D-Bus system tray icon: submenus can be created after context menu

QMenuPrivate::init() calls QPlatformTheme::createPlatformMenu() to
create a platform menu, but on Linux, that returns null for now.
QSystemTrayIcon::setContextMenu() results in recursive calls to
QSystemTrayIconPrivate::addPlatformMenu() which then calls
QDBusTrayIcon::createMenu() for the context menu and each submenu.
However if a submenu is added afterwards, a corresponding platform
menu is not immediately created.  Now copyActionToPlatformItem()
will detect and create the missing platform submenu, by calling
a new method: DBusPlatformMenu::createSubMenu().  This is because
there is no way of knowing that it's a tray-specific context menu
(which is so far the only case in which we use DBusPlatformMenu).
So, QPlatformMenu::createSubMenu() needs to exist as a new
QPA interface for this use case.

Task-number: QTBUG-45803
Change-Id: Ib319e873082196515ea0580d70d069099cf2c175
Reviewed-by: Jørgen Lind <jorgen.lind@theqtcompany.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/platformsupport/dbusmenu/qdbusplatformmenu_p.h b/src/platformsupport/dbusmenu/qdbusplatformmenu_p.h
index 2519533e32..16bb4f195c 100644
--- a/src/platformsupport/dbusmenu/qdbusplatformmenu_p.h
+++ b/src/platformsupport/dbusmenu/qdbusplatformmenu_p.h
@@ -124,7 +124,7 @@ public:
     quintptr tag()const Q_DECL_OVERRIDE { return m_tag; }
     void setTag(quintptr tag) Q_DECL_OVERRIDE;
 
-    const QString text() { return m_text; }
+    const QString text() const { return m_text; }
     void setText(const QString &text) Q_DECL_OVERRIDE;
     void setIcon(const QIcon &icon) Q_DECL_OVERRIDE;
     void setEnabled(bool enabled) Q_DECL_OVERRIDE;
@@ -150,6 +150,7 @@ public:
     const QList<QDBusPlatformMenuItem *> items() const;
 
     QPlatformMenuItem *createMenuItem() const Q_DECL_OVERRIDE;
+    QPlatformMenu *createSubMenu() const Q_DECL_OVERRIDE;
 
     bool operator==(const QDBusPlatformMenu& other) { return m_tag == other.m_tag; }
 
@@ -175,6 +176,7 @@ private:
     uint m_revision;
     QHash<quintptr, QDBusPlatformMenuItem *> m_itemsByTag;
     QList<QDBusPlatformMenuItem *> m_items;
+    QDBusPlatformMenuItem *m_containingMenuItem;
     static QList<QDBusPlatformMenu *> m_topLevelMenus;
 };