AuroraMiddleware/qt5base-lts
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add dedicated child and parent events for QWindow reparenting

Browse Source 
When a QWindow is parented into another window, either via its constructor,
or via setParent(), we also update the QObject parent of the window. This
in turn sends ChildAdded and ChildRemoved events to the new and old parent
of the window, as well as ParentAboutToChange and ParentChange to the window
itself.

But at the point when these events are sent, the QWindow parent relationship
has not been fully established. We have not updated d->parentWindow, nor
have we propagated the parent relationship to the platform window.

This is problematic because clients can not use these events to react to
window parent changes synchronously. For example. trying to raise a child
window when added to a parent is not going to work, because at that point
the child window isn't a native child of the parent.

Instead of re-using the QObject events for QWindow, like QWidget does,
by delaying the events or sending them manually at a point when the
window parent relationship has been fully formed, we opt to add new
dedicated events.

Change-Id: I019c14eba444861f537e4f68ab3a82297f843cf7
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
This commit is contained in:
Tor Arne Vestbø 2023-11-04 11:17:30 +01:00
parent c94bcecb22
commit 99c70de9a6
7 changed files with 253 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
src/corelib/kernel/qcoreevent.cpp
View File

@ -79,6 +79,8 @@ Q_TRACE_POINT(qtcore, QEvent_dtor, QEvent *event, QEvent::Type type);
\value ChildAdded An object gets a child (QChildEvent).
\value ChildPolished A widget child gets polished (QChildEvent).
\value ChildRemoved An object loses a child (QChildEvent).
\value [since 6.7] ChildWindowAdded A child window was added to the window.
\value [since 6.7] ChildWindowRemoved A child window was removed from the window.
\value Clipboard The clipboard contents have changed.
\value Close Widget was closed (QCloseEvent).
\value CloseSoftwareInputPanel A widget wants to close the software input panel (SIP).
@ -164,6 +166,8 @@ Q_TRACE_POINT(qtcore, QEvent_dtor, QEvent *event, QEvent::Type type);
Only sent to some object types, such as QWidget.
\value ParentChange The object parent has changed.
Only sent to some object types, such as QWidget.
\value [since 6.7] ParentWindowAboutToChange The parent window is about to change.
\value [since 6.7] ParentWindowChange The parent window has changed.
\value PlatformPanel A platform specific panel has been requested.
\value PlatformSurface A native platform surface has been created or is about to be destroyed (QPlatformSurfaceEvent).
\omitvalue Pointer

5
src/corelib/kernel/qcoreevent.h
View File

@ -286,6 +286,11 @@ public:
DevicePixelRatioChange = 222,
ChildWindowAdded = 223,
ChildWindowRemoved = 224,
ParentWindowAboutToChange = 225,
ParentWindowChange = 226,
// 512 reserved for Qt Jambi's MetaCall event
// 513 reserved for Qt Jambi's DeleteOnMainThread event

40
src/gui/kernel/qevent.cpp
View File

@ -4759,6 +4759,46 @@ Q_IMPL_EVENT_COMMON(QApplicationStateChangeEvent)
Returns the state of the application.
*/
/*!
\class QChildWindowEvent
\inmodule QtGui
\since 6.7
\brief The QChildWindowEvent class contains event parameters for
child window changes.
\ingroup events
Child window events are sent to windows when children are
added or removed.
In both cases you can only rely on the child being a QWindow
— not any subclass thereof. This is because in the
QEvent::ChildWindowAdded case the subclass is not yet fully
constructed, and in the QEvent::ChildWindowRemoved case it
might have already been destructed.
*/
/*!
Constructs a child window event object of a particular \a type
for the \a childWindow.
\a type can be QEvent::ChildWindowAdded or QEvent::ChildWindowRemoved.
\sa child()
*/
QChildWindowEvent::QChildWindowEvent(Type type, QWindow *childWindow)
: QEvent(type), c(childWindow)
{
}
Q_IMPL_EVENT_COMMON(QChildWindowEvent)
/*!
\fn QWindow *QChildWindowEvent::child() const
Returns the child window that was added or removed.
*/
QMutableTouchEvent::~QMutableTouchEvent()
= default;

