1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "ash/wm/drag_window_resizer.h"
6
7#include "ash/display/mouse_cursor_event_filter.h"
8#include "ash/screen_util.h"
9#include "ash/shell.h"
10#include "ash/wm/coordinate_conversion.h"
11#include "ash/wm/drag_window_controller.h"
12#include "ash/wm/window_state.h"
13#include "ash/wm/window_util.h"
14#include "base/memory/weak_ptr.h"
15#include "ui/aura/client/aura_constants.h"
16#include "ui/aura/env.h"
17#include "ui/aura/window.h"
18#include "ui/aura/window_delegate.h"
19#include "ui/aura/window_event_dispatcher.h"
20#include "ui/base/hit_test.h"
21#include "ui/base/ui_base_types.h"
22#include "ui/gfx/screen.h"
23#include "ui/wm/core/coordinate_conversion.h"
24#include "ui/wm/core/window_util.h"
25
26namespace ash {
27namespace {
28
29// The maximum opacity of the drag phantom window.
30const float kMaxOpacity = 0.8f;
31
32// Returns true if Ash has more than one root window.
33bool HasSecondaryRootWindow() {
34  return Shell::GetAllRootWindows().size() > 1;
35}
36
37// When there are two root windows, returns one of the root windows which is not
38// |root_window|. Returns NULL if only one root window exists.
39aura::Window* GetAnotherRootWindow(aura::Window* root_window) {
40  aura::Window::Windows root_windows = Shell::GetAllRootWindows();
41  if (root_windows.size() < 2)
42    return NULL;
43  DCHECK_EQ(2U, root_windows.size());
44  if (root_windows[0] == root_window)
45    return root_windows[1];
46  return root_windows[0];
47}
48
49}  // namespace
50
51// static
52DragWindowResizer* DragWindowResizer::instance_ = NULL;
53
54DragWindowResizer::~DragWindowResizer() {
55  if (window_state_)
56    window_state_->DeleteDragDetails();
57  Shell* shell = Shell::GetInstance();
58  shell->mouse_cursor_filter()->set_mouse_warp_mode(
59      MouseCursorEventFilter::WARP_ALWAYS);
60  shell->mouse_cursor_filter()->HideSharedEdgeIndicator();
61  if (instance_ == this)
62    instance_ = NULL;
63}
64
65// static
66DragWindowResizer* DragWindowResizer::Create(
67    WindowResizer* next_window_resizer,
68    wm::WindowState* window_state) {
69  return new DragWindowResizer(next_window_resizer, window_state);
70}
71
72void DragWindowResizer::Drag(const gfx::Point& location, int event_flags) {
73  base::WeakPtr<DragWindowResizer> resizer(weak_ptr_factory_.GetWeakPtr());
74  next_window_resizer_->Drag(location, event_flags);
75
76  if (!resizer)
77    return;
78
79  last_mouse_location_ = location;
80  // Show a phantom window for dragging in another root window.
81  if (HasSecondaryRootWindow()) {
82    gfx::Point location_in_screen = location;
83    ::wm::ConvertPointToScreen(GetTarget()->parent(), &location_in_screen);
84    const bool in_original_root =
85        wm::GetRootWindowAt(location_in_screen) == GetTarget()->GetRootWindow();
86    UpdateDragWindow(GetTarget()->bounds(), in_original_root);
87  } else {
88    drag_window_controller_.reset();
89  }
90}
91
92void DragWindowResizer::CompleteDrag() {
93  next_window_resizer_->CompleteDrag();
94
95  GetTarget()->layer()->SetOpacity(details().initial_opacity);
96  drag_window_controller_.reset();
97
98  // Check if the destination is another display.
99  gfx::Point last_mouse_location_in_screen = last_mouse_location_;
100  ::wm::ConvertPointToScreen(GetTarget()->parent(),
101                             &last_mouse_location_in_screen);
102  gfx::Screen* screen = Shell::GetScreen();
103  const gfx::Display dst_display =
104      screen->GetDisplayNearestPoint(last_mouse_location_in_screen);
105
106  if (dst_display.id() !=
107      screen->GetDisplayNearestWindow(GetTarget()->GetRootWindow()).id()) {
108    // Adjust the size and position so that it doesn't exceed the size of
109    // work area.
110    const gfx::Size& size = dst_display.work_area().size();
111    gfx::Rect bounds = GetTarget()->bounds();
112    if (bounds.width() > size.width()) {
113      int diff = bounds.width() - size.width();
114      bounds.set_x(bounds.x() + diff / 2);
115      bounds.set_width(size.width());
116    }
117    if (bounds.height() > size.height())
118      bounds.set_height(size.height());
119
120    gfx::Rect dst_bounds =
121        ScreenUtil::ConvertRectToScreen(GetTarget()->parent(), bounds);
122
123    // Adjust the position so that the cursor is on the window.
