File indexing completed on 2024-05-12 15:56:38

 /* This file is part of the KDE project
  *
  * SPDX-FileCopyrightText: 2006, 2008-2009 Thomas Zander <zander@kde.org>
  * SPDX-FileCopyrightText: 2006 Peter Simonsson <peter.simonsson@gmail.com>
  * SPDX-FileCopyrightText: 2006, 2009 Thorsten Zachmann <zachmann@kde.org>
  * SPDX-FileCopyrightText: 2007-2010 Boudewijn Rempt <boud@valdyas.org>
  * SPDX-FileCopyrightText: 2007 C. Boemann <cbo@boemann.dk>
  * SPDX-FileCopyrightText: 2006-2008 Jan Hambrecht <jaham@gmx.net>
  *
  * SPDX-License-Identifier: LGPL-2.0-or-later
  */
 
 #include "KoCanvasControllerWidget.h"
 #include "KoCanvasControllerWidget_p.h"
 
 #include "KoCanvasControllerWidgetViewport_p.h"
 #include "KoShape.h"
 #include "KoViewConverter.h"
 #include "KoCanvasBase.h"
 #include "KoCanvasObserverBase.h"
 #include "KoCanvasSupervisor.h"
 #include "KoToolManager_p.h"
 
 #include <FlakeDebug.h>
 #include <QMouseEvent>
 #include <QPainter>
 #include <QScrollBar>
 #include <QEvent>
 #include <QDockWidget>
 #include <QTimer>
 #include <QPointer>
 
 #include <QOpenGLWidget>
 
 #include <math.h>
 
 void KoCanvasControllerWidget::Private::setDocumentOffset()
 {
     // The margins scroll the canvas widget inside the viewport, not
     // the document. The documentOffset is meant to be the value that
     // the canvas must add to the update rect in its paint event, to
     // compensate.
 
     QPoint pt(q->horizontalScrollBar()->value(), q->verticalScrollBar()->value());
     q->proxyObject->emitMoveDocumentOffset(pt);
 
     QWidget *canvasWidget = canvas->canvasWidget();
 
     if (canvasWidget) {
         // If it isn't an OpenGL canvas
         if (qobject_cast<QOpenGLWidget*>(canvasWidget) == 0) {
             QPoint diff = q->documentOffset() - pt;
             canvasWidget->scroll(diff.x(), diff.y(), canvasWidget->rect());
         }
     }
 
     q->setDocumentOffset(pt);
 }
 
 void KoCanvasControllerWidget::Private::resetScrollBars()
 {
     // The scrollbar value always points at the top-left corner of the
     // bit of image we paint.
 
     int docH = (int)q->documentSize().height() + q->margin();
     int docW = (int)q->documentSize().width() + q->margin();
     int drawH = viewportWidget->height();
     int drawW = viewportWidget->width();
 
     QScrollBar *hScroll = q->horizontalScrollBar();
     QScrollBar *vScroll = q->verticalScrollBar();
 
     int horizontalReserve = vastScrollingFactor * drawW;
     int verticalReserve = vastScrollingFactor * drawH;
 
     int xMin = -horizontalReserve;
     int yMin = -verticalReserve;
 
     int xMax = docW - drawW + horizontalReserve;
     int yMax = docH - drawH + verticalReserve;
 
     hScroll->setRange(xMin, xMax);
     vScroll->setRange(yMin, yMax);
 
     int fontheight = QFontMetrics(q->font()).height();
 
     vScroll->setPageStep(drawH);
     vScroll->setSingleStep(fontheight);
     hScroll->setPageStep(drawW);
     hScroll->setSingleStep(fontheight);
 
 }
 
 void KoCanvasControllerWidget::Private::emitPointerPositionChangedSignals(QEvent *event)
 {
     if (!canvas) return;
     if (!canvas->viewConverter()) return;
 
     QPoint pointerPos;
     QMouseEvent *mouseEvent = dynamic_cast<QMouseEvent*>(event);
     if (mouseEvent) {
         pointerPos = mouseEvent->pos();
     } else {
         QTabletEvent *tabletEvent = dynamic_cast<QTabletEvent*>(event);
         if (tabletEvent) {
             pointerPos = tabletEvent->pos();
         }
     }
 
     QPoint pixelPos = (pointerPos - canvas->documentOrigin()) + q->documentOffset();
     QPointF documentPos = canvas->viewConverter()->viewToDocument(pixelPos);
 
     q->proxyObject->emitDocumentMousePositionChanged(documentPos);
     q->proxyObject->emitCanvasMousePositionChanged(pointerPos);
 }
 
