| // Copyright 2013 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/scrollbar_layer_impl_base.h" |
| |
| #include <algorithm> |
| #include "cc/trees/layer_tree_impl.h" |
| #include "ui/gfx/rect_conversions.h" |
| |
| namespace cc { |
| |
| ScrollbarLayerImplBase::ScrollbarLayerImplBase( |
| LayerTreeImpl* tree_impl, |
| int id, |
| ScrollbarOrientation orientation, |
| bool is_left_side_vertical_scrollbar, |
| bool is_overlay) |
| : LayerImpl(tree_impl, id), |
| scroll_layer_(NULL), |
| clip_layer_(NULL), |
| is_overlay_scrollbar_(is_overlay), |
| thumb_thickness_scale_factor_(1.f), |
| current_pos_(0.f), |
| maximum_(0), |
| orientation_(orientation), |
| is_left_side_vertical_scrollbar_(is_left_side_vertical_scrollbar), |
| vertical_adjust_(0.f), |
| visible_to_total_length_ratio_(1.f) {} |
| |
| ScrollbarLayerImplBase::~ScrollbarLayerImplBase() {} |
| |
| void ScrollbarLayerImplBase::PushPropertiesTo(LayerImpl* layer) { |
| float active_opacity = layer->opacity(); |
| LayerImpl::PushPropertiesTo(layer); |
| layer->SetOpacity(active_opacity); |
| DCHECK(layer->ToScrollbarLayer()); |
| layer->ToScrollbarLayer()->set_is_overlay_scrollbar(is_overlay_scrollbar_); |
| PushScrollClipPropertiesTo(layer); |
| } |
| |
| void ScrollbarLayerImplBase::PushScrollClipPropertiesTo(LayerImpl* layer) { |
| DCHECK(layer->ToScrollbarLayer()); |
| layer->ToScrollbarLayer()->SetScrollLayerById(ScrollLayerId()); |
| layer->ToScrollbarLayer()->SetClipLayerById(ClipLayerId()); |
| } |
| |
| ScrollbarLayerImplBase* ScrollbarLayerImplBase::ToScrollbarLayer() { |
| return this; |
| } |
| |
| namespace { |
| |
| typedef void (LayerImpl::*ScrollbarRegistrationOperation)( |
| ScrollbarLayerImplBase*); |
| |
| void RegisterScrollbarWithLayers(ScrollbarLayerImplBase* scrollbar, |
| LayerImpl* container_layer, |
| LayerImpl* scroll_layer, |
| ScrollbarRegistrationOperation operation) { |
| if (!container_layer || !scroll_layer) |
| return; |
| |
| DCHECK(scrollbar); |
| |
| // Scrollbars must be notifed of changes to their scroll and container layers |
| // and all scrollable layers in between. |
| for (LayerImpl* current_layer = scroll_layer; |
| current_layer && current_layer != container_layer->parent(); |
| current_layer = current_layer->parent()) { |
| // TODO(wjmaclean) We shouldn't need to exempt the scroll_layer from the |
| // scrollable() test below. https://crbug.com/367858. |
| if (current_layer->scrollable() || current_layer == container_layer || |
| current_layer == scroll_layer) |
| (current_layer->*operation)(scrollbar); |
| } |
| } |
| } // namespace |
| |
| void ScrollbarLayerImplBase::SetScrollLayerById(int id) { |
| LayerImpl* scroll_layer = layer_tree_impl()->LayerById(id); |
| if (scroll_layer_ == scroll_layer) |
| return; |
| |
| RegisterScrollbarWithLayers( |
| this, clip_layer_, scroll_layer_, &LayerImpl::RemoveScrollbar); |
| scroll_layer_ = scroll_layer; |
| RegisterScrollbarWithLayers( |
| this, clip_layer_, scroll_layer_, &LayerImpl::AddScrollbar); |
| } |
| |
| void ScrollbarLayerImplBase::SetClipLayerById(int id) { |
| LayerImpl* clip_layer = layer_tree_impl()->LayerById(id); |
| if (clip_layer_ == clip_layer) |
| return; |
| |
| RegisterScrollbarWithLayers( |
| this, clip_layer_, scroll_layer_, &LayerImpl::RemoveScrollbar); |
| clip_layer_ = clip_layer; |
| RegisterScrollbarWithLayers( |
| this, clip_layer_, scroll_layer_, &LayerImpl::AddScrollbar); |
| } |
| |
| gfx::Rect ScrollbarLayerImplBase::ScrollbarLayerRectToContentRect( |
| const gfx::RectF& layer_rect) const { |
| // Don't intersect with the bounds as in LayerRectToContentRect() because |
| // layer_rect here might be in coordinates of the containing layer. |
| gfx::RectF content_rect = gfx::ScaleRect(layer_rect, |
| contents_scale_x(), |
| contents_scale_y()); |
| return gfx::ToEnclosingRect(content_rect); |
| } |
| |
| void ScrollbarLayerImplBase::SetCurrentPos(float current_pos) { |
| if (current_pos_ == current_pos) |
| return; |
| current_pos_ = current_pos; |
| NoteLayerPropertyChanged(); |
| } |
| |
| void ScrollbarLayerImplBase::SetMaximum(int maximum) { |
| if (maximum_ == maximum) |
| return; |
| maximum_ = maximum; |
| NoteLayerPropertyChanged(); |
| } |
| |
| void ScrollbarLayerImplBase::SetVerticalAdjust(float vertical_adjust) { |
| if (vertical_adjust_ == vertical_adjust) |
| return; |
| vertical_adjust_ = vertical_adjust; |
| NoteLayerPropertyChanged(); |
| } |
| |
