| // Copyright 2015 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 "cc/layers/viewport.h" |
| |
| #include "base/logging.h" |
| #include "cc/input/top_controls_manager.h" |
| #include "cc/trees/layer_tree_host_impl.h" |
| #include "cc/trees/layer_tree_impl.h" |
| #include "ui/gfx/geometry/vector2d_conversions.h" |
| #include "ui/gfx/geometry/vector2d_f.h" |
| |
| namespace cc { |
| |
| // static |
| scoped_ptr<Viewport> Viewport::Create( |
| LayerTreeHostImpl* host_impl) { |
| return make_scoped_ptr(new Viewport(host_impl)); |
| } |
| |
| Viewport::Viewport(LayerTreeHostImpl* host_impl) |
| : host_impl_(host_impl) { |
| DCHECK(host_impl_); |
| } |
| |
| Viewport::ScrollResult Viewport::ScrollBy(const gfx::Vector2dF& delta, |
| const gfx::Point& viewport_point, |
| bool is_wheel_scroll) { |
| gfx::Vector2dF content_delta = delta; |
| ScrollResult result; |
| |
| if (ShouldTopControlsConsumeScroll(delta)) { |
| result.top_controls_applied_delta = ScrollTopControls(delta); |
| content_delta -= result.top_controls_applied_delta; |
| } |
| |
| gfx::Vector2dF pending_content_delta = content_delta; |
| |
| if (OuterScrollLayer()) { |
| pending_content_delta -= host_impl_->ScrollLayer(OuterScrollLayer(), |
| pending_content_delta, |
| viewport_point, |
| is_wheel_scroll); |
| } |
| |
| // TODO(bokan): This shouldn't be needed but removing it causes subtle |
| // viewport movement during top controls manipulation. |
| if (!gfx::ToRoundedVector2d(pending_content_delta).IsZero()) { |
| pending_content_delta -= host_impl_->ScrollLayer(InnerScrollLayer(), |
| pending_content_delta, |
| viewport_point, |
| is_wheel_scroll); |
| result.unused_scroll_delta = AdjustOverscroll(pending_content_delta); |
| } |
| |
| |
| result.applied_delta = content_delta - pending_content_delta; |
| return result; |
| } |
| |
| gfx::Vector2dF Viewport::ScrollTopControls(const gfx::Vector2dF& delta) { |
| gfx::Vector2dF excess_delta = |
| host_impl_->top_controls_manager()->ScrollBy(delta); |
| |
| return delta - excess_delta; |
| } |
| |
| bool Viewport::ShouldTopControlsConsumeScroll( |
| const gfx::Vector2dF& scroll_delta) const { |
| // Always consume if it's in the direction to show the top controls. |
| if (scroll_delta.y() < 0) |
| return true; |
| |
| if (TotalScrollOffset().y() < MaxTotalScrollOffset().y()) |
| return true; |
| |
| return false; |
| } |
| |
| gfx::Vector2dF Viewport::AdjustOverscroll(const gfx::Vector2dF& delta) const { |
| const float kEpsilon = 0.1f; |
| gfx::Vector2dF adjusted = delta; |
| |
| if (std::abs(adjusted.x()) < kEpsilon) |
| adjusted.set_x(0.0f); |
| if (std::abs(adjusted.y()) < kEpsilon) |
| adjusted.set_y(0.0f); |
| |
| // Disable overscroll on axes which are impossible to scroll. |
| if (host_impl_->settings().report_overscroll_only_for_scrollable_axes) { |
| if (std::abs(MaxTotalScrollOffset().x()) <= kEpsilon || |
| !InnerScrollLayer()->user_scrollable_horizontal()) |
| adjusted.set_x(0.0f); |
| if (std::abs(MaxTotalScrollOffset().y()) <= kEpsilon || |
| !InnerScrollLayer()->user_scrollable_vertical()) |
| adjusted.set_y(0.0f); |
| } |
| |
| return adjusted; |
| } |
| |
| gfx::ScrollOffset Viewport::MaxTotalScrollOffset() const { |
| gfx::ScrollOffset offset; |
| |
| offset += InnerScrollLayer()->MaxScrollOffset(); |
| |
| if (OuterScrollLayer()) |
| offset += OuterScrollLayer()->MaxScrollOffset(); |
| |
| return offset; |
| } |
| |
| gfx::ScrollOffset Viewport::TotalScrollOffset() const { |
| gfx::ScrollOffset offset; |
| |
| offset += InnerScrollLayer()->CurrentScrollOffset(); |
| |
| if (OuterScrollLayer()) |
| offset += OuterScrollLayer()->CurrentScrollOffset(); |
| |
| return offset; |
| } |
| |
| LayerImpl* Viewport::InnerScrollLayer() const { |
| return host_impl_->InnerViewportScrollLayer(); |
| } |
| |
| LayerImpl* Viewport::OuterScrollLayer() const { |
| return host_impl_->OuterViewportScrollLayer(); |
| } |
| |
| } // namespace cc |