ash/system/overview/overview_button_tray.cc

// Copyright 2014 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 "ash/system/overview/overview_button_tray.h"

#include "ash/metrics/user_metrics_recorder.h"
#include "ash/resources/vector_icons/vector_icons.h"
#include "ash/session/session_controller.h"
#include "ash/shelf/shelf_constants.h"
#include "ash/shell.h"
#include "ash/strings/grit/ash_strings.h"
#include "ash/system/tray/tray_constants.h"
#include "ash/system/tray/tray_container.h"
#include "ash/wm/mru_window_tracker.h"
#include "ash/wm/overview/window_selector_controller.h"
#include "ash/wm/tablet_mode/tablet_mode_controller.h"
#include "ash/wm/window_state.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/gfx/paint_vector_icon.h"
#include "ui/views/border.h"
#include "ui/views/controls/image_view.h"

namespace ash {

OverviewButtonTray::OverviewButtonTray(Shelf* shelf)
    : TrayBackgroundView(shelf),
      icon_(new views::ImageView()),
      scoped_session_observer_(this) {
  SetInkDropMode(InkDropMode::ON);

  gfx::ImageSkia image =
      gfx::CreateVectorIcon(kShelfOverviewIcon, kShelfIconColor);
  icon_->SetImage(image);
  const int vertical_padding = (kTrayItemSize - image.height()) / 2;
  const int horizontal_padding = (kTrayItemSize - image.width()) / 2;
  icon_->SetBorder(views::CreateEmptyBorder(
      gfx::Insets(vertical_padding, horizontal_padding)));
  tray_container()->AddChildView(icon_);

  // Since OverviewButtonTray is located on the rightmost position of a
  // horizontal shelf, no separator is required.
  set_separator_visibility(false);

  Shell::Get()->AddShellObserver(this);
  Shell::Get()->tablet_mode_controller()->AddObserver(this);
}

OverviewButtonTray::~OverviewButtonTray() {
  if (Shell::Get()->tablet_mode_controller())
    Shell::Get()->tablet_mode_controller()->RemoveObserver(this);
  Shell::Get()->RemoveShellObserver(this);
}

void OverviewButtonTray::UpdateAfterLoginStatusChange(LoginStatus status) {
  UpdateIconVisibility();
}

bool OverviewButtonTray::PerformAction(const ui::Event& event) {
  if (event.type() == ui::ET_GESTURE_TAP) {
    if (event.AsGestureEvent()->details().tap_count() == 2) {
      // If the second tap is not on the window selection page, that means we
      // started on the window selection page. Ignore these double taps. (ie.
      // treat them as single taps by ignoring the second tap)
      if (!Shell::Get()->window_selector_controller()->IsSelecting())
        return true;

      MruWindowTracker::WindowList mru_window_list =
          Shell::Get()->mru_window_tracker()->BuildMruWindowList();

      // Switch to the second most recently used window (most recent is the
      // current window), if it exists.
      if (mru_window_list.size() > 1) {
        AnimateInkDrop(views::InkDropState::DEACTIVATED, nullptr);
        wm::GetWindowState(mru_window_list[1])->Activate();
        return true;
      }
    }
  }

  WindowSelectorController* controller =
      Shell::Get()->window_selector_controller();
  // Note: Toggling overview mode will fail if there is no window to show, the
  // screen is locked, a modal dialog is open or is running in kiosk app
  // session.
  bool performed = controller->ToggleOverview();
  Shell::Get()->metrics()->RecordUserMetricsAction(UMA_TRAY_OVERVIEW);
  return performed;
}

void OverviewButtonTray::OnSessionStateChanged(
    session_manager::SessionState state) {
  UpdateIconVisibility();
}

void OverviewButtonTray::OnTabletModeStarted() {
  UpdateIconVisibility();
}

void OverviewButtonTray::OnTabletModeEnded() {
  UpdateIconVisibility();
}

void OverviewButtonTray::OnOverviewModeStarting() {
  SetIsActive(true);
}

void OverviewButtonTray::OnOverviewModeEnded() {
  SetIsActive(false);
}

void OverviewButtonTray::ClickedOutsideBubble() {}

base::string16 OverviewButtonTray::GetAccessibleNameForTray() {
  return l10n_util::GetStringUTF16(IDS_ASH_OVERVIEW_BUTTON_ACCESSIBLE_NAME);
}

void OverviewButtonTray::HideBubbleWithView(
    const views::TrayBubbleView* bubble_view) {
  // This class has no bubbles to hide.
}

void OverviewButtonTray::UpdateIconVisibility() {
  // The visibility of the OverviewButtonTray has diverged from
  // WindowSelectorController::CanSelect. The visibility of the button should
  // not change during transient times in which CanSelect is false. Such as when
  // a modal dialog is present.
  SessionController* session_controller = Shell::Get()->session_controller();

  Shell* shell = Shell::Get();
  SetVisible(
      shell->tablet_mode_controller()->IsTabletModeWindowManagerEnabled() &&
      session_controller->IsActiveUserSessionStarted() &&
      !session_controller->IsScreenLocked() &&
      session_controller->GetSessionState() ==
          session_manager::SessionState::ACTIVE &&
      !session_controller->IsKioskSession());
}

}  // namespace ash