Add --debug-views-paint switch that shows damaged rectangles in red

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6489015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@74706 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 31 insertions, 0 deletions

diff --git a/views/widget/root_view.cc b/views/widget/root_view.cc
index 83e33e8..0a20f10 100644
--- a/views/widget/root_view.cc
+++ b/views/widget/root_view.cc
@@ -63,6 +63,8 @@ class PaintTask : public Task {
 };
 
 const char RootView::kViewClassName[] = "views/RootView";
+// static
+bool RootView::debug_paint_enabled_ = false;
 
 /////////////////////////////////////////////////////////////////////////////
 //
@@ -777,6 +779,11 @@ void RootView::ClearPaintRect() {
   paint_task_needed_ = false;
 }
 
+// static
+void RootView::EnableDebugPaint() {
+  debug_paint_enabled_ = true;
+}
+
 /////////////////////////////////////////////////////////////////////////////
 //
 // RootView - accessibility
diff --git a/views/widget/root_view.h b/views/widget/root_view.h
index aabf339..4a8f07f 100644
--- a/views/widget/root_view.h
+++ b/views/widget/root_view.h
@@ -189,6 +189,9 @@ class RootView : public View,
   void SetGestureManager(GestureManager* g) { gesture_manager_ = g; }
 #endif
 
+  // Enables debug painting. See |debug_paint_enabled_| for details.
+  static void EnableDebugPaint();
+
  protected:
 
   // Overridden to properly reset our event propagation member
@@ -353,6 +356,11 @@ class RootView : public View,
   // True if we're currently processing paint.
   bool is_processing_paint_;
 #endif
+
+  // True to enable debug painting. Enabling causes the damaged
+  // region to be painted to flash in red.
+  static bool debug_paint_enabled_;
+
   DISALLOW_COPY_AND_ASSIGN(RootView);
 };
 }  // namespace views
diff --git a/views/widget/root_view_gtk.cc b/views/widget/root_view_gtk.cc
index 5edfd63..deffbe4 100644
--- a/views/widget/root_view_gtk.cc
+++ b/views/widget/root_view_gtk.cc
@@ -5,19 +5,35 @@
 #include "views/widget/root_view.h"
 
 #include <gtk/gtk.h>
+#include <X11/Xlib.h>
 
 #include "base/logging.h"
+#include "ui/base/x/x11_util.h"
 #include "ui/gfx/canvas_skia_paint.h"
 #include "views/widget/widget_gtk.h"
 
 namespace views {
 
 void RootView::OnPaint(GdkEventExpose* event) {
+
   WidgetGtk* widget = static_cast<WidgetGtk*>(GetWidget());
   if (!widget) {
     NOTREACHED();
     return;
   }
+  if (debug_paint_enabled_) {
+    // Using cairo directly because using skia didn't have immediate effect.
+    cairo_t* cr = gdk_cairo_create(event->window);
+    gdk_cairo_region(cr, event->region);
+    cairo_set_source_rgb(cr, 1, 0, 0);  // red
+    cairo_rectangle(cr,
+                    event->area.x, event->area.y,
+                    event->area.width, event->area.height);
+    cairo_fill(cr);
+    cairo_destroy(cr);
+    // Make sure that users see the red flash.
+    XSync(ui::GetXDisplay(), false /* don't discard events */);
+  }
   gfx::Rect scheduled_dirty_rect = GetScheduledPaintRectConstrainedToSize();
   gfx::Rect expose_rect = gfx::Rect(event->area);
   gfx::CanvasSkiaPaint canvas(event);