ash/wm/window_positioner.cc

   1 // Copyright 2013 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/window_positioner.h"
   6
   7 #include "ash/ash_switches.h"
   8 #include "ash/screen_util.h"
   9 #include "ash/shell.h"
  10 #include "ash/shell_window_ids.h"
  11 #include "ash/wm/mru_window_tracker.h"
  12 #include "ash/wm/window_resizer.h"
  13 #include "ash/wm/window_state.h"
  14 #include "ash/wm/window_util.h"
  15 #include "base/command_line.h"
  16 #include "ui/aura/window.h"
  17 #include "ui/aura/window_delegate.h"
  18 #include "ui/aura/window_event_dispatcher.h"
  19 #include "ui/compositor/layer.h"
  20 #include "ui/compositor/scoped_layer_animation_settings.h"
  21 #include "ui/gfx/screen.h"
  22 #include "ui/views/corewm/window_animations.h"
  23
  24 namespace ash {
  25
  26 const int WindowPositioner::kMinimumWindowOffset = 32;
  27
  28 // The number of pixels which are kept free top, left and right when a window
  29 // gets positioned to its default location.
  30 // static
  31 const int WindowPositioner::kDesktopBorderSize = 16;
  32
  33 // Maximum width of a window even if there is more room on the desktop.
  34 // static
  35 const int WindowPositioner::kMaximumWindowWidth = 1100;
  36
  37 namespace {
  38
  39 // When a window gets opened in default mode and the screen is less than or
  40 // equal to this width, the window will get opened in maximized mode. This value
  41 // can be reduced to a "tame" number if the feature is disabled.
  42 const int kForceMaximizeWidthLimit = 1366;
  43
  44 // The time in milliseconds which should be used to visually move a window
  45 // through an automatic "intelligent" window management option.
  46 const int kWindowAutoMoveDurationMS = 125;
  47
  48 // If set to true all window repositioning actions will be ignored. Set through
  49 // WindowPositioner::SetIgnoreActivations().
  50 static bool disable_auto_positioning = false;
  51
  52 // If set to true, by default the first window in ASH will be maxmized.
  53 static bool maximize_first_window = false;
  54
  55 // Check if any management should be performed (with a given |window|).
  56 bool UseAutoWindowManager(const aura::Window* window) {
  57   if (disable_auto_positioning)
  58     return false;
  59   const wm::WindowState* window_state = wm::GetWindowState(window);
  60   return !window_state->is_dragged() && window_state->window_position_managed();
  61 }
  62
  63 // Check if a given |window| can be managed. This includes that it's state is
  64 // not minimized/maximized/the user has changed it's size by hand already.
  65 // It furthermore checks for the WindowIsManaged status.
  66 bool WindowPositionCanBeManaged(const aura::Window* window) {
  67   if (disable_auto_positioning)
  68     return false;
  69   const wm::WindowState* window_state = wm::GetWindowState(window);
  70   return window_state->window_position_managed() &&
  71       !window_state->IsMinimized() &&
  72       !window_state->IsMaximized() &&
  73       !window_state->bounds_changed_by_user();
  74 }
  75
  76 // Get the work area for a given |window| in parent coordinates.
  77 gfx::Rect GetWorkAreaForWindowInParent(aura::Window* window) {
  78 #if defined(OS_WIN)
  79   // On Win 8, the host window can't be resized, so
  80   // use window's bounds instead.
  81   // TODO(oshima): Emulate host window resize on win8.
  82   gfx::Rect work_area = gfx::Rect(window->parent()->bounds().size());
  83   work_area.Inset(Shell::GetScreen()->GetDisplayMatching(
  84       window->parent()->GetBoundsInScreen()).GetWorkAreaInsets());
  85   return work_area;
  86 #else
  87   return ScreenUtil::GetDisplayWorkAreaBoundsInParent(window);
  88 #endif
  89 }
  90
  91 // Move the given |bounds| on the available |work_area| in the direction
  92 // indicated by |move_right|. If |move_right| is true, the rectangle gets moved
  93 // to the right edge, otherwise to the left one.
