Client|NotificationWidget: Showing/hiding children, animation

The notification area now provides facilities for showing or hiding
specific widgets in it. The area is automatically animated in and out
of the view depending on whether notifications are visible.

doomsday/client/include/ui/widgets/notificationwidget.h

@@ -35,16 +35,47 @@
  */
 class NotificationWidget : public GuiWidget
 {
+    Q_OBJECT
+
 public:
     NotificationWidget(de::String const &name = "");
 
+    de::Rule const &shift();
+
+    /**
+     * Adds a notification to the notification area. The NotificationWidget
+     * takes ownership of @a notif (the latter is made a child).
+     *
+     * @param notif  Notification widget.
+     */
+    void showChild(GuiWidget *notif);
+
+    /**
+     * Hides a notification. The widget is hidden and gets returned to its
+     * original parent, if there was one.
+     *
+     * @param notif  Notification widget.
+     */
+    void hideChild(GuiWidget &notif);
+
+    void showOrHide(GuiWidget *notif, bool doShow) {
+        if(doShow) showChild(notif); else hideChild(*notif);
+    }
+
+    bool isChildShown(GuiWidget &notif) const;
+
     // Events.
     void viewResized();
     void drawContent();
 
+public slots:
+    void dismiss();
+
 protected:
     void glInit();
     void glDeinit();
+    void addedChildWidget(GuiWidget &widget);
+    void removedChildWidget(GuiWidget &widget);
 
 private:
     DENG2_PRIVATE(d)

doomsday/client/src/ui/widgets/notificationwidget.cpp

@@ -21,11 +21,24 @@
 
 #include <de/Drawable>
 #include <de/Matrix>
+#include <de/ScalarRule>
+
+#include <QMap>
+#include <QTimer>
 
 using namespace de;
 
+static TimeDelta const ANIM_SPAN = .5;
+
 DENG2_PIMPL(NotificationWidget)
 {
+    ScalarRule *shift;
+
+    typedef QMap<GuiWidget *, Widget *> OldParents;
+    OldParents oldParents;
+    QTimer dismissTimer;
+    QList<GuiWidget *> pendingDismiss;
+
     // GL objects:
     typedef DefaultVertexBuf VertexBuf;
     Drawable drawable;
@@ -37,9 +50,19 @@ DENG2_PIMPL(NotificationWidget)
           uMvpMatrix("uMvpMatrix", GLUniform::Mat4),
           uColor    ("uColor",     GLUniform::Vec4)
     {
+        dismissTimer.setSingleShot(true);
+        dismissTimer.setInterval(ANIM_SPAN.asMilliSeconds());
+        QObject::connect(&dismissTimer, SIGNAL(timeout()), thisPublic, SLOT(dismiss()));
+
+        shift = new ScalarRule(0);
         updateStyle();
     }
 
+    ~Instance()
+    {
+        releaseRef(shift);
+    }
+
     void updateStyle()
     {
         self.set(Background(self.style().colors().colorf("background")));
@@ -73,8 +96,7 @@ DENG2_PIMPL(NotificationWidget)
 
     void updateChildLayout()
     {
-        Rule const &outer = self.style().rules().rule("gap");
-        Rule const &inner = self.style().rules().rule("unit");
+        Rule const &gap = self.style().rules().rule("unit");
 
         Rule const *totalWidth = 0;
         Rule const *totalHeight = 0;
@@ -85,15 +107,15 @@ DENG2_PIMPL(NotificationWidget)
             GuiWidget &w = children[i]->as<GuiWidget>();
 
             // The children are laid out simply in a row from right to left.
-            w.rule().setInput(Rule::Top, self.rule().top() + outer);
+            w.rule().setInput(Rule::Top, self.rule().top());
             if(i > 0)
             {
-                w.rule().setInput(Rule::Right, children[i - 1]->as<GuiWidget>().rule().left() - inner);
-                changeRef(totalWidth, *totalWidth + inner + w.rule().width());
+                w.rule().setInput(Rule::Right, children[i - 1]->as<GuiWidget>().rule().left() - gap);
+                changeRef(totalWidth, *totalWidth + gap + w.rule().width());
             }
             else
             {
-                w.rule().setInput(Rule::Right, self.rule().right() - outer);
+                w.rule().setInput(Rule::Right, self.rule().right());
                 totalWidth = holdRef(w.rule().width());
             }
 
