Don't overlap the menu scrollers with QAction items

The QAction items overlap with the menu scrollers. The patch is to
set correct clip regions for QAction items in order not to overlap
with the scroll arrows.

Change-Id: Ie724bd2be522daf5935fb489523b5d5f32bb7f71
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@qt.io>

1 files changed, 62 insertions, 27 deletions

diff --git a/src/widgets/widgets/qmenu.cpp b/src/widgets/widgets/qmenu.cpp
index a983dc6fde..b0c9512344 100644
--- a/src/widgets/widgets/qmenu.cpp
+++ b/src/widgets/widgets/qmenu.cpp
@@ -2539,51 +2539,85 @@ void QMenu::paintEvent(QPaintEvent *e)
     menuOpt.tabWidth = 0;
     style()->drawPrimitive(QStyle::PE_PanelMenu, &menuOpt, &p, this);
 
+    //calculate the scroll up / down rect
+    const int fw = style()->pixelMetric(QStyle::PM_MenuPanelWidth, 0, this);
+    QRect scrollUpRect, scrollDownRect;
+    if (d->scroll) {
+        if (d->scroll->scrollFlags & QMenuPrivate::QMenuScroller::ScrollUp)
+            scrollUpRect.setRect(fw, fw, width() - (fw * 2), d->scrollerHeight());
+
+        if (d->scroll->scrollFlags & QMenuPrivate::QMenuScroller::ScrollDown)
+            scrollDownRect.setRect(fw, height() - d->scrollerHeight() - fw, width() - (fw * 2),
+                                     d->scrollerHeight());
+    }
+
+    //calculate the tear off rect
+    QRect tearOffRect;
+    if (d->tearoff) {
+        tearOffRect.setRect(fw, fw, width() - (fw * 2),
+                             style()->pixelMetric(QStyle::PM_MenuTearoffHeight, 0, this));
+        if (d->scroll && d->scroll->scrollFlags & QMenuPrivate::QMenuScroller::ScrollUp)
+            tearOffRect.translate(0, d->scrollerHeight());
+    }
+
     //draw the items that need updating..
+    QRect scrollUpTearOffRect = scrollUpRect.united(tearOffRect);
     for (int i = 0; i < d->actions.count(); ++i) {
         QAction *action = d->actions.at(i);
-        QRect adjustedActionRect = d->actionRects.at(i);
-        if (!e->rect().intersects(adjustedActionRect)
+        QRect actionRect = d->actionRects.at(i);
+        if (!e->rect().intersects(actionRect)
             || d->widgetItems.value(action))
            continue;
         //set the clip region to be extra safe (and adjust for the scrollers)
+        emptyArea -= QRegion(actionRect);
+
+        QRect adjustedActionRect = actionRect;
+        if (adjustedActionRect.intersects(scrollUpTearOffRect)) {
+            if (adjustedActionRect.bottom() <= scrollUpTearOffRect.bottom())
+                continue;
+            else
+                adjustedActionRect.setTop(scrollUpTearOffRect.bottom()+1);
+        }
+
+        if (adjustedActionRect.intersects(scrollDownRect)) {
+            if (adjustedActionRect.top() >= scrollDownRect.top())
+                continue;
+            else
+                adjustedActionRect.setBottom(scrollDownRect.top()-1);
+        }
+
         QRegion adjustedActionReg(adjustedActionRect);
-        emptyArea -= adjustedActionReg;
         p.setClipRegion(adjustedActionReg);
 
         QStyleOptionMenuItem opt;
         initStyleOption(&opt, action);
-        opt.rect = adjustedActionRect;
+        opt.rect = actionRect;
         style()->drawControl(QStyle::CE_MenuItem, &opt, &p, this);
     }
 
-    const int fw = style()->pixelMetric(QStyle::PM_MenuPanelWidth, 0, this);
-    //draw the scroller regions..
-    if (d->scroll) {
+    if (!scrollUpRect.isEmpty()) {
         menuOpt.menuItemType = QStyleOptionMenuItem::Scroller;
         menuOpt.state |= QStyle::State_Enabled;
-        if (d->scroll->scrollFlags & QMenuPrivate::QMenuScroller::ScrollUp) {
-            menuOpt.rect.setRect(fw, fw, width() - (fw * 2), d->scrollerHeight());
-            emptyArea -= QRegion(menuOpt.rect);
-            p.setClipRect(menuOpt.rect);
-            style()->drawControl(QStyle::CE_MenuScroller, &menuOpt, &p, this);
-        }
-        if (d->scroll->scrollFlags & QMenuPrivate::QMenuScroller::ScrollDown) {
-            menuOpt.rect.setRect(fw, height() - d->scrollerHeight() - fw, width() - (fw * 2),
-                                     d->scrollerHeight());
-            emptyArea -= QRegion(menuOpt.rect);
-            menuOpt.state |= QStyle::State_DownArrow;
-            p.setClipRect(menuOpt.rect);
-            style()->drawControl(QStyle::CE_MenuScroller, &menuOpt, &p, this);
-        }
+        menuOpt.rect = scrollUpRect;
+        emptyArea -= QRegion(menuOpt.rect);
+        p.setClipRect(menuOpt.rect);
+        style()->drawControl(QStyle::CE_MenuScroller, &menuOpt, &p, this);
+    }
+
+    if (!scrollDownRect.isEmpty()) {
+        menuOpt.menuItemType = QStyleOptionMenuItem::Scroller;
+        menuOpt.state |= QStyle::State_Enabled;
+        menuOpt.state |= QStyle::State_DownArrow;
+        menuOpt.rect = scrollDownRect;
+        emptyArea -= QRegion(menuOpt.rect);
+        p.setClipRect(menuOpt.rect);
+        style()->drawControl(QStyle::CE_MenuScroller, &menuOpt, &p, this);
     }
+
     //paint the tear off..
-    if (d->tearoff) {
+    if (!tearOffRect.isEmpty()) {
         menuOpt.menuItemType = QStyleOptionMenuItem::TearOff;
-        menuOpt.rect.setRect(fw, fw, width() - (fw * 2),
-                             style()->pixelMetric(QStyle::PM_MenuTearoffHeight, 0, this));
-        if (d->scroll && d->scroll->scrollFlags & QMenuPrivate::QMenuScroller::ScrollUp)
-            menuOpt.rect.translate(0, d->scrollerHeight());
+        menuOpt.rect = tearOffRect;
         emptyArea -= QRegion(menuOpt.rect);
         p.setClipRect(menuOpt.rect);
         menuOpt.state = QStyle::State_None;
@@ -2591,6 +2625,7 @@ void QMenu::paintEvent(QPaintEvent *e)
             menuOpt.state |= QStyle::State_Selected;
         style()->drawControl(QStyle::CE_MenuTearoff, &menuOpt, &p, this);
     }
+
     //draw border
     if (fw) {
         QRegion borderReg;
@@ -2609,7 +2644,7 @@ void QMenu::paintEvent(QPaintEvent *e)
         style()->drawPrimitive(QStyle::PE_FrameMenu, &frame, &p, this);
     }
 
-    //finally the rest of the space
+    //finally the rest of the spaces
     p.setClipRegion(emptyArea);
     menuOpt.state = QStyle::State_None;
     menuOpt.menuItemType = QStyleOptionMenuItem::EmptyArea;