Make touch-resizing windows to screen edge possible

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 <cmath>
+
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/wm/property_util.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/ui_base_types.h"
@@ skipping 83 matching lines @@
 const int WindowResizer::kBoundsChangeDirection_Horizontal = 1;
 // static
 const int WindowResizer::kBoundsChangeDirection_Vertical = 2;
 
 WindowResizer::Details::Details()
     : window(NULL),
       window_component(HTNOWHERE),
       bounds_change(0),
       position_change_direction(0),
       size_change_direction(0),
-      is_resizable(false) {
+      is_resizable(false),
+      is_touch(false) {
 }
 
 WindowResizer::Details::Details(aura::Window* window,
                                 const gfx::Point& location,
                                 int window_component)
     : window(window),
       initial_bounds_in_parent(window->bounds()),
       restore_bounds(gfx::Rect()),
       initial_location_in_parent(location),
       initial_opacity(window->layer()->opacity()),
       window_component(window_component),
       bounds_change(GetBoundsChangeForWindowComponent(window_component)),
       position_change_direction(
           GetPositionChangeDirectionForWindowComponent(window_component)),
       size_change_direction(
           GetSizeChangeDirectionForWindowComponent(window_component)),
-      is_resizable(bounds_change != kBoundsChangeDirection_None) {
+      is_resizable(bounds_change != kBoundsChangeDirection_None),
+      is_touch(window->GetRootWindow()->current_event()->IsGestureEvent()) {
   if (wm::IsWindowNormal(window) &&
       GetRestoreBoundsInScreen(window) &&
       window_component == HTCAPTION)
     restore_bounds = *GetRestoreBoundsInScreen(window);
 }
 
 WindowResizer::Details::~Details() {
 }
 
 WindowResizer::WindowResizer() {
@@ skipping 36 matching lines @@
   if (!details.is_resizable)
     return details.initial_bounds_in_parent;
 
   gfx::Point location = passed_location;
   gfx::Rect work_area =
       ScreenAsh::GetDisplayWorkAreaBoundsInParent(details.window);
 
   int delta_x = location.x() - details.initial_location_in_parent.x();
   int delta_y = location.y() - details.initial_location_in_parent.y();
 
+  // Adjust values of |delta_x| and |delta_y| for touch resizes.
+  AdjustDeltaForTouch(details, &delta_x, &delta_y);

[sadrul, 2013/05/29 04:01:51]

My suggestion was to make AdjustDeltaForTouch more like the other static methods
here (e.g. AdjustBoundsToGrid). So you could do:

 gfx::Vector2d delta = location - detials.initial_location;
 delta = AdjustDeltaForTouch(details, delta);
 ..

But looking at how GetSizeForDrag takes the deltas as int*s, that wouldn't be an
improvement.

+
   // 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::Point origin = GetOriginForDrag(details, delta_x, delta_y);
   gfx::Rect new_bounds(origin, size);
 
   // Sizing has to keep the result on the screen. Note that this correction
   // has to come first since it might have an impact on the origin as well as
   // on the size.
@@ skipping 64 matching lines @@
                             new_bounds_in_screen.x())));
       new_bounds =
           ScreenAsh::ConvertRectFromScreen(parent, new_bounds_in_screen);
     }
   }
 
   return new_bounds;
 }
 
 // static
+void WindowResizer::AdjustDeltaForTouch(const Details& details,
+                                        int* delta_x,
+                                        int* delta_y) {
+  if (!details.is_touch || !(details.bounds_change & kBoundsChange_Resizes))
+    return;
+
+  if (details.size_change_direction & kBoundsChangeDirection_Horizontal) {
+    if (IsRightEdge(details.window_component) && *delta_x > 0) {
+      int display_width = Shell::GetScreen()->GetDisplayNearestWindow(
+          details.window).bounds().width();
+      int right = details.initial_bounds_in_parent.right();
+      float window_distance = display_width - right;
+      float touch_distance = display_width -
+          details.initial_location_in_parent.x();
+      *delta_x = static_cast<int>(
+          ceil(*delta_x * window_distance / touch_distance));
+    } else if (!IsRightEdge(details.window_component) && *delta_x < 0) {
+      float window_distance = details.initial_bounds_in_parent.x();
+      float touch_distance = details.initial_location_in_parent.x();
+      *delta_x = static_cast<int>(
+          ceil(*delta_x * window_distance / touch_distance));
+    }
+  }
+  if (details.size_change_direction & kBoundsChangeDirection_Vertical) {
+    if (IsBottomEdge(details.window_component) && *delta_y > 0) {
+      int display_height = Shell::GetScreen()->GetDisplayNearestWindow(
+          details.window).bounds().height();
+      int bottom = details.initial_bounds_in_parent.bottom();
+      float window_distance = display_height - bottom;
+      float touch_distance = display_height -
+          details.initial_location_in_parent.y();
+      *delta_y = static_cast<int>(
+          ceil(*delta_y * window_distance / touch_distance));
+    } else if (!IsBottomEdge(details.window_component) && *delta_y < 0) {
+      float window_distance = details.initial_bounds_in_parent.y();
+      float touch_distance = details.initial_location_in_parent.y();
+      *delta_y = static_cast<int>(
+          ceil(*delta_y * window_distance / touch_distance));
+    }
+  }
+}
+
+// static
 bool WindowResizer::IsBottomEdge(int window_component) {
   return window_component == HTBOTTOMLEFT ||
       window_component == HTBOTTOM ||
       window_component == HTBOTTOMRIGHT ||
       window_component == HTGROWBOX;
 }
 
 // static
 gfx::Point WindowResizer::GetOriginForDrag(const Details& details,
                                            int delta_x,
@@ skipping 85 matching lines @@
     if (height > max_height) {
       height = max_height;
       *delta_y = -y_multiplier * (details.initial_bounds_in_parent.height() -
                                   max_height);
     }
   }
   return height;
 }
 
 }  // namespace aura