Allow effects to render the outline

effects.cpp

@@ -1159,6 +1159,16 @@ EffectFrame* EffectsHandlerImpl::effectFrame(EffectFrameStyle style, bool static
     return new EffectFrameImpl(style, staticSize, position, alignment);
 }
 
+void EffectsHandlerImpl::slotShowOutline(const QRect& geometry)
+{
+    emit showOutline(geometry);
+}
+
+void EffectsHandlerImpl::slotHideOutline()
+{
+    emit hideOutline();
+}
+
 //****************************************
 // EffectWindowImpl
 //****************************************

effects.h

@@ -171,6 +171,8 @@ public Q_SLOTS:
     void slotClientGroupItemSwitched(EffectWindow* from, EffectWindow* to);
     void slotClientGroupItemAdded(EffectWindow* from, EffectWindow* to);
     void slotClientGroupItemRemoved(EffectWindow* c, EffectWindow* group);
+    void slotShowOutline(const QRect &geometry);
+    void slotHideOutline();
 
 protected Q_SLOTS:
     void slotDesktopChanged(int old);

libkwineffects/kwineffects.h

@@ -330,7 +330,8 @@ public:
     };
 
     enum Feature {
-        Nothing = 0, Resize, GeometryTip
+        Nothing = 0, Resize, GeometryTip,
+        Outline
     };
 
     /**
@@ -980,6 +981,22 @@ Q_SIGNALS:
      * @since 4.7
      */
     void propertyNotify(EffectWindow* w, long atom);
+    /**
+     * Requests to show an outline. An effect providing to show an outline should
+     * connect to the signal and render an outline.
+     * The outline should be shown till the signal is emitted again with a new
+     * geometry or the @link hideOutline signal is emitted.
+     * @param outline The geometry of the outline to render.
+     * @see hideOutline
+     * @since 4.7
+     **/
+    void showOutline(const QRect& outline);
+    /**
+     * Signal emitted when the outline should no longer be shown.
+     * @see showOutline
+     * @since 4.7
+     **/
+    void hideOutline();
 
 protected:
     QVector< EffectPair > loaded_effects;

outline.cpp

@@ -19,6 +19,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *********************************************************************/
 
 #include "outline.h"
+#include "effects.h"
 #include <QtCore/QRect>
 #include <QtGui/QX11Info>
 #include <QtGui/QPainter>
@@ -43,11 +44,19 @@ Outline::~Outline()
 
 void Outline::show()
 {
+    if (effects && static_cast<EffectsHandlerImpl*>(effects)->provides(Effect::Outline)) {
+        static_cast<EffectsHandlerImpl*>(effects)->slotShowOutline(m_outlineGeometry);
+        return; // done by effect
+    }
     showWithX();
 }
 
 void Outline::hide()
 {
+    if (effects && static_cast<EffectsHandlerImpl*>(effects)->provides(Effect::Outline)) {
+        static_cast<EffectsHandlerImpl*>(effects)->slotHideOutline();
+        return; // done by effect
+    }
     hideWithX();
 }