chrome/browser/ui/window_sizer/window_sizer_ash.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 "chrome/browser/ui/window_sizer/window_sizer.h"

#include "ash/ash_switches.h"
#include "ash/shell.h"
#include "ash/wm/mru_window_tracker.h"
#include "ash/wm/window_state.h"
#include "ash/wm/window_util.h"
#include "ash/wm/workspace/auto_window_management.h"
#include "base/command_line.h"
#include "base/compiler_specific.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_list.h"
#include "chrome/browser/ui/browser_window.h"
#include "ui/aura/root_window.h"
#include "ui/aura/window.h"
#include "ui/aura/window_delegate.h"
#include "ui/gfx/screen.h"

namespace {

// When a window gets opened in default mode and the screen is less than or
// equal to this width, the window will get opened in maximized mode. This value
// can be reduced to a "tame" number if the feature is disabled.
const int kForceMaximizeWidthLimit = 1366;
const int kForceMaximizeWidthLimitDisabled = 640;

// Check if the given browser is 'valid': It is a tabbed, non minimized
// window, which intersects with the |bounds_in_screen| area of a given screen.
bool IsValidBrowser(Browser* browser, const gfx::Rect& bounds_in_screen) {
  return (browser && browser->window() &&
          !browser->is_type_popup() &&
          !browser->window()->IsMinimized() &&
          browser->window()->GetNativeWindow() &&
          bounds_in_screen.Intersects(
              browser->window()->GetNativeWindow()->GetBoundsInScreen()));
}

// Return the number of valid top level windows on the screen defined by
// the |bounds_in_screen| rectangle.
int GetNumberOfValidTopLevelBrowserWindows(const gfx::Rect& bounds_in_screen) {
  int count = 0;
  const BrowserList* ash_browser_list =
      BrowserList::GetInstance(chrome::HOST_DESKTOP_TYPE_ASH);
  for (BrowserList::const_iterator iter = ash_browser_list->begin();
       iter != ash_browser_list->end();
       ++iter) {
    if (IsValidBrowser(*iter, bounds_in_screen))
      count++;
  }
  return count;
}

// Move the given |bounds_in_screen| on the available |work_area| to the
// direction. If |move_right| is true, the rectangle gets moved to the right
// corner. Otherwise to the left side.
bool MoveRect(const gfx::Rect& work_area,
              gfx::Rect& bounds_in_screen,
              bool move_right) {
  if (move_right) {
    if (work_area.right() > bounds_in_screen.right()) {
      bounds_in_screen.set_x(work_area.right() - bounds_in_screen.width());
      return true;
    }
  } else {
    if (work_area.x() < bounds_in_screen.x()) {
      bounds_in_screen.set_x(work_area.x());
      return true;
    }
  }
  return false;
}

}  // namespace

// static
int WindowSizer::GetForceMaximizedWidthLimit() {
  static int maximum_limit = 0;
  if (!maximum_limit) {
    maximum_limit = CommandLine::ForCurrentProcess()->HasSwitch(
                        ash::switches::kAshDisableAutoMaximizing) ?
        kForceMaximizeWidthLimitDisabled : kForceMaximizeWidthLimit;
  }
  return maximum_limit;
}

void WindowSizer::GetTabbedBrowserBoundsAsh(
    gfx::Rect* bounds_in_screen,
    ui::WindowShowState* show_state) const {
  DCHECK(show_state);
  DCHECK(bounds_in_screen);
  DCHECK(!browser_ || browser_->is_type_tabbed());

  bounds_in_screen->SetRect(0, 0, 0, 0);

  // Experiment: Force the maximize mode for all tabbed windows
  if (ash::Shell::IsForcedMaximizeMode())
    *show_state = ui::SHOW_STATE_MAXIMIZED;

  ui::WindowShowState passed_show_state = *show_state;
  bool has_saved_bounds = true;
  if (!GetSavedWindowBounds(bounds_in_screen, show_state)) {
    has_saved_bounds = false;
    GetDefaultWindowBoundsAsh(bounds_in_screen);
  }

  aura::RootWindow* target = ash::Shell::GetTargetRootWindow();
  // Always open new window in the active display.
  gfx::Rect work_area =
      screen_->GetDisplayMatching(target->GetBoundsInScreen()).work_area();

  // This is a window / app. See if there is no window and try to place it.
  int count = GetNumberOfValidTopLevelBrowserWindows(work_area);
  aura::Window* top_window = ash::GetTopWindowForNewWindow(target);
  // Our window should not have any impact if we are already on top.
  if (browser_->window() &&
      top_window == browser_->window()->GetNativeWindow())
    top_window = NULL;

  // If there is no valid other window we take the coordinates as is.
  if ((!count || !top_window)) {
    if (has_saved_bounds) {
      // Restore to previous state - if there is one.
      bounds_in_screen->AdjustToFit(work_area);
      return;
    }

    // When using "small screens" we want to always open in full screen mode.
    if (passed_show_state == ui::SHOW_STATE_DEFAULT &&
        !browser_->is_session_restore() &&
        work_area.width() <= GetForceMaximizedWidthLimit() &&
        (!browser_->window() || !browser_->window()->IsFullscreen()))
      *show_state = ui::SHOW_STATE_MAXIMIZED;
    return;
  }
  bool maximized = ash::wm::GetWindowState(top_window)->IsMaximized();
  // We ignore the saved show state, but look instead for the top level
  // window's show state.
  if (passed_show_state == ui::SHOW_STATE_DEFAULT) {
    *show_state = maximized ? ui::SHOW_STATE_MAXIMIZED :
        ui::SHOW_STATE_DEFAULT;
  }

  // Use the size of the other window. The window's bound will be rearranged
  // in ash::WorkspaceLayoutManager using this location.
  *bounds_in_screen = top_window->GetBoundsInScreen();
}

void WindowSizer::GetDefaultWindowBoundsAsh(gfx::Rect* default_bounds) const {
  DCHECK(default_bounds);

  gfx::Rect work_area = screen_->GetPrimaryDisplay().work_area();

  // There should be a 'desktop' border around the window at the left and right
  // side.
  int default_width = work_area.width() - 2 * kDesktopBorderSize;
  // There should also be a 'desktop' border around the window at the top.
  // Since the workspace excludes the tray area we only need one border size.
  int default_height = work_area.height() - kDesktopBorderSize;
  // We align the size to the grid size to avoid any surprise when the
  // monitor height isn't divide-able by our alignment factor.
  default_width -= default_width % kDesktopBorderSize;
  default_height -= default_height % kDesktopBorderSize;
  int offset_x = kDesktopBorderSize;
  if (default_width > kMaximumWindowWidth) {
    // The window should get centered on the screen and not follow the grid.
    offset_x = (work_area.width() - kMaximumWindowWidth) / 2;
    default_width = kMaximumWindowWidth;
  }
  default_bounds->SetRect(work_area.x() + offset_x,
                          work_area.y() + kDesktopBorderSize,
                          default_width,
                          default_height);
}