 
 #include <QTime>
 
 void KoCanvasControllerWidget::Private::activate()
 {
     if (!observerProvider) {
         return;
     }
     KoCanvasBase *canvas = q->canvas();
     Q_FOREACH (KoCanvasObserverBase *docker, observerProvider->canvasObservers()) {
         KoCanvasObserverBase *observer = dynamic_cast<KoCanvasObserverBase*>(docker);
         if (observer) {
             observer->setObservedCanvas(canvas);
         }
     }
 
 }
 
 void KoCanvasControllerWidget::Private::unsetCanvas()
 {
     if (!observerProvider) {
         return;
     }
     Q_FOREACH (KoCanvasObserverBase *docker, observerProvider->canvasObservers()) {
         KoCanvasObserverBase *observer = dynamic_cast<KoCanvasObserverBase*>(docker);
        if (observer) {
             if (observer->observedCanvas() == q->canvas()) {
                 observer->unsetObservedCanvas();
             }
         }
     }
 }
 
 ////////////
 KoCanvasControllerWidget::KoCanvasControllerWidget(KisKActionCollection * actionCollection, KoCanvasSupervisor *observerProvider, QWidget *parent)
     : QAbstractScrollArea(parent)
     , KoCanvasController(actionCollection)
     , d(new Private(this, observerProvider))
 {
     // We need to set this as QDeclarativeView sets them a bit different from QAbstractScrollArea
     setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
 
     // And then our own Viewport
     d->viewportWidget = new Viewport(this);
     setViewport(d->viewportWidget);
     d->viewportWidget->setFocusPolicy(Qt::NoFocus);
     setFocusPolicy(Qt::NoFocus);
     setFrameStyle(0);
 
     //setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
     setAutoFillBackground(false);
     /*
       Fixes:   apps starting at zero zoom.
       Details: Since the document is set on the mainwindow before loading commences the inial show/layout can choose
           to set the document to be very small, even to be zero pixels tall.  Setting a sane minimum size on the
           widget means we no longer get rounding errors in zooming and we no longer end up with zero-zoom.
       Note: KoPage apps should probably startup with a sane document size; for Krita that's impossible
      */
     setMinimumSize(QSize(50, 50));
     setMouseTracking(true);
 
     connect(horizontalScrollBar(), SIGNAL(valueChanged(int)), this, SLOT(updateCanvasOffsetX()));
     connect(verticalScrollBar(), SIGNAL(valueChanged(int)), this, SLOT(updateCanvasOffsetY()));
     connect(d->viewportWidget, SIGNAL(sizeChanged()), this, SLOT(updateCanvasOffsetX()));
     connect(proxyObject, SIGNAL(moveDocumentOffset(QPoint)), d->viewportWidget, SLOT(documentOffsetMoved(QPoint)));
 }
 
 KoCanvasControllerWidget::~KoCanvasControllerWidget()
 {
     delete d;
 }
 
 void KoCanvasControllerWidget::activate()
 {
     d->activate();
 }
 
 void KoCanvasControllerWidget::scrollContentsBy(int dx, int dy)
 {
     Q_UNUSED(dx);
     Q_UNUSED(dy);
     d->setDocumentOffset();
 }
 
 QSizeF KoCanvasControllerWidget::viewportSize() const
 {
     // Calculate viewport size aligned to device pixels to match KisOpenGLCanvas2.
     qreal dpr = viewport()->devicePixelRatioF();
     int viewportWidth = static_cast<int>(viewport()->width() * dpr);
     int viewportHeight = static_cast<int>(viewport()->height() * dpr);
     return QSizeF(viewportWidth / dpr, viewportHeight / dpr);
 }
 
 void KoCanvasControllerWidget::resizeEvent(QResizeEvent *resizeEvent)
 {
     proxyObject->emitSizeChanged(resizeEvent->size());
 
     // XXX: When resizing, keep the area we're looking at now in the
     // center of the resized view.
     resetScrollBars();
     d->setDocumentOffset();
 }
 
 void KoCanvasControllerWidget::setCanvas(KoCanvasBase *canvas)
 {
     if (d->canvas) {
         d->unsetCanvas();
         proxyObject->emitCanvasRemoved(this);
         d->canvas->setCanvasController(0);
         d->canvas->canvasWidget()->removeEventFilter(this);
     }
 
     d->canvas = canvas;
 
     if (d->canvas) {
         d->canvas->setCanvasController(this);
         changeCanvasWidget(d->canvas->canvasWidget());
 
         proxyObject->emitCanvasSet(this);
         QTimer::singleShot(0, this, SLOT(activate()));
 
         setPreferredCenterFractionX(0);
         setPreferredCenterFractionY(0);
     }
 }
 
