Remove Toplevel::compositing() and Workspace::compositing()

It is error-prone to have multiple sources for the same data. If the
base implementation (Compositor::compositing()) changes, other helpers
can get out of sync.

autotests/mock_workspace.h

@@ -40,10 +40,6 @@ public:
     void registerEventFilter(X11EventFilter *filter);
     void unregisterEventFilter(X11EventFilter *filter);
 
-    bool compositing() const {
-        return false;
-    }
-
     static Workspace *self();
 
 Q_SIGNALS:

src/events.cpp

@@ -351,7 +351,7 @@ bool X11Client::windowEvent(xcb_generic_event_t *e)
         if ((dirtyProperties2 & NET::WM2StartupId) != 0)
             startupIdChanged();
         if (dirtyProperties2 & NET::WM2Opacity) {
-            if (compositing()) {
+            if (Compositor::compositing()) {
                 setOpacity(info->opacityF());
             } else {
                 // forward to the frame if there's possibly another compositing manager running
@@ -1183,7 +1183,7 @@ bool Unmanaged::windowEvent(xcb_generic_event_t *e)
     NET::Properties2 dirtyProperties2;
     info->event(e, &dirtyProperties, &dirtyProperties2);   // pass through the NET stuff
     if (dirtyProperties2 & NET::WM2Opacity) {
-        if (compositing()) {
+        if (Compositor::compositing()) {
             setOpacity(info->opacityF());
         }
     }

src/tabbox/tabbox.cpp

@@ -23,6 +23,7 @@
 #ifdef KWIN_BUILD_ACTIVITIES
 #include "activities.h"
 #endif
+#include "composite.h"
 #include "x11client.h"
 #include "effects.h"
 #include "input.h"
@@ -282,8 +283,9 @@ TabBoxClientList TabBoxHandlerImpl::stackingOrder() const
     return ret;
 }
 
-bool TabBoxHandlerImpl::isKWinCompositing() const {
-    return Workspace::self()->compositing();
+bool TabBoxHandlerImpl::isKWinCompositing() const
+{
+    return Compositor::compositing();
 }
 
 void TabBoxHandlerImpl::raiseClient(TabBoxClient* c) const

src/toplevel.cpp

@@ -255,7 +255,7 @@ void Toplevel::setOpacity(qreal opacity)
     }
     const qreal oldOpacity = m_opacity;
     m_opacity = opacity;
-    if (compositing()) {
+    if (Compositor::compositing()) {
         addRepaintFull();
         Q_EMIT opacityChanged(this, oldOpacity);
     }
@@ -263,7 +263,7 @@ void Toplevel::setOpacity(qreal opacity)
 
 bool Toplevel::setupCompositing()
 {
-    if (!compositing())
+    if (!Compositor::compositing())
         return false;
 
     effect_window = new EffectWindowImpl(this);
@@ -283,11 +283,6 @@ void Toplevel::finishCompositing(ReleaseReason)
     }
 }
 
-bool Toplevel::compositing() const
-{
-    return Compositor::compositing();
-}
-
 void Toplevel::addRepaint(const QRect &rect)
 {
     addRepaint(QRegion(rect));
@@ -332,14 +327,14 @@ void Toplevel::addWorkspaceRepaint(int x, int y, int w, int h)
 
 void Toplevel::addWorkspaceRepaint(const QRect& r2)
 {
-    if (!compositing())
+    if (!Compositor::compositing())
         return;
     Compositor::self()->addRepaint(r2);
 }
 
 void Toplevel::addWorkspaceRepaint(const QRegion &region)
 {
-    if (compositing()) {
+    if (Compositor::compositing()) {
         Compositor::self()->addRepaint(region);
     }
 }
@@ -348,7 +343,7 @@ void Toplevel::setReadyForPainting()
 {
     if (!ready_for_painting) {
         ready_for_painting = true;
-        if (compositing()) {
+        if (Compositor::compositing()) {
             addRepaintFull();
             Q_EMIT windowShown(this);
         }

src/toplevel.h

@@ -671,10 +671,6 @@ protected:
     void readWmClientLeader(Xcb::Property &p);
     void getWmClientLeader();
     void getWmClientMachine();
-    /**
-     * @returns Whether there is a compositor and it is active.
-     */
-    bool compositing() const;
 
     /**
      * This function fetches the opaque region from this Toplevel.

src/workspace.cpp

@@ -1214,7 +1214,7 @@ void Workspace::updateCurrentActivity(const QString &new_activity)
 
     //if ( effects != NULL && old_desktop != 0 && old_desktop != new_desktop )
     //    static_cast<EffectsHandlerImpl*>( effects )->desktopChanged( old_desktop );
-    if (compositing() && m_compositor)
+    if (Compositor::compositing() && m_compositor)
         m_compositor->addRepaintFull();
 #else
     Q_UNUSED(new_activity)
@@ -1889,11 +1889,6 @@ Toplevel *Workspace::findInternal(QWindow *w) const
     return nullptr;
 }
 
-bool Workspace::compositing() const
-{
-    return Compositor::compositing();
-}
-
 void Workspace::markXStackingOrderAsDirty()
 {
     m_xStackingDirty = true;

src/workspace.h

@@ -369,10 +369,6 @@ public:
         return movingClient;
     }
 
-    /**
-     * @returns Whether we have a Compositor and it is active (Scene created)
-     */
-    bool compositing() const;
     void markXStackingOrderAsDirty();
 
     void quickTileWindow(QuickTileMode mode);

src/x11client.cpp

@@ -839,7 +839,7 @@ bool X11Client::manage(xcb_window_t w, bool isMapped)
         workspace()->restoreSessionStackingOrder(this);
     }
 
