File indexing completed on 2024-04-28 05:26:20

 /*
  * SPDX-FileCopyrightText: 2014 Hugo Pereira Da Costa <hugo.pereira@free.fr>
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #include "breezeframeshadow.h"
 
 #include "breezemetrics.h"
 
 #include <QAbstractScrollArea>
 #include <QApplication>
 #include <QDebug>
 #include <QFrame>
 #include <QMouseEvent>
 #include <QPainter>
 #include <QSplitter>
 
 #include <KColorUtils>
 
 namespace Breeze
 {
 //____________________________________________________________________________________
 bool FrameShadowFactory::registerWidget(QWidget *widget, Helper &helper)
 {
     if (!widget) {
         return false;
     }
     if (isRegistered(widget)) {
         return false;
     }
 
     // check whether widget is a frame, and has the proper shape
     bool accepted = false;
 
     // cast to frame and check
     QFrame *frame(qobject_cast<QFrame *>(widget));
     if (frame) {
         // also do not install on QSplitter
         /*
         due to Qt, splitters are set with a frame style that matches the condition below,
         though no shadow should be installed, obviously
         */
         if (qobject_cast<QSplitter *>(widget)) {
             return false;
         }
 
         // further checks on frame shape, and parent
         if (frame->frameStyle() == (QFrame::StyledPanel | QFrame::Sunken)) {
             accepted = true;
         }
 
     } else if (widget->inherits("KTextEditor::View")) {
         accepted = true;
     }
 
     if (!accepted) {
         return false;
     }
 
     // make sure that the widget is not embedded into a KHTMLView
     QWidget *parent(widget->parentWidget());
     while (parent && !parent->isWindow()) {
         if (parent->inherits("KHTMLView")) {
             return false;
         }
         parent = parent->parentWidget();
     }
 
     // store in set
     _registeredWidgets.insert(widget);
 
     // catch object destruction
     connect(widget, &QObject::destroyed, this, &FrameShadowFactory::widgetDestroyed);
 
     // install shadow
     installShadows(widget, helper);
 
     return true;
 }
 
 //____________________________________________________________________________________
 void FrameShadowFactory::unregisterWidget(QWidget *widget)
 {
     if (!isRegistered(widget)) {
         return;
     }
     _registeredWidgets.remove(widget);
     removeShadows(widget);
 }
 
 //____________________________________________________________________________________
 bool FrameShadowFactory::eventFilter(QObject *object, QEvent *event)
 {
     switch (event->type()) {
     // TODO: possibly implement ZOrderChange event, to make sure that
     // the shadow is always painted on top
     case QEvent::ZOrderChange: {
         raiseShadows(object);
         break;
     }
 
     default:
         break;
     }
 
     return QObject::eventFilter(object, event);
 }
 
 //____________________________________________________________________________________
 void FrameShadowFactory::installShadows(QWidget *widget, Helper &helper)
 {
     removeShadows(widget);
 
     widget->installEventFilter(this);
 
     widget->installEventFilter(&_addEventFilter);
     installShadow(widget, helper, SideTop);
     installShadow(widget, helper, SideBottom);
     widget->removeEventFilter(&_addEventFilter);
 }
 
 //____________________________________________________________________________________
 void FrameShadowFactory::removeShadows(QWidget *widget)
 {
     widget->removeEventFilter(this);
 
     const QList<QObject *> children = widget->children();
     for (QObject *child : children) {
         if (FrameShadow *shadow = qobject_cast<FrameShadow *>(child)) {
             shadow->hide();
             shadow->setParent(nullptr);
             shadow->deleteLater();
         }
     }
 }
 
 //____________________________________________________________________________________
 void FrameShadowFactory::updateShadowsGeometry(const QObject *object, QRect rect) const
 {
     const QList<QObject *> &children = object->children();
     for (QObject *child : children) {
         if (FrameShadow *shadow = qobject_cast<FrameShadow *>(child)) {
             shadow->updateGeometry(rect);
         }
     }
 }
 
 //____________________________________________________________________________________
 void FrameShadowFactory::raiseShadows(QObject *object) const
 {
     const QList<QObject *> &children = object->children();
     for (QObject *child : children) {
         if (FrameShadow *shadow = qobject_cast<FrameShadow *>(child)) {
             shadow->raise();
         }
     }
 }
 
 //____________________________________________________________________________________
 void FrameShadowFactory::update(QObject *object) const
 {
     const QList<QObject *> &children = object->children();
     for (QObject *child : children) {
         if (FrameShadow *shadow = qobject_cast<FrameShadow *>(child)) {
             shadow->update();
         }
     }
 }
 
 //____________________________________________________________________________________
 void FrameShadowFactory::updateState(const QWidget *widget, bool focus, bool hover, qreal opacity, AnimationMode mode) const
 {
     const QList<QObject *> &children = widget->children();
     for (QObject *child : children) {
         if (FrameShadow *shadow = qobject_cast<FrameShadow *>(child)) {
             shadow->updateState(focus, hover, opacity, mode);
         }
     }
 }
 