  94 bool MoveRectToOneSide(const gfx::Rect& work_area,
  95                        bool move_right,
  96                        gfx::Rect* bounds) {
  97   if (move_right) {
  98     if (work_area.right() > bounds->right()) {
  99       bounds->set_x(work_area.right() - bounds->width());
 100       return true;
 101     }
 102   } else {
 103     if (work_area.x() < bounds->x()) {
 104       bounds->set_x(work_area.x());
 105       return true;
 106     }
 107   }
 108   return false;
 109 }
 110
 111 // Move a |window| to a new |bound|. Animate if desired by user.
 112 // Note: The function will do nothing if the bounds did not change.
 113 void SetBoundsAnimated(aura::Window* window, const gfx::Rect& bounds) {
 114   if (bounds == window->GetTargetBounds())
 115     return;
 116
 117   if (views::corewm::WindowAnimationsDisabled(window)) {
 118     window->SetBounds(bounds);
 119     return;
 120   }
 121
 122   ui::ScopedLayerAnimationSettings settings(window->layer()->GetAnimator());
 123   settings.SetTransitionDuration(
 124       base::TimeDelta::FromMilliseconds(kWindowAutoMoveDurationMS));
 125   window->SetBounds(bounds);
 126 }
 127
 128 // Move |window| into the center of the screen - or restore it to the previous
 129 // position.
 130 void AutoPlaceSingleWindow(aura::Window* window, bool animated) {
 131   gfx::Rect work_area = GetWorkAreaForWindowInParent(window);
 132   gfx::Rect bounds = window->bounds();
 133   const gfx::Rect* user_defined_area =
 134       wm::GetWindowState(window)->pre_auto_manage_window_bounds();
 135   if (user_defined_area) {
 136     bounds = *user_defined_area;
 137     ash::wm::AdjustBoundsToEnsureMinimumWindowVisibility(work_area, &bounds);
 138   } else {
 139     // Center the window (only in x).
 140     bounds.set_x(work_area.x() + (work_area.width() - bounds.width()) / 2);
 141   }
 142
 143   if (animated)
 144     SetBoundsAnimated(window, bounds);
 145   else
 146     window->SetBounds(bounds);
 147 }
 148
 149 // Get the first open (non minimized) window which is on the screen defined.
 150 aura::Window* GetReferenceWindow(const aura::Window* root_window,
 151                                  const aura::Window* exclude,
 152                                  bool *single_window) {
 153   if (single_window)
 154     *single_window = true;
 155   // Get the active window.
 156   aura::Window* active = ash::wm::GetActiveWindow();
 157   if (active && active->GetRootWindow() != root_window)
 158     active = NULL;
 159
 160   // Get a list of all windows.
 161   const std::vector<aura::Window*> windows =
 162       ash::MruWindowTracker::BuildWindowList(false);
 163
 164   if (windows.empty())
 165     return NULL;
 166
 167   aura::Window::Windows::const_iterator iter = windows.begin();
 168   // Find the index of the current active window.
 169   if (active)
 170     iter = std::find(windows.begin(), windows.end(), active);
 171
 172   int index = (iter == windows.end()) ? 0 : (iter - windows.begin());
 173
 174   // Scan the cycle list backwards to see which is the second topmost window
 175   // (and so on). Note that we might cycle a few indices twice if there is no
 176   // suitable window. However - since the list is fairly small this should be
 177   // very fast anyways.
 178   aura::Window* found = NULL;
 179   for (int i = index + windows.size(); i >= 0; i--) {
 180     aura::Window* window = windows[i % windows.size()];
 181     if (window != exclude && window->type() == ui::wm::WINDOW_TYPE_NORMAL &&
 182         window->GetRootWindow() == root_window && window->TargetVisibility() &&
 183         wm::GetWindowState(window)->window_position_managed()) {
 184       if (found && found != window) {
 185         // no need to check !signle_window because the function must have
 186         // been already returned in the "if (!single_window)" below.
