tdf#156376 qt: Open help for focused native menu entry on F1

In order to allow have pressing F1 (`QKeySequence::HelpContents`)
open the corresponding help entry for the currently selected
menu entry, connect to the signal that gets emitted when
a menu entry is selected (`QAction::hovered`) and remember
its help ID. Register the F1 shortcut for the menu
and connect its `activated`/`activatedAmbiguously`
signal with a slot that opens the help for the current/
last selected menu entry.

Change-Id: I24eec4806e5a202052a49c239e4836b92c9f0228
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/155055
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/vcl/inc/qt5/QtMenu.hxx b/vcl/inc/qt5/QtMenu.hxx
index 3e43272b6212..bd704507f69c 100644
--- a/vcl/inc/qt5/QtMenu.hxx
+++ b/vcl/inc/qt5/QtMenu.hxx
@@ -53,6 +53,9 @@ private:
     QMenu* mpQMenu;
     QButtonGroup* m_pButtonGroup;
 
+    // help ID of currently/last selected item
+    static OUString m_sCurrentHelpId;
+
     void DoFullMenuUpdate(Menu* pMenuBar);
     static void NativeItemText(OUString& rItemText);
 
@@ -64,6 +67,9 @@ private:
     bool validateQMenuBar() const;
     QPushButton* ImplAddMenuBarButton(const QIcon& rIcon, const QString& rToolTip, int nId);
     void ImplRemoveMenuBarButton(int nId);
+    void connectHelpShortcut(QMenu* pMenu);
+    // set slots that handle signals relevent for help menu
+    void connectHelpSignalSlots(QMenu* pMenu, QtMenuItem* pSalMenuItem);
 
 public:
     QtMenu(bool bMenuBar);
@@ -102,6 +108,8 @@ public:
     QtMenuItem* GetItemAtPos(unsigned nPos) { return maItems[nPos]; }
 
 private slots:
+    static void slotShowHelp();
+    static void slotMenuHovered(QtMenuItem* pItem);
     static void slotMenuTriggered(QtMenuItem* pQItem);
     static void slotMenuAboutToShow(QtMenuItem* pQItem);
     static void slotMenuAboutToHide(QtMenuItem* pQItem);