 KoCanvasBase* KoCanvasControllerWidget::canvas() const
 {
     if (d->canvas.isNull()) return 0;
     return d->canvas;
 }
 
 void KoCanvasControllerWidget::changeCanvasWidget(QWidget *widget)
 {
     if (d->viewportWidget->canvas()) {
         widget->setCursor(d->viewportWidget->canvas()->cursor());
         d->viewportWidget->canvas()->removeEventFilter(this);
     }
 
     d->viewportWidget->setCanvas(widget);
     setFocusProxy(d->canvas->canvasWidget());
 }
 
 int KoCanvasControllerWidget::visibleHeight() const
 {
     if (d->canvas == 0)
         return 0;
     QWidget *canvasWidget = canvas()->canvasWidget();
 
     int height1;
     if (canvasWidget == 0)
         height1 = viewport()->height();
     else
         height1 = qMin(viewport()->height(), canvasWidget->height());
     int height2 = height();
     return qMin(height1, height2);
 }
 
 int KoCanvasControllerWidget::visibleWidth() const
 {
     if (d->canvas == 0)
         return 0;
     QWidget *canvasWidget = canvas()->canvasWidget();
 
     int width1;
     if (canvasWidget == 0)
         width1 = viewport()->width();
     else
         width1 = qMin(viewport()->width(), canvasWidget->width());
     int width2 = width();
     return qMin(width1, width2);
 }
 
 int KoCanvasControllerWidget::canvasOffsetX() const
 {
     int offset = -horizontalScrollBar()->value();
 
     if (d->canvas) {
         offset += d->canvas->canvasWidget()->x() + frameWidth();
     }
 
     return offset;
 }
 
 int KoCanvasControllerWidget::canvasOffsetY() const
 {
     int offset = -verticalScrollBar()->value();
 
     if (d->canvas) {
         offset += d->canvas->canvasWidget()->y() + frameWidth();
     }
 
     return offset;
 }
 
 void KoCanvasControllerWidget::updateCanvasOffsetX()
 {
     proxyObject->emitCanvasOffsetXChanged(canvasOffsetX());
     if (d->ignoreScrollSignals)
         return;
 
     setPreferredCenterFractionX((horizontalScrollBar()->value()
                                  + viewport()->width() / 2.0) / documentSize().width());
 }
 
 void KoCanvasControllerWidget::updateCanvasOffsetY()
 {
     proxyObject->emitCanvasOffsetYChanged(canvasOffsetY());
     if (d->ignoreScrollSignals)
         return;
 
     setPreferredCenterFractionY((verticalScrollBar()->value()
                                  + verticalScrollBar()->pageStep() / 2.0) / documentSize().height());
 }
 
 void KoCanvasControllerWidget::ensureVisible(KoShape *shape)
 {
     Q_ASSERT(shape);
     ensureVisible(d->canvas->viewConverter()->documentToView(shape->boundingRect()));
 }
 
 void KoCanvasControllerWidget::ensureVisible(const QRectF &rect, bool smooth)
 {
     QRect currentVisible(-canvasOffsetX(), -canvasOffsetY(), visibleWidth(), visibleHeight());
 
     QRect viewRect = rect.toRect();
     viewRect.translate(d->canvas->documentOrigin());
     if (!viewRect.isValid() || currentVisible.contains(viewRect))
         return; // its visible. Nothing to do.
 
     // if we move, we move a little more so the amount of times we have to move is less.
     int jumpWidth = smooth ? 0 : currentVisible.width() / 5;
     int jumpHeight = smooth ? 0 : currentVisible.height() / 5;
     if (!smooth && viewRect.width() + jumpWidth > currentVisible.width())
         jumpWidth = 0;
     if (!smooth && viewRect.height() + jumpHeight > currentVisible.height())
         jumpHeight = 0;
 
     int horizontalMove = 0;
     if (currentVisible.width() <= viewRect.width())      // center view
         horizontalMove = viewRect.center().x() - currentVisible.center().x();
     else if (currentVisible.x() > viewRect.x())          // move left
         horizontalMove = viewRect.x() - currentVisible.x() - jumpWidth;
     else if (currentVisible.right() < viewRect.right())  // move right
         horizontalMove = viewRect.right() - qMax(0, currentVisible.right() - jumpWidth);
 
     int verticalMove = 0;
     if (currentVisible.height() <= viewRect.height())       // center view
         verticalMove = viewRect.center().y() - currentVisible.center().y();
     if (currentVisible.y() > viewRect.y())               // move up
         verticalMove = viewRect.y() - currentVisible.y() - jumpHeight;
     else if (currentVisible.bottom() < viewRect.bottom()) // move down
         verticalMove = viewRect.bottom() - qMax(0, currentVisible.bottom() - jumpHeight);
 
     pan(QPoint(horizontalMove, verticalMove));
 }
 
 void KoCanvasControllerWidget::recenterPreferred()
 {
     const bool oldIgnoreScrollSignals = d->ignoreScrollSignals;
     d->ignoreScrollSignals = true;
 