 187         *single_window = false;
 188         return found;
 189       }
 190       found = window;
 191       // If there is no need to check single window, return now.
 192       if (!single_window)
 193         return found;
 194     }
 195   }
 196   return found;
 197 }
 198
 199 }  // namespace
 200
 201 // static
 202 int WindowPositioner::GetForceMaximizedWidthLimit() {
 203   return kForceMaximizeWidthLimit;
 204 }
 205
 206 // static
 207 void WindowPositioner::GetBoundsAndShowStateForNewWindow(
 208     const gfx::Screen* screen,
 209     const aura::Window* new_window,
 210     bool is_saved_bounds,
 211     ui::WindowShowState show_state_in,
 212     gfx::Rect* bounds_in_out,
 213     ui::WindowShowState* show_state_out) {
 214
 215   // Always open new window in the target display.
 216   aura::Window* target = Shell::GetTargetRootWindow();
 217
 218   aura::Window* top_window = GetReferenceWindow(target, NULL, NULL);
 219   // Our window should not have any impact if we are already on top.
 220   if (top_window == new_window)
 221     top_window = NULL;
 222
 223   // If there is no valid other window we take and adjust the passed coordinates
 224   // and show state.
 225   if (!top_window) {
 226     gfx::Rect work_area = screen->GetDisplayNearestWindow(target).work_area();
 227
 228     bounds_in_out->AdjustToFit(work_area);
 229     // Use adjusted saved bounds, if there is one.
 230     if (is_saved_bounds)
 231       return;
 232     // When using "small screens" we want to always open in full screen mode.
 233     if (show_state_in == ui::SHOW_STATE_DEFAULT && (maximize_first_window ||
 234          (work_area.width() <= GetForceMaximizedWidthLimit() &&
 235          (!new_window || !wm::GetWindowState(new_window)->IsFullscreen())))) {
 236       *show_state_out = ui::SHOW_STATE_MAXIMIZED;
 237     }
 238     return;
 239   }
 240   bool maximized = wm::GetWindowState(top_window)->IsMaximized();
 241   // We ignore the saved show state, but look instead for the top level
 242   // window's show state.
 243   if (show_state_in == ui::SHOW_STATE_DEFAULT) {
 244     *show_state_out = maximized ? ui::SHOW_STATE_MAXIMIZED :
 245         ui::SHOW_STATE_DEFAULT;
 246   }
 247
 248   // Use the size of the other window. The window's bound will be rearranged
 249   // in ash::WorkspaceLayoutManager using this location.
 250   *bounds_in_out = top_window->GetBoundsInScreen();
 251 }
 252
 253 // static
 254 void WindowPositioner::RearrangeVisibleWindowOnHideOrRemove(
 255     const aura::Window* removed_window) {
 256   if (!UseAutoWindowManager(removed_window))
 257     return;
 258   // Find a single open browser window.
 259   bool single_window;
 260   aura::Window* other_shown_window = GetReferenceWindow(
 261       removed_window->GetRootWindow(), removed_window, &single_window);
 262   if (!other_shown_window || !single_window ||
 263       !WindowPositionCanBeManaged(other_shown_window))
 264     return;
 265   AutoPlaceSingleWindow(other_shown_window, true);
 266 }
 267
 268 // static
 269 bool WindowPositioner::DisableAutoPositioning(bool ignore) {
 270   bool old_state = disable_auto_positioning;
 271   disable_auto_positioning = ignore;
 272   return old_state;
 273 }
 274
 275 // static
 276 void WindowPositioner::RearrangeVisibleWindowOnShow(
 277     aura::Window* added_window) {
 278   wm::WindowState* added_window_state = wm::GetWindowState(added_window);
 279   if (!added_window->TargetVisibility())
 280     return;
 281
 282   if (!UseAutoWindowManager(added_window) ||
 283       added_window_state->bounds_changed_by_user()) {
 284     if (added_window_state->minimum_visibility()) {
 285       // Guarante minimum visibility within the work area.
