| // Copyright 2019 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 "base/cancelable_callback.h" |
| #include "cc/base/math_util.h" |
| #include "cc/input/scrollbar.h" |
| #include "cc/input/scrollbar_controller.h" |
| #include "cc/trees/layer_tree_impl.h" |
| #include "cc/trees/scroll_node.h" |
| |
| namespace cc { |
| ScrollbarController::~ScrollbarController() { |
| if (cancelable_autoscroll_task_) { |
| cancelable_autoscroll_task_->Cancel(); |
| cancelable_autoscroll_task_.reset(); |
| } |
| } |
| |
| ScrollbarController::ScrollbarController( |
| LayerTreeHostImpl* layer_tree_host_impl) |
| : layer_tree_host_impl_(layer_tree_host_impl), |
| scrollbar_scroll_is_active_(false), |
| last_known_pointer_position_(gfx::PointF(0, 0)), |
| drag_processed_for_current_frame_(false), |
| cancelable_autoscroll_task_(nullptr) {} |
| |
| void ScrollbarController::WillBeginImplFrame() { |
| drag_processed_for_current_frame_ = false; |
| RecomputeAutoscrollStateIfNeeded(); |
| } |
| |
| gfx::Vector2dF ScrollbarController::GetThumbRelativePoint( |
| const ScrollbarLayerImplBase* scrollbar, |
| const gfx::PointF position_in_widget) { |
| bool clipped; |
| const gfx::PointF position_in_layer = |
| GetScrollbarRelativePosition(scrollbar, position_in_widget, &clipped); |
| |
| if (clipped) |
| return gfx::Vector2d(0, 0); |
| |
| const gfx::RectF thumb_rect(scrollbar->ComputeThumbQuadRect()); |
| DCHECK(thumb_rect.Contains(position_in_layer)); |
| return position_in_layer - gfx::PointF(thumb_rect.origin()); |
| } |
| |
| // Retrieves the ScrollbarLayerImplBase corresponding to the stashed ElementId. |
| ScrollbarLayerImplBase* ScrollbarController::ScrollbarLayer() { |
| if (!captured_scrollbar_metadata_.has_value()) |
| return nullptr; |
| |
| const ScrollbarSet scrollbars = layer_tree_host_impl_->ScrollbarsFor( |
| captured_scrollbar_metadata_->scroll_element_id); |
| for (ScrollbarLayerImplBase* scrollbar : scrollbars) { |
| if (captured_scrollbar_metadata_->orientation == scrollbar->orientation()) |
| return scrollbar; |
| } |
| return nullptr; |
| } |
| |
| // Performs hit test and prepares scroll deltas that will be used by GSB and |
| // GSU. |
| InputHandlerPointerResult ScrollbarController::HandlePointerDown( |
| const gfx::PointF position_in_widget, |
| bool shift_modifier) { |
| LayerImpl* layer_impl = GetLayerHitByPoint(position_in_widget); |
| |
| // If a non-custom scrollbar layer was not found, we return early as there is |
| // no point in setting additional state in the ScrollbarController. Return an |
| // empty InputHandlerPointerResult in this case so that when it is bubbled up |
| // to InputHandlerProxy::RouteToTypeSpecificHandler, the pointer event gets |
| // passed on to the main thread. |
| if (!(layer_impl && layer_impl->ToScrollbarLayer())) |
| return InputHandlerPointerResult(); |
| |
| const ScrollbarLayerImplBase* scrollbar = layer_impl->ToScrollbarLayer(); |
| captured_scrollbar_metadata_ = CapturedScrollbarMetadata(); |
| captured_scrollbar_metadata_->scroll_element_id = |
| scrollbar->scroll_element_id(); |
| captured_scrollbar_metadata_->orientation = scrollbar->orientation(); |
| |
| InputHandlerPointerResult scroll_result; |
| scroll_result.target_scroller = scrollbar->scroll_element_id(); |
| scroll_result.type = PointerResultType::kScrollbarScroll; |
| layer_tree_host_impl_->active_tree()->UpdateScrollbarGeometries(); |
| const ScrollbarPart scrollbar_part = |
| GetScrollbarPartFromPointerDown(scrollbar, position_in_widget); |
