point (\a vx, \a vy) on the viewport() widget to a
     point (\a x, \a y) in the contents.
 */
 void KtlQ3ScrollView::viewportToContents(int vx, int vy, int &x, int &y) const
 {
     const QPoint c = viewportToContents(QPoint(vx, vy));
     x = c.x();
     y = c.y();
 }
 
 /*!
     \reimp
 */
 QSize KtlQ3ScrollView::sizeHint() const
 {
     if (d->use_cached_size_hint && d->cachedSizeHint.isValid())
         return d->cachedSizeHint;
 
     // constPolish(); // 2018.11.30
     ensurePolished();
     int f = 2 * frameWidth();
     int h = fontMetrics().height();
     QSize sz(f, f);
     if (d->policy > Manual) {
         QSVChildRec *r = d->children.first();
         if (r) {
             QSize cs = r->child->sizeHint();
             if (cs.isValid())
                 sz += cs.boundedTo(r->child->maximumSize());
             else
                 sz += r->child->size();
         }
     } else {
         sz += QSize(d->contentsWidth(), contentsHeight());
     }
     if (d->vMode == AlwaysOn)
         sz.setWidth(sz.width() + d->vbar->sizeHint().width());
     if (d->hMode == AlwaysOn)
         sz.setHeight(sz.height() + d->hbar->sizeHint().height());
     return sz.expandedTo(QSize(12 * h, 8 * h)).boundedTo(QSize(36 * h, 24 * h));
 }
 
 /*!
     \reimp
 */
 QSize KtlQ3ScrollView::minimumSizeHint() const
 {
     int h = fontMetrics().height();
     if (h < 10)
         h = 10;
     int f = 2 * frameWidth();
     return QSize((6 * h) + f, (4 * h) + f);
 }
 
 /*!
     \reimp
 
     (Implemented to get rid of a compiler warning.)
 */
 void KtlQ3ScrollView::drawContents(QPainter *)
 {
 }
 
 #ifndef QT_NO_DRAGANDDROP
 
 /*!
   \internal
 */
 void KtlQ3ScrollView::startDragAutoScroll()
 {
     if (!d->autoscroll_timer.isActive()) {
         d->autoscroll_time = initialScrollTime;
         d->autoscroll_accel = initialScrollAccel;
         d->autoscroll_timer.start(d->autoscroll_time);
     }
 }
 
 /*!
   \internal
 */
 void KtlQ3ScrollView::stopDragAutoScroll()
 {
     d->autoscroll_timer.stop();
 }
 
 /*!
   \internal
 */
 void KtlQ3ScrollView::doDragAutoScroll()
 {
     QPoint p = d->viewport->mapFromGlobal(QCursor::pos());
 
     if (d->autoscroll_accel-- <= 0 && d->autoscroll_time) {
         d->autoscroll_accel = initialScrollAccel;
         d->autoscroll_time--;
         d->autoscroll_timer.start(d->autoscroll_time);
     }
     int l = qMax(1, (initialScrollTime - d->autoscroll_time));
 
     int dx = 0, dy = 0;
     if (p.y() < autoscroll_margin) {
         dy = -l;
     } else if (p.y() > visibleHeight() - autoscroll_margin) {
         dy = +l;
     }
     if (p.x() < autoscroll_margin) {
         dx = -l;
     } else if (p.x() > visibleWidth() - autoscroll_margin) {
         dx = +l;
     }
     if (dx || dy) {
         scrollBy(dx, dy);
     } else {
         stopDragAutoScroll();
     }
 }
 
 /*!
     \property KtlQ3ScrollView::dragAutoScroll
     \brief whether autoscrolling in drag move events is enabled
 
     If this property is set to true (the default), the KtlQ3ScrollView
     automatically scrolls the contents in drag move events if the user
     moves the cursor close to a border of the view. Of course this
     works only if the viewport accepts drops. Specifying false
     disables this autoscroll feature.
 */
 
 void KtlQ3ScrollView::setDragAutoScroll(bool b)
 {
     d->drag_autoscroll = b;
 }
 
 bool KtlQ3ScrollView::dragAutoScroll() const
 {
     return d->drag_autoscroll;
 }
 
 #endif // QT_NO_DRAGANDDROP
 
 /*!\internal
  */
 void KtlQ3ScrollView::setCachedSizeHint(const QSize &sh) const
 {
     if (isVisible() && !d->cachedSizeHint.isValid())
         d->cachedSizeHint = sh;
 }
 
 /*!\internal
  */
 void KtlQ3ScrollView::disableSizeHintCaching()
 {
     d->use_cached_size_hint = false;
 }
 
 /*!\internal
  */
 QSize KtlQ3ScrollView::cachedSizeHint() const
 {
     return d->use_cached_size_hint ? d->cachedSizeHint : QSize();
 }
 
 // QT_END_NAMESPACE
 
 #include "moc_ktlq3scrollview.cpp"