 286       gfx::Rect work_area = GetWorkAreaForWindowInParent(added_window);
 287       gfx::Rect bounds = added_window->bounds();
 288       gfx::Rect new_bounds = bounds;
 289       ash::wm::AdjustBoundsToEnsureMinimumWindowVisibility(work_area,
 290                                                            &new_bounds);
 291       if (new_bounds != bounds)
 292         added_window->SetBounds(new_bounds);
 293     }
 294     return;
 295   }
 296   // Find a single open managed window.
 297   bool single_window;
 298   aura::Window* other_shown_window = GetReferenceWindow(
 299       added_window->GetRootWindow(), added_window, &single_window);
 300
 301   if (!other_shown_window) {
 302     // It could be that this window is the first window joining the workspace.
 303     if (!WindowPositionCanBeManaged(added_window) || other_shown_window)
 304       return;
 305     // Since we might be going from 0 to 1 window, we have to arrange the new
 306     // window to a good default.
 307     AutoPlaceSingleWindow(added_window, false);
 308     return;
 309   }
 310
 311   gfx::Rect other_bounds = other_shown_window->bounds();
 312   gfx::Rect work_area = GetWorkAreaForWindowInParent(added_window);
 313   bool move_other_right =
 314       other_bounds.CenterPoint().x() > work_area.x() + work_area.width() / 2;
 315
 316   // Push the other window to the size only if there are two windows left.
 317   if (single_window) {
 318     // When going from one to two windows both windows loose their
 319     // "positioned by user" flags.
 320     added_window_state->set_bounds_changed_by_user(false);
 321     wm::WindowState* other_window_state =
 322         wm::GetWindowState(other_shown_window);
 323     other_window_state->set_bounds_changed_by_user(false);
 324
 325     if (WindowPositionCanBeManaged(other_shown_window)) {
 326       // Don't override pre auto managed bounds as the current bounds
 327       // may not be original.
 328       if (!other_window_state->pre_auto_manage_window_bounds())
 329         other_window_state->SetPreAutoManageWindowBounds(other_bounds);
 330
 331       // Push away the other window after remembering its current position.
 332       if (MoveRectToOneSide(work_area, move_other_right, &other_bounds))
 333         SetBoundsAnimated(other_shown_window, other_bounds);
 334     }
 335   }
 336
 337   // Remember the current location of the window if it's new and push
 338   // it also to the opposite location if needed.  Since it is just
 339   // being shown, we do not need to animate it.
 340   gfx::Rect added_bounds = added_window->bounds();
 341   if (!added_window_state->pre_auto_manage_window_bounds())
 342     added_window_state->SetPreAutoManageWindowBounds(added_bounds);
 343   if (MoveRectToOneSide(work_area, !move_other_right, &added_bounds))
 344     added_window->SetBounds(added_bounds);
 345 }
 346
 347 WindowPositioner::WindowPositioner()
 348     : pop_position_offset_increment_x(0),
 349       pop_position_offset_increment_y(0),
 350       popup_position_offset_from_screen_corner_x(0),
 351       popup_position_offset_from_screen_corner_y(0),
 352       last_popup_position_x_(0),
 353       last_popup_position_y_(0) {
 354 }
 355
 356 WindowPositioner::~WindowPositioner() {
 357 }
 358
 359 gfx::Rect WindowPositioner::GetDefaultWindowBounds(
 360     const gfx::Display& display) {
 361   const gfx::Rect work_area = display.work_area();
 362   // There should be a 'desktop' border around the window at the left and right
 363   // side.
 364   int default_width = work_area.width() - 2 * kDesktopBorderSize;
 365   // There should also be a 'desktop' border around the window at the top.
 366   // Since the workspace excludes the tray area we only need one border size.