     QPointF center = preferredCenter();
 
     // convert into a viewport based point
     center.rx() += d->canvas->canvasWidget()->x() + frameWidth();
     center.ry() += d->canvas->canvasWidget()->y() + frameWidth();
 
     // scroll to a new center point
     QPointF topLeft = center - 0.5 * QPointF(viewport()->width(), viewport()->height());
     setScrollBarValue(topLeft.toPoint());
 
     d->ignoreScrollSignals = oldIgnoreScrollSignals;
 }
 
 void KoCanvasControllerWidget::zoomIn(const QPoint &center)
 {
     zoomBy(center, sqrt(2.0));
 }
 
 void KoCanvasControllerWidget::zoomOut(const QPoint &center)
 {
     zoomBy(center, sqrt(0.5));
 }
 
 
 void KoCanvasControllerWidget::zoomBy(const QPoint &center, qreal zoom)
 {
     const QPointF oldCenter = preferredCenter();
     const QPointF newCenter = center + scrollBarValue();
     const QPointF stillPoint = (zoom * newCenter - oldCenter) / (zoom - 1.0);
 
     proxyObject->emitZoomRelative(zoom, stillPoint);
 }
 
 void KoCanvasControllerWidget::zoomTo(const QRect &viewRect)
 {
     qreal scale;
 
     if (1.0 * viewport()->width() / viewRect.width() > 1.0 * viewport()->height() / viewRect.height())
         scale = 1.0 * viewport()->height() / viewRect.height();
     else
         scale = 1.0 * viewport()->width() / viewRect.width();
 
     zoomBy(viewRect.center(), scale);
 }
 
 void KoCanvasControllerWidget::updateDocumentSize(const QSizeF &sz, bool recalculateCenter)
 {
     // Don't update if the document-size didn't changed to prevent infinite loops and unneeded updates.
     if (KoCanvasController::documentSize() == sz)
         return;
 
     if (!recalculateCenter) {
         // assume the distance from the top stays equal and recalculate the center.
         setPreferredCenterFractionX(documentSize().width() * preferredCenterFractionX() / sz.width());
         setPreferredCenterFractionY(documentSize().height() * preferredCenterFractionY() / sz.height());
     }
 
     const bool oldIgnoreScrollSignals = d->ignoreScrollSignals;
     d->ignoreScrollSignals = true;
     KoCanvasController::setDocumentSize(sz);
     d->viewportWidget->setDocumentSize(sz);
     resetScrollBars();
 
     // Always emit the new offset.
     updateCanvasOffsetX();
     updateCanvasOffsetY();
 
     d->ignoreScrollSignals = oldIgnoreScrollSignals;
 }
 
 void KoCanvasControllerWidget::setZoomWithWheel(bool zoom)
 {
     d->zoomWithWheel = zoom;
 }
 
 void KoCanvasControllerWidget::setVastScrolling(qreal factor)
 {
     d->vastScrollingFactor = factor;
 }
 
 QPointF KoCanvasControllerWidget::currentCursorPosition() const
 {
     QWidget *canvasWidget = d->canvas->canvasWidget();
     const KoViewConverter *converter = d->canvas->viewConverter();
     return converter->viewToDocument(canvasWidget->mapFromGlobal(QCursor::pos()) + d->canvas->canvasController()->documentOffset() - canvasWidget->pos());
 }
 
 void KoCanvasControllerWidget::pan(const QPoint &distance)
 {
     QPoint sourcePoint = scrollBarValue();
     setScrollBarValue(sourcePoint + distance);
 }
 
 void KoCanvasControllerWidget::panUp()
 {
     pan(QPoint(0, verticalScrollBar()->singleStep()));
 }
 
 void KoCanvasControllerWidget::panDown()
 {
     pan(QPoint(0, -verticalScrollBar()->singleStep()));
 }
 
 void KoCanvasControllerWidget::panLeft()
 {
     pan(QPoint(horizontalScrollBar()->singleStep(), 0));
 }
 
 void KoCanvasControllerWidget::panRight()
 {
     pan(QPoint(-horizontalScrollBar()->singleStep(), 0));
 }
 
 void KoCanvasControllerWidget::setPreferredCenter(const QPointF &viewPoint)
 {
     setPreferredCenterFractionX(viewPoint.x() / documentSize().width());
     setPreferredCenterFractionY(viewPoint.y() / documentSize().height());
     recenterPreferred();
 }
 
