KisScreenMigrationTracker Class Reference

#include <KisScreenMigrationTracker.h>

Inheritance diagram for KisScreenMigrationTracker:

Signals
void	sigScreenChanged (QScreen *screen)
void	sigScreenOrResolutionChanged (QScreen *screen)

Public Member Functions
QScreen *	currentScreen () const
QScreen *	currentScreenSafe () const
	KisScreenMigrationTracker (QWidget *trackedWidget, QObject *parent=nullptr)

Protected Member Functions
bool	eventFilter (QObject *watched, QEvent *event) override

Private Slots
void	slotResolutionCompressorTriggered ()
void	slotScreenChanged (QScreen *screen)
void	slotScreenLogicalResolutionChanged (qreal value)
void	slotScreenResolutionChanged (qreal value)

Private Member Functions
void	connectScreenSignals (QScreen *screen)
void	connectTopLevelWindow (QWindow *window)

Private Attributes
KisSignalCompressor *	m_resolutionChangeCompressor
KisSignalAutoConnectionsStore	m_screenConnections
QPointer< QWindow >	m_trackedTopLevelWindow
QWidget *	m_trackedWidget {nullptr}

Detailed Description

A simple class that tracks the current screen assigned to the widget. When the widget migrates to a different screen, a signal is emitted.

If KisScreenMigrationTracker is created before the actual window for the widget is created, then it subscribes to widget's QEvent::Show event and waits until the widget is displayed.

Definition at line 29 of file KisScreenMigrationTracker.h.

Constructor & Destructor Documentation

KisScreenMigrationTracker()

KisScreenMigrationTracker::KisScreenMigrationTracker	(	QWidget *	trackedWidget,
		QObject *	parent = nullptr )

The window of the tracked widget may be not initialized at the construction of the widget. Hence we should postpone initialization of the window handle till the widget gets shown on screen.

Definition at line 32 of file KisScreenMigrationTracker.cpp.

    : QObject(parent)
    , m_trackedWidget(trackedWidget)
    , m_resolutionChangeCompressor(new KisSignalCompressor(100, KisSignalCompressor::POSTPONE, this))
{
    KIS_SAFE_ASSERT_RECOVER_RETURN(trackedWidget);
 
    m_trackedTopLevelWindow = findNearestParentWithNativeWindow(trackedWidget);
    if (m_trackedTopLevelWindow) {
        connectTopLevelWindow(m_trackedTopLevelWindow);
    } else {
        trackedWidget->installEventFilter(this);
    }
 
    connect(m_resolutionChangeCompressor, &KisSignalCompressor::timeout,
            this, &KisScreenMigrationTracker::slotResolutionCompressorTriggered);
}

References connect(), connectTopLevelWindow(), KIS_SAFE_ASSERT_RECOVER_RETURN, m_resolutionChangeCompressor, m_trackedTopLevelWindow, slotResolutionCompressorTriggered(), and KisSignalCompressor::timeout().

Member Function Documentation

connectScreenSignals()

void KisScreenMigrationTracker::connectScreenSignals ( QScreen * screen )

private

Definition at line 66 of file KisScreenMigrationTracker.cpp.

{
    m_screenConnections.clear();
    m_screenConnections.addConnection(screen, &QScreen::physicalDotsPerInchChanged,
                                      this, &KisScreenMigrationTracker::slotScreenResolutionChanged);
    m_screenConnections.addConnection(screen, &QScreen::logicalDotsPerInchChanged,
                                      this, &KisScreenMigrationTracker::slotScreenLogicalResolutionChanged);
}

References KisSignalAutoConnectionsStore::addConnection(), KisSignalAutoConnectionsStore::clear(), m_screenConnections, slotScreenLogicalResolutionChanged(), and slotScreenResolutionChanged().

connectTopLevelWindow()

void KisScreenMigrationTracker::connectTopLevelWindow ( QWindow * window )

private

Definition at line 75 of file KisScreenMigrationTracker.cpp.

{
    KIS_SAFE_ASSERT_RECOVER_RETURN(window);
    connect(window, &QWindow::screenChanged, this, &KisScreenMigrationTracker::slotScreenChanged);
    connectScreenSignals(window->screen());
 
    Q_EMIT sigScreenChanged(window->screen());
    Q_EMIT sigScreenOrResolutionChanged(window->screen());
}

References connect(), connectScreenSignals(), KIS_SAFE_ASSERT_RECOVER_RETURN, sigScreenChanged(), sigScreenOrResolutionChanged(), and slotScreenChanged().

currentScreen()

QScreen * KisScreenMigrationTracker::currentScreen

(

)

const

Return the screen currently assigned to the tracked widget. If the widget has no native window associated, then the function asserts.

