Use scroll-boundary-behavior to control overscroll-refresh/glow on android.

content/browser/android/overscroll_controller_android.cc

 // Copyright 2014 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 "content/browser/android/overscroll_controller_android.h"
 
 #include "base/android/build_info.h"
 #include "base/command_line.h"
 #include "base/memory/ptr_util.h"
 #include "cc/layers/layer.h"
@@ skipping 78 matching lines @@
           switches::kDisablePullToRefreshEffect)) {
     return nullptr;
   }
 
   return base::MakeUnique<OverscrollRefresh>(overscroll_refresh_handler);
 }
 
 }  // namespace
 
 OverscrollControllerAndroid::OverscrollControllerAndroid(
+    ui::OverscrollGlow* glow_effect,
+    ui::OverscrollRefresh* refresh_effect,
+    ui::WindowAndroidCompositor* compositor,
+    float dpi_scale)
+    : compositor_(compositor),
+      dpi_scale_(dpi_scale),
+      enabled_(true),
+      scroll_update_consumed_(false),
+      glow_effect_(glow_effect),
+      refresh_effect_(refresh_effect) {
+  DCHECK(compositor_);
+}
+
+OverscrollControllerAndroid::OverscrollControllerAndroid(
     ui::OverscrollRefreshHandler* overscroll_refresh_handler,
     ui::WindowAndroidCompositor* compositor,
     float dpi_scale)
     : compositor_(compositor),
       dpi_scale_(dpi_scale),
       enabled_(true),
+      scroll_update_consumed_(false),
       glow_effect_(CreateGlowEffect(this, dpi_scale_)),
       refresh_effect_(CreateRefreshEffect(overscroll_refresh_handler)) {

[majidvp, 2017/07/12 21:04:20]

This constructor should delegate to the one above only
passing in newly created glow and refresh effects.

[sunyunjia, 2017/07/19 20:44:11]

Done. I'm not sure if the delegate is worth it. I have to initialize compositor_
and dpi_scale_ any way, as they are constants.

   DCHECK(compositor_);
 }
 
 OverscrollControllerAndroid::~OverscrollControllerAndroid() {
 }
 
 bool OverscrollControllerAndroid::WillHandleGestureEvent(
     const blink::WebGestureEvent& event) {
   if (!enabled_)
     return false;
 
   if (!refresh_effect_)
     return false;
 
   // Suppress refresh detection if the glow effect is still prominent.
   if (glow_effect_ && glow_effect_->IsActive()) {
     if (glow_effect_->GetVisibleAlpha() > MinGlowAlphaToDisableRefresh())
       return false;
   }
 
   bool handled = false;
   switch (event.GetType()) {
     case blink::WebInputEvent::kGestureScrollBegin:
       refresh_effect_->OnScrollBegin();
+      scroll_update_consumed_ = false;
       break;
 
     case blink::WebInputEvent::kGestureScrollUpdate: {
       gfx::Vector2dF scroll_delta(event.data.scroll_update.delta_x,
                                   event.data.scroll_update.delta_y);
       scroll_delta.Scale(dpi_scale_);
       handled = refresh_effect_->WillHandleScrollUpdate(scroll_delta);
     } break;
 
     case blink::WebInputEvent::kGestureScrollEnd:
@@ skipping 41 matching lines @@
   // sent from the renderer compositor.
   if (event.GetType() == blink::WebInputEvent::kGestureScrollEnd ||
       event.GetType() == blink::WebInputEvent::kGestureFlingStart) {
     OnOverscrolled(DidOverscrollParams());
   }
 
   if (event.GetType() == blink::WebInputEvent::kGestureScrollUpdate &&
       refresh_effect_) {
     // The effect should only be allowed if both the causal touch events go
     // unconsumed and the generated scroll events go unconsumed.
-    bool consumed =
+    scroll_update_consumed_ =
         ack_result == INPUT_EVENT_ACK_STATE_CONSUMED ||
         event.data.scroll_update.previous_update_in_sequence_prevented;
-    refresh_effect_->OnScrollUpdateAck(consumed);
   }
 }
 
 void OverscrollControllerAndroid::OnOverscrolled(
-    const DidOverscrollParams& params) {
+    const DidOverscrollParams& overscroll_params) {
   if (!enabled_)
     return;
 
-  if (refresh_effect_ && (refresh_effect_->IsActive() ||
-                          refresh_effect_->IsAwaitingScrollUpdateAck())) {
-    // An active (or potentially active) refresh effect should always pre-empt
-    // the passive glow effect.
-    return;
+  DidOverscrollParams params = overscroll_params;

[majidvp, 2017/07/12 21:04:20]

Seems a bit inefficient and unnecessary to create a copy of
whole params, reset some value conditionally and then copy
those values again to pass into the |glow_effect_->OnOverscrolled|.

Instead probably best to do

Vector2d accumulated_overscroll =
gfx::ScaleVector2d(overscroll_params.accumulated_overscroll, dpi_scale_);

if  (boundar_behavior = none)
  accumulated_overscroll.set_y(0);


glow_effect_->OnOverscrolled(..., accumulated_overscroll, ...)

[sunyunjia, 2017/07/19 20:44:11]

Done.

+
+  if (refresh_effect_) {
+    bool can_navigate =
+        (!scroll_update_consumed_) &&
+        (params.scroll_boundary_behavior.y ==
+         cc::ScrollBoundaryBehavior::ScrollBoundaryBehaviorType::
+             kScrollBoundaryBehaviorTypeAuto);
+    refresh_effect_->OnOverscrolled(can_navigate);
+
+    if (refresh_effect_->IsActive() ||
+        refresh_effect_->IsAwaitingScrollUpdateAck()) {
+      // An active (or potentially active) refresh effect should always pre-empt
+      // the passive glow effect.
+      return;
+    }
+  }
+
+  if (params.scroll_boundary_behavior.x ==
+      cc::ScrollBoundaryBehavior::ScrollBoundaryBehaviorType::
+          kScrollBoundaryBehaviorTypeNone) {
+    params.accumulated_overscroll.set_x(0);
+    params.latest_overscroll_delta.set_x(0);
+    params.current_fling_velocity.set_x(0);
+  }
+
+  if (params.scroll_boundary_behavior.y ==
+      cc::ScrollBoundaryBehavior::ScrollBoundaryBehaviorType::
+          kScrollBoundaryBehaviorTypeNone) {
+    params.accumulated_overscroll.set_y(0);
+    params.latest_overscroll_delta.set_y(0);
+    params.current_fling_velocity.set_y(0);
   }
 
   if (glow_effect_ &&
       glow_effect_->OnOverscrolled(
           base::TimeTicks::Now(),
           gfx::ScaleVector2d(params.accumulated_overscroll, dpi_scale_),
           gfx::ScaleVector2d(params.latest_overscroll_delta, dpi_scale_),
           gfx::ScaleVector2d(params.current_fling_velocity, dpi_scale_),
           gfx::ScaleVector2d(
               params.causal_event_viewport_point.OffsetFromOrigin(),
@@ skipping 55 matching lines @@
 std::unique_ptr<EdgeEffectBase>
 OverscrollControllerAndroid::CreateEdgeEffect() {
   return CreateGlowEdgeEffect(&compositor_->GetResourceManager(), dpi_scale_);
 }
 
 void OverscrollControllerAndroid::SetNeedsAnimate() {
   compositor_->SetNeedsAnimate();
 }
 
 }  // namespace content