1 files changed, 110 insertions, 0 deletions
diff --git a/chromium/ash/wm/gestures/overview_gesture_handler.cc b/chromium/ash/wm/gestures/overview_gesture_handler.cc
new file mode 100644
index 00000000000..ebff8e680bc
--- /dev/null
+++ b/chromium/ash/wm/gestures/overview_gesture_handler.cc
@@ -0,0 +1,110 @@
+// Copyright 2013 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/wm/gestures/overview_gesture_handler.h"
+
+#include "ash/metrics/user_metrics_recorder.h"
+#include "ash/shell.h"
+#include "ash/wm/coordinate_conversion.h"
+#include "ash/wm/overview/window_selector_controller.h"
+#include "ui/aura/window.h"
+#include "ui/events/event.h"
+#include "ui/events/event_constants.h"
+#include "ui/gfx/rect.h"
+#include "ui/gfx/screen.h"
+
+namespace ash {
+namespace internal {
+
+namespace {
+
+// The number of pixels from the top of the screen (a virtual bezel) to allow
+// the overview swipe down gesture to begin within. Note this does not actually
+// prevent handling of the touches so a fullscreen page which consumes these can
+// prevent entering overview with a swipe down.
+const int kTopBezelExtraPixels = 5;
+
+// The threshold before engaging overview on a three finger swipe on the
+// touchpad.
+const float kSwipeThresholdPixels = 300;
+
+}  // namespace;
+
+OverviewGestureHandler::OverviewGestureHandler()
+    : in_top_bezel_gesture_(false),
+      scroll_x_(0),
+      scroll_y_(0) {
+}
+
+OverviewGestureHandler::~OverviewGestureHandler() {
+}
+
+bool OverviewGestureHandler::ProcessScrollEvent(const ui::ScrollEvent& event) {
+  if (event.type() == ui::ET_SCROLL_FLING_START ||
+      event.type() == ui::ET_SCROLL_FLING_CANCEL ||
+      event.finger_count() != 3) {
+    scroll_x_ = scroll_y_ = 0;
+    return false;
+  }
+
+  scroll_x_ += event.x_offset();
+  scroll_y_ += event.y_offset();
+
+  // Horizontal swiping is ignored.
+  if (std::fabs(scroll_x_) >= std::fabs(scroll_y_)) {
+    scroll_x_ = scroll_y_ = 0;
+    return false;
+  }
+
+  // Only allow swipe up to enter overview, down to exit. Ignore extra swiping
+  // in the wrong direction.
+  Shell* shell = Shell::GetInstance();
+  if (shell->window_selector_controller()->IsSelecting()) {
+    if (scroll_y_ < 0)
+      scroll_x_ = scroll_y_ = 0;
+    if (scroll_y_ < kSwipeThresholdPixels)
+      return false;
+  } else {
+    if (scroll_y_ > 0)
+      scroll_x_ = scroll_y_ = 0;
+    if (scroll_y_ > -kSwipeThresholdPixels)
+      return false;
+  }
+
+  // Reset scroll amount on toggling.
+  scroll_x_ = scroll_y_ = 0;
+  shell->metrics()->RecordUserMetricsAction(UMA_TOUCHPAD_GESTURE_OVERVIEW);
+  shell->window_selector_controller()->ToggleOverview();
+  return true;
+}
+
+bool OverviewGestureHandler::ProcessGestureEvent(
+    const ui::GestureEvent& event) {
+  // Detect at the beginning of any gesture whether it begins on the top bezel.
+  if (event.type() == ui::ET_GESTURE_BEGIN &&
+      event.details().touch_points() == 1) {
+    gfx::Point point_in_screen(event.location());
+    aura::Window* target = static_cast<aura::Window*>(event.target());
+    wm::ConvertPointToScreen(target, &point_in_screen);
+    in_top_bezel_gesture_ = !Shell::GetScreen()->GetDisplayNearestPoint(
+        point_in_screen).bounds().y() + kTopBezelExtraPixels >
+            point_in_screen.y();
+    return false;
+  }
+
+  if (!in_top_bezel_gesture_ ||
+      event.type() != ui::ET_GESTURE_MULTIFINGER_SWIPE ||
+      !event.details().swipe_down() ||
+      event.details().touch_points() != 3) {
+    return false;
+  }
+
+  Shell* shell = Shell::GetInstance();
+  shell->metrics()->RecordUserMetricsAction(UMA_GESTURE_OVERVIEW);
+  shell->window_selector_controller()->ToggleOverview();
+  return true;
+}
+
+}  // namespace internal
+}  // namespace ash