content/browser/web_contents/aura/overscroll_window_delegate.cc

   1 // Copyright 2015 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 "content/browser/web_contents/aura/overscroll_window_delegate.h"
   6
   7 #include "base/i18n/rtl.h"
   8 #include "content/browser/frame_host/navigation_controller_impl.h"
   9 #include "content/browser/frame_host/navigation_entry_impl.h"
  10 #include "content/browser/renderer_host/overscroll_controller_delegate.h"
  11 #include "content/public/browser/overscroll_configuration.h"
  12 #include "ui/aura/window.h"
  13 #include "ui/gfx/image/image_png_rep.h"
  14
  15 namespace content {
  16
  17 OverscrollWindowDelegate::OverscrollWindowDelegate(
  18     OverscrollControllerDelegate* delegate,
  19     const gfx::Image& image)
  20     : delegate_(delegate),
  21       overscroll_mode_(OVERSCROLL_NONE),
  22       delta_x_(0.f),
  23       complete_threshold_ratio_(content::GetOverscrollConfig(
  24           content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_COMPLETE)),
  25       start_threshold_touchscreen_(content::GetOverscrollConfig(
  26           content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_START_TOUCHSCREEN)),
  27       start_threshold_touchpad_(content::GetOverscrollConfig(
  28           content::OVERSCROLL_CONFIG_HORIZ_THRESHOLD_START_TOUCHPAD)),
  29       active_start_threshold_(0.f) {
  30   SetImage(image);
  31 }
  32
  33 OverscrollWindowDelegate::~OverscrollWindowDelegate() {
  34 }
  35
  36 void OverscrollWindowDelegate::StartOverscroll() {
  37   OverscrollMode old_mode = overscroll_mode_;
  38   if (delta_x_ > 0)
  39     overscroll_mode_ = OVERSCROLL_EAST;
  40   else
  41     overscroll_mode_ = OVERSCROLL_WEST;
  42   delegate_->OnOverscrollModeChange(old_mode, overscroll_mode_);
  43 }
  44
  45 void OverscrollWindowDelegate::ResetOverscroll() {
  46   delegate_->OnOverscrollModeChange(overscroll_mode_, OVERSCROLL_NONE);
  47   overscroll_mode_ = OVERSCROLL_NONE;
  48   delta_x_ = 0;
  49 }
  50
  51 void OverscrollWindowDelegate::CompleteOrResetOverscroll() {
  52   if (overscroll_mode_ == OVERSCROLL_NONE)
  53     return;
  54   int width = delegate_->GetVisibleBounds().width();
  55   float ratio = (fabs(delta_x_)) / width;
  56   if (ratio < complete_threshold_ratio_) {
  57     ResetOverscroll();
  58     return;
  59   }
  60   delegate_->OnOverscrollComplete(overscroll_mode_);
  61   overscroll_mode_ = OVERSCROLL_NONE;
  62   delta_x_ = 0;
  63 }
  64
  65 void OverscrollWindowDelegate::UpdateOverscroll(float delta_x) {
  66   float old_delta_x = delta_x_;
  67   delta_x_ += delta_x;
  68   if (overscroll_mode_ == OVERSCROLL_NONE) {
  69     if (fabs(delta_x_) > active_start_threshold_)
  70       StartOverscroll();
  71     return;
  72   }
  73   if ((old_delta_x < 0 && delta_x_ > 0) || (old_delta_x > 0 && delta_x_ < 0)) {
  74     ResetOverscroll();
  75     return;
  76   }
  77   delegate_->OnOverscrollUpdate(delta_x_, 0.f);
  78 }
  79
  80 void OverscrollWindowDelegate::OnKeyEvent(ui::KeyEvent* event) {
  81   ResetOverscroll();
  82 }
  83
  84 void OverscrollWindowDelegate::OnMouseEvent(ui::MouseEvent* event) {
  85   if (!(event->flags() & ui::EF_IS_SYNTHESIZED) &&
  86       event->type() != ui::ET_MOUSE_CAPTURE_CHANGED) {
  87     ResetOverscroll();
  88   }
  89 }
  90
  91 void OverscrollWindowDelegate::OnScrollEvent(ui::ScrollEvent* event) {
  92   active_start_threshold_ = start_threshold_touchpad_;
  93   if (event->type() == ui::ET_SCROLL)
  94     UpdateOverscroll(event->x_offset_ordinal());
  95   else if (event->type() == ui::ET_SCROLL_FLING_START)
  96     CompleteOrResetOverscroll();
  97   else
  98     ResetOverscroll();
  99   event->SetHandled();
 100 }
 101
 102 void OverscrollWindowDelegate::OnGestureEvent(ui::GestureEvent* event) {
 103   active_start_threshold_ = start_threshold_touchscreen_;
 104   switch (event->type()) {
 105     case ui::ET_GESTURE_SCROLL_UPDATE:
 106       UpdateOverscroll(event->details().scroll_x());
 107       break;
 108
 109     case ui::ET_GESTURE_SCROLL_END:
 110       CompleteOrResetOverscroll();
 111       break;
 112
 113     case ui::ET_SCROLL_FLING_START:
 114       CompleteOrResetOverscroll();
 115       break;
 116
 117     case ui::ET_GESTURE_PINCH_BEGIN:
 118     case ui::ET_GESTURE_PINCH_UPDATE:
 119     case ui::ET_GESTURE_PINCH_END:
 120       ResetOverscroll();
 121       break;
 122
 123     default:
 124       break;
 125   }
 126   event->SetHandled();
 127 }
 128
 129 }  // namespace content