 367   int default_height = work_area.height() - kDesktopBorderSize;
 368   int offset_x = kDesktopBorderSize;
 369   if (default_width > kMaximumWindowWidth) {
 370     // The window should get centered on the screen and not follow the grid.
 371     offset_x = (work_area.width() - kMaximumWindowWidth) / 2;
 372     default_width = kMaximumWindowWidth;
 373   }
 374   return gfx::Rect(work_area.x() + offset_x,
 375                    work_area.y() + kDesktopBorderSize,
 376                    default_width,
 377                    default_height);
 378 }
 379
 380 gfx::Rect WindowPositioner::GetPopupPosition(const gfx::Rect& old_pos) {
 381   int grid = kMinimumWindowOffset;
 382   popup_position_offset_from_screen_corner_x = grid;
 383   popup_position_offset_from_screen_corner_y = grid;
 384   if (!pop_position_offset_increment_x) {
 385     // When the popup position increment is , the last popup position
 386     // was not yet initialized.
 387     last_popup_position_x_ = popup_position_offset_from_screen_corner_x;
 388     last_popup_position_y_ = popup_position_offset_from_screen_corner_y;
 389   }
 390   pop_position_offset_increment_x = grid;
 391   pop_position_offset_increment_y = grid;
 392   // We handle the Multi monitor support by retrieving the active window's
 393   // work area.
 394   aura::Window* window = wm::GetActiveWindow();
 395   const gfx::Rect work_area = window && window->IsVisible() ?
 396       Shell::GetScreen()->GetDisplayNearestWindow(window).work_area() :
 397       Shell::GetScreen()->GetPrimaryDisplay().work_area();
 398   // Only try to reposition the popup when it is not spanning the entire
 399   // screen.
 400   if ((old_pos.width() + popup_position_offset_from_screen_corner_x >=
 401       work_area.width()) ||
 402       (old_pos.height() + popup_position_offset_from_screen_corner_y >=
 403        work_area.height()))
 404     return AlignPopupPosition(old_pos, work_area, grid);
 405   const gfx::Rect result = SmartPopupPosition(old_pos, work_area, grid);
 406   if (!result.IsEmpty())
 407     return AlignPopupPosition(result, work_area, grid);
 408   return NormalPopupPosition(old_pos, work_area);
 409 }
 410
 411 // static
 412 void WindowPositioner::SetMaximizeFirstWindow(bool maximize) {
 413   maximize_first_window = maximize;
 414 }
 415
 416 gfx::Rect WindowPositioner::NormalPopupPosition(
 417     const gfx::Rect& old_pos,
 418     const gfx::Rect& work_area) {
 419   int w = old_pos.width();
 420   int h = old_pos.height();
 421   // Note: The 'last_popup_position' is checked and kept relative to the
 422   // screen size. The offsetting will be done in the last step when the
 423   // target rectangle gets returned.
 424   bool reset = false;
 425   if (last_popup_position_y_ + h > work_area.height() ||
 426       last_popup_position_x_ + w > work_area.width()) {
 427     // Popup does not fit on screen. Reset to next diagonal row.
 428     last_popup_position_x_ -= last_popup_position_y_ -
 429                               popup_position_offset_from_screen_corner_x -
 430                               pop_position_offset_increment_x;
 431     last_popup_position_y_ = popup_position_offset_from_screen_corner_y;
 432     reset = true;
 433   }
 434   if (last_popup_position_x_ + w > work_area.width()) {
 435     // Start again over.
 436     last_popup_position_x_ = popup_position_offset_from_screen_corner_x;
 437     last_popup_position_y_ = popup_position_offset_from_screen_corner_y;
 438     reset = true;
 439   }
 440   int x = last_popup_position_x_;
 441   int y = last_popup_position_y_;
 442   if (!reset) {
 443     last_popup_position_x_ += pop_position_offset_increment_x;
 444     last_popup_position_y_ += pop_position_offset_increment_y;
 445   }
 446   return gfx::Rect(x + work_area.x(), y + work_area.y(), w, h);
 447 }
 448
 449 gfx::Rect WindowPositioner::SmartPopupPosition(
 450     const gfx::Rect& old_pos,
 451     const gfx::Rect& work_area,
 452     int grid) {
 453   const std::vector<aura::Window*> windows =
 454       MruWindowTracker::BuildWindowList(false);
 455
 456   std::vector<const gfx::Rect*> regions;
 457   // Process the window list and check if we can bail immediately.
