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

ash/wm/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/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 168 matching lines @@
 // static
 int WindowResizer::AlignToGridRoundDown(int location, int grid_size) {
   if (grid_size <= 1 || location % grid_size == 0)
     return location;
   return location / grid_size * grid_size;
 }
 
 // static
 gfx::Rect WindowResizer::CalculateBoundsForDrag(
     const Details& details,
-    const gfx::Point& location) {
+    const gfx::Point& location,
+    bool disable_snap_to_grid) {
   if (!details.is_resizable)
     return details.initial_bounds;
 
   int delta_x = location.x() - details.initial_location_in_parent.x();
   int delta_y = location.y() - details.initial_location_in_parent.y();
 
   // The minimize size constraint may limit how much we change the window
   // position.  For example, dragging the left edge to the right should stop
   // repositioning the window when the minimize size is reached.
-  gfx::Size size = GetSizeForDrag(details, &delta_x, &delta_y);
+  gfx::Size size = GetSizeForDrag(details, &delta_x, &delta_y,
+                                  disable_snap_to_grid);
   gfx::Point origin = GetOriginForDrag(details, delta_x, delta_y);
 
   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.
   if (details.window_component == HTBOTTOM ||
       details.window_component == HTBOTTOMRIGHT ||
       details.window_component == HTBOTTOMLEFT) {
     gfx::Rect work_area = gfx::Screen::GetMonitorWorkAreaNearestWindow(
         details.window);
@@ skipping 40 matching lines @@
       origin.Offset(delta_x, 0);
     if (pos_change_direction & kBoundsChangeDirection_Vertical)
       origin.Offset(0, delta_y);
   }
   return origin;
 }
 
 // static
 gfx::Size WindowResizer::GetSizeForDrag(const Details& details,
                                         int* delta_x,
-                                        int* delta_y) {
+                                        int* delta_y,
+                                        bool disable_snap_to_grid) {
   gfx::Size size = details.initial_bounds.size();
   if (details.bounds_change & kBoundsChange_Resizes) {
     gfx::Size min_size = details.window->delegate()->GetMinimumSize();
-    min_size.set_width(AlignToGridRoundUp(min_size.width(), details.grid_size));
-    min_size.set_height(AlignToGridRoundUp(min_size.height(),
-                                           details.grid_size));
-    size.SetSize(GetWidthForDrag(details, min_size.width(), delta_x),
-                 GetHeightForDrag(details, min_size.height(), delta_y));
+    min_size.set_width(
+        AlignToGridRoundUp(min_size.width(),
+                           disable_snap_to_grid ? 0 : details.grid_size));
+    min_size.set_height(
+        AlignToGridRoundUp(min_size.height(),
+                           disable_snap_to_grid? 0 : details.grid_size));
+    size.SetSize(GetWidthForDrag(details, min_size.width(), delta_x,
+                                 disable_snap_to_grid),
+                 GetHeightForDrag(details, min_size.height(), delta_y,
+                                  disable_snap_to_grid));
   }
   return size;
 }
 
 // static
 int WindowResizer::GetWidthForDrag(const Details& details,
                                    int min_width,
-                                   int* delta_x) {
+                                   int* delta_x,
+                                   bool disable_snap_to_grid) {
   int width = details.initial_bounds.width();
   if (details.size_change_direction & kBoundsChangeDirection_Horizontal) {
     // Along the right edge, positive delta_x increases the window size.
     int x_multiplier = IsRightEdge(details.window_component) ? 1 : -1;
     width += x_multiplier * (*delta_x);
-    int adjusted_width = AlignToGrid(width, details.grid_size);
+    int adjusted_width =
+        AlignToGrid(width, disable_snap_to_grid ? 0 : details.grid_size);
     if (adjusted_width != width) {
       *delta_x += -x_multiplier * (width - adjusted_width);
       width = adjusted_width;
     }
 
     // Ensure we don't shrink past the minimum width and clamp delta_x
     // for the window origin computation.
     if (width < min_width) {
       width = min_width;
       *delta_x = -x_multiplier * (details.initial_bounds.width() - min_width);
     }
 
     // And don't let the window go bigger than the monitor.
     int max_width =
         gfx::Screen::GetMonitorAreaNearestWindow(details.window).width();
     if (width > max_width) {
       width = max_width;
       *delta_x = -x_multiplier * (details.initial_bounds.width() - max_width);
     }
   }
   return width;
 }
 
 // static
 int WindowResizer::GetHeightForDrag(const Details& details,
                                     int min_height,
-                                    int* delta_y) {
+                                    int* delta_y,
+                                    bool disable_snap_to_grid) {
   int height = details.initial_bounds.height();
   if (details.size_change_direction & kBoundsChangeDirection_Vertical) {
     // Along the bottom edge, positive delta_y increases the window size.
     int y_multiplier = IsBottomEdge(details.window_component) ? 1 : -1;
     height += y_multiplier * (*delta_y);
-    int adjusted_height = AlignToGrid(height, details.grid_size);
+    int adjusted_height =
+        AlignToGrid(height, disable_snap_to_grid ? 0 : details.grid_size);
     if (height != adjusted_height) {
       *delta_y += -y_multiplier * (height - adjusted_height);
       height = adjusted_height;
     }
 
     // Ensure we don't shrink past the minimum height and clamp delta_y
     // for the window origin computation.
     if (height < min_height) {
       height = min_height;
       *delta_y = -y_multiplier * (details.initial_bounds.height() - min_height);
     }
 
     // And don't let the window go bigger than the monitor.
     int max_height =
         gfx::Screen::GetMonitorAreaNearestWindow(details.window).height();
     if (height > max_height) {
       height = max_height;
       *delta_y = -y_multiplier * (details.initial_bounds.height() - max_height);
     }
   }
   return height;
 }
 
 }  // namespace aura