-    if (compositing())
+    if (Compositor::compositing())
         // Sending ConfigureNotify is done when setting mapping state below,
         // Getting the first sync response means window is ready for compositing
         sendSyncRequest();
@@ -1135,7 +1135,7 @@ void X11Client::destroyDecoration()
         maybeDestroyX11DecorationRenderer();
         resize(adjustedSize());
         move(grav);
-        if (compositing())
+        if (Compositor::compositing())
             discardWindowPixmap();
         if (!isZombie()) {
             Q_EMIT geometryShapeChanged(this, oldgeom);
@@ -1149,7 +1149,7 @@ void X11Client::maybeCreateX11DecorationRenderer()
     if (kwinApp()->operationMode() != Application::OperationModeX11) {
         return;
     }
-    if (!compositing() && decoratedClient()) {
+    if (!Compositor::compositing() && decoratedClient()) {
         m_decorationRenderer.reset(new X11DecorationRenderer(decoratedClient()));
         decoration()->update();
     }
@@ -1170,7 +1170,7 @@ void X11Client::layoutDecorationRects(QRect &left, QRect &top, QRect &right, QRe
     NETStrut strut = info->frameOverlap();
 
     // Ignore the overlap strut when compositing is disabled
-    if (!compositing())
+    if (!Compositor::compositing())
         strut.left = strut.top = strut.right = strut.bottom = 0;
     else if (strut.left == -1 && strut.top == -1 && strut.right == -1 && strut.bottom == -1) {
         top = QRect(r.x(), r.y(), r.width(), r.height() / 3);
@@ -1196,7 +1196,7 @@ QRect X11Client::transparentRect() const
 
     NETStrut strut = info->frameOverlap();
     // Ignore the strut when compositing is disabled or the decoration doesn't support it
-    if (!compositing())
+    if (!Compositor::compositing())
         strut.left = strut.top = strut.right = strut.bottom = 0;
     else if (strut.left == -1 && strut.top == -1 && strut.right == -1 && strut.bottom == -1)
         return QRect();
@@ -1374,7 +1374,7 @@ void X11Client::updateShape()
     // Decoration mask (i.e. 'else' here) setting is done in setMask()
     // when the decoration calls it or when the decoration is created/destroyed
     updateInputShape();
-    if (compositing()) {
+    if (Compositor::compositing()) {
         addRepaintFull();
         addWorkspaceRepaint(visibleGeometry());   // In case shape change removes part of this window
     }
@@ -1592,7 +1592,7 @@ void X11Client::updateVisibility()
     if (hidden) {
         info->setState(NET::Hidden, NET::Hidden);
         setSkipTaskbar(true);   // Also hide from taskbar
-        if (compositing() && options->hiddenPreviews() == HiddenPreviewsAlways)
+        if (Compositor::compositing() && options->hiddenPreviews() == HiddenPreviewsAlways)
             internalKeep();
         else
             internalHide();
@@ -1601,7 +1601,7 @@ void X11Client::updateVisibility()
     setSkipTaskbar(originalSkipTaskbar());   // Reset from 'hidden'
     if (isMinimized()) {
         info->setState(NET::Hidden, NET::Hidden);
-        if (compositing() && options->hiddenPreviews() == HiddenPreviewsAlways)
+        if (Compositor::compositing() && options->hiddenPreviews() == HiddenPreviewsAlways)
             internalKeep();
         else
             internalHide();
@@ -1609,14 +1609,14 @@ void X11Client::updateVisibility()
     }
     info->setState(NET::States(), NET::Hidden);
     if (!isOnCurrentDesktop()) {
-        if (compositing() && options->hiddenPreviews() != HiddenPreviewsNever)
+        if (Compositor::compositing() && options->hiddenPreviews() != HiddenPreviewsNever)
             internalKeep();
         else
             internalHide();
         return;
     }
     if (!isOnCurrentActivity()) {
-        if (compositing() && options->hiddenPreviews() != HiddenPreviewsNever)
+        if (Compositor::compositing() && options->hiddenPreviews() != HiddenPreviewsNever)
             internalKeep();
         else
             internalHide();
@@ -1678,7 +1678,7 @@ void X11Client::internalHide()
 
 void X11Client::internalKeep()
 {
-    Q_ASSERT(compositing());
+    Q_ASSERT(Compositor::compositing());
     if (mapping_state == Kept)
         return;
     MappingState old = mapping_state;
@@ -1703,7 +1703,7 @@ void X11Client::map()
     // XComposite invalidates backing pixmaps on unmap (minimize, different
     // virtual desktop, etc.).  We kept the last known good pixmap around
     // for use in effects, but now we want to have access to the new pixmap
-    if (compositing())
+    if (Compositor::compositing())
         discardWindowPixmap();
     m_frame.map();
     if (!isShade()) {
@@ -4133,7 +4133,7 @@ void X11Client::updateServerGeometry()
         updateShape();
     } else {
         if (isInteractiveMoveResize()) {
-            if (compositing()) { // Defer the X update until we leave this mode
+            if (Compositor::compositing()) { // Defer the X update until we leave this mode
                 needsXWindowMove = true;
             } else {
                 m_frame.move(m_bufferGeometry.topLeft()); // sendSyntheticConfigureNotify() on finish shall be sufficient