11
src/gui/kernel/qevent.h
View File

@ -1020,6 +1020,17 @@ private:
Qt::ApplicationState m_applicationState;
};
class Q_GUI_EXPORT QChildWindowEvent : public QEvent
{
Q_DECL_EVENT_COMMON(QChildWindowEvent)
public:
QChildWindowEvent(Type type, QWindow *childWindow);
QWindow *child() const { return c; }
private:
QWindow *c;
};
QT_END_NAMESPACE
#endif // QEVENT_H

34
src/gui/kernel/qwindow.cpp
View File

@ -128,7 +128,7 @@ QWindow::QWindow(QScreen *targetScreen)
, QSurface(QSurface::Window)
{
Q_D(QWindow);
d->init(targetScreen);
d->init(nullptr, targetScreen);
}
static QWindow *nonDesktopParent(QWindow *parent)
@ -169,11 +169,11 @@ QWindow::QWindow(QWindow *parent)
\sa setParent()
*/
QWindow::QWindow(QWindowPrivate &dd, QWindow *parent)
: QObject(dd, nonDesktopParent(parent))
: QObject(dd, nullptr)
, QSurface(QSurface::Window)
{
Q_D(QWindow);
d->init();
d->init(nonDesktopParent(parent));
}
/*!
@ -183,6 +183,8 @@ QWindow::~QWindow()
{
Q_D(QWindow);
d->destroy();
// Decouple from parent before window goes under
setParent(nullptr);
QGuiApplicationPrivate::window_list.removeAll(this);
if (!QGuiApplicationPrivate::is_app_closing)
QGuiApplicationPrivate::instance()->modalWindowList.removeOne(this);
@ -206,10 +208,12 @@ QWindowPrivate::QWindowPrivate()
QWindowPrivate::~QWindowPrivate()
= default;
void QWindowPrivate::init(QScreen *targetScreen)
void QWindowPrivate::init(QWindow *parent, QScreen *targetScreen)
{
Q_Q(QWindow);
q->QObject::setParent(parent);
isWindow = true;
parentWindow = static_cast<QWindow *>(q->QObject::parent());
@ -242,6 +246,11 @@ void QWindowPrivate::init(QScreen *targetScreen)
#endif
updateDevicePixelRatio();
});
if (parentWindow) {
QChildWindowEvent childAddedEvent(QEvent::ChildWindowAdded, q);
QCoreApplication::sendEvent(parentWindow, &childAddedEvent);
}
}
/*!
@ -771,6 +780,10 @@ void QWindow::setParent(QWindow *parent)
return;
}
QEvent parentAboutToChangeEvent(QEvent::ParentWindowAboutToChange);
QCoreApplication::sendEvent(this, &parentAboutToChangeEvent);
const auto previousParent = d->parentWindow;
QObject::setParent(parent);
d->parentWindow = parent;
@ -793,6 +806,19 @@ void QWindow::setParent(QWindow *parent)
}
QGuiApplicationPrivate::updateBlockedStatus(this);
if (previousParent) {
QChildWindowEvent childRemovedEvent(QEvent::ChildWindowRemoved, this);
QCoreApplication::sendEvent(previousParent, &childRemovedEvent);
}
if (parent) {
QChildWindowEvent childAddedEvent(QEvent::ChildWindowAdded, this);
QCoreApplication::sendEvent(parent, &childAddedEvent);
}
QEvent parentChangedEvent(QEvent::ParentWindowChange);
QCoreApplication::sendEvent(this, &parentChangedEvent);
}
/*!

2
src/gui/kernel/qwindow_p.h
View File

@ -44,7 +44,7 @@ public:
QWindowPrivate();
~QWindowPrivate() override;
void init(QScreen *targetScreen = nullptr);
void init(QWindow *parent, QScreen *targetScreen = nullptr);
#ifndef QT_NO_CURSOR
void setCursor(const QCursor *c = nullptr);

