ash: Move out the system-pinch handler into a separate location.

This is the first step of tidying up SystemGestureEventFilter. Subsequent patches will
move bezel and long-press functionality into separate files as well.

BUG=none

Review URL: https://chromiumcodereview.appspot.com/10898021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@153827 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 239 insertions, 0 deletions

diff --git a/ash/wm/gestures/system_pinch_handler.cc b/ash/wm/gestures/system_pinch_handler.cc
new file mode 100644
index 0000000..ddfd13c
--- /dev/null
+++ b/ash/wm/gestures/system_pinch_handler.cc
@@ -0,0 +1,155 @@
+// Copyright (c) 2012 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/system_pinch_handler.h"
+
+#include "ash/launcher/launcher.h"
+#include "ash/screen_ash.h"
+#include "ash/shell.h"
+#include "ash/wm/property_util.h"
+#include "ash/wm/window_util.h"
+#include "ash/wm/workspace/snap_sizer.h"
+#include "ui/aura/window.h"
+#include "ui/base/events.h"
+#include "ui/base/gestures/gesture_types.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/gfx/rect.h"
+#include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_delegate.h"
+
+const double kPinchThresholdForMaximize = 1.5;
+const double kPinchThresholdForMinimize = 0.7;
+
+namespace ash {
+namespace internal {
+
+const int SystemPinchHandler::kSystemGesturePoints = 4;
+
+SystemPinchHandler::SystemPinchHandler(aura::Window* target)
+    : target_(target),
+      phantom_(target),
+      phantom_state_(PHANTOM_WINDOW_NORMAL),
+      pinch_factor_(1.) {
+  widget_ = views::Widget::GetWidgetForNativeWindow(target_);
+}
+
+SystemPinchHandler::~SystemPinchHandler() {
+}
+
+SystemGestureStatus SystemPinchHandler::ProcessGestureEvent(
+    const ui::GestureEvent& event) {
+  // The target has changed, somehow. Let's bale.
+  if (!widget_ || !widget_->widget_delegate()->CanResize())
+    return SYSTEM_GESTURE_END;
+
+  switch (event.type()) {
+    case ui::ET_GESTURE_END: {
+      if (event.details().touch_points() > kSystemGesturePoints)
+        break;
+
+      if (phantom_state_ == PHANTOM_WINDOW_MAXIMIZED) {
+        if (!wm::IsWindowMaximized(target_) &&
+            !wm::IsWindowFullscreen(target_))
+          wm::MaximizeWindow(target_);
+      } else if (phantom_state_ == PHANTOM_WINDOW_MINIMIZED) {
+        if (wm::IsWindowMaximized(target_) ||
+            wm::IsWindowFullscreen(target_)) {
+          wm::RestoreWindow(target_);
+        } else {
+          wm::MinimizeWindow(target_);
+
+          // NOTE: Minimizing the window will cause this handler to be
+          // destroyed. So do not access anything from |this| from here.
+          return SYSTEM_GESTURE_END;
+        }
+      }
+      return SYSTEM_GESTURE_END;
+    }
+
+    case ui::ET_GESTURE_PINCH_UPDATE: {
+      // The PINCH_UPDATE events contain incremental scaling updates.
+      pinch_factor_ *= event.details().scale();
+      gfx::Rect bounds =
+          GetPhantomWindowScreenBounds(target_, event.location());
+      if (phantom_state_ != PHANTOM_WINDOW_NORMAL || phantom_.IsShowing())
+        phantom_.Show(bounds);
+      break;
+    }
+
+    case ui::ET_GESTURE_MULTIFINGER_SWIPE: {
+      phantom_.Hide();
+      pinch_factor_ = 1.0;
+      phantom_state_ = PHANTOM_WINDOW_NORMAL;
+
+      if (event.details().swipe_left() || event.details().swipe_right()) {
+        // Snap for left/right swipes. In case the window is
+        // maximized/fullscreen, then restore the window first so that tiling
+        // works correctly.
+        if (wm::IsWindowMaximized(target_) ||
+            wm::IsWindowFullscreen(target_))
+          wm::RestoreWindow(target_);
+
+        ui::ScopedLayerAnimationSettings settings(
+            target_->layer()->GetAnimator());
+        SnapSizer sizer(target_,
+            gfx::Point(),
+            event.details().swipe_left() ? internal::SnapSizer::LEFT_EDGE :
+                                           internal::SnapSizer::RIGHT_EDGE,
+            Shell::GetInstance()->GetGridSize());
+        target_->SetBounds(sizer.GetSnapBounds(target_->bounds()));
+      } else if (event.details().swipe_up()) {
+        if (!wm::IsWindowMaximized(target_) &&
