ash/wm/gestures/edge_gesture_handler.cc

   1 // Copyright (c) 2013 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/edge_gesture_handler.h"
   6
   7 #include "ash/root_window_controller.h"
   8 #include "ash/shelf/shelf_layout_manager.h"
   9 #include "ash/shelf/shelf_types.h"
  10 #include "ash/shelf/shelf_widget.h"
  11 #include "ash/shell.h"
  12 #include "ui/base/events/event.h"
  13 #include "ui/gfx/screen.h"
  14
  15 namespace {
  16 const int kBottomEdgeGestureThreshold = 10;
  17 const int kLeftEdgeGestureThreshold = 10;
  18 const int kRightEdgeGestureThreshold = 10;
  19 const int kTopEdgeGestureThreshold = 10;
  20
  21 // Bit positions of edge start flags
  22 enum EdgeStart {
  23   EDGE_START_TOP = 0,
  24   EDGE_START_LEFT = 1,
  25   EDGE_START_RIGHT = 2,
  26   EDGE_START_BOTTOM = 3
  27 };
  28
  29 // Helpers for manipulating edge start flags
  30 #define CLEAR_FLAGS(FLAGS) (FLAGS = 0)
  31 #define SET_FLAG(FLAGS, FLAG_POS) (FLAGS |= 1 << FLAG_POS)
  32 #define IS_FLAG_SET(FLAGS, FLAG_POS) (0 != (FLAGS & (1 << FLAG_POS)))
  33 #define ANY_FLAGS_SET(FLAGS) (FLAGS != 0)
  34 }  // namespace
  35
  36 namespace ash {
  37 namespace internal {
  38
  39 EdgeGestureHandler::EdgeGestureHandler() :
  40     orientation_(EDGE_SCROLL_ORIENTATION_UNSET) {
  41   CLEAR_FLAGS(start_location_);
  42 }
  43
  44 EdgeGestureHandler::~EdgeGestureHandler() {
  45 }
  46
  47 bool EdgeGestureHandler::ProcessGestureEvent(aura::Window* target,
  48                                              const ui::GestureEvent& event) {
  49   // TODO(crbug.com/222746): Rewrite this code to ignore events that are for
  50   // edges that a bezel is present for instead of hardcoding the layout of edge
  51   // v bezel.
  52   switch (event.type()) {
  53     case ui::ET_GESTURE_SCROLL_BEGIN:
  54       return HandleEdgeGestureStart(target, event);
  55     case ui::ET_GESTURE_SCROLL_UPDATE:
  56       if (ANY_FLAGS_SET(start_location_)) {
  57         if (DetermineGestureOrientation(event)) {
  58           return HandleEdgeGestureUpdate(target, event);
  59         }
  60       }
  61       break;
  62     case ui::ET_GESTURE_SCROLL_END:
  63     case ui::ET_SCROLL_FLING_START:
  64       return HandleEdgeGestureEnd(target, event);
  65     default:
  66       break;
  67   }
  68   return false;
  69 }
  70
  71 bool EdgeGestureHandler::HandleLauncherControl(const ui::GestureEvent& event) {
  72   ShelfLayoutManager* shelf =
  73       Shell::GetPrimaryRootWindowController()->GetShelfLayoutManager();
  74   // If visible then let the shelf handle it as a normal widget.
  75   if (shelf->IsVisible())
  76     return false;
  77
  78   switch (shelf->GetAlignment()) {
  79     case SHELF_ALIGNMENT_LEFT:
  80       if (IS_FLAG_SET(start_location_, EDGE_START_LEFT))
  81         return shelf_handler_.ProcessGestureEvent(event);
  82       break;
  83     case SHELF_ALIGNMENT_RIGHT:
  84       if (IS_FLAG_SET(start_location_, EDGE_START_RIGHT))
  85         return shelf_handler_.ProcessGestureEvent(event);
  86       break;
  87     // Let the BezelGestureHandler handle gestures on the bottom edge of the
  88     // screen and there are no implemented gestures for the top edge at the
  89     // moment.
