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// Copyright (C) 2023 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "hoverwatcher.h"
#include <QGuiApplication>
#include <QWidget>
#include <QMouseEvent>
HoverWatcher::HoverWatcher(QWidget *watched)
: QObject(watched), m_watched(watched)
{
Q_ASSERT(watched);
m_cursorShapes[Entered].emplace(Qt::OpenHandCursor);
m_cursorShapes[MousePress].emplace(Qt::ClosedHandCursor);
m_cursorShapes[MouseRelease].emplace(Qt::OpenHandCursor);
// no default for Left => restore override cursor
m_watched->installEventFilter(this);
}
HoverWatcher::~HoverWatcher()
{
m_watched->removeEventFilter(this);
}
typedef QHash<QWidget *, HoverWatcher*> WatchMap;
Q_GLOBAL_STATIC(WatchMap, qt_allHoverWatchers)
HoverWatcher *HoverWatcher::watcher(QWidget *watched)
{
if (qt_allHoverWatchers()->contains(watched))
return qt_allHoverWatchers()->value(watched);
HoverWatcher *watcher = new HoverWatcher(watched);
qt_allHoverWatchers()->insert(watched, watcher);
return watcher;
}
/*!
\overload Const version of watcher
*/
const HoverWatcher *HoverWatcher::watcher(const QWidget *watched)
{
return watcher(const_cast<QWidget *>(watched));
}
void HoverWatcher::dismiss(QWidget *watched)
{
if (!hasWatcher(watched))
return;
delete qt_allHoverWatchers()->take(watched);
}
bool HoverWatcher::hasWatcher(QWidget *widget)
{
return qt_allHoverWatchers()->contains(widget);
}
static constexpr HoverWatcher::HoverAction toHoverAction(QEvent::Type et)
{
switch (et) {
case QEvent::Type::Enter:
return HoverWatcher::HoverAction::Entered;
case QEvent::Type::Leave:
return HoverWatcher::HoverAction::Left;
case QEvent::Type::MouseButtonPress:
return HoverWatcher::HoverAction::MousePress;
case QEvent::Type::MouseButtonRelease:
return HoverWatcher::HoverAction::MouseRelease;
default:
return HoverWatcher::HoverAction::Ignore;
}
}
void HoverWatcher::handleAction (HoverWatcher::HoverAction action)
{
const Qt::CursorShape newShape = cursorShape(action);
if (QGuiApplication::overrideCursor()
&& (QGuiApplication::overrideCursor()->shape() == newShape
|| action == HoverAction::Ignore)) {
return;
}
QGuiApplication::setOverrideCursor(cursorShape(action));
emit hoverAction(action);
switch (action) {
case HoverAction::Entered:
emit entered();
break;
case HoverAction::Left:
emit left();
break;
case HoverAction::MousePress:
emit mousePressed();
break;
case HoverAction::MouseRelease: {
emit mouseReleased();
}
break;
case HoverAction::Ignore:
break;
}
}
bool HoverWatcher::hasShape(HoverAction action) const
{
return action != HoverAction::Ignore && m_cursorShapes[action].has_value();
}
void HoverWatcher::setApplicationCursor(HoverAction action) const
{
if (!hasShape(action)) {
QGuiApplication::restoreOverrideCursor();
return;
}
QGuiApplication::setOverrideCursor(cursorShape(action));
}
bool HoverWatcher::eventFilter(QObject *obj, QEvent *event)
{
Q_ASSERT(obj == m_watched); // don't install event filters elsewhere
// Ignore irrelevant events
const auto action = toHoverAction(event->type());
if (action == HoverAction::Ignore)
return false;
// React to a QScroller having been installed or removed
// A Scroller sends a fake mouse release to QPoint (-1, -1)
// => needs to be ignored and end of scrolling processed instead
static bool hasScroller = false;
if (QScroller::hasScroller(m_watched) != hasScroller) {
hasScroller = QScroller::hasScroller(m_watched);
static QMetaObject::Connection con;
if (hasScroller) {
con = connect(QScroller::scroller(m_watched), &QScroller::stateChanged,
this, &HoverWatcher::handleScrollerStateChange);
} else {
disconnect(con);
}
}
// Ignore fake mouse release event sent by scroller
if (action == HoverAction::MouseRelease && hasScroller) {
QMouseEvent *me = static_cast<QMouseEvent *>(event);
if (me->pos().x() < -9000000 )
return false;
}
// Ignore unpermitted mouse buttons
if (action == HoverAction::MousePress) {
QMouseEvent *me = static_cast<QMouseEvent *>(event);
if (!m_mouseButtons.testFlag(me->button()))
return false;
}
handleAction(action);
return false;
}
Qt::CursorShape HoverWatcher::cursorShape(HoverAction type) const
{
const Qt::CursorShape fallback = Qt::ArrowCursor;
if (type == HoverAction::Ignore)
return fallback;
return m_cursorShapes[type].value_or(fallback);
}
void HoverWatcher::setCursorShape(HoverAction type, Qt::CursorShape shape)
{
if (type == HoverAction::Ignore)
return;
m_cursorShapes[type].emplace(shape);
}
void HoverWatcher::unSetCursorShape(HoverAction type)
{
if (type == HoverAction::Ignore)
return;
m_cursorShapes[type].reset();
}
void HoverWatcher::setMouseButtons(Qt::MouseButtons buttons)
{
m_mouseButtons = buttons;
}
void HoverWatcher::setMouseButton(Qt::MouseButton button, bool enable)
{
m_mouseButtons.setFlag(button, enable);;
}
/*!
\brief This slot handles a QScroller state change, in case the watched
widget uses a scroller. It translates \param state into the appropriate
action.
*/
void HoverWatcher::handleScrollerStateChange(QScroller::State state)
{
switch (state) {
case QScroller::State::Pressed:
case QScroller::State::Dragging:
case QScroller::State::Scrolling:
handleAction(HoverAction::MousePress);
break;
case QScroller::State::Inactive:
handleAction(HoverAction::MouseRelease);
break;
}
}
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