124    if (!dst_bounds.Contains(last_mouse_location_in_screen)) {
125      if (last_mouse_location_in_screen.x() < dst_bounds.x())
126        dst_bounds.set_x(last_mouse_location_in_screen.x());
127      else if (last_mouse_location_in_screen.x() > dst_bounds.right())
128        dst_bounds.set_x(
129            last_mouse_location_in_screen.x() - dst_bounds.width());
130    }
131    ash::wm::AdjustBoundsToEnsureMinimumWindowVisibility(
132        dst_display.bounds(), &dst_bounds);
133
134    GetTarget()->SetBoundsInScreen(dst_bounds, dst_display);
135  }
136}
137
138void DragWindowResizer::RevertDrag() {
139  next_window_resizer_->RevertDrag();
140
141  drag_window_controller_.reset();
142  GetTarget()->layer()->SetOpacity(details().initial_opacity);
143}
144
145DragWindowResizer::DragWindowResizer(WindowResizer* next_window_resizer,
146                                     wm::WindowState* window_state)
147    : WindowResizer(window_state),
148      next_window_resizer_(next_window_resizer),
149      weak_ptr_factory_(this) {
150  // The pointer should be confined in one display during resizing a window
151  // because the window cannot span two displays at the same time anyway. The
152  // exception is window/tab dragging operation. During that operation,
153  // |mouse_warp_mode_| should be set to WARP_DRAG so that the user could move a
154  // window/tab to another display.
155  MouseCursorEventFilter* mouse_cursor_filter =
156      Shell::GetInstance()->mouse_cursor_filter();
157  mouse_cursor_filter->set_mouse_warp_mode(
158      ShouldAllowMouseWarp() ?
159      MouseCursorEventFilter::WARP_DRAG : MouseCursorEventFilter::WARP_NONE);
160  if (ShouldAllowMouseWarp())
161    mouse_cursor_filter->ShowSharedEdgeIndicator(GetTarget()->GetRootWindow());
162  instance_ = this;
163}
164
165void DragWindowResizer::UpdateDragWindow(const gfx::Rect& bounds,
166                                         bool in_original_root) {
167  if (details().window_component != HTCAPTION || !ShouldAllowMouseWarp())
168    return;
169
170  // It's available. Show a phantom window on the display if needed.
171  aura::Window* another_root =
172      GetAnotherRootWindow(GetTarget()->GetRootWindow());
173  const gfx::Rect root_bounds_in_screen(another_root->GetBoundsInScreen());
174  const gfx::Rect bounds_in_screen =
175      ScreenUtil::ConvertRectToScreen(GetTarget()->parent(), bounds);
176  gfx::Rect bounds_in_another_root =
177      gfx::IntersectRects(root_bounds_in_screen, bounds_in_screen);
178  const float fraction_in_another_window =
179      (bounds_in_another_root.width() * bounds_in_another_root.height()) /
180      static_cast<float>(bounds.width() * bounds.height());
181
182  if (fraction_in_another_window > 0) {
183    if (!drag_window_controller_) {
184      drag_window_controller_.reset(
185          new DragWindowController(GetTarget()));
186      // Always show the drag phantom on the |another_root| window.
187      drag_window_controller_->SetDestinationDisplay(
188          Shell::GetScreen()->GetDisplayNearestWindow(another_root));
189      drag_window_controller_->Show();
190    } else {
191      // No animation.
192      drag_window_controller_->SetBounds(bounds_in_screen);
193    }
194    const float phantom_opacity =
195      !in_original_root ? 1 : (kMaxOpacity * fraction_in_another_window);
196    const float window_opacity =
197        in_original_root ? 1 : (kMaxOpacity * (1 - fraction_in_another_window));
198    drag_window_controller_->SetOpacity(phantom_opacity);
199    GetTarget()->layer()->SetOpacity(window_opacity);
200  } else {
201    drag_window_controller_.reset();
202    GetTarget()->layer()->SetOpacity(1.0f);
203  }
204}
205
206bool DragWindowResizer::ShouldAllowMouseWarp() {
207  return (details().window_component == HTCAPTION) &&
208      !::wm::GetTransientParent(GetTarget()) &&
209      (GetTarget()->type() == ui::wm::WINDOW_TYPE_NORMAL ||
210       GetTarget()->type() == ui::wm::WINDOW_TYPE_PANEL);
211}
212
213}  // namespace ash
214