tdf#92110 KDE4: cleanup IsNativeControlSupported

Be (more) correct about the widgets and parts, we actually can draw
natively in KDE4.

Also add an assert, so drawNativeControl won't be called with values
not supported by IsNativeControlSupported.

Change-Id: Iac6c78194191a9cd059ace560c285263ce7c1045

vcl/unx/kde4/KDESalGraphics.cxx

@@ -85,47 +85,38 @@ KDESalGraphics::~KDESalGraphics()
 
 bool KDESalGraphics::IsNativeControlSupported( ControlType type, ControlPart part )
 {
-    if (type == CTRL_PUSHBUTTON) return true;
-
-    if (type == CTRL_MENUBAR) return true;
-
-    if (type == CTRL_MENU_POPUP) return true;
-
-    if (type == CTRL_EDITBOX) return true;
-
-    if (type == CTRL_COMBOBOX) return true;
-
-    if (type == CTRL_TOOLBAR) return true;
-
-    if (type == CTRL_CHECKBOX) return true;
-
-    if (type == CTRL_LISTBOX) return true;
-
-    if (type == CTRL_LISTNODE) return true;
-
-    if (type == CTRL_FRAME) return true;
-
-    if (type == CTRL_SCROLLBAR) return true;
-
-    if (type == CTRL_WINDOW_BACKGROUND) return true;
-
-    if (type == CTRL_SPINBOX && (part == PART_ENTIRE_CONTROL || part == HAS_BACKGROUND_TEXTURE) ) return true;
-
-    // no spinbuttons for KDE, paint spinbox complete
-    //if (type == CTRL_SPINBUTTONS) return true;
-
-    if (type == CTRL_GROUPBOX) return true;
-
-    if (type == CTRL_FIXEDLINE) return true;
+    switch (type)
+    {
+        case CTRL_PUSHBUTTON:
+        case CTRL_RADIOBUTTON:
+        case CTRL_CHECKBOX:
+        case CTRL_TOOLTIP:
+        case CTRL_PROGRESS:
+        case CTRL_LISTNODE:
+            return (part == PART_ENTIRE_CONTROL);
 
-    if (type == CTRL_TOOLTIP) return true;
+        case CTRL_MENUBAR:
+        case CTRL_MENU_POPUP:
+        case CTRL_EDITBOX:
+        case CTRL_COMBOBOX:
+        case CTRL_TOOLBAR:
+        case CTRL_LISTBOX:
+        case CTRL_FRAME:
+        case CTRL_SCROLLBAR:
+        case CTRL_WINDOW_BACKGROUND:
+        case CTRL_GROUPBOX:
+        case CTRL_FIXEDLINE:
+            return true;
 
-    if (type == CTRL_RADIOBUTTON) return true;
+        case CTRL_SPINBOX:
+            return (part == PART_ENTIRE_CONTROL || part == HAS_BACKGROUND_TEXTURE);
 
-    if (type == CTRL_SLIDER && (part == PART_TRACK_HORZ_AREA || part == PART_TRACK_VERT_AREA) )
-        return true;
+        case CTRL_SLIDER:
+            return (part == PART_TRACK_HORZ_AREA || part == PART_TRACK_VERT_AREA);
 
-    if ( (type == CTRL_PROGRESS) && (part == PART_ENTIRE_CONTROL) ) return true;
+        default:
+            break;
+    }
 
     return false;
 }
@@ -221,15 +212,15 @@ bool KDESalGraphics::drawNativeControl( ControlType type, ControlPart part,
                                         const ImplControlValue& value,
                                         const OUString& )
 {
-    if( lastPopupRect.isValid() && ( type != CTRL_MENU_POPUP || part != PART_MENU_ITEM ))
-        lastPopupRect = QRect();
-
-    // put not implemented types here
-    if (type == CTRL_SPINBUTTONS)
-    {
+    bool nativeSupport = IsNativeControlSupported( type, part );
+    if( ! nativeSupport ) {
+        assert( ! nativeSupport && "drawNativeControl called without native support!" );
         return false;
     }
 
+    if( lastPopupRect.isValid() && ( type != CTRL_MENU_POPUP || part != PART_MENU_ITEM ))
+        lastPopupRect = QRect();
+
     bool returnVal = true;
 
     QRect widgetRect = region2QRect(rControlRegion);