add the template interface

svn path=/trunk/KDE/kdelibs/; revision=958529

private/actionwidgetinterface_p.h

@@ -0,0 +1,80 @@
+#ifndef ACTIONWIDGETINTERFACE_P_H
+    /**
+     * update the icon's text, icon, etc. to reflect the properties of its associated action.
+     */
+#include <QAction>
+
+namespace Plasma
+{
+
+template <class T>
+class ActionWidgetInterface
+{
+public:
+    T *t;
+    QAction *action;
+
+    ActionWidgetInterface(T *publicClass)
+        : t(publicClass),
+          action(0)
+    {
+    }
+
+    virtual ~ActionWidgetInterface()
+    {
+    }
+
+    virtual void changed()
+    {
+    }
+
+    void clearAction()
+    {
+        action = 0;
+        syncToAction();
+        changed();
+    }
+
+    void syncToAction()
+    {
+        if (!action) {
+            t->setIcon(QIcon());
+            t->setText(QString());
+            t->setEnabled(false);
+            return;
+        }
+        //we don't get told *what* changed, just that something changed
+        //so we update everything we care about
+        t->setIcon(action->icon());
+        t->setText(action->iconText());
+        t->setEnabled(action->isEnabled());
+        t->setVisible(action->isVisible());
+
+        if (!t->toolTip().isEmpty()) {
+            t->setToolTip(action->text());
+        }
+
+        changed();
+    }
+
+    void setAction(QAction *a)
+    {
+        if (action) {
+            QObject::disconnect(action, 0, t, 0);
+            QObject::disconnect(t, 0, action, 0);
+        }
+
+        action = a;
+
+        if (action) {
+            QObject::connect(action, SIGNAL(changed()), t, SLOT(syncToAction()));
+            QObject::connect(action, SIGNAL(destroyed(QObject*)), t, SLOT(clearAction()));
+            QObject::connect(t, SIGNAL(clicked()), action, SLOT(trigger()));
+            syncToAction();
+        }
+    }
+};
+
+} // namespace Plasma
+#endif
+