Add ctrl+drag feature for allowing resizing window with exact positioning.

ash/wm/default_window_resizer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/default_window_resizer.h"
 
 #include "ash/shell.h"
 #include "ash/wm/root_window_event_filter.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
@@ skipping 15 matching lines @@
 // static
 DefaultWindowResizer*
 DefaultWindowResizer::Create(aura::Window* window,
                              const gfx::Point& location,
                              int window_component,
                              int grid_size) {
   Details details(window, location, window_component, grid_size);
   return details.is_resizable ? new DefaultWindowResizer(details) : NULL;
 }
 
-void DefaultWindowResizer::Drag(const gfx::Point& location) {
-  gfx::Rect bounds(CalculateBoundsForDrag(details_, location));
+void DefaultWindowResizer::Drag(const gfx::Point& location, int event_flags) {
+  bool disable_snap_to_grid = event_flags & ui::EF_CONTROL_DOWN ? true : false;
+  gfx::Rect bounds(
+      CalculateBoundsForDrag(details_, location, disable_snap_to_grid));
   if (bounds != details_.window->bounds()) {
     did_move_or_resize_ = true;
     details_.window->SetBounds(bounds);
   }
 }
 
 void DefaultWindowResizer::CompleteDrag() {
   if (details_.grid_size <= 1 || !did_move_or_resize_)
     return;
   gfx::Rect new_bounds(
       AdjustBoundsToGrid(details_.window->bounds(), details_.grid_size));

[sky, 2012/04/12 18:08:14]

Isn't this going to snap it to the grid?

Now that we need to dynamically change the grid size, I think it's to error
prone to bake the grid size into Details. Instead pass it around. That way we're
sure someone doesn't accidentally use the wrong thing.

[jennyz, 2012/04/12 18:25:16]

CompleteDrag is only called when user release the mouse press for moving a
window, not for resizing a window. So I don't think we need to change the snap
to grid behavior for moving windows. But I agree that it is kind of error prone
to bake the grid size in Details now, I will take it out of the Details and pass
it around as a parameter.
On 2012/04/12 18:08:14, sky wrote:

   if (new_bounds == details_.window->bounds())
     return;
 
   if (new_bounds.size() != details_.window->bounds().size()) {
     // Don't attempt to animate a size change.
     details_.window->SetBounds(new_bounds);
     return;
   }
 
   ui::ScopedLayerAnimationSettings scoped_setter(
@@ skipping 14 matching lines @@
     : details_(details),
       did_move_or_resize_(false),
       root_filter_(NULL) {
   DCHECK(details_.is_resizable);
   root_filter_ = Shell::GetInstance()->root_filter();
   if (root_filter_)
     root_filter_->LockCursor();
 }
 
 }  // namespace aura