Adding four bezel gestures

ash/wm/system_gesture_event_filter.cc

Index: ash/wm/system_gesture_event_filter.cc
diff --git a/ash/wm/system_gesture_event_filter.cc b/ash/wm/system_gesture_event_filter.cc
index 1568052561a3f6187925387d067338ee27bb48b6..1de41ca7600443f6f7622fc2b69f1ffc53550387 100644
--- a/ash/wm/system_gesture_event_filter.cc
+++ b/ash/wm/system_gesture_event_filter.cc
@@ -5,14 +5,23 @@
 #include "ash/wm/system_gesture_event_filter.h"
 
 #include "ash/shell.h"
+#include "ash/accelerators/accelerator_controller.h"
+#include "ash/system/brightness/brightness_control_delegate.h"
+#include "ash/volume_control_delegate.h"
 #include "ui/aura/event.h"
 #include "ui/aura/root_window.h"
+#include "ui/gfx/screen.h"
 
 namespace ash {
 namespace internal {
 
 SystemGestureEventFilter::SystemGestureEventFilter()
-    : aura::EventFilter() {
+    : aura::EventFilter(),
+      kOverlapPercent(5),
+      start_location_(bezel_start_unset),
+      orientation_(scroll_orientation_unset),
+      is_scrubbing_(false),
+      touch_id_(0) {
 }
 
 SystemGestureEventFilter::~SystemGestureEventFilter() {
@@ -39,10 +48,126 @@ ui::GestureStatus SystemGestureEventFilter::PreHandleGestureEvent(
   // TODO(tdresser) handle system level gesture events
   if (event->type() == ui::ET_GESTURE_THREE_FINGER_SWIPE)
     return ui::GESTURE_STATUS_CONSUMED;
-  if (target == Shell::GetRootWindow())
+  if (!target || target == Shell::GetRootWindow()) {
+    switch (event->type()) {
+      case ui::ET_GESTURE_SCROLL_BEGIN:
+        if (start_location_ == bezel_start_unset) {
+          gfx::Rect screen =
+              gfx::Screen::GetPrimaryMonitor().bounds_in_pixel();
+          int overlap_area = screen.width() * kOverlapPercent / 100;
+
+          if (event->x() <= screen.x() + overlap_area) {
+            start_location_ = bezel_start_left;
+          } else if (event->x() >= screen.right() - overlap_area) {
+            start_location_ = bezel_start_right;
+          } else if (event->y() >= screen.bottom()) {
+            start_location_ = bezel_start_bottom;
+          } else {
+            break;
+          }
+          orientation_ = scroll_orientation_unset;
+          touch_id_ = event->GetLowestTouchId();
+        }
+        break;
+      case ui::ET_GESTURE_SCROLL_UPDATE:
+        if (start_location_ == bezel_start_unset ||
+            touch_id_ != event->GetLowestTouchId())
+          break;
+        if (orientation_ == scroll_orientation_unset) {
+          if (!event->delta_x() && !event->delta_y())
+            break;
+          // For left and right the scroll angle needs to be much steeper to
+          // be accepted for a 'device configuration' gesture.
+          if (start_location_ == bezel_start_left ||
+              start_location_ == bezel_start_right)
+            orientation_ = abs(event->delta_y()) > abs(event->delta_x()) * 3 ?
+                scroll_orientation_vertical : scroll_orientation_horizontal;
+          else
+            orientation_ = abs(event->delta_y()) > abs(event->delta_x()) ?
+                scroll_orientation_vertical : scroll_orientation_horizontal;
+        }
+        if (orientation_ == scroll_orientation_horizontal) {
+          if (HandleApplicationControl(event))
+            start_location_ = bezel_start_unset;
+        } else {
+          if (start_location_ == bezel_start_bottom) {
+            if (HandleLauncherControl(event))
+              start_location_ = bezel_start_unset;
+          } else {
+            if (HandleDeviceControl(event))
+              start_location_ = bezel_start_unset;
+          }
+        }
+        break;
+      case ui::ET_GESTURE_SCROLL_END:
+        if (touch_id_ == event->GetLowestTouchId())
+          start_location_ = bezel_start_unset;
+        break;
+      default:
+        break;
+    }
     return ui::GESTURE_STATUS_CONSUMED;
+  }
   return ui::GESTURE_STATUS_UNKNOWN;
 }
 
+bool SystemGestureEventFilter::HandleDeviceControl(aura::GestureEvent* event) {
+  gfx::Rect screen = gfx::Screen::GetPrimaryMonitor().bounds_in_pixel();
+  double percent = 100.0 * (event->y() - screen.y()) / screen.height();
+  if (percent > 100.0)
+    percent = 100.0;
+  if (percent < 0.0)
+    percent = 0.0;
+  ash::AcceleratorController* accelerator =
+      ash::Shell::GetInstance()->accelerator_controller();
+  if (start_location_ == bezel_start_left) {
+    ash::BrightnessControlDelegate* delegate =
+        accelerator->brightness_control_delegate();
+    if (delegate)
+      delegate->SetBrightnessPercent(100.0 - percent, true);
+  } else if (start_location_ == bezel_start_right) {
+    ash::VolumeControlDelegate* delegate =
+        accelerator->volume_control_delegate();
+    if (delegate)
+      delegate->SetVolumePercent(100.0 - percent);
+  } else {
+    return true;
+  }
+  // More notifications can be send.
+  return false;
+}
+
+bool SystemGestureEventFilter::HandleLauncherControl(
+    aura::GestureEvent* event) {
+  ash::AcceleratorController* accelerator =
+      ash::Shell::GetInstance()->accelerator_controller();
+  if (start_location_ == bezel_start_bottom && event->delta_y() < 0)
+    // We leave the work to switch to the next window to our accelerators.
+    accelerator->AcceleratorPressed(
+        ui::Accelerator(ui::VKEY_LWIN, false, true, false));
+  else
+    return false;
+  // No further notifications for this gesture.
+  return true;
+}
+
+bool SystemGestureEventFilter::HandleApplicationControl(
+    aura::GestureEvent* event) {
+  ash::AcceleratorController* accelerator =
+      ash::Shell::GetInstance()->accelerator_controller();
+  if (start_location_ == bezel_start_left && event->delta_x() > 0)
+    // We leave the work to switch to the next window to our accelerators.
+    accelerator->AcceleratorPressed(
+        ui::Accelerator(ui::VKEY_F5, true, false, false));
+  else if (start_location_ == bezel_start_right && event->delta_x() < 0)
+    // We leave the work to switch to the previous window to our accelerators.
+    accelerator->AcceleratorPressed(
+        ui::Accelerator(ui::VKEY_F5, false, false, false));
+  else
+    return false;
+  // No further notifications for this gesture.
+  return true;
+}
+
 }  // namespace internal
 }  // namespace ash