 QPointF KoCanvasControllerWidget::preferredCenter() const
 {
     QPointF center;
     center.setX(preferredCenterFractionX() * documentSize().width());
     center.setY(preferredCenterFractionY() * documentSize().height());
     return center;
 }
 
 void KoCanvasControllerWidget::paintEvent(QPaintEvent *event)
 {
     QPainter gc(viewport());
     d->viewportWidget->handlePaintEvent(gc, event);
 }
 
 void KoCanvasControllerWidget::dragEnterEvent(QDragEnterEvent *event)
 {
     d->viewportWidget->handleDragEnterEvent(event);
 }
 
 void KoCanvasControllerWidget::dropEvent(QDropEvent *event)
 {
     d->viewportWidget->handleDropEvent(event);
 }
 
 void KoCanvasControllerWidget::dragMoveEvent(QDragMoveEvent *event)
 {
     d->viewportWidget->handleDragMoveEvent(event);
 }
 
 void KoCanvasControllerWidget::dragLeaveEvent(QDragLeaveEvent *event)
 {
     d->viewportWidget->handleDragLeaveEvent(event);
 }
 
 void KoCanvasControllerWidget::wheelEvent(QWheelEvent *event)
 {
     if (d->zoomWithWheel != ((event->modifiers() & Qt::ControlModifier) == Qt::ControlModifier)) {
         const qreal zoomCoeff = event->delta() > 0 ? sqrt(2.0) : sqrt(0.5);
         zoomRelativeToPoint(event->pos(), zoomCoeff);
 
         event->accept();
     } else
         QAbstractScrollArea::wheelEvent(event);
 }
 
 void KoCanvasControllerWidget::zoomRelativeToPoint(const QPoint &widgetPoint, qreal zoomCoeff)
 {
     const QPoint offset = scrollBarValue();
     const QPoint mousePos(widgetPoint + offset);
 
     const bool oldIgnoreScrollSignals = d->ignoreScrollSignals;
     d->ignoreScrollSignals = true;
     proxyObject->emitZoomRelative(zoomCoeff, mousePos);
     d->ignoreScrollSignals = oldIgnoreScrollSignals;
 }
 
 bool KoCanvasControllerWidget::focusNextPrevChild(bool)
 {
     // we always return false meaning the canvas takes keyboard focus, but never gives it away.
     return false;
 }
 
 bool KoCanvasControllerWidget::viewportEvent(QEvent *event) {
     // Workaround: Don't let QAbstractScrollArea handle Gesture events. Because
     // Qt's detection of touch point positions is a bit buggy, it is handled
     // with custom algorithms in the KisInputManager. But we must also not let
     // the corresponding event propagate to the parent QAbstractScrollArea.
     if (event->type() == QEvent::Gesture) {
         return false;
     }
     return QAbstractScrollArea::viewportEvent(event);
 }
 
 void KoCanvasControllerWidget::setMargin(int margin)
 {
     KoCanvasController::setMargin(margin);
     Q_ASSERT(d->viewportWidget);
     d->viewportWidget->setMargin(margin);
 }
 
 QPoint KoCanvasControllerWidget::scrollBarValue() const
 {
     QScrollBar * hBar = horizontalScrollBar();
     QScrollBar * vBar = verticalScrollBar();
 
     return QPoint(hBar->value(), vBar->value());
 }
 
 void KoCanvasControllerWidget::setScrollBarValue(const QPoint &value)
 {
     QScrollBar * hBar = horizontalScrollBar();
     QScrollBar * vBar = verticalScrollBar();
 
     hBar->setValue(value.x());
     vBar->setValue(value.y());
 }
 
 void KoCanvasControllerWidget::resetScrollBars()
 {
     d->resetScrollBars();
 }
 
 qreal KoCanvasControllerWidget::vastScrollingFactor() const
 {
     return d->vastScrollingFactor;
 }
 
 KoCanvasControllerWidget::Private *KoCanvasControllerWidget::priv()
 {
     return d;
 }
 
 //have to include this because of Q_PRIVATE_SLOT
 #include "moc_KoCanvasControllerWidget.cpp"