ash/wm/gestures/tray_gesture_handler.cc

   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/gestures/tray_gesture_handler.h"
   6
   7 #include "ash/shell.h"
   8 #include "ash/system/tray/system_tray.h"
   9 #include "ash/system/tray/system_tray_bubble.h"
  10 #include "ui/aura/window.h"
  11 #include "ui/base/events/event.h"
  12 #include "ui/compositor/layer.h"
  13 #include "ui/gfx/transform.h"
  14 #include "ui/views/widget/widget.h"
  15
  16 const int kMinBubbleHeight = 13;
  17
  18 namespace ash {
  19 namespace internal {
  20
  21 TrayGestureHandler::TrayGestureHandler()
  22     : widget_(NULL),
  23       gesture_drag_amount_(0) {
  24   // TODO(oshima): Support multiple display case.
  25   SystemTray* tray = Shell::GetInstance()->GetPrimarySystemTray();
  26   tray->ShowDefaultView(BUBBLE_CREATE_NEW);
  27   SystemTrayBubble* bubble = tray->GetSystemBubble();
  28   if (!bubble)
  29     return;
  30   bubble->bubble_view()->set_gesture_dragging(true);
  31   widget_ = bubble->bubble_view()->GetWidget();
  32   widget_->AddObserver(this);
  33
  34   gfx::Rect bounds = widget_->GetWindowBoundsInScreen();
  35   int height_change = bounds.height() - kMinBubbleHeight;
  36   bounds.set_height(kMinBubbleHeight);
  37   bounds.set_y(bounds.y() + height_change);
  38   widget_->SetBounds(bounds);
  39 }
  40
  41 TrayGestureHandler::~TrayGestureHandler() {
  42   if (widget_)
  43     widget_->RemoveObserver(this);
  44 }
  45
  46 bool TrayGestureHandler::UpdateGestureDrag(const ui::GestureEvent& event) {
  47   CHECK_EQ(ui::ET_GESTURE_SCROLL_UPDATE, event.type());
  48   if (!widget_)
  49     return false;
  50
  51   gesture_drag_amount_ += event.details().scroll_y();
  52   if (gesture_drag_amount_ > 0 && gesture_drag_amount_ < kMinBubbleHeight) {
  53     widget_->Close();
  54     return false;
  55   }
  56
  57   gfx::Rect bounds = widget_->GetWindowBoundsInScreen();
  58   int new_height = std::min(
  59       kMinBubbleHeight + std::max(0, static_cast<int>(-gesture_drag_amount_)),
  60       widget_->GetContentsView()->GetPreferredSize().height());
  61   int height_change = bounds.height() - new_height;
  62   bounds.set_height(new_height);
  63   bounds.set_y(bounds.y() + height_change);
  64   widget_->SetBounds(bounds);
  65   return true;
  66 }
  67
  68 void TrayGestureHandler::CompleteGestureDrag(const ui::GestureEvent& event) {
  69   if (!widget_)
  70     return;
  71
  72   widget_->RemoveObserver(this);
  73
  74   // Close the widget if it hasn't been dragged enough.
  75   bool should_close = false;
  76   int height = widget_->GetWindowBoundsInScreen().height();
  77   int preferred_height =
  78       widget_->GetContentsView()->GetPreferredSize().height();
  79   if (event.type() == ui::ET_GESTURE_SCROLL_END) {
  80     const float kMinThresholdGestureDrag = 0.4f;
  81     if (height < preferred_height * kMinThresholdGestureDrag)
  82       should_close = true;
  83   } else if (event.type() == ui::ET_SCROLL_FLING_START) {
  84     const float kMinThresholdGestureDragExposeFling = 0.25f;
  85     const float kMinThresholdGestureFling = 1000.f;
  86     if (height < preferred_height * kMinThresholdGestureDragExposeFling &&
  87         event.details().velocity_y() > -kMinThresholdGestureFling)
  88       should_close = true;
  89   } else {
  90     NOTREACHED();
  91   }
  92
  93   if (should_close) {
  94     widget_->Close();
  95   } else {
  96     SystemTrayBubble* bubble =
  97         Shell::GetInstance()->GetPrimarySystemTray()->GetSystemBubble();
  98     if (bubble)
  99       bubble->bubble_view()->set_gesture_dragging(false);
 100   }
 101 }
 102
 103 void TrayGestureHandler::OnWidgetDestroying(views::Widget* widget) {
 104   CHECK_EQ(widget_, widget);
 105   widget_ = NULL;
 106 }
 107
 108 }  // namespace internal
 109 }  // namespace ash