 458   for (size_t i = 0; i < windows.size(); i++) {
 459     // We only include opaque and visible windows.
 460     if (windows[i] && windows[i]->IsVisible() && windows[i]->layer() &&
 461         (!windows[i]->transparent() ||
 462          windows[i]->layer()->GetTargetOpacity() == 1.0)) {
 463       wm::WindowState* window_state = wm::GetWindowState(windows[i]);
 464       // When any window is maximized we cannot find any free space.
 465       if (window_state->IsMaximizedOrFullscreen())
 466         return gfx::Rect(0, 0, 0, 0);
 467       if (window_state->IsNormalOrSnapped())
 468         regions.push_back(&windows[i]->bounds());
 469     }
 470   }
 471
 472   if (regions.empty())
 473     return gfx::Rect(0, 0, 0, 0);
 474
 475   int w = old_pos.width();
 476   int h = old_pos.height();
 477   int x_end = work_area.width() / 2;
 478   int x, x_increment;
 479   // We parse for a proper location on the screen. We do this in two runs:
 480   // The first run will start from the left, parsing down, skipping any
 481   // overlapping windows it will encounter until the popup's height can not
 482   // be served anymore. Then the next grid position to the right will be
 483   // taken, and the same cycle starts again. This will be repeated until we
 484   // hit the middle of the screen (or we find a suitable location).
 485   // In the second run we parse beginning from the right corner downwards and
 486   // then to the left.
 487   // When no location was found, an empty rectangle will be returned.
 488   for (int run = 0; run < 2; run++) {
 489     if (run == 0) { // First run: Start left, parse right till mid screen.
 490       x = 0;
 491       x_increment = pop_position_offset_increment_x;
 492     } else { // Second run: Start right, parse left till mid screen.
 493       x = work_area.width() - w;
 494       x_increment = -pop_position_offset_increment_x;
 495     }
 496     // Note: The passing (x,y,w,h) window is always relative to the work area's
 497     // origin.
 498     for (; x_increment > 0 ? (x < x_end) : (x > x_end); x += x_increment) {
 499       int y = 0;
 500       while (y + h <= work_area.height()) {
 501         size_t i;
 502         for (i = 0; i < regions.size(); i++) {
 503           if (regions[i]->Intersects(gfx::Rect(x + work_area.x(),
 504                                                y + work_area.y(), w, h))) {
 505             y = regions[i]->bottom() - work_area.y();
 506             break;
 507           }
 508         }
 509         if (i >= regions.size())
 510           return gfx::Rect(x + work_area.x(), y + work_area.y(), w, h);
 511       }
 512     }
 513   }
 514   return gfx::Rect(0, 0, 0, 0);
 515 }
 516
 517 gfx::Rect WindowPositioner::AlignPopupPosition(
 518     const gfx::Rect& pos,
 519     const gfx::Rect& work_area,
 520     int grid) {
 521   if (grid <= 1)
 522     return pos;
 523
 524   int x = pos.x() - (pos.x() - work_area.x()) % grid;
 525   int y = pos.y() - (pos.y() - work_area.y()) % grid;
 526   int w = pos.width();
 527   int h = pos.height();
 528
 529   // If the alignment was pushing the window out of the screen, we ignore the
 530   // alignment for that call.
 531   if (abs(pos.right() - work_area.right()) < grid)
 532     x = work_area.right() - w;
 533   if (abs(pos.bottom() - work_area.bottom()) < grid)
 534     y = work_area.bottom() - h;
 535   return gfx::Rect(x, y, w, h);
 536 }
 537
 538 }  // namespace ash