From 1e0b16f8695498e4eea7c2208aabf7e7664ce749 Mon Sep 17 00:00:00 2001
From: Michael Weghorn <m.weghorn@posteo.de>
Date: Wed, 12 Feb 2020 08:07:42 +0100
Subject: [PATCH] tdf#128921 tdf#130341 tdf#122053 qt5: Native PopupMenus

This implements native PopupMenus for the qt5 VCL plugin,
which not only gives them the native look and feel, but also
makes context menus faster (tdf#128921), accessible (e.g. to the
Orca screen reader, tdf#122053), and makes them work for a case
in Base's relationship dialog where entries in the non-native context
menu were not selectable/clickable (tdf#130341).

For now, this always shows the popup menu at cursor position, which
can be changed by taking the Rectangle passed to
'Qt5Menu::ShowNativePopupMenu' into account if there should be any
need.

Change-Id: Ie52cbc682acacb92716ff51e8bf7f1ab07d34cf0
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/88512
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
---
 vcl/inc/qt5/Qt5Menu.hxx | 16 ++++++++++++++++
 vcl/qt5/Qt5Menu.cxx     | 34 ++++++++++++++++++++++++++++++++--
 2 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/vcl/inc/qt5/Qt5Menu.hxx b/vcl/inc/qt5/Qt5Menu.hxx
index efcfb8eeb81c..2e5434f4db74 100644
--- a/vcl/inc/qt5/Qt5Menu.hxx
+++ b/vcl/inc/qt5/Qt5Menu.hxx
@@ -24,6 +24,17 @@ class QMenuBar;
 class Qt5MenuItem;
 class Qt5Frame;
 
+/*
+ * Qt5Menu can represent
+ * (1) the top-level menu of a menubar, in which case 'mbMenuBar' is true and
+ *     'mpQMenuBar' refers to the corresponding QMenuBar
+ * (2) another kind of menu (like a PopupMenu), in which case the corresponding QMenu
+ *     object is instantiated and owned by this Qt5Menu (held in 'mpOwnedQMenu').
+ * (3) a "submenu" in an existing menu (like (1)), in which case the corresponding
+ *     QMenu object is owned by the corresponding Qt5MenuItem.
+ *
+ * For (2) and (3), member 'mpQMenu' points to the corresponding QMenu object.
+ */
 class Qt5Menu : public QObject, public SalMenu
 {
     Q_OBJECT
@@ -34,6 +45,9 @@ private:
     Qt5Frame* mpFrame;
     bool mbMenuBar;
     QMenuBar* mpQMenuBar;
+    // self-created QMenu that this Qt5Menu represents, if applicable (s. comment for class)
+    std::unique_ptr<QMenu> mpOwnedQMenu;
+    // pointer to QMenu owned by the corresponding Qt5MenuItem or self (-> mpOwnedQMenu)
     QMenu* mpQMenu;
     QPushButton* mpCloseButton;
     QMetaObject::Connection maCloseButtonConnection;
@@ -58,6 +72,8 @@ public:
     virtual void SetFrame(const SalFrame* pFrame) override;
     const Qt5Frame* GetFrame() const;
     virtual void ShowMenuBar(bool bVisible) override;
+    virtual bool ShowNativePopupMenu(FloatingWindow* pWin, const tools::Rectangle& rRect,
+                                     FloatWinPopupFlags nFlags) override;
     Qt5Menu* GetTopLevel();
     virtual void SetItemBits(unsigned nPos, MenuItemBits nBits) override;
     virtual void CheckItem(unsigned nPos, bool bCheck) override;
diff --git a/vcl/qt5/Qt5Menu.cxx b/vcl/qt5/Qt5Menu.cxx
index b2e752faedaa..98615247035a 100644
--- a/vcl/qt5/Qt5Menu.cxx
+++ b/vcl/qt5/Qt5Menu.cxx
@@ -24,6 +24,9 @@
 #include <strings.hrc>
 #include <bitmaps.hlst>
 
+#include <vcl/floatwin.hxx>
+#include <window.h>
+
 Qt5Menu::Qt5Menu(bool bMenuBar)
     : mpVCLMenu(nullptr)
     , mpParentSalMenu(nullptr)
@@ -77,8 +80,15 @@ void Qt5Menu::InsertMenuItem(Qt5MenuItem* pSalMenuItem, unsigned nPos)
                     [pSalMenuItem] { slotMenuAboutToHide(pSalMenuItem); });
         }
     }
-    else if (mpQMenu)
+    else
     {
+        if (!mpQMenu)
+        {
+            // no QMenu set, instantiate own one
+            mpOwnedQMenu.reset(new QMenu);
+            mpQMenu = mpOwnedQMenu.get();
+        }
+
         if (pSalMenuItem->mpSubMenu)
         {
             // submenu
@@ -148,7 +158,9 @@ void Qt5Menu::InsertMenuItem(Qt5MenuItem* pSalMenuItem, unsigned nPos)
 
                 UpdateActionGroupItem(pSalMenuItem);
 
-                pAction->setShortcut(toQString(nAccelKey.GetName(GetFrame()->GetWindow())));
+                const Qt5Frame* pFrame = GetFrame();
+                if (pFrame)
+                    pAction->setShortcut(toQString(nAccelKey.GetName(pFrame->GetWindow())));
 
                 connect(pAction, &QAction::triggered, this,
                         [pSalMenuItem] { slotMenuTriggered(pSalMenuItem); });
@@ -442,6 +454,11 @@ void Qt5Menu::DoFullMenuUpdate(Menu* pMenuBar)
         Qt5MenuItem* pSalMenuItem = GetItemAtPos(nItem);
         InsertMenuItem(pSalMenuItem, nItem);
         SetItemImage(nItem, pSalMenuItem, pSalMenuItem->maImage);
+        const bool bShowDisabled
+            = bool(pMenuBar->GetMenuFlags() & MenuFlags::AlwaysShowDisabledEntries)
+              || !bool(pMenuBar->GetMenuFlags() & MenuFlags::HideDisabledEntries);
+        const bool bVisible = bShowDisabled || mpVCLMenu->IsItemEnabled(pSalMenuItem->mnId);
+        pSalMenuItem->getAction()->setVisible(bVisible);
 
         if (pSalMenuItem->mpSubMenu != nullptr)
         {
@@ -651,6 +668,19 @@ void Qt5Menu::ShowCloseButton(bool bShow)
         pButton->hide();
 }
 
+bool Qt5Menu::ShowNativePopupMenu(FloatingWindow*, const tools::Rectangle&,
+                                  FloatWinPopupFlags nFlags)
+{
+    assert(mpQMenu);
+    DoFullMenuUpdate(mpVCLMenu);
+    mpQMenu->setTearOffEnabled(bool(nFlags & FloatWinPopupFlags::AllowTearOff));
+
+    const QPoint aPos = QCursor::pos();
+    mpQMenu->exec(aPos);
+
+    return true;
+}
+
 Qt5MenuItem::Qt5MenuItem(const SalItemParams* pItemData)
     : mpParentMenu(nullptr)
     , mpSubMenu(nullptr)