| scroll_result.scroll_offset = GetScrollOffsetForScrollbarPart( |
| scrollbar, scrollbar_part, shift_modifier); |
| last_known_pointer_position_ = position_in_widget; |
| scrollbar_scroll_is_active_ = true; |
| scroll_result.scroll_units = Granularity(scrollbar_part, shift_modifier); |
| if (scrollbar_part == ScrollbarPart::THUMB) { |
| drag_state_ = DragState(); |
| drag_state_->anchor_relative_to_thumb_ = |
| GetThumbRelativePoint(scrollbar, position_in_widget); |
| |
| // Record the current scroller offset. This will be needed to snap the |
| // thumb back to its original position if the pointer moves too far away |
| // from the track during a thumb drag. |
| drag_state_->scroll_position_at_start_ = scrollbar->current_pos(); |
| } |
| |
| if (!scroll_result.scroll_offset.IsZero()) { |
| // Thumb drag is the only scrollbar manipulation that cannot produce an |
| // autoscroll. All other interactions like clicking on arrows/trackparts |
| // have the potential of initiating an autoscroll (if held down for long |
| // enough). |
| DCHECK(scrollbar_part != ScrollbarPart::THUMB); |
| cancelable_autoscroll_task_ = std::make_unique<base::CancelableOnceClosure>( |
| base::BindOnce(&ScrollbarController::StartAutoScrollAnimation, |
| base::Unretained(this), |
| InitialDeltaToAutoscrollVelocity( |
| scrollbar, scroll_result.scroll_offset), |
| scrollbar, scrollbar_part)); |
| layer_tree_host_impl_->task_runner_provider() |
| ->ImplThreadTaskRunner() |
| ->PostDelayedTask(FROM_HERE, cancelable_autoscroll_task_->callback(), |
| kInitialAutoscrollTimerDelay); |
| } |
| return scroll_result; |
| } |
| |
| bool ScrollbarController::SnapToDragOrigin( |
| const ScrollbarLayerImplBase* scrollbar, |
| const gfx::PointF pointer_position_in_widget) { |
| // Consult the ScrollbarTheme to check if thumb snapping is supported on the |
| // current platform. |
| if (!(scrollbar && scrollbar->SupportsDragSnapBack())) |
| return false; |
| |
| bool clipped = false; |
| const gfx::PointF pointer_position_in_layer = GetScrollbarRelativePosition( |
| scrollbar, pointer_position_in_widget, &clipped); |
| |
| if (clipped) |
| return false; |
| |
| layer_tree_host_impl_->active_tree()->UpdateScrollbarGeometries(); |
| const ScrollbarOrientation orientation = scrollbar->orientation(); |
| const gfx::Rect forward_track_rect = scrollbar->ForwardTrackRect(); |
| |
| // When dragging the thumb, there needs to exist "gutters" on either side of |
| // the track. The thickness of these gutters is a multiple of the track (or |
| // thumb) thickness. As long as the pointer remains within the bounds of these |
| // gutters in the non-scrolling direction, thumb drag proceeds as expected. |
| // The moment the pointer moves outside the bounds, the scroller needs to snap |
| // back to the drag_origin (aka the scroll offset of the parent scroller |
| // before the thumb drag initiated). |
| int track_thickness = orientation == ScrollbarOrientation::VERTICAL |
| ? forward_track_rect.width() |
| : forward_track_rect.height(); |
| |
| if (!track_thickness) { |
| // For overlay scrollbars (or for tests that do not set up a track |
| // thickness), use the thumb_thickness instead to determine the gutters. |
| const int thumb_thickness = scrollbar->ThumbThickness(); |
| |
| // If the thumb doesn't have thickness, the gutters can't be determined. |
| // Snapping shouldn't occur in this case. |
| if (!thumb_thickness) |
| return false; |
| |
| track_thickness = thumb_thickness; |
| } |
| |
| const float gutter_thickness = kOffSideMultiplier * track_thickness; |
