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