Revert of CrOS: Fix appearance of notification toasts when sliding out via gesture

ui/views/controls/slide_out_view.cc

+// 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 "ui/views/controls/slide_out_view.h"
+
+#include "ui/compositor/layer.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/gfx/transform.h"
+
+namespace views {
+
+SlideOutView::SlideOutView() {
+  // If accelerated compositing is not available, this widget tracks the
+  // OnSlideOut event but does not render any visible changes.
+  SetPaintToLayer();
+  layer()->SetFillsBoundsOpaquely(false);
+}
+
+SlideOutView::~SlideOutView() {
+}
+
+void SlideOutView::OnGestureEvent(ui::GestureEvent* event) {
+  const float kScrollRatioForClosingNotification = 0.5f;
+
+  if (event->type() == ui::ET_SCROLL_FLING_START) {
+    // The threshold for the fling velocity is computed empirically.
+    // The unit is in pixels/second.
+    const float kFlingThresholdForClose = 800.f;
+    if (is_slide_out_enabled_ &&
+        fabsf(event->details().velocity_x()) > kFlingThresholdForClose) {
+      SlideOutAndClose(event->details().velocity_x() < 0 ? SLIDE_LEFT :
+                       SLIDE_RIGHT);
+      event->StopPropagation();
+      return;
+    }
+    RestoreVisualState();
+    return;
+  }
+
+  if (!event->IsScrollGestureEvent())
+    return;
+
+  if (event->type() == ui::ET_GESTURE_SCROLL_BEGIN) {
+    gesture_amount_ = 0.f;
+  } else if (event->type() == ui::ET_GESTURE_SCROLL_UPDATE) {
+    // The scroll-update events include the incremental scroll amount.
+    gesture_amount_ += event->details().scroll_x();
+
+    float scroll_amount;
+    if (is_slide_out_enabled_) {
+      scroll_amount = gesture_amount_;
+      layer()->SetOpacity(1.f - std::min(fabsf(scroll_amount) / width(), 1.f));
+    } else {
+      if (gesture_amount_ >= 0) {
+        scroll_amount = std::min(0.5f * gesture_amount_,
+                                 width() * kScrollRatioForClosingNotification);
+      } else {
+        scroll_amount =
+            std::max(0.5f * gesture_amount_,
+                     -1.f * width() * kScrollRatioForClosingNotification);
+      }
+    }
+
+    gfx::Transform transform;
+    transform.Translate(scroll_amount, 0.0);
+    layer()->SetTransform(transform);
+
+  } else if (event->type() == ui::ET_GESTURE_SCROLL_END) {
+    float scrolled_ratio = fabsf(gesture_amount_) / width();
+    if (is_slide_out_enabled_ &&
+        scrolled_ratio >= kScrollRatioForClosingNotification) {
+      SlideOutAndClose(gesture_amount_ < 0 ? SLIDE_LEFT : SLIDE_RIGHT);
+      event->StopPropagation();
+      return;
+    }
+    RestoreVisualState();
+  }
+
+  event->SetHandled();
+}
+
+void SlideOutView::RestoreVisualState() {
+  // Restore the layer state.
+  const int kSwipeRestoreDurationMS = 150;
+  ui::ScopedLayerAnimationSettings settings(layer()->GetAnimator());
+  settings.SetTransitionDuration(
+      base::TimeDelta::FromMilliseconds(kSwipeRestoreDurationMS));
+  layer()->SetTransform(gfx::Transform());
+  layer()->SetOpacity(1.f);
+}
+
+void SlideOutView::SlideOutAndClose(SlideDirection direction) {
+  const int kSwipeOutTotalDurationMS = 150;
+  int swipe_out_duration = kSwipeOutTotalDurationMS * layer()->opacity();
+  ui::ScopedLayerAnimationSettings settings(layer()->GetAnimator());
+  settings.SetTransitionDuration(
+      base::TimeDelta::FromMilliseconds(swipe_out_duration));
+  settings.AddObserver(this);
+
+  gfx::Transform transform;
+  transform.Translate(direction == SLIDE_LEFT ? -width() : width(), 0.0);
+  layer()->SetTransform(transform);
+  layer()->SetOpacity(0.f);
+}
+
+void SlideOutView::OnImplicitAnimationsCompleted() {
+  OnSlideOut();
+}
+
+}  // namespace views