Dont allow the user to 'resize a window out of the workarea'

ash/wm/window_resizer.cc

Index: ash/wm/window_resizer.cc
diff --git a/ash/wm/window_resizer.cc b/ash/wm/window_resizer.cc
index c759c9162ab84bda43fb1a4c3f6afacfd7e38ac7..587817c7bfa0a4cecc843b6d7e103f305d756755 100644
--- a/ash/wm/window_resizer.cc
+++ b/ash/wm/window_resizer.cc
@@ -100,6 +100,9 @@ const int WindowResizer::kBoundsChangeDirection_Horizontal = 1;
 // static
 const int WindowResizer::kBoundsChangeDirection_Vertical = 2;
 
+// static
+const int WindowResizer::kMinimumOnScreenSize = 0;

[sky, 2012/10/11 00:48:29]

0?
This should be the same value as in
WorkspaceLayoutManager2::AdjustWindowSizeForScreenChange. Promote a constant
that both places share.

[Mr4D (OOO till 08-26), 2012/10/11 19:41:13]

Yes - 0 is what moving does - which was requested. It essentially means that the
e.g. left most pixel of a window can land on -1, allowing the user to grab the
shadow / resizer. (Yes, this is a bit odd which is the reason why I thought that
enforcing a bit of visibility might be good, but Alex and you were requesting it
to be the same as move.)

For the 10 pixels from WindowManager: Never seen that constant before, but once
we decide of keeping the window always partially visible we can do that. 

+
 WindowResizer::Details::Details()
     : window(NULL),
       window_component(HTNOWHERE),
@@ -169,10 +172,36 @@ int WindowResizer::GetBoundsChangeForWindowComponent(int component) {
 // static
 gfx::Rect WindowResizer::CalculateBoundsForDrag(
     const Details& details,
-    const gfx::Point& location) {
+    const gfx::Point& passed_location) {
   if (!details.is_resizable)
     return details.initial_bounds;
 
+  gfx::Point location = passed_location;
+  gfx::Rect work_area =
+      ScreenAsh::GetDisplayWorkAreaBoundsInParent(details.window);
+
+  // Don't allow the user to "resize a window" out of the screen.
+  if (details.bounds_change & kBoundsChange_Resizes) {
+    if (details.size_change_direction & kBoundsChangeDirection_Horizontal) {
+      if (IsRightEdge(details.window_component)) {
+        location.set_x(
+            std::max(location.x(),
+                     work_area.x() + WindowResizer::kMinimumOnScreenSize));
+      } else {
+        location.set_x(
+            std::min(location.x(),
+                     work_area.right() - WindowResizer::kMinimumOnScreenSize));
+      }
+    }
+    if (details.size_change_direction & kBoundsChangeDirection_Vertical) {
+      if (!IsBottomEdge(details.window_component)) {
+        location.set_y(
+            std::min(location.y(), work_area.bottom() -
+                                   WindowResizer::kMinimumOnScreenSize));
+      }
+    }
+  }
+
   int delta_x = location.x() - details.initial_location_in_parent.x();
   int delta_y = location.y() - details.initial_location_in_parent.y();
 
@@ -195,12 +224,10 @@ gfx::Rect WindowResizer::CalculateBoundsForDrag(
 
   gfx::Rect new_bounds(origin, size);
   // Update bottom edge to stay in the work area when we are resizing
-  // by dragging the bottome edge or corners.
+  // by dragging the bottom edge or corners.
   if (details.window_component == HTBOTTOM ||
       details.window_component == HTBOTTOMRIGHT ||
       details.window_component == HTBOTTOMLEFT) {
-    gfx::Rect work_area =
-        ScreenAsh::GetDisplayWorkAreaBoundsInParent(details.window);
     if (new_bounds.bottom() > work_area.bottom())
       new_bounds.Inset(0, 0, 0,
                        new_bounds.bottom() - work_area.bottom());
@@ -211,6 +238,7 @@ gfx::Rect WindowResizer::CalculateBoundsForDrag(
     new_bounds.set_y(0);
     new_bounds.set_height(new_bounds.height() + delta);
   }
+
   return new_bounds;
 }