  90     case SHELF_ALIGNMENT_BOTTOM:
  91     case SHELF_ALIGNMENT_TOP:
  92     default:
  93       break;
  94   }
  95   return false;
  96 }
  97
  98 bool EdgeGestureHandler::HandleEdgeGestureStart(
  99     aura::Window* target,
 100     const ui::GestureEvent& event) {
 101   gfx::Rect screen =
 102       Shell::GetScreen()->GetDisplayNearestWindow(target).bounds();
 103
 104   orientation_ = EDGE_SCROLL_ORIENTATION_UNSET;
 105   if (GestureStartInEdgeArea(screen, event))
 106     return HandleLauncherControl(event);
 107   return false;
 108 }
 109
 110 bool EdgeGestureHandler::DetermineGestureOrientation(
 111     const ui::GestureEvent& event) {
 112   if (orientation_ == EDGE_SCROLL_ORIENTATION_UNSET) {
 113     if (!event.details().scroll_x() && !event.details().scroll_y())
 114       return false;
 115     orientation_ = abs(event.details().scroll_y()) >
 116         abs(event.details().scroll_x()) ?
 117         EDGE_SCROLL_ORIENTATION_VERTICAL : EDGE_SCROLL_ORIENTATION_HORIZONTAL;
 118   }
 119   return true;
 120 }
 121
 122 bool EdgeGestureHandler::HandleEdgeGestureUpdate(
 123     aura::Window* target,
 124     const ui::GestureEvent& event) {
 125   if (IsGestureInLauncherOrientation(event))
 126     return HandleLauncherControl(event);
 127   return false;
 128 }
 129
 130 bool EdgeGestureHandler::HandleEdgeGestureEnd(aura::Window* target,
 131                                               const ui::GestureEvent& event) {
 132   bool ret_val = HandleLauncherControl(event);
 133   CLEAR_FLAGS(start_location_);
 134   return ret_val;
 135 }
 136
 137 bool EdgeGestureHandler::GestureStartInEdgeArea(
 138     const gfx::Rect& screen,
 139     const ui::GestureEvent& event) {
 140   CLEAR_FLAGS(start_location_);
 141
 142   if (abs(event.y() - screen.y()) < kTopEdgeGestureThreshold &&
 143       event.y() >= 0)
 144     SET_FLAG(start_location_, EDGE_START_TOP);
 145   if (abs(event.x() - screen.x()) < kLeftEdgeGestureThreshold &&
 146       event.x() >= 0)
 147     SET_FLAG(start_location_, EDGE_START_LEFT);
 148   if (abs(event.x() - screen.right()) < kRightEdgeGestureThreshold &&
 149       event.x() >= 0)
 150     SET_FLAG(start_location_, EDGE_START_RIGHT);
 151   if (abs(event.y() - screen.bottom()) < kBottomEdgeGestureThreshold &&
 152       event.y() >= 0)
 153     SET_FLAG(start_location_, EDGE_START_BOTTOM);
 154   return ANY_FLAGS_SET(start_location_);
 155 }
 156
 157 bool EdgeGestureHandler::IsGestureInLauncherOrientation(
 158     const ui::GestureEvent& event) {
 159   EdgeScrollOrientation  new_orientation = abs(event.details().scroll_y()) >
 160       abs(event.details().scroll_x()) ?
 161       EDGE_SCROLL_ORIENTATION_VERTICAL : EDGE_SCROLL_ORIENTATION_HORIZONTAL;
 162
 163   if (new_orientation != orientation_)
 164     return false;
 165
 166   ShelfLayoutManager* shelf =
 167       Shell::GetPrimaryRootWindowController()->GetShelfLayoutManager();
 168   switch (shelf->GetAlignment()) {
 169     case SHELF_ALIGNMENT_BOTTOM:
 170       if (orientation_ == EDGE_SCROLL_ORIENTATION_VERTICAL)
 171         return true;
 172       break;
 173     case SHELF_ALIGNMENT_LEFT:
 174       if (orientation_ == EDGE_SCROLL_ORIENTATION_HORIZONTAL)
 175         return true;
 176       break;
 177     case SHELF_ALIGNMENT_RIGHT:
 178       if (orientation_ == EDGE_SCROLL_ORIENTATION_HORIZONTAL)
 179         return true;
 180       break;
 181     case SHELF_ALIGNMENT_TOP:
 182       if (orientation_ == EDGE_SCROLL_ORIENTATION_VERTICAL)
 183         return true;
 184       break;
 185     default:
 186       break;
 187   }
 188   return false;
 189 }
 190
 191 }  // namespace internal
 192 }  // namespace ash