Fix tab dragging in unity2d

ui/base/x/x11_util.cc

Index: ui/base/x/x11_util.cc
diff --git a/ui/base/x/x11_util.cc b/ui/base/x/x11_util.cc
index 8a1d5e6697e46b61d9d2641c9a7e6c5e9973dda1..d47a7b71a49302240646f2a8872e0a61f831dee8 100644
--- a/ui/base/x/x11_util.cc
+++ b/ui/base/x/x11_util.cc
@@ -19,6 +19,7 @@
 
 #include <X11/extensions/Xrandr.h>
 #include <X11/extensions/randr.h>
+#include <X11/extensions/shape.h>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ -612,6 +613,44 @@ bool GetWindowRect(XID window, gfx::Rect* rect) {
   return true;
 }
 
+
+bool WindowContainsPoint(XID window, gfx::Point screen_loc) {
+  gfx::Rect window_rect;
+  if (!GetWindowRect(window, &window_rect))
+    return false;
+
+  if (!window_rect.Contains(screen_loc))
+    return false;
+
+  // According to http://www.x.org/releases/X11R7.6/doc/libXext/shapelib.html,
+  // if an X display supports the shape extension the bounds of a window are
+  // defined as the intersection of the window bounds and the interior
+  // rectangles. This means to determine if a point is inside a window for the
+  // purpose of input handling we have to check the rectangles in the ShapeInput
+  // list.
+  int dummy;
+  if (XShapeQueryExtension(ui::GetXDisplay(), &dummy, &dummy)) {

[sadrul, 2012/09/24 23:39:24]

It would make sense to cache the return value of XShapeQueryExtension

+    int input_rects_size = 0;
+    XRectangle* input_rects = XShapeGetRectangles(
+        ui::GetXDisplay(), window, ShapeInput, &input_rects_size, &dummy);
+    bool is_in_input_rects = false;
+    for (int i = 0; i < input_rects_size; ++i) {
+      gfx::Rect input_rect =
+          gfx::Rect(input_rects[i].x, input_rects[i].y,
+                    input_rects[i].width, input_rects[i].height);
+      if (input_rect.Contains(screen_loc)) {
+        is_in_input_rects = true;
+        break;
+      }
+    }

[Elliot Glaysher, 2012/09/24 23:35:05]

You'll need an XFree(input_rects); here.

+    if (!is_in_input_rects)
+      return false;
+  }
+
+  return true;
+}
+
+
 bool PropertyExists(XID window, const std::string& property_name) {
   Atom type = None;
   int format = 0;  // size in bits of each item in 'property'