wxDFB: fix rendering artefacts when scrolling wxScrolledWindow that contains other widgets

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44290 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/menu.h

@@ -488,6 +488,8 @@ public:
     // update all menu item states in all menus
     virtual void UpdateMenus();
 
+    virtual bool CanBeOutsideClientArea() const { return true; }
+
 protected:
     // the list of all our menus
     wxMenuList m_menus;

include/wx/statusbr.h

@@ -97,6 +97,8 @@ public:
     // don't want status bars to accept the focus at all
     virtual bool AcceptsFocus() const { return false; }
 
+    virtual bool CanBeOutsideClientArea() const { return true; }
+
 protected:
     // set the widths array to NULL
     void InitWidths();

include/wx/window.h

@@ -1136,6 +1136,10 @@ public:
     // behaviour in the most common case
     virtual bool ShouldInheritColours() const { return false; }
 
+    // returns true if the window can be positioned outside of parent's client
+    // area (normal windows can't, but e.g. menubar or statusbar can):
+    virtual bool CanBeOutsideClientArea() const { return false; }
+
 protected:
     // event handling specific to wxWindow
     virtual bool TryValidator(wxEvent& event);

src/dfb/dcclient.cpp

@@ -58,6 +58,11 @@ static wxRect GetUncoveredWindowArea(wxWindow *win)
     // coordinates; this will remove parts of 'r' that are outside of the
     // parent's area:
     wxRect rp(GetUncoveredWindowArea(parent));
+
+    // normal windows cannot extend out of its parent's client area:
+    if ( !win->CanBeOutsideClientArea() )
+        rp.Intersect(parent->GetClientRect());
+
     rp.Offset(-win->GetPosition());
     rp.Offset(-parent->GetClientAreaOrigin());
     r.Intersect(rp);

src/dfb/window.cpp

@@ -492,6 +492,15 @@ void wxWindowDFB::DoMoveWindow(int x, int y, int width, int height)
     {
         // queue both former and new position of the window for repainting:
         wxWindow *parent = GetParent();
+
+        // only refresh the visible parts:
+        if ( !CanBeOutsideClientArea() )
+        {
+            wxRect parentClient(parent->GetClientSize());
+            oldpos.Intersect(parentClient);
+            newpos.Intersect(parentClient);
+        }
+
         parent->RefreshRect(oldpos);
         parent->RefreshRect(newpos);
     }
@@ -682,6 +691,11 @@ void wxWindowDFB::DoRefreshRect(const wxRect& rect)
     r.Offset(GetPosition());
     r.Offset(parent->GetClientAreaOrigin());
 
+    // normal windows cannot extend out of its parent's client area, so don't
+    // refresh any hidden parts:
+    if ( !CanBeOutsideClientArea() )
+        r.Intersect(parent->GetClientRect());
+
     parent->DoRefreshRect(r);
 }
 
@@ -763,6 +777,10 @@ void wxWindowDFB::PaintWindow(const wxRect& rect)
 
     m_updateRegion.Clear();
 
+    // client area portion of 'rect':
+    wxRect rectClientOnly(rect);
+    rectClientOnly.Intersect(clientRect);
+
     // paint the children:
     wxPoint origin = GetClientAreaOrigin();
     wxWindowList& children = GetChildren();
@@ -777,7 +795,12 @@ void wxWindowDFB::PaintWindow(const wxRect& rect)
         // compute child's area to repaint
         wxRect childrect(child->GetRect());
         childrect.Offset(origin);
+
+        if ( child->CanBeOutsideClientArea() )
             childrect.Intersect(rect);
+        else
+            childrect.Intersect(rectClientOnly);
+
         if ( childrect.IsEmpty() )
             continue;
 

src/univ/winuniv.cpp

@@ -60,6 +60,29 @@
 // implementation
 // ============================================================================
 
+// ----------------------------------------------------------------------------
+// scrollbars class
+// ----------------------------------------------------------------------------
+
+// This is scrollbar class used to implement wxWindow's "built-in" scrollbars;
+// unlike the standard wxScrollBar class, this one is positioned outside of its
+// parent's client area
+class wxWindowScrollBar : public wxScrollBar
+{
+public:
+    wxWindowScrollBar(wxWindow *parent,
+                      wxWindowID id,
+                      const wxPoint& pos = wxDefaultPosition,
+                      const wxSize& size = wxDefaultSize,
+                      long style = wxSB_HORIZONTAL)
+        : wxScrollBar(parent, id, pos, size, style)
+    {
+    }
+
+    virtual bool CanBeOutsideClientArea() const { return true; }
+};
+
+
 // ----------------------------------------------------------------------------
 // event tables
 // ----------------------------------------------------------------------------
@@ -156,7 +179,7 @@ bool wxWindow::Create(wxWindow *parent,
         SetInsertIntoMain( true );
 #endif
 #if wxUSE_SCROLLBAR
-        m_scrollbarVert = new wxScrollBar(this, wxID_ANY,
+        m_scrollbarVert = new wxWindowScrollBar(this, wxID_ANY,
                                                 wxDefaultPosition, wxDefaultSize,
                                                 wxSB_VERTICAL);
 #endif // wxUSE_SCROLLBAR
@@ -172,7 +195,7 @@ bool wxWindow::Create(wxWindow *parent,
         SetInsertIntoMain( true );
 #endif
 #if wxUSE_SCROLLBAR
-        m_scrollbarHorz = new wxScrollBar(this, wxID_ANY,
+        m_scrollbarHorz = new wxWindowScrollBar(this, wxID_ANY,
                                                 wxDefaultPosition, wxDefaultSize,
                                                 wxSB_HORIZONTAL);
 #endif // wxUSE_SCROLLBAR
@@ -903,7 +926,7 @@ void wxWindow::SetScrollbar(int orient,
 #if wxUSE_TWO_WINDOWS
             SetInsertIntoMain( true );
 #endif
-            scrollbar = new wxScrollBar(this, wxID_ANY,
+            scrollbar = new wxWindowScrollBar(this, wxID_ANY,
                                               wxDefaultPosition, wxDefaultSize,
                                               orient & wxVERTICAL ? wxSB_VERTICAL
                                                                   : wxSB_HORIZONTAL);