Respect the PM_SmallIconSize setting for icons in a menu on OS X

When a platform menu is used then it would hard code the icon size to
16x16. Instead of using the hard coded value then PM_SmallIconSize should
be used instead.

Change-Id: I27540ebc4397501e8f57686a118c28cd7167c0a1
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

src/gui/kernel/qplatformmenu.h

@@ -86,7 +86,7 @@ public:
     virtual void setChecked(bool isChecked) = 0;
     virtual void setShortcut(const QKeySequence& shortcut) = 0;
     virtual void setEnabled(bool enabled) = 0;
-
+    virtual void setIconSize(int size) = 0;
     virtual void setNativeContents(WId item) { Q_UNUSED(item); }
 
 Q_SIGNALS:

src/plugins/platforms/android/qandroidplatformmenuitem.cpp

@@ -181,4 +181,9 @@ bool QAndroidPlatformMenuItem::isEnabled() const
     return m_isEnabled;
 }
 
+void QAndroidPlatformMenuItem::setIconSize(int size)
+{
+    Q_UNUSED(size)
+}
+
 QT_END_NAMESPACE

src/plugins/platforms/android/qandroidplatformmenuitem.h

@@ -85,6 +85,8 @@ public:
     void setEnabled(bool enabled);
     bool isEnabled() const;
 
+    void setIconSize(int size);
+
 private:
     quintptr m_tag;
     QString m_text;

src/plugins/platforms/cocoa/qcocoamenuitem.h

@@ -86,6 +86,7 @@ public:
     void setCheckable(bool checkable) { Q_UNUSED(checkable) }
     void setChecked(bool isChecked);
     void setEnabled(bool isEnabled);
+    void setIconSize(int size);
 
     void setNativeContents(WId item);
 
@@ -123,6 +124,7 @@ private:
     bool m_checked;
     bool m_merged;
     quintptr m_tag;
+    int m_iconSize;
 };
 
 #define COCOA_MENU_ANCESTOR(m) ((m)->property("_qCocoaMenuAncestor").value<QObject *>())

src/plugins/platforms/cocoa/qcocoamenuitem.mm

@@ -100,7 +100,8 @@ QCocoaMenuItem::QCocoaMenuItem() :
     m_role(NoRole),
     m_checked(false),
     m_merged(false),
-    m_tag(0)
+    m_tag(0),
+    m_iconSize(16)
 {
 }
 
@@ -332,7 +333,7 @@ NSMenuItem *QCocoaMenuItem::sync()
     NSImage *img = nil;
     if (!m_icon.isNull()) {
         img = qt_mac_create_nsimage(m_icon);
-        [img setSize:NSMakeSize(16, 16)];
+        [img setSize:NSMakeSize(m_iconSize, m_iconSize)];
     }
     [m_native setImage:img];
     [img release];
@@ -403,3 +404,8 @@ QPlatformMenuItem::MenuRole QCocoaMenuItem::effectiveRole() const
     else
         return m_detectedRole;
 }
+
+void QCocoaMenuItem::setIconSize(int size)
+{
+    m_iconSize = size;
+}

src/widgets/widgets/qmenu.cpp

@@ -2978,8 +2978,17 @@ static void copyActionToPlatformItem(const QAction *action, QPlatformMenuItem* i
 {
     item->setText(action->text());
     item->setIsSeparator(action->isSeparator());
-    if (action->isIconVisibleInMenu())
+    if (action->isIconVisibleInMenu()) {
         item->setIcon(action->icon());
+        if (QWidget *w = action->parentWidget()) {
+            QStyleOption opt;
+            opt.init(w);
+            item->setIconSize(w->style()->pixelMetric(QStyle::PM_SmallIconSize, &opt, w));
+        } else {
+            QStyleOption opt;
+            item->setIconSize(qApp->style()->pixelMetric(QStyle::PM_SmallIconSize, &opt, 0));
+        }
+    }
     item->setVisible(action->isVisible());
     item->setShortcut(action->shortcut());
     item->setCheckable(action->isCheckable());