 //____________________________________________________________________________________
 void FrameShadowFactory::installShadow(QWidget *widget, Helper &helper, Side area) const
 {
     FrameShadow *shadow(nullptr);
     shadow = new FrameShadow(area, helper);
     shadow->setParent(widget);
     shadow->hide();
 }
 
 //____________________________________________________________________________________
 void FrameShadowFactory::widgetDestroyed(QObject *object)
 {
     _registeredWidgets.remove(object);
 }
 
 //____________________________________________________________________________________
 FrameShadow::FrameShadow(Side area, Helper &helper)
     : _helper(helper)
     , _area(area)
 {
     setAttribute(Qt::WA_OpaquePaintEvent, false);
 
     setFocusPolicy(Qt::NoFocus);
     setAttribute(Qt::WA_TransparentForMouseEvents, true);
     setContextMenuPolicy(Qt::NoContextMenu);
 
     // grab viewport widget
     QWidget *viewport(this->viewport());
 
     // set cursor from viewport
     if (viewport) {
         setCursor(viewport->cursor());
     }
 }
 
 //____________________________________________________________________________________
 void FrameShadow::updateGeometry(QRect rect)
 {
     // show on first call
     if (isHidden()) {
         show();
     }
 
     // store offsets between passed rect and parent widget rect
     QRect parentRect(parentWidget()->contentsRect());
     _margins = QMargins(rect.left() - parentRect.left(), rect.top() - parentRect.top(), rect.right() - parentRect.right(), rect.bottom() - parentRect.bottom());
 
     // for efficiency, take out the part for which nothing is rendered
     rect.adjust(1, 1, -1, -1);
 
     // adjust geometry
     const int shadowSize(Metrics::Frame_FrameRadius);
     switch (_area) {
     case SideTop:
         rect.setHeight(shadowSize);
         break;
 
     case SideBottom:
         rect.setTop(rect.bottom() - shadowSize + 1);
         break;
 
     case SideLeft:
         rect.setWidth(shadowSize);
         rect.adjust(0, shadowSize, 0, -shadowSize);
         break;
 
     case SideRight:
         rect.setLeft(rect.right() - shadowSize + 1);
         rect.adjust(0, shadowSize, 0, -shadowSize);
         break;
 
     default:
         return;
     }
 
     setGeometry(rect);
 }
 
 //____________________________________________________________________________________
 void FrameShadow::updateState(bool focus, bool hover, qreal opacity, AnimationMode mode)
 {
     bool changed(false);
     if (_hasFocus != focus) {
         _hasFocus = focus;
         changed |= true;
     }
     if (_mouseOver != hover) {
         _mouseOver = hover;
         changed |= !_hasFocus;
     }
     if (_mode != mode) {
         _mode = mode;
         changed |= (_mode == AnimationNone) || (_mode == AnimationFocus) || (_mode == AnimationHover && !_hasFocus);
     }
 
     if (_opacity != opacity) {
         _opacity = opacity;
         changed |= (_mode != AnimationNone);
     }
     if (changed) {
         if (QWidget *viewport = this->viewport()) {
             // need to disable viewport updates to avoid some redundant painting
             // besides it fixes one visual glitch (from Qt) in QTableViews
             viewport->setUpdatesEnabled(false);
             update();
             viewport->setUpdatesEnabled(true);
 
         } else {
             update();
         }
     }
 }
 
 //____________________________________________________________________________________
 void FrameShadow::paintEvent(QPaintEvent *event)
 {
     // this fixes shadows in frames that change frameStyle() after polish()
     if (QFrame *frame = qobject_cast<QFrame *>(parentWidget())) {
         if (frame->frameStyle() != (QFrame::StyledPanel | QFrame::Sunken)) {
             return;
         }
     }
 
     const QRect parentRect(parentWidget()->contentsRect().translated(mapFromParent(QPoint(0, 0))));
     const QRect rect(parentRect.adjusted(_margins.left(), _margins.top(), _margins.right(), _margins.bottom()));
 
     // render
     QPainter painter(this);
     painter.setClipRegion(event->region());
     painter.setRenderHint(QPainter::Antialiasing);
 
     const QColor outline(_helper.frameOutlineColor(palette(), _mouseOver, _hasFocus, _opacity, _mode));
     painter.setCompositionMode(QPainter::CompositionMode_SourceOver);
     _helper.renderFrame(&painter, rect, QColor(), outline);
 }
 
 //____________________________________________________________________________________
 QWidget *FrameShadow::viewport() const
 {
     if (!parentWidget()) {
         return nullptr;
     } else if (QAbstractScrollArea *widget = qobject_cast<QAbstractScrollArea *>(parentWidget())) {
         return widget->viewport();
 
     } else {
         return nullptr;
     }
 }
 
 }