From 9ac4aa9e6210d5aae92fe6b8a5669a13b6c9d27e Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Tue, 13 May 2008 20:14:17 +0000
Subject: [PATCH] refine Windows gui-update repairs

svn: r9827
---
 src/wxwindow/include/msw/wx_canvs.h |  2 +-
 src/wxwindow/include/msw/wx_dc.h    |  1 +
 src/wxwindow/src/msw/wx_canvs.cxx   | 41 ++++++++++++++++++++++++++---
 src/wxwindow/src/msw/wx_dc.cxx      | 24 +++++++++++++----
 4 files changed, 59 insertions(+), 9 deletions(-)

diff --git a/src/wxwindow/include/msw/wx_canvs.h b/src/wxwindow/include/msw/wx_canvs.h
index 49caa957b7..b114241887 100644
--- a/src/wxwindow/include/msw/wx_canvs.h
+++ b/src/wxwindow/include/msw/wx_canvs.h
@@ -22,7 +22,7 @@ class wxCanvas: public wxbCanvas
 {
  public:
   wxWindow *combo;
-  int need_update;
+  HRGN need_update;
 
   wxCanvas(void);
   wxCanvas(wxWindow *parent, int x=-1, int y=-1, int width=-1, int height=-1,
diff --git a/src/wxwindow/include/msw/wx_dc.h b/src/wxwindow/include/msw/wx_dc.h
index 130fe7cb0f..78c913848c 100644
--- a/src/wxwindow/include/msw/wx_dc.h
+++ b/src/wxwindow/include/msw/wx_dc.h
@@ -36,6 +36,7 @@ class wxDC: public wxbDC
   int window_ext_x;
   int window_ext_y;
 
+  HRGN limit_rgn;
   int canvas_scroll_dx, canvas_scroll_dy;
 
   wxCanvas *canvas;
diff --git a/src/wxwindow/src/msw/wx_canvs.cxx b/src/wxwindow/src/msw/wx_canvs.cxx
index 029f71104b..d9dec9a869 100644
--- a/src/wxwindow/src/msw/wx_canvs.cxx
+++ b/src/wxwindow/src/msw/wx_canvs.cxx
@@ -127,6 +127,10 @@ wxCanvas::~wxCanvas (void)
     wxwmReleaseDC(wnd->handle, dc);
     delete wx_dc;
   }
+  if (need_update) {
+    DeleteObject(need_update);
+    need_update = NULL;
+  }
 }
 
 void wxCanvas::GetSize(int *width, int *height)
@@ -669,6 +673,7 @@ BOOL wxCanvasWnd::OnPaint(void)
     
     if (GetUpdateRgn(handle, tRgn, FALSE)) {
       PAINTSTRUCT ps;
+      HRGN need_update;
 
       BeginPaint(handle, &ps);
 
@@ -676,7 +681,14 @@ BOOL wxCanvasWnd::OnPaint(void)
 	 now we queue an event. The need_update flag
          avoids multiple updats with we queue multiple
          events before the first is handled. */
-      ((wxCanvas *)wx_window)->need_update = 1;
+
+      need_update = ((wxCanvas *)wx_window)->need_update;
+      if (!need_update) {
+	need_update = CreateRectRgn(0,0,0,0);
+	((wxCanvas *)wx_window)->need_update = need_update;
+      }
+      CombineRgn(need_update, tRgn, need_update, RGN_OR);
+
       MrEdQueuePaint(wx_window);
 
       EndPaint(handle, &ps);
@@ -694,7 +706,30 @@ BOOL wxCanvasWnd::OnPaint(void)
 void wxCanvas::DoPaint()
 {
   if (need_update) {
-    need_update = 0;
-    OnPaint();
+    RECT r;
+    if (GetRgnBox(need_update, &r) != NULLREGION) {
+      wxDC *dc;
+      HDC hdc;
+      HRGN paint_rgn;
+
+      paint_rgn = CreateRectRgn(0,0,0,0);
+      CombineRgn(paint_rgn, need_update, paint_rgn, RGN_COPY);
+      SetRectRgn(need_update, 0, 0, 0, 0);
+    
+      dc = GetDC();
+      dc->limit_rgn = paint_rgn;
+      hdc = dc->ThisDC(FALSE);
+      dc->DoClipping(hdc);
+      dc->DoneDC(hdc);
+
+      OnPaint();
+
+      dc->limit_rgn = NULL;
+      hdc = dc->ThisDC(FALSE);
+      dc->DoClipping(hdc);
+      dc->DoneDC(hdc);
+
+      DeleteObject(paint_rgn);
+    }
   }
 }
diff --git a/src/wxwindow/src/msw/wx_dc.cxx b/src/wxwindow/src/msw/wx_dc.cxx
index 1fff293ed8..4bf98ae9d3 100644
--- a/src/wxwindow/src/msw/wx_dc.cxx
+++ b/src/wxwindow/src/msw/wx_dc.cxx
@@ -437,17 +437,31 @@ void wxDC::DoClipping(HDC dc)
     HRGN rgn;
     rgn = clipping->GetRgn();
     if (rgn) {
-      SelectClipRgn(dc, rgn);
-      OffsetClipRgn(dc, canvas_scroll_dx, canvas_scroll_dy);
+      if (limit_rgn) {
+	HRGN together_rgn;
+	together_rgn = CreateRectRgn(0,0,0,0);
+	CombineRgn(together_rgn, rgn, together_rgn, RGN_COPY);
+	OffsetRgn(together_rgn, canvas_scroll_dx, canvas_scroll_dy);
+	CombineRgn(together_rgn, limit_rgn, together_rgn, RGN_AND);
+	SelectClipRgn(dc, together_rgn);
+	DeleteObject(together_rgn);
+      } else {
+	SelectClipRgn(dc, rgn);
+	OffsetClipRgn(dc, canvas_scroll_dx, canvas_scroll_dy);
+      }
     } else {
       if (!empty_rgn)
 	empty_rgn = CreateRectRgn(0, 0, 0, 0);
       SelectClipRgn(dc, empty_rgn);
     }
   } else {
-    if (!full_rgn)
-      full_rgn = CreateRectRgn(0, 0, 32000, 32000);
-    SelectClipRgn(dc, full_rgn);
+    if (limit_rgn) {
+      SelectClipRgn(dc, limit_rgn);
+    } else {
+      if (!full_rgn)
+	full_rgn = CreateRectRgn(0, 0, 32000, 32000);
+      SelectClipRgn(dc, full_rgn);
+    }
   }
 }