Add an opacity attribute. GUI portion coming later

svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=793581

applet.cpp

@@ -116,7 +116,8 @@ public:
           hasConfigurationInterface(false),
           failed(false),
           isContainment(false),
-          square(false)
+          square(false),
+          opacity(1.0)
     {
         if (appletId == 0) {
             appletId = ++s_maxAppletId;
@@ -331,6 +332,7 @@ public:
     bool failed : 1;
     bool isContainment : 1;
     bool square : 1;
+    qreal opacity;
 };
 
 uint Applet::Private::s_maxAppletId = 0;
@@ -398,6 +400,7 @@ void Applet::save(KConfigGroup* group) const
     //kDebug() << pluginName() << "geometry is" << geometry() << "pos is" << pos() << "bounding rect is" << boundingRect();
     group->writeEntry("geometry", geometry());
     group->writeEntry("zvalue", zValue());
+    group->writeEntry("opacity", d->opacity);
 
     if (transform() == QTransform()) {
         group->deleteEntry("transform");
@@ -435,6 +438,8 @@ void Applet::restore(KConfigGroup *c)
     if (c->readEntry("locked", false)) {
         setImmutable(true);
     }
+
+    setOpacity(c->readEntry("opacity", 1.0));
 }
 
 void Applet::saveState(KConfigGroup* group) const
@@ -933,6 +938,12 @@ void Applet::paintWidget(QPainter *painter, const QStyleOptionGraphicsItem *opti
     }
 
     painter->save();
+
+    //Set opacity
+    if (d->opacity >= 0.1 && d->opacity <= 0.9) {
+        painter->setOpacity(d->opacity);
+    }
+
     if (transform().isRotating()) {
         painter->setRenderHint(QPainter::SmoothPixmapTransform);
         painter->setRenderHint(QPainter::Antialiasing);
@@ -1595,6 +1606,16 @@ void Applet::themeChanged()
     update();
 }
 
+void Applet::setOpacity( qreal opacity )
+{
+    d->opacity = opacity;
+}
+
+qreal Applet::opacity() const
+{
+    return d->opacity;
+}
+
 } // Plasma namespace
 
 #include "applet.moc"

applet.h

@@ -628,6 +628,17 @@ class PLASMA_EXPORT Applet : public Widget
          **/
         Containment* containment() const;
 
+        /**
+         * Sets the opacity of this Plasma::Applet
+         * @param opacity the new opacity
+         */
+        void setOpacity( qreal opacity );
+
+        /**
+         * @return opacity of this Applet
+         **/
+        qreal opacity() const;
+
     Q_SIGNALS:
         /**
          * Emitted when the applet needs to take (or lose) keyboard focus.