Move children together with their group when the group gets moved, and add a group convenience function to extender to avoid needing all those casts from extenderitem to extendergroup. Plus some minor code cleanups.

svn path=/trunk/KDE/kdelibs/; revision=959604

extender.cpp

@@ -170,6 +170,11 @@ ExtenderItem *Extender::item(const QString &name) const
     return 0;
 }
 
+ExtenderGroup *Extender::group(const QString &name) const
+{
+    return qobject_cast<ExtenderGroup*>(item(name));
+}
+
 bool Extender::hasItem(const QString &name) const
 {
     if (item(name)) {
@@ -177,7 +182,8 @@ bool Extender::hasItem(const QString &name) const
     }
 
     //if item(name) returns false, that doesn't mean that the item doesn't exist, just that it has
-    //not been instantiated yet.
+    //not been instantiated yet. check to see if there's mention of this item existing in the
+    //plasma config's section DetachedExtenderItems
     Corona *corona = qobject_cast<Corona*>(scene());
     KConfigGroup extenderItemGroup(corona->config(), "DetachedExtenderItems");
     foreach (const QString &extenderItemId, extenderItemGroup.groupList()) {
@@ -340,13 +346,17 @@ void Extender::dropEvent(QGraphicsSceneDragDropEvent *event)
 void Extender::itemAddedEvent(ExtenderItem *item, const QPointF &pos)
 {
     if (pos == QPointF(-1, -1)) {
+        //if just plain adding an item, add it at a sane position:
 	if (!item->group()) {
             if (appearance() == BottomUpStacked) {
+                //at the top
                 d->layout->insertItem(0, item);
             } else {
+                //at the bottom
                 d->layout->addItem(item);
             }
         } else {
+            //at the top in the group it belongs to
             d->layout->insertItem(d->insertIndexFromPos(item->group()->pos()) + 1, item);
         }
     } else {

extender.h

@@ -138,6 +138,13 @@ class PLASMA_EXPORT Extender : public QGraphicsWidget
          */
         ExtenderItem *item(const QString &name) const;
 
+        /**
+         * Extra convenience function for obtaining groups specified by name. This will avoid needed
+         * to call item and casting to ExtenderGroup, which is otherwise quite common.
+         * @returns the requested group
+         */
+        ExtenderGroup *group(const QString &name) const;
+
         /**
          * This function can be used for easily determining if a certain item is already displayed
          * in an extender item somewhere, so your applet doesn't duplicate this item. This is needed

extendergroup.cpp

@@ -68,8 +68,8 @@ ExtenderGroup::ExtenderGroup(Extender *parent, uint groupId)
     }
 
     if (items().isEmpty() && d->autoHide && !isDetached()) {
-        hide();
         extender()->itemRemovedEvent(this);
+        hide();
     }
 
     connect(Plasma::Theme::defaultTheme(), SIGNAL(themeChanged()),
@@ -101,9 +101,9 @@ bool ExtenderGroup::autoHide() const
 void ExtenderGroup::setAutoHide(bool autoHide)
 {
     d->autoHide = autoHide;
-    if (autoHide && items().count() < 2) {
-        hide();
+    if (autoHide && items().isEmpty()) {
         extender()->itemRemovedEvent(this);
+        hide();
     } else if (!autoHide && !isVisible()) {
         extender()->itemAddedEvent(this);
         show();
@@ -151,41 +151,27 @@ ExtenderGroupPrivate::~ExtenderGroupPrivate()
 void ExtenderGroupPrivate::addItemToGroup(Plasma::ExtenderItem *item)
 {
     if (item->group() == q) {
-        int itemCount = q->items().count();
-        if (collapsed && !(autoHide && itemCount == 1)) {
-            //the group is collapsed, so hide the new item unless there's only one item and autohide
-            //is true, in which case we hide this group, and not the item in it.
+        if (!q->isVisible() && !q->items().isEmpty()) {
+            q->extender()->itemAddedEvent(q);
+            q->show();
+        }
+        if (collapsed) {
             q->extender()->itemRemovedEvent(item);
             item->hide();
         } else {
-            //the group isn't collapsed so show and readd this item to the extender, which takes
-            //care of placing the new item directly under the group widget.
             q->extender()->itemAddedEvent(item);
             item->show();
         }
-        if (!q->isVisible() && (itemCount > 1 || !autoHide)) {
-            //show the group if needed, depending on autoHide policy.
-            q->extender()->itemAddedEvent(q);
-            q->show();
-            if (collapsed) {
-                q->extender()->itemRemovedEvent(q->items().first());
-                q->items().first()->hide();
-            }
-        }
     }
 }
 
