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