[kwineffects] Add hide/show cursor to EffectsHandler

Summary:
The implementation delegates to the Platform to perform the actual
show/hide of the cursor image.

This replaces the implementation in the zoom effect which so far
directly interacted with xfixes to show/hide the cursor. This is now
provided by the x11/standalone platform. And due to this change the zoom
effect can now properly hide the cursor on platform DRM (wayland) as
well.

Test Plan: Zoom effect on Wayland hides the cursor

Reviewers: #kwin, #plasma_on_wayland

Subscribers: plasma-devel, kwin

Tags: #plasma_on_wayland, #kwin

Differential Revision: https://phabricator.kde.org/D3120

autotests/mock_effectshandler.h

@@ -241,6 +241,10 @@ public:
         return KWin::PlatformCursorImage();
     }
 
+    void hideCursor() override {}
+
+    void showCursor() override {}
+
 private:
     bool m_animationsSuported = true;
 };

effects.cpp

@@ -1564,6 +1564,16 @@ PlatformCursorImage EffectsHandlerImpl::cursorImage() const
     return kwinApp()->platform()->cursorImage();
 }
 
+void EffectsHandlerImpl::hideCursor()
+{
+    kwinApp()->platform()->hideCursor();
+}
+
+void EffectsHandlerImpl::showCursor()
+{
+    kwinApp()->platform()->showCursor();
+}
+
 //****************************************
 // EffectWindowImpl
 //****************************************

effects.h

@@ -230,6 +230,9 @@ public:
 
     PlatformCursorImage cursorImage() const override;
 
+    void hideCursor() override;
+    void showCursor() override;
+
     Scene *scene() const {
         return m_scene;
     }

effects/zoom/zoom.cpp

@@ -38,7 +38,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <kwinxrenderutils.h>
 #include <xcb/render.h>
 #endif
-#include <xcb/xfixes.h>
 
 namespace KWin
 {
@@ -153,7 +152,7 @@ void ZoomEffect::showCursor()
     if (isMouseHidden) {
         disconnect(effects, &EffectsHandler::cursorShapeChanged, this, &ZoomEffect::recreateTexture);
         // show the previously hidden mouse-pointer again and free the loaded texture/picture.
-        xcb_xfixes_show_cursor(xcbConnection(), x11RootWindow());
+        effects->showCursor();
         texture.reset();
 #ifdef KWIN_HAVE_XRENDER_COMPOSITING
         xrenderPicture.reset();
@@ -178,7 +177,7 @@ void ZoomEffect::hideCursor()
 #endif
         }
         if (shouldHide) {
-            xcb_xfixes_hide_cursor(xcbConnection(), x11RootWindow());
+            effects->hideCursor();
             connect(effects, &EffectsHandler::cursorShapeChanged, this, &ZoomEffect::recreateTexture);
             isMouseHidden = true;
         }

libkwineffects/kwineffects.h

@@ -1192,6 +1192,20 @@ public:
      **/
     virtual PlatformCursorImage cursorImage() const = 0;
 
+    /**
+     * The cursor image should be hidden.
+     * @see showCursor
+     * @since 5.9
+     **/
+    virtual void hideCursor() = 0;
+
+    /**
+     * The cursor image should be shown again after having been hidden..
+     * @see hideCursor
+     * @since 5.9
+     **/
+    virtual void showCursor() = 0;
+
     /**
      * @return @ref KConfigGroup which holds given effect's config options
      **/