 void ExtenderGroupPrivate::removeItemFromGroup(Plasma::ExtenderItem *item)
 {
     if (item->group() == q) {
-        if (q->items().count() < 2 && autoHide && !q->isDetached()) {
+        if (q->items().isEmpty() && autoHide && !q->isDetached()) {
             q->extender()->itemRemovedEvent(q);
             q->hide();
         }
-        if (q->items().count() == 1 && autoHide) {
-            q->extender()->itemAddedEvent(q->items().first());
-            q->items().first()->show();
-        }
     }
 }
 

extenderitem.cpp

@@ -188,6 +188,12 @@ void ExtenderItem::setWidget(QGraphicsItem *widget)
     widget->setPos(QPointF(d->bgLeft + d->dragLeft, panelSize.height() + d->bgTop));
     d->widget = widget;
     d->updateSizeHints();
+
+    /**
+    if (isGroup() && !isVisible()) {
+        widget->hide();
+    }
+    */
 }
 
 QGraphicsItem *ExtenderItem::widget() const
@@ -284,10 +290,24 @@ Extender *ExtenderItem::extender() const
 
 void ExtenderItem::setGroup(ExtenderGroup *group)
 {
+    if (isGroup()) {
+        //nesting extender groups is just insane. I don't think we'd even want to support that.
+        kWarning() << "Nesting ExtenderGroups is not supported";
+        return;
+    }
+
     d->group = group;
-    config().writeEntry("group", group->name());
-    if (!group->isDetached()) {
+
+    if (group) {
+        config().writeEntry("group", group->name());
+        //TODO: move to another extender if the group we set is actually detached.
+        if (group->extender() != extender()) {
+            kDebug() << "moving to another extender because we're joining a detached group.";
+            setExtender(group->extender());
+        }
         group->d->addItemToGroup(this);
+    } else {
+        config().deleteEntry("group");
     }
 }
 
@@ -563,6 +583,15 @@ void ExtenderItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
         }
     }
 
+    ExtenderGroup *group = qobject_cast<ExtenderGroup*>(this);
+    QList<ExtenderItem*> childItems;
+    bool collapsedGroup;
+    if (isGroup()) {
+        collapsedGroup = group->d->collapsed;
+        group->collapseGroup();
+        childItems = group->items();
+    }
+
     //and execute the drag.
     QWidget *dragParent = extender()->d->applet->view();
     QDrag *drag = new QDrag(dragParent);
@@ -578,6 +607,18 @@ void ExtenderItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
         d->extender->itemAddedEvent(this, curPos);
     }
 
+    //invoke setGroup on all items belonging to this group, to make sure all children move to the
+    //new extender together with the group.
+    if (isGroup()) {
+        foreach (ExtenderItem *item, childItems) {
+            item->setGroup(group);
+        }
+    }
+
+    if (isGroup() && !collapsedGroup) {
+        group->expandGroup();
+    }
+
     d->dragStarted = false;
 }
 

extenderitem.h

@@ -173,7 +173,8 @@ class PLASMA_EXPORT ExtenderItem : public QGraphicsWidget
         Extender *extender() const;
 
         /**
-         * @param group the group you want this item to belong to.
+         * @param group the group you want this item to belong to. Note that you can't nest
+         * ExtenderGroups.
          * @since 4.3
          */
         void setGroup(ExtenderGroup *group);