+            !wm::IsWindowFullscreen(target_))
+          wm::MaximizeWindow(target_);
+      } else if (event.details().swipe_down()) {
+        wm::MinimizeWindow(target_);
+      } else {
+        NOTREACHED() << "Swipe happened without a direction.";
+      }
+      break;
+    }
+
+    default:
+      break;
+  }
+
+  return SYSTEM_GESTURE_PROCESSED;
+}
+
+gfx::Rect SystemPinchHandler::GetPhantomWindowScreenBounds(
+    aura::Window* window,
+    const gfx::Point& point) {
+  if (pinch_factor_ > kPinchThresholdForMaximize) {
+    phantom_state_ = PHANTOM_WINDOW_MAXIMIZED;
+    return ScreenAsh::ConvertRectToScreen(
+        target_->parent(),
+        ScreenAsh::GetMaximizedWindowBoundsInParent(target_));
+  }
+
+  if (pinch_factor_ < kPinchThresholdForMinimize) {
+    if (wm::IsWindowMaximized(window) || wm::IsWindowFullscreen(window)) {
+      const gfx::Rect* restore = GetRestoreBoundsInScreen(window);
+      if (restore) {
+        phantom_state_ = PHANTOM_WINDOW_MINIMIZED;
+        return *restore;
+      }
+      return window->bounds();
+    }
+
+    Launcher* launcher = Shell::GetInstance()->launcher();
+    gfx::Rect rect = launcher->GetScreenBoundsOfItemIconForWindow(target_);
+    if (rect.IsEmpty())
+      rect = launcher->widget()->GetWindowBoundsInScreen();
+    else
+      rect.Inset(-8, -8);
+    phantom_state_ = PHANTOM_WINDOW_MINIMIZED;
+    return rect;
+  }
+
+  phantom_state_ = PHANTOM_WINDOW_NORMAL;
+  return window->bounds();
+}
+
+}  // namespace internal
+}  // namespace ash
diff --git a/ash/wm/gestures/system_pinch_handler.h b/ash/wm/gestures/system_pinch_handler.h
new file mode 100644
index 0000000..33700ca
--- /dev/null
+++ b/ash/wm/gestures/system_pinch_handler.h
@@ -0,0 +1,84 @@
+// Copyright (c) 2012 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.
+
+#ifndef ASH_WM_GESTURES_SYSTEM_PINCH_HANDLER_H_
+#define ASH_WM_GESTURES_SYSTEM_PINCH_HANDLER_H_
+
+#include "ash/wm/workspace/phantom_window_controller.h"
+
+namespace aura {
+class Window;
+}
+
+namespace gfx {
+class Point;
+}
+
+namespace ui {
+class GestureEvent;
+}
+
+namespace views {
+class Widget;
+}
+
+namespace ash {
+namespace internal {
+
+enum SystemGestureStatus {
+  SYSTEM_GESTURE_PROCESSED,  // The system gesture has been processed.
+  SYSTEM_GESTURE_IGNORED,    // The system gesture was ignored.
+  SYSTEM_GESTURE_END,        // Marks the end of the sytem gesture.
+};
+
+class SystemPinchHandler {
+ public:
+  explicit SystemPinchHandler(aura::Window* target);
+  virtual ~SystemPinchHandler();
+
+  // Processes a gesture event. Returns SYSTEM_GESTURE_PROCESSED if the gesture
+  // event has been processed. Returns SYSTEM_GESTURE_END if the gesture event
+  // has been processed, and marks the end of the gesture sequence (i.e. the
+  // handler should receive no more input events).
+  SystemGestureStatus ProcessGestureEvent(const ui::GestureEvent& event);
+
+  static const int kSystemGesturePoints;
+
+ private:
+  // Returns the appropriate bounds for the phantom window depending on the
+  // state of the window, the state of the gesture sequence, and the current
+  // event location.
+  gfx::Rect GetPhantomWindowScreenBounds(aura::Window* window,
+                                         const gfx::Point& point);
+
+  enum PhantomWindowState {
+    PHANTOM_WINDOW_NORMAL,
+    PHANTOM_WINDOW_MAXIMIZED,
+    PHANTOM_WINDOW_MINIMIZED,
+  };
+
+  aura::Window* target_;
+  views::Widget* widget_;
+
+  // A phantom window is used to provide visual cues for
+  // pinch-to-resize/maximize/minimize gestures.
+  PhantomWindowController phantom_;
+
+  // When the phantom window is in minimized or maximized state, moving the
+  // target window should not move the phantom window. So |phantom_state_| is
+  // used to track the state of the phantom window.
+  PhantomWindowState phantom_state_;
+
+  // PINCH_UPDATE events include incremental pinch-amount. But it is necessary
+  // to keep track of the overall pinch-amount. |pinch_factor_| is used for
+  // that.
+  double pinch_factor_;
+
+  DISALLOW_COPY_AND_ASSIGN(SystemPinchHandler);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_WM_GESTURES_SYSTEM_PINCH_HANDLER_H_