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      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 
     26 namespace ash {
     27 namespace {
     28 
     29 // The maximum opacity of the drag phantom window.
     30 const float kMaxOpacity = 0.8f;
     31 
     32 // Returns true if Ash has more than one root window.
     33 bool 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.
     39 aura::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
     52 DragWindowResizer* DragWindowResizer::instance_ = NULL;
     53 
     54 DragWindowResizer::~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
     66 DragWindowResizer* DragWindowResizer::Create(
     67     WindowResizer* next_window_resizer,
     68     wm::WindowState* window_state) {
     69   return new DragWindowResizer(next_window_resizer, window_state);
     70 }
     71 
     72 void 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 
     92 void 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 
    138 void DragWindowResizer::RevertDrag() {
    139   next_window_resizer_->RevertDrag();
    140 
    141   drag_window_controller_.reset();
    142   GetTarget()->layer()->SetOpacity(details().initial_opacity);
    143 }
    144 
    145 DragWindowResizer::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 
    165 void 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 
    206 bool 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