Definition at line 55 of file KisScreenMigrationTracker.cpp.

{
    KIS_SAFE_ASSERT_RECOVER_RETURN_VALUE(m_trackedTopLevelWindow, qApp->screens().first());
    return m_trackedTopLevelWindow->screen();
}

References KIS_SAFE_ASSERT_RECOVER_RETURN_VALUE, and m_trackedTopLevelWindow.

currentScreenSafe()

QScreen * KisScreenMigrationTracker::currentScreenSafe

(

)

const

Return the screen currently assigned to the tracked widget or the default screen if the widget has no native window association (usually it means that the widget hasn't yet been added into the window hierarchy).

Definition at line 61 of file KisScreenMigrationTracker.cpp.

{
    return m_trackedTopLevelWindow ? m_trackedTopLevelWindow->screen() : qApp->screens().first();
}

References m_trackedTopLevelWindow.

eventFilter()

bool KisScreenMigrationTracker::eventFilter ( QObject * watched, QEvent * event )

overrideprotected

Definition at line 85 of file KisScreenMigrationTracker.cpp.

{
    if (watched == m_trackedWidget && event->type() == QEvent::Show) {
        m_trackedTopLevelWindow = findNearestParentWithNativeWindow(m_trackedWidget);
        if (m_trackedTopLevelWindow) {
            connectTopLevelWindow(m_trackedTopLevelWindow);
            m_trackedWidget->removeEventFilter(this);
        }
    }
 
    return QObject::eventFilter(watched, event);
}

References connectTopLevelWindow(), m_trackedTopLevelWindow, and m_trackedWidget.

sigScreenChanged

void KisScreenMigrationTracker::sigScreenChanged ( QScreen * screen )

signal

Emitted when the widget migrates to a different screen

sigScreenOrResolutionChanged

void KisScreenMigrationTracker::sigScreenOrResolutionChanged ( QScreen * screen )

signal

Emitted when the widget migrates to a different screen or screen resolution changes. This signal is useful for adjusting the display scale factor.

slotResolutionCompressorTriggered

void KisScreenMigrationTracker::slotResolutionCompressorTriggered ( )

privateslot

Definition at line 118 of file KisScreenMigrationTracker.cpp.

{
    KIS_SAFE_ASSERT_RECOVER_RETURN(m_trackedTopLevelWindow);
    Q_EMIT sigScreenOrResolutionChanged(m_trackedTopLevelWindow->screen());
}

References KIS_SAFE_ASSERT_RECOVER_RETURN, m_trackedTopLevelWindow, and sigScreenOrResolutionChanged().

slotScreenChanged

void KisScreenMigrationTracker::slotScreenChanged ( QScreen * screen )

privateslot

Definition at line 98 of file KisScreenMigrationTracker.cpp.

{
    connectScreenSignals(screen);
 
    Q_EMIT sigScreenChanged(screen);
    Q_EMIT sigScreenOrResolutionChanged(screen);
}

References connectScreenSignals(), sigScreenChanged(), and sigScreenOrResolutionChanged().

slotScreenLogicalResolutionChanged

void KisScreenMigrationTracker::slotScreenLogicalResolutionChanged ( qreal value )

privateslot

Definition at line 112 of file KisScreenMigrationTracker.cpp.

{
    Q_UNUSED(value)
    m_resolutionChangeCompressor->start();
}

References m_resolutionChangeCompressor, KisSignalCompressor::start(), and value().

slotScreenResolutionChanged

void KisScreenMigrationTracker::slotScreenResolutionChanged ( qreal value )

privateslot

Definition at line 106 of file KisScreenMigrationTracker.cpp.

{
    Q_UNUSED(value)
    m_resolutionChangeCompressor->start();
}

References m_resolutionChangeCompressor, KisSignalCompressor::start(), and value().

Member Data Documentation

m_resolutionChangeCompressor

KisSignalCompressor* KisScreenMigrationTracker::m_resolutionChangeCompressor

private

Definition at line 79 of file KisScreenMigrationTracker.h.

m_screenConnections

KisSignalAutoConnectionsStore KisScreenMigrationTracker::m_screenConnections

private

Definition at line 78 of file KisScreenMigrationTracker.h.

m_trackedTopLevelWindow

QPointer<QWindow> KisScreenMigrationTracker::m_trackedTopLevelWindow

private

Definition at line 77 of file KisScreenMigrationTracker.h.

m_trackedWidget

QWidget* KisScreenMigrationTracker::m_trackedWidget {nullptr}

private

Definition at line 76 of file KisScreenMigrationTracker.h.

{nullptr};

---

The documentation for this class was generated from the following files:

• libs/widgetutils/KisScreenMigrationTracker.h
• libs/widgetutils/KisScreenMigrationTracker.cpp