162
tests/auto/gui/kernel/qwindow/tst_qwindow.cpp
View File

@ -7,6 +7,7 @@
#include <qpa/qplatformwindow.h>
#include <private/qguiapplication_p.h>
#include <private/qhighdpiscaling_p.h>
#include <private/qwindow_p.h>
#include <QtGui/QPainter>
#include <QTest>
@ -101,6 +102,8 @@ private slots:
void enterLeaveOnWindowShowHide();
#endif
void windowExposedAfterReparent();
void childEvents();
void parentEvents();
private:
QPoint m_availableTopLeft;
@ -3058,6 +3061,165 @@ void tst_QWindow::windowExposedAfterReparent()
QVERIFY(QTest::qWaitForWindowExposed(&child));
}
struct ParentWindow : public QWindow
{
bool event(QEvent *event) override
{
[&]() -> void {
if (event->type() == QEvent::ChildWindowAdded
|| event->type() == QEvent::ChildWindowRemoved) {
// We should not receive child events after the window has been destructed
QVERIFY(this->isWindowType());
auto *parentWindow = this;
auto *childEvent = static_cast<QChildWindowEvent*>(event);
auto *childWindow = childEvent->child();
if (event->type() == QEvent::ChildWindowAdded) {
QVERIFY(childWindow->parent());
QVERIFY(parentWindow->isAncestorOf(childWindow));
if (childWindow->handle())
QVERIFY(childWindow->handle()->parent() == parentWindow->handle());
} else {
QVERIFY(!childWindow->parent());
QVERIFY(!parentWindow->isAncestorOf(childWindow));
if (childWindow->handle())
QVERIFY(childWindow->handle()->parent() != parentWindow->handle());
}
}
}();
return QWindow::event(event);
}
};
void tst_QWindow::childEvents()
{
ParentWindow parent;
{
// ChildAdded via constructor
QWindow constructorChild(&parent);
if (QTest::currentTestFailed()) return;
// ChildRemoved via destructor
}
if (QTest::currentTestFailed()) return;
// ChildAdded and ChildRemoved via setParent
QWindow child;
child.setParent(&parent);
if (QTest::currentTestFailed()) return;
child.setParent(nullptr);
if (QTest::currentTestFailed()) return;
parent.create();
child.create();
// ChildAdded and ChildRemoved after creation
child.setParent(&parent);
if (QTest::currentTestFailed()) return;
child.setParent(nullptr);
if (QTest::currentTestFailed()) return;
}
struct ChildWindowPrivate;
struct ChildWindow : public QWindow
{
ChildWindow(QWindow *parent = nullptr);
};
struct ChildWindowPrivate : public QWindowPrivate
{
ChildWindowPrivate() : QWindowPrivate()
{
receiveParentEvents = true;
}
};
ChildWindow::ChildWindow(QWindow *parent)
: QWindow(*new ChildWindowPrivate, parent)
{}
struct ParentEventTester : public QObject
{
bool eventFilter(QObject *object, QEvent *event) override
{
[&]() -> void {
if (event->type() == QEvent::ParentWindowAboutToChange
|| event->type() == QEvent::ParentWindowChange) {
// We should not receive parent events after the window has been destructed
QVERIFY(object->isWindowType());
auto *window = static_cast<QWindow*>(object);
if (event->type() == QEvent::ParentWindowAboutToChange) {
QVERIFY(window->parent() != nextExpectedParent);
if (window->handle()) {
QVERIFY(window->handle()->parent() !=
(nextExpectedParent ? nextExpectedParent->handle() : nullptr));
}
} else {
QVERIFY(window->parent() == nextExpectedParent);
if (window->handle()) {
QVERIFY(window->handle()->parent() ==
(nextExpectedParent ? nextExpectedParent->handle() : nullptr));
}
}
}
}();
return QObject::eventFilter(object, event);
}
QWindow *nextExpectedParent = nullptr;
};
void tst_QWindow::parentEvents()
{
QWindow parent;
{
ParentEventTester tester;
{
// We can't hook in early enough to get the parent change during
// QObject construction.
ChildWindow child(&parent);
// But we can observe the one during destruction
child.installEventFilter(&tester);
tester.nextExpectedParent = nullptr;
}
}
if (QTest::currentTestFailed()) return;
ParentEventTester tester;
ChildWindow child;
child.installEventFilter(&tester);
tester.nextExpectedParent = &parent;
child.setParent(&parent);
if (QTest::currentTestFailed()) return;
tester.nextExpectedParent = nullptr;
child.setParent(nullptr);
if (QTest::currentTestFailed()) return;
parent.create();
child.create();
tester.nextExpectedParent = &parent;
child.setParent(&parent);
if (QTest::currentTestFailed()) return;
tester.nextExpectedParent = nullptr;
child.setParent(nullptr);
if (QTest::currentTestFailed()) return;
}
#include <tst_qwindow.moc>
QTEST_MAIN(tst_QWindow)