| const float gutter_min_bound = |
| orientation == ScrollbarOrientation::VERTICAL |
| ? (forward_track_rect.x() - gutter_thickness) |
| : (forward_track_rect.y() - gutter_thickness); |
| const float gutter_max_bound = |
| orientation == ScrollbarOrientation::VERTICAL |
| ? (forward_track_rect.x() + track_thickness + gutter_thickness) |
| : (forward_track_rect.y() + track_thickness + gutter_thickness); |
| |
| const float pointer_location = orientation == ScrollbarOrientation::VERTICAL |
| ? pointer_position_in_layer.x() |
| : pointer_position_in_layer.y(); |
| |
| return pointer_location < gutter_min_bound || |
| pointer_location > gutter_max_bound; |
| } |
| |
| ui::input_types::ScrollGranularity ScrollbarController::Granularity( |
| const ScrollbarPart scrollbar_part, |
| const bool shift_modifier) { |
| const bool shift_click_on_scrollbar_track = |
| shift_modifier && (scrollbar_part == ScrollbarPart::FORWARD_TRACK || |
| scrollbar_part == ScrollbarPart::BACK_TRACK); |
| if (shift_click_on_scrollbar_track || scrollbar_part == ScrollbarPart::THUMB) |
| return ui::input_types::ScrollGranularity::kScrollByPrecisePixel; |
| |
| // TODO(arakeri): This needs to be updated to kLine once cc implements |
| // handling it. crbug.com/959441 |
| return ui::input_types::ScrollGranularity::kScrollByPixel; |
| } |
| |
| float ScrollbarController::GetScrollDeltaForAbsoluteJump( |
| const ScrollbarLayerImplBase* scrollbar) { |
| layer_tree_host_impl_->active_tree()->UpdateScrollbarGeometries(); |
| |
| bool clipped = false; |
| const gfx::PointF pointer_position_in_layer = GetScrollbarRelativePosition( |
| scrollbar, last_known_pointer_position_, &clipped); |
| |
| if (clipped) |
| return 0; |
| |
| const float pointer_location = |
| scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? pointer_position_in_layer.y() |
| : pointer_position_in_layer.x(); |
| |
| // During a shift + click, the pointers current location (on the track) needs |
| // to be considered as the center of the thumb and the thumb origin needs to |
| // be calculated based on that. This will ensure that when shift + click is |
| // processed, the thumb will be centered on the pointer. |
| const int thumb_length = scrollbar->ThumbLength(); |
| const float desired_thumb_origin = pointer_location - thumb_length / 2.f; |
| |
| const gfx::Rect thumb_rect(scrollbar->ComputeThumbQuadRect()); |
| const float current_thumb_origin = |
| scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? thumb_rect.y() |
| : thumb_rect.x(); |
| |
| const float delta = |
| round(std::abs(desired_thumb_origin - current_thumb_origin)); |
| return delta * GetScrollerToScrollbarRatio(scrollbar); |
| } |
| |
| gfx::ScrollOffset ScrollbarController::GetScrollOffsetForDragPosition( |
| const ScrollbarLayerImplBase* scrollbar, |
| const gfx::PointF pointer_position_in_widget) { |
| layer_tree_host_impl_->active_tree()->UpdateScrollbarGeometries(); |
| |
| if (SnapToDragOrigin(scrollbar, pointer_position_in_widget)) { |
| const float delta = |
| scrollbar->current_pos() - drag_state_->scroll_position_at_start_; |
| return scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? gfx::ScrollOffset(0, -delta) |
| : gfx::ScrollOffset(-delta, 0); |
| } |
| |
| const gfx::Rect thumb_rect(scrollbar->ComputeThumbQuadRect()); |
| const gfx::PointF drag_position_relative_to_layer = |
| gfx::PointF(thumb_rect.origin()) + drag_state_->anchor_relative_to_thumb_; |
| |
| bool clipped = false; |
| const gfx::PointF pointer_position_in_layer = GetScrollbarRelativePosition( |
