Two tweaks to ToplevelWindowEventFilter:

. don't let windows resize bigger than screen area.
. don't let windows be dragged to a -y location. We currently restrict
  this in ToplevelLayoutManager, which lead to not letting the y
  location go negative but having the window resize from the bottom
  when dragging from the top.

BUG=106762
TEST=covered by tests.
R=ben@chromium.org


Review URL: http://codereview.chromium.org/9186048

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@117538 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 56 insertions, 6 deletions

diff --git a/ash/wm/toplevel_window_event_filter.cc b/ash/wm/toplevel_window_event_filter.cc
index 1ff6edc..44c0e68 100644
--- a/ash/wm/toplevel_window_event_filter.cc
+++ b/ash/wm/toplevel_window_event_filter.cc
@@ -300,6 +300,12 @@ bool ToplevelWindowEventFilter::HandleDrag(aura::Window* target,
       new_bounds.Inset(0, 0, 0,
                        new_bounds.bottom() - work_area.bottom());
   }
+  if (bounds_change & kBoundsChange_Resizes &&
+      bounds_change & kBoundsChange_Repositions && new_bounds.y() < 0) {
+    int delta = new_bounds.y();
+    new_bounds.set_y(0);
+    new_bounds.set_height(new_bounds.height() + delta);
+  }
   target->SetBounds(new_bounds);
   return true;
 }
@@ -347,13 +353,16 @@ gfx::Size ToplevelWindowEventFilter::GetSizeForDrag(
     int size_change_direction =
         GetSizeChangeDirectionForWindowComponent(window_component_);
     size.SetSize(
-      GetWidthForDrag(size_change_direction, min_size.width(), delta_x),
-      GetHeightForDrag(size_change_direction, min_size.height(), delta_y));
+        GetWidthForDrag(target, size_change_direction, min_size.width(),
+                        delta_x),
+        GetHeightForDrag(target, size_change_direction, min_size.height(),
+                         delta_y));
   }
   return size;
 }
 
-int ToplevelWindowEventFilter::GetWidthForDrag(int size_change_direction,
+int ToplevelWindowEventFilter::GetWidthForDrag(aura::Window* target,
+                                               int size_change_direction,
                                                int min_width,
                                                int* delta_x) const {
   int width = mouse_down_bounds_.width();
@@ -368,11 +377,20 @@ int ToplevelWindowEventFilter::GetWidthForDrag(int size_change_direction,
       width = min_width;
       *delta_x = -x_multiplier * (mouse_down_bounds_.width() - min_width);
     }
+
+    // And don't let the window go bigger than the monitor.
+    int max_width =
+        gfx::Screen::GetMonitorAreaNearestWindow(target).width();
+    if (width > max_width) {
+      width = max_width;
+      *delta_x = -x_multiplier * (mouse_down_bounds_.width() - max_width);
+    }
   }
   return width;
 }
 
-int ToplevelWindowEventFilter::GetHeightForDrag(int size_change_direction,
+int ToplevelWindowEventFilter::GetHeightForDrag(aura::Window* target,
+                                                int size_change_direction,
                                                 int min_height,
                                                 int* delta_y) const {
   int height = mouse_down_bounds_.height();
@@ -387,6 +405,14 @@ int ToplevelWindowEventFilter::GetHeightForDrag(int size_change_direction,
       height = min_height;
       *delta_y = -y_multiplier * (mouse_down_bounds_.height() - min_height);
     }
+
+    // And don't let the window go bigger than the monitor.
+    int max_height =
+        gfx::Screen::GetMonitorAreaNearestWindow(target).height();
+    if (height > max_height) {
+      height = max_height;
+      *delta_y = -y_multiplier * (mouse_down_bounds_.height() - max_height);
+    }
   }
   return height;
 }
diff --git a/ash/wm/toplevel_window_event_filter.h b/ash/wm/toplevel_window_event_filter.h
index 4da26d8..a08e973 100644
--- a/ash/wm/toplevel_window_event_filter.h
+++ b/ash/wm/toplevel_window_event_filter.h
@@ -82,14 +82,16 @@ class ASH_EXPORT ToplevelWindowEventFilter :
   // Calculates new width of a window during a drag where the mouse
   // position changed by |delta_x|.  |delta_x| may be clamped if the window
   // size is constrained by |min_width|.
-  int GetWidthForDrag(int size_change_direction,
+  int GetWidthForDrag(aura::Window* target,
+                      int size_change_direction,
                       int min_width,
                       int* delta_x) const;
 
   // Calculates new height of a window during a drag where the mouse
   // position changed by |delta_y|.  |delta_y| may be clamped if the window
   // size is constrained by |min_height|.
-  int GetHeightForDrag(int size_change_direction,
+  int GetHeightForDrag(aura::Window* target,
+                       int size_change_direction,
                        int min_height,
                        int* delta_y) const;
 
diff --git a/ash/wm/toplevel_window_event_filter_unittest.cc b/ash/wm/toplevel_window_event_filter_unittest.cc
index 2ab742c..0fef59d 100644
--- a/ash/wm/toplevel_window_event_filter_unittest.cc
+++ b/ash/wm/toplevel_window_event_filter_unittest.cc
@@ -363,5 +363,27 @@ TEST_F(ToplevelWindowEventFilterTest, BottomWorkArea) {
             target->bounds().size());
 }
 
+// Verifies we don't let windows drag to a -y location.
+TEST_F(ToplevelWindowEventFilterTest, DontDragToNegativeY) {
+  scoped_ptr<aura::Window> target(CreateWindow(HTTOP));
+  gfx::Rect work_area =
+      gfx::Screen::GetMonitorWorkAreaNearestWindow(target.get());
+  aura::test::EventGenerator generator(target.get());
+  generator.MoveMouseTo(0, 5);
+  generator.DragMouseBy(0, -5);
+  // The y location and height should not have changed.
+  EXPECT_EQ(0, target->bounds().y());
+  EXPECT_EQ(100, target->bounds().height());
+}
+
+// Verifies we don't let windows go bigger than the monitor width.
+TEST_F(ToplevelWindowEventFilterTest, DontGotWiderThanScreen) {
+  scoped_ptr<aura::Window> target(CreateWindow(HTRIGHT));
+  gfx::Rect work_area = gfx::Screen::GetMonitorAreaNearestWindow(target.get());
+  DragFromCenterBy(target.get(), work_area.width() * 2, 0);
+  // The y location and height should not have changed.
+  EXPECT_EQ(work_area.width(), target->bounds().width());
+}
+
 }  // namespace test
 }  // namespace aura