diff --git a/lib/kcommondecoration.cpp b/lib/kcommondecoration.cpp
index b5b4d7c67a..56b8e8ff00 100644
--- a/lib/kcommondecoration.cpp
+++ b/lib/kcommondecoration.cpp
@@ -193,6 +193,12 @@ void KCommonDecoration::updateButtons() const
         if (m_button[n]) m_button[n]->update();
 }
 
+void KCommonDecoration::resetButtons() const
+{
+    for (int n=0; n<NumButtons; n++)
+        if (m_button[n]) m_button[n]->reset(KCommonDecorationButton::ManualReset);
+}
+
 void KCommonDecoration::resetLayout()
 {
     for (int n=0; n<NumButtons; n++) {
@@ -738,7 +744,7 @@ ButtonType KCommonDecorationButton::type()
     return m_type;;
 }
 
-void KCommonDecorationButton::reset()
+void KCommonDecorationButton::reset(unsigned long)
 {
 }
 
@@ -749,10 +755,12 @@ void KCommonDecorationButton::setRealizeButtons(int btns)
 
 void KCommonDecorationButton::setSize(const QSize &s)
 {
-    m_size = s;
+    if (s != size() ) {
+        m_size = s;
 
-    setFixedSize(m_size);
-    reset();
+        setFixedSize(m_size);
+        reset(SizeChange);
+    }
 }
 
 QSize KCommonDecorationButton::sizeHint() const
@@ -768,13 +776,15 @@ void KCommonDecorationButton::setTipText(const QString &tip) {
 void KCommonDecorationButton::setToggleButton(bool toggle)
 {
     QButton::setToggleButton(toggle);
-    reset();
+    reset(ToggleChange);
 }
 
 void KCommonDecorationButton::setOn(bool on)
 {
-    QButton::setOn(on);
-    reset();
+    if (on != isOn() ) {
+        QButton::setOn(on);
+        reset(StateChange);
+    }
 }
 
 void KCommonDecorationButton::mousePressEvent(QMouseEvent* e)
diff --git a/lib/kcommondecoration.h b/lib/kcommondecoration.h
index e57451661c..2f8a71898c 100644
--- a/lib/kcommondecoration.h
+++ b/lib/kcommondecoration.h
@@ -201,6 +201,10 @@ class KWIN_EXPORT KCommonDecoration : public KDecoration
          * Makes sure all buttons are repainted.
          */
         void updateButtons() const;
+        /**
+         * Manually call reset() on each button.
+         */
+        void resetButtons() const;
 
         /**
          * Convenience method.
@@ -276,10 +280,21 @@ class KWIN_EXPORT KCommonDecorationButton : public QButton
         KCommonDecorationButton(ButtonType type, KCommonDecoration *parent, const char *name);
         ~KCommonDecorationButton();
 
+        /**
+         * These flags specify what has changed, e.g. the reason for a reset().
+         */
+        enum
+        {
+            ManualReset     = 1 << 0, ///< The button might want to do a full reset for some reason...
+            SizeChange      = 1 << 1, ///< The button size changed @see setSize()
+            ToggleChange    = 1 << 2, ///< The button toggle state has changed @see setToggleButton()
+            StateChange     = 1 << 3, ///< The button has been set pressed or not... @see setOn()
+            DecorationReset = 1 << 4  ///< E.g. when decoration colors have changed
+        };
         /**
          * Initialize the button after size change etc.
          */
-        virtual void reset();
+        virtual void reset(unsigned long changed);
         /**
          * @returns the KCommonDecoration the button belongs to.
          */