Convert EffectView to a QQuickWidget

Summary:
The Qt Wayland support for subsurfaces is broken in many ways, producing
graphical glitches and crashes:
https://bugreports.qt.io/browse/QTBUG-54888 for instance.

Using a QQuickWidget instead of a QQuickView avoids those issues, with
the additional benefit of a nicer API.

Test Plan:
Opened the KCM with kcmshell and systemsettings, no subsurfaces used
anymore.

Reviewers: #plasma, graesslin, davidedmundson

Reviewed By: #plasma, graesslin, davidedmundson

Subscribers: kwin, plasma-devel, #kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D11066

kcmkwin/kwincompositing/CMakeLists.txt

@@ -34,6 +34,7 @@ add_library(kwincompositing MODULE ${kwincomposing_SRC})
 
 target_link_libraries(kwincompositing
     Qt5::Quick
+    Qt5::QuickWidgets
     Qt5::DBus
     Qt5::Widgets
     KF5::CoreAddons
@@ -64,6 +65,7 @@ ecm_mark_as_test(effectModelTest)
 
 target_link_libraries(effectModelTest
     Qt5::Quick
+    Qt5::QuickWidgets
     Qt5::DBus
     Qt5::Test
     Qt5::Widgets

kcmkwin/kwincompositing/main.cpp

@@ -229,16 +229,12 @@ KWinCompositingKCM::KWinCompositingKCM(QWidget* parent, const QVariantList& args
 {
     QVBoxLayout *vl = new QVBoxLayout(this);
 
-    QWidget *w = QWidget::createWindowContainer(m_view.data(), this);
-    connect(m_view.data(), &QWindow::minimumWidthChanged, w, &QWidget::setMinimumWidth);
-    connect(m_view.data(), &QWindow::minimumHeightChanged, w, &QWidget::setMinimumHeight);
-    w->setMinimumSize(m_view->initialSize());
-    vl->addWidget(w);
+    vl->addWidget(m_view.data());
     setLayout(vl);
     connect(m_view.data(), &KWin::Compositing::EffectView::changed, [this]{
         emit changed(true);
     });
-    w->setFocusPolicy(Qt::StrongFocus);
+    m_view->setFocusPolicy(Qt::StrongFocus);
 }
 
 KWinCompositingKCM::~KWinCompositingKCM()

kcmkwin/kwincompositing/model.cpp

@@ -581,8 +581,8 @@ void EffectFilterModel::defaults()
     m_effectModel->defaults();
 }
 
-EffectView::EffectView(ViewType type, QWindow *parent)
-    : QQuickView(parent)
+EffectView::EffectView(ViewType type, QWidget *parent)
+    : QQuickWidget(parent)
 {
     qRegisterMetaType<OpenGLPlatformInterfaceModel*>();
     qmlRegisterType<EffectConfig>("org.kde.kwin.kwincompositing", 1, 0, "EffectConfig");
@@ -608,7 +608,7 @@ void EffectView::init(ViewType type)
         break;
     }
     QString mainFile = QStandardPaths::locate(QStandardPaths::GenericDataLocation, path, QStandardPaths::LocateFile);
-    setResizeMode(QQuickView::SizeRootObjectToView);
+    setResizeMode(QQuickWidget::SizeRootObjectToView);
     setSource(QUrl(mainFile));
     rootObject()->setProperty("color",
                               KColorScheme(QPalette::Active, KColorScheme::Window, KSharedConfigPtr(0)).background(KColorScheme::NormalBackground).color());

kcmkwin/kwincompositing/model.h

@@ -27,7 +27,7 @@
 #include <QAbstractItemModel>
 #include <QHash>
 #include <QList>
-#include <QQuickView>
+#include <QQuickWidget>
 #include <QSortFilterProxyModel>
 #include <QString>
 #include <KPluginInfo>
@@ -114,7 +114,7 @@ private:
 
 };
 
-class EffectView : public QQuickView
+class EffectView : public QQuickWidget
 {
 
     Q_OBJECT
@@ -124,7 +124,7 @@ public:
         DesktopEffectsView,
         CompositingSettingsView
     };
-    EffectView(ViewType type, QWindow *parent = 0);
+    EffectView(ViewType type, QWidget *parent = 0);
 
     void save();
     void load();