Menu: Add aboutToShow, aboutToHide signals

These do the same as for QMenu, and are emitted
right before the pop-up is shown or hidden. On
Mac, these signals are emitted by the QPA plugin
and relayed by QQuickMenu.

Task-number: QTBUG-40576
Change-Id: I59113d8d9cc8c5b3140f4f552772d33dd0b6e138
Reviewed-by: Caroline Chao <caroline.chao@theqtcompany.com>

4 files changed, 65 insertions, 7 deletions

diff --git a/src/controls/Menu.qml b/src/controls/Menu.qml
index b85008eb..7334c28c 100644
--- a/src/controls/Menu.qml
+++ b/src/controls/Menu.qml
@@ -150,7 +150,7 @@ MenuPrivate {
     /*! \internal */
     property int __currentIndex: -1
     /*! \internal */
-    on__MenuClosed: __currentIndex = -1
+    onAboutToHide: __currentIndex = -1
     on__MenuPopupDestroyed: contentLoader.active = false
     onPopupVisibleChanged: {
         if (__popupVisible)
diff --git a/src/controls/qquickmenu.cpp b/src/controls/qquickmenu.cpp
index c476c5f3..617a3d03 100644
--- a/src/controls/qquickmenu.cpp
+++ b/src/controls/qquickmenu.cpp
@@ -106,8 +106,12 @@ QT_BEGIN_NAMESPACE
 /*!
     \qmlproperty bool Menu::visible
 
-    Whether the menu should be visible. This is only enabled when the menu is used as
-    a submenu or in the menubar. Its value defaults to \c true.
+    Whether the menu should be visible as a submenu of another Menu, or as a menu on a MenuBar.
+    Its value defaults to \c true.
+
+    \note This has nothing to do with the actual menu pop-up window being visible. Use
+    \l aboutToShow() and \l aboutToHide() if you need to know when the pop-up window will
+    be shown or hidden.
 */
 
 /*!
@@ -231,6 +235,25 @@ QT_BEGIN_NAMESPACE
     \sa insertItem()
 */
 
+
+/*!
+    \qmlsignal Menu::aboutToShow()
+    \since QtQuick.Controls 1.4
+
+    This signal is emitted just before the menu is shown to the user.
+
+    \sa aboutToHide()
+*/
+
+/*!
+    \qmlsignal Menu::aboutToHide()
+    \since QtQuick.Controls 1.4
+
+    This signal is emitted just before the menu is hidden from the user.
+
+    \sa aboutToShow()
+*/
+
 QQuickMenu::QQuickMenu(QObject *parent)
     : QQuickMenuText(parent, QQuickMenuItemType::Menu),
       m_itemsCount(0),
@@ -248,6 +271,7 @@ QQuickMenu::QQuickMenu(QObject *parent)
 
     m_platformMenu = QGuiApplicationPrivate::platformTheme()->createPlatformMenu();
     if (m_platformMenu) {
+        connect(m_platformMenu, SIGNAL(aboutToShow()), this, SIGNAL(aboutToShow()));
         connect(m_platformMenu, SIGNAL(aboutToHide()), this, SLOT(__closeMenu()));
         if (platformItem())
             platformItem()->setMenu(m_platformMenu);
@@ -435,6 +459,7 @@ void QQuickMenu::__popup(const QRectF &targetRect, int atItemIndex, MenuType men
 
         m_popupWindow->setPosition(targetRect.x() + m_xOffset + renderOffset.x(),
                                    targetRect.y() + targetRect.height() + m_yOffset + renderOffset.y());
+        emit aboutToShow();
         m_popupWindow->show();
     }
 }
@@ -465,11 +490,13 @@ QRect QQuickMenu::popupGeometry() const
 
 void QQuickMenu::__closeMenu()
 {
-    setPopupVisible(false);
+    if (m_popupVisible) {
+        emit aboutToHide();
+        setPopupVisible(false);
+    }
     if (m_popupWindow)
         m_popupWindow->setVisible(false);
     m_parentWindow = 0;
-    emit __menuClosed();
 }
 
 QQuickMenuPopupWindow *QQuickMenu::topMenuPopup() const
diff --git a/src/controls/qquickmenu_p.h b/src/controls/qquickmenu_p.h
index b468828c..a16e720a 100644
--- a/src/controls/qquickmenu_p.h
+++ b/src/controls/qquickmenu_p.h
@@ -99,9 +99,10 @@ Q_SIGNALS:
     void titleChanged();
 
     void __selectedIndexChanged();
-    void __menuClosed();
-    void __menuPopupDestroyed();
+    void aboutToShow();
+    void aboutToHide();
     void popupVisibleChanged();
+    void __menuPopupDestroyed();
     void __popupGeometryChanged();
     void menuContentItemChanged();
     void minimumWidthChanged();
diff --git a/tests/auto/controls/data/tst_menu.qml b/tests/auto/controls/data/tst_menu.qml
index ca266466..83411bcf 100644
--- a/tests/auto/controls/data/tst_menu.qml
+++ b/tests/auto/controls/data/tst_menu.qml
@@ -65,6 +65,18 @@ TestCase {
         signalName: "triggered"
     }
 
+    SignalSpy {
+        id: aboutToShowSpy
+        target: testcase.menu
+        signalName: "aboutToShow"
+    }
+
+    SignalSpy {
+        id: aboutToHideSpy
+        target: testcase.menu
+        signalName: "aboutToHide"
+    }
+
     Component {
         id: creationComponent
         Menu {
@@ -82,6 +94,8 @@ TestCase {
     function cleanup() {
         menuSpy.clear()
         menuItemSpy.clear()
+        aboutToShowSpy.clear()
+        aboutToHideSpy.clear()
         if (menu !== 0)
             menu.destroy()
     }
@@ -218,4 +232,20 @@ TestCase {
                 compare(item.text, "Item " + i)
         }
     }
+
+    function test_popupSignals() {
+        if (Qt.platform.os === "osx") {
+            // On Mac the popup() function blocks. The signals are still
+            // emitted by the QPA plugin and the relayed by QQuickMenu.
+            return;
+        }
+        menu.__popup(Qt.rect(50, 50, 20, 20))
+        wait(100) // Give it a chance to actually pop-up
+        compare(aboutToShowSpy.count, 1)
+        compare(aboutToHideSpy.count, 0)
+        aboutToShowSpy.clear()
+        menu.__dismissMenu()
+        compare(aboutToShowSpy.count, 0)
+        compare(aboutToHideSpy.count, 1)
+    }
 }