| void ScrollbarLayerImplBase::SetVisibleToTotalLengthRatio(float ratio) { |
| if (!IsThumbResizable()) |
| return; |
| |
| if (visible_to_total_length_ratio_ == ratio) |
| return; |
| visible_to_total_length_ratio_ = ratio; |
| NoteLayerPropertyChanged(); |
| } |
| |
| void ScrollbarLayerImplBase::SetThumbThicknessScaleFactor(float factor) { |
| if (thumb_thickness_scale_factor_ == factor) |
| return; |
| thumb_thickness_scale_factor_ = factor; |
| NoteLayerPropertyChanged(); |
| } |
| |
| gfx::Rect ScrollbarLayerImplBase::ComputeThumbQuadRect() const { |
| // Thumb extent is the length of the thumb in the scrolling direction, thumb |
| // thickness is in the perpendicular direction. Here's an example of a |
| // horizontal scrollbar - inputs are above the scrollbar, computed values |
| // below: |
| // |
| // |<------------------- track_length_ ------------------->| |
| // |
| // |--| <-- start_offset |
| // |
| // +--+----------------------------+------------------+-------+--+ |
| // |<|| |##################| ||>| |
| // +--+----------------------------+------------------+-------+--+ |
| // |
| // |<- thumb_length ->| |
| // |
| // |<------- thumb_offset -------->| |
| // |
| // For painted, scrollbars, the length is fixed. For solid color scrollbars we |
| // have to compute it. The ratio of the thumb's length to the track's length |
| // is the same as that of the visible viewport to the total viewport, unless |
| // that would make the thumb's length less than its thickness. |
| // |
| // vertical_adjust_ is used when the layer geometry from the main thread is |
| // not in sync with what the user sees. For instance on Android scrolling the |
| // top bar controls out of view reveals more of the page content. We want the |
| // root layer scrollbars to reflect what the user sees even if we haven't |
| // received new layer geometry from the main thread. If the user has scrolled |
| // down by 50px and the initial viewport size was 950px the geometry would |
| // look something like this: |
| // |
| // vertical_adjust_ = 50, scroll position 0, visible ratios 99% |
| // Layer geometry: Desired thumb positions: |
| // +--------------------+-+ +----------------------+ <-- 0px |
| // | |v| | #| |
| // | |e| | #| |
| // | |r| | #| |
| // | |t| | #| |
| // | |i| | #| |
| // | |c| | #| |
| // | |a| | #| |
| // | |l| | #| |
| // | | | | #| |
| // | |l| | #| |
| // | |a| | #| |
| // | |y| | #| |
| // | |e| | #| |
| // | |r| | #| |
| // +--------------------+-+ | #| |
| // | horizontal layer | | | #| |
| // +--------------------+-+ | #| <-- 950px |
| // | | | #| |
| // | | |##################### | |
| // +----------------------+ +----------------------+ <-- 1000px |
| // |
| // The layer geometry is set up for a 950px tall viewport, but the user can |
| // actually see down to 1000px. Thus we have to move the quad for the |
| // horizontal scrollbar down by the vertical_adjust_ factor and lay the |
| // vertical thumb out on a track lengthed by the vertical_adjust_ factor. This |
| // means the quads may extend outside the layer's bounds. |
| |
| // With the length known, we can compute the thumb's position. |
| float track_length = TrackLength(); |
| int thumb_length = ThumbLength(); |
| int thumb_thickness = ThumbThickness(); |
| |
| // With the length known, we can compute the thumb's position. |
| float clamped_current_pos = |
| std::min(std::max(current_pos_, 0.f), static_cast<float>(maximum_)); |
| float ratio = clamped_current_pos / maximum_; |
| float max_offset = track_length - thumb_length; |
| int thumb_offset = static_cast<int>(ratio * max_offset) + TrackStart(); |
| |
| float thumb_thickness_adjustment = |
| thumb_thickness * (1.f - thumb_thickness_scale_factor_); |
| |
| gfx::RectF thumb_rect; |
| if (orientation_ == HORIZONTAL) { |
| thumb_rect = gfx::RectF(thumb_offset, |
| vertical_adjust_ + thumb_thickness_adjustment, |
| thumb_length, |
| thumb_thickness - thumb_thickness_adjustment); |
| } else { |
| thumb_rect = gfx::RectF( |
| is_left_side_vertical_scrollbar_ |
| ? bounds().width() - thumb_thickness |
| : thumb_thickness_adjustment, |
| thumb_offset, |
| thumb_thickness - thumb_thickness_adjustment, |
| thumb_length); |
| } |
| |
| return ScrollbarLayerRectToContentRect(thumb_rect); |
| } |
| |
| void ScrollbarLayerImplBase::ScrollbarParametersDidChange() { |
| if (!clip_layer_ || !scroll_layer_) |
| return; |
| |
| scroll_layer_->SetScrollbarPosition(this, clip_layer_); |
| } |
| |
| } // namespace cc |