@@ -109,21 +131,126 @@ DENG2_PIMPL(NotificationWidget)
 
         // Update the total size of the notification area.
         self.rule()
-                .setInput(Rule::Width,  *totalWidth  + outer * 2)
-                .setInput(Rule::Height, *totalHeight + outer * 2);
+                .setInput(Rule::Width,  *totalWidth)
+                .setInput(Rule::Height, *totalHeight);
 
         releaseRef(totalWidth);
         releaseRef(totalHeight);
     }
+
+    void show()
+    {
+        //self.setOpacity(1, ANIM_SPAN);
+        shift->set(0, ANIM_SPAN);
+        shift->setStyle(Animation::EaseOut);
+    }
+
+    void hide(TimeDelta const &span = ANIM_SPAN)
+    {
+        //self.setOpacity(0, span);
+        shift->set(self.rule().height() + self.style().rules().rule("gap"), span);
+        shift->setStyle(Animation::EaseIn);
+    }
+
+    void dismissChild(GuiWidget &notif)
+    {
+        notif.hide();
+        self.remove(notif);
+
+        if(oldParents.contains(&notif))
+        {
+            oldParents[&notif]->add(&notif);
+            oldParents.remove(&notif);
+        }
+    }
+
+    void performPendingDismiss()
+    {
+        dismissTimer.stop();
+
+        // The pending children were already asked to be dismissed.
+        foreach(GuiWidget *w, pendingDismiss)
+        {
+            dismissChild(*w);
+        }
+        pendingDismiss.clear();
+    }
 };
 
 NotificationWidget::NotificationWidget(String const &name) : d(new Instance(this))
 {
     // Initially the widget is empty.
     rule().setSize(Const(0), Const(0));
+    d->shift->set(style().fonts().font("default").height().valuei() +
+                  style().rules().rule("gap").valuei() * 3);
     hide();
 }
 
+Rule const &NotificationWidget::shift()
+{
+    return *d->shift;
+}
+
+void NotificationWidget::showChild(GuiWidget *notif)
+{
+    DENG2_ASSERT(notif != 0);
+
+    if(isChildShown(*notif))
+    {
+        // Already in the notification area.
+        return;
+    }
+
+    // Cancel a pending dismissal.
+    d->performPendingDismiss();
+
+    if(notif->parentWidget())
+    {
+        d->oldParents.insert(notif, notif->parentWidget());
+        /// @todo Should observe if the old parent is destroyed.
+    }
+    add(notif);
+    notif->show();
+    d->show();
+}
+
+void NotificationWidget::hideChild(GuiWidget &notif)
+{
+    if(!isChildShown(notif))
+    {
+        // Already in the notification area.
+        return;
+    }
+
+    if(childCount() > 1)
+    {
+        // Dismiss immediately, the area itself remains open.
+        d->dismissChild(notif);
+    }
+    else
+    {
+        // The last one should be deferred until the notification area
+        // itself is dismissed.
+        d->dismissTimer.start();
+        d->pendingDismiss << &notif;
+        d->hide();
+    }
+}
+
+void NotificationWidget::dismiss()
+{
+    d->performPendingDismiss();
+}
+
+bool NotificationWidget::isChildShown(GuiWidget &notif) const
+{
+    if(d->pendingDismiss.contains(&notif))
+    {
+        return false;
+    }
+    return notif.parentWidget() == this;
+}
+
 void NotificationWidget::viewResized()
 {
     d->uMvpMatrix = root().projMatrix2D();
@@ -147,3 +274,17 @@ void NotificationWidget::glDeinit()
     d->glDeinit();
 }
 
+void NotificationWidget::addedChildWidget(GuiWidget &)
+{
+    d->updateChildLayout();
+    show();
+}
+
+void NotificationWidget::removedChildWidget(GuiWidget &)
+{
+    d->updateChildLayout();
+    if(!childCount())
+    {
+        hide();
+    }
+}