From ebf757e804bc2772169880c47f674df13a3f8755 Mon Sep 17 00:00:00 2001
From: "kipp%netscape.com" <kipp%netscape.com>
Date: Thu, 18 Mar 1999 16:35:16 +0000
Subject: [PATCH] Teach the widget how to manage an update rect so that we
 avoid gratuitous full window paints

---
 widget/src/gtk/nsWidget.cpp | 59 ++++++++++++++++++++++++-------------
 widget/src/gtk/nsWidget.h   |  4 +++
 widget/src/gtk/nsWindow.cpp | 10 +++++++
 3 files changed, 53 insertions(+), 20 deletions(-)

diff --git a/widget/src/gtk/nsWidget.cpp b/widget/src/gtk/nsWidget.cpp
index ed93f204e062..1ce2aef45326 100644
--- a/widget/src/gtk/nsWidget.cpp
+++ b/widget/src/gtk/nsWidget.cpp
@@ -1,4 +1,4 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  *
  * The contents of this file are subject to the Netscape Public License
  * Version 1.0 (the "NPL"); you may not use this file except in
@@ -59,6 +59,7 @@ nsWidget::nsWidget()
   mIsDestroying = PR_FALSE;
   mOnDestroyCalled = PR_FALSE;
   mIsToplevel = PR_FALSE;
+  mUpdateArea.SetRect(0, 0, 0, 0);
 }
 
 nsWidget::~nsWidget()
@@ -440,15 +441,13 @@ NS_METHOD nsWidget::Invalidate(PRBool aIsSynchronous)
     ::gtk_widget_queue_draw(mWidget);
 
 #ifdef DEBUG_pavlov
-  g_print("nsWidget::Invalidate(%i)\n", aIsSynchronous);
+  g_print("nsWidget::Invalidate(this=%p, %i)\n", this, aIsSynchronous);
 #endif
   return NS_OK;
 }
 
 NS_METHOD nsWidget::Invalidate(const nsRect & aRect, PRBool aIsSynchronous)
 {
-  GdkRectangle nRect;
-  
   if (mWidget == nsnull) {
     return NS_OK;  // mWidget is null during printing
   }
@@ -461,20 +460,24 @@ NS_METHOD nsWidget::Invalidate(const nsRect & aRect, PRBool aIsSynchronous)
     return NS_ERROR_FAILURE;
   }
 
-  nRect.width = aRect.width;
-  nRect.height = aRect.height;
-  nRect.x = aRect.x;
-  nRect.y = aRect.y;
 
-  if ( aIsSynchronous)
+  if ( aIsSynchronous) {
+      GdkRectangle nRect;
+      nRect.width = aRect.width;
+      nRect.height = aRect.height;
+      nRect.x = aRect.x;
+      nRect.y = aRect.y;
       ::gtk_widget_draw(mWidget, &nRect);
-  else
+  } else {
+      mUpdateArea.UnionRect(mUpdateArea, aRect);
       ::gtk_widget_queue_draw_area(mWidget,
                                    aRect.x, aRect.y,
                                    aRect.width, aRect.height);
+  }
 
 #ifdef DEBUG_pavlov
-  g_print("nsWidget::Invalidate({x=%i,y=%i,w=%i,h=%i}, %i)\n", aRect.x, aRect.y, aRect.width, aRect.height, aIsSynchronous);
+  g_print("nsWidget::Invalidate(this=%p, {x=%i,y=%i,w=%i,h=%i}, %i)\n",
+          this, aRect.x, aRect.y, aRect.width, aRect.height, aIsSynchronous);
 #endif
 
   return NS_OK;
@@ -485,17 +488,33 @@ NS_METHOD nsWidget::Update(void)
   if (! mWidget)
     return NS_OK;
 
-  GdkRectangle foo;
-  foo.width = mBounds.width;
-  foo.height = mBounds.height;
-  foo.x = 0;
-  foo.y = 0;
+  if (mUpdateArea.width && mUpdateArea.height) {
+    if (!mIsDestroying) {
+      GdkRectangle nRect;
+      nRect.width = mUpdateArea.width;
+      nRect.height = mUpdateArea.height;
+      nRect.x = mUpdateArea.x;
+      nRect.y = mUpdateArea.y;
+#ifdef DEBUG_pavlov
+      g_print("nsWidget::Update(this=%p): update {%i,%i,%i,%i}\n",
+              this, mUpdateArea.x, mUpdateArea.y,
+              mUpdateArea.width, mUpdateArea.height);
+#endif
+      ::gtk_widget_draw(mWidget, &nRect);
 
-  if (!mIsDestroying) {
-    ::gtk_widget_draw(mWidget, &foo);
-    return NS_OK;
+      mUpdateArea.SetRect(0, 0, 0, 0);
+      return NS_OK;
+    }
+    else {
+      return NS_ERROR_FAILURE;
+    }
   }
-  return NS_ERROR_FAILURE;
+  else {
+#ifdef DEBUG_pavlov
+  g_print("nsWidget::Update(this=%p): avoided update of empty area\n", this);
+#endif
+  }
+  return NS_OK;
 }
 
 //-------------------------------------------------------------------------
diff --git a/widget/src/gtk/nsWidget.h b/widget/src/gtk/nsWidget.h
index ec2d28deb066..e5ef62bfdad0 100644
--- a/widget/src/gtk/nsWidget.h
+++ b/widget/src/gtk/nsWidget.h
@@ -136,6 +136,10 @@ class nsWidget : public nsBaseWidget
     GtkWidget *mWidget;
     nsWidget *mParent;
 
+    // This is the composite update area (union of all the calls to
+    // Invalidate)
+    nsRect mUpdateArea;
+
     PRBool mShown;
 
     PRUint32 mPreferredWidth, mPreferredHeight;
diff --git a/widget/src/gtk/nsWindow.cpp b/widget/src/gtk/nsWindow.cpp
index 9f6638792fa0..4cbd00c742d7 100644
--- a/widget/src/gtk/nsWindow.cpp
+++ b/widget/src/gtk/nsWindow.cpp
@@ -409,6 +409,16 @@ PRBool nsWindow::OnPaint(nsPaintEvent &event)
   if (mEventCallback) {
 
     event.renderingContext = nsnull;
+#if 0
+    if (event.rect) {
+      g_print("nsWindow::OnPaint(this=%p, {%i,%i,%i,%i})\n", this,
+              event.rect->x, event.rect->y,
+              event.rect->width, event.rect->height);
+    }
+    else {
+      g_print("nsWindow::OnPaint(this=%p, NO RECT)\n", this);
+    }
+#endif
     static NS_DEFINE_IID(kRenderingContextCID, NS_RENDERING_CONTEXT_CID);
     static NS_DEFINE_IID(kRenderingContextIID, NS_IRENDERING_CONTEXT_IID);
     if (NS_OK == nsComponentManager::CreateInstance(kRenderingContextCID,