StackView::clear() allow specifying a transition

This turns out to be a useful feature wanted for the Coffee Machine
demo, which is being cleaned up.

[ChangeLog][Controls][StackView] Allowed specifying a transition
when clearing the stack view.

Change-Id: I12ed18ca24c247980bab1fe93e1810c0d25d85e7
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

2 files changed, 22 insertions, 4 deletions

diff --git a/src/quicktemplates2/qquickstackview.cpp b/src/quicktemplates2/qquickstackview.cpp
index 155f5f4d..e1740273 100644
--- a/src/quicktemplates2/qquickstackview.cpp
+++ b/src/quicktemplates2/qquickstackview.cpp
@@ -780,13 +780,31 @@ void QQuickStackView::replace(QQmlV4Function *args)
 }
 
 /*!
-    \qmlmethod void QtQuick.Controls::StackView::clear()
+    \qmlmethod void QtQuick.Controls::StackView::clear(transition)
 
-    Removes all items from the stack. No animations are applied.
+    Removes all items from the stack.
+
+    Since QtQuick.Controls 2.3, a \a transition can be optionally specified. Supported transitions:
+
+    \value StackView.Immediate Clear the stack immediately without any transition (default).
+    \value StackView.PushTransition Clear the stack with a push transition.
+    \value StackView.ReplaceTransition Clear the stack with a replace transition.
+    \value StackView.PopTransition Clear the stack with a pop transition.
 */
-void QQuickStackView::clear()
+void QQuickStackView::clear(Operation operation)
 {
     Q_D(QQuickStackView);
+    if (d->elements.isEmpty())
+        return;
+
+    if (operation != Immediate) {
+        QQuickStackElement *exit = d->elements.pop();
+        exit->removal = true;
+        d->removing.insert(exit);
+        d->startTransition(QQuickStackTransition::popExit(operation, exit, this),
+                           QQuickStackTransition::popEnter(operation, nullptr, this), false);
+    }
+
     d->setCurrentItem(nullptr);
     qDeleteAll(d->elements);
     d->elements.clear();
diff --git a/src/quicktemplates2/qquickstackview_p.h b/src/quicktemplates2/qquickstackview_p.h
index b74a162d..22392698 100644
--- a/src/quicktemplates2/qquickstackview_p.h
+++ b/src/quicktemplates2/qquickstackview_p.h
@@ -135,7 +135,7 @@ public:
     Q_INVOKABLE void replace(QQmlV4Function *args);
 
 public Q_SLOTS:
-    void clear();
+    void clear(Operation operation = Immediate);
 
 Q_SIGNALS:
     void busyChanged();