| scrollbar, pointer_position_in_widget, &clipped); |
| |
| if (clipped) |
| return gfx::ScrollOffset(0, 0); |
| |
| // Calculate the delta based on the previously known thumb drag point. |
| const gfx::Vector2dF pointer_delta = |
| pointer_position_in_layer - drag_position_relative_to_layer; |
| |
| float scaled_scroller_to_scrollbar_ratio = |
| GetScrollerToScrollbarRatio(scrollbar); |
| float current_scroll_position = scrollbar->current_pos(); |
| |
| // Thumb position needs to be floored and Values between 0 and 1 are rounded |
| // to one to match main thread per pixel behavior. Corresponding main thread |
| // code in ScrollbarTheme::ThumbPosition |
| float thumb_position = std::max(0.0f, current_scroll_position) / |
| scaled_scroller_to_scrollbar_ratio; |
| thumb_position = (thumb_position < 1.0 && thumb_position > 0.0) |
| ? 1.0 |
| : floorf(thumb_position); |
| |
| float delta_in_orientation = |
| scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? pointer_delta.y() |
| : pointer_delta.x(); |
| |
| // This is effectively equal to delta_in_orientation * |
| // scaled_scroller_to_scrollbar_ratio but is necessary due to truncated delta |
| // value. Floored thumb_position cancels out the rounding error introduced |
| // in pointer_delta due to static_cast<int> in |
| // ScrollbarLayerImplBase::ComputeThumbQuadRectWithThumbThicknessScale |
| float scroll_delta = (delta_in_orientation + thumb_position) * |
| scaled_scroller_to_scrollbar_ratio - |
| current_scroll_position; |
| |
| gfx::ScrollOffset scaled_thumb_drag_delta; |
| |
| // Scroll delta floored to match main thread per pixel behavior |
| scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? scaled_thumb_drag_delta.set_y(floorf(scroll_delta)) |
| : scaled_thumb_drag_delta.set_x(floorf(scroll_delta)); |
| |
| return scaled_thumb_drag_delta; |
| } |
| |
| // Performs hit test and prepares scroll deltas that will be used by GSU. |
| InputHandlerPointerResult ScrollbarController::HandlePointerMove( |
| const gfx::PointF position_in_widget) { |
| last_known_pointer_position_ = position_in_widget; |
| RecomputeAutoscrollStateIfNeeded(); |
| InputHandlerPointerResult scroll_result; |
| |
| const ScrollbarLayerImplBase* scrollbar = ScrollbarLayer(); |
| if (!scrollbar || !drag_state_.has_value()) |
| return scroll_result; |
| |
| // If the scrollbar thumb is being dragged, it qualifies as a kScrollbarScroll |
| // (although the delta might still be zero). Setting the "type" to |
| // kScrollbarScroll ensures that the correct event modifier (in |
| // InputHandlerProxy) is set which in-turn tells the main thread to invalidate |
| // the respective scrollbar parts. This needs to be done for all |
| // pointermove(s) since they are not VSync aligned. |
| scroll_result.type = PointerResultType::kScrollbarScroll; |
| |
| // If a GSU was already produced for a thumb drag in this frame, there's no |
| // point in continuing on. Please see the header file for details. |
| if (drag_processed_for_current_frame_) |
| return scroll_result; |
| |
| const ScrollNode* currently_scrolling_node = |
| layer_tree_host_impl_->CurrentlyScrollingNode(); |
| |
| // Thumb drag needs a scroll_node. Clear the thumb drag state and exit if it |
| // is unset. |
| if (currently_scrolling_node == nullptr) { |
| drag_state_ = base::nullopt; |
| return scroll_result; |
| } |
| |
| // If scroll_offset can't be consumed, there's no point in continuing on. |
| const gfx::ScrollOffset scroll_offset( |
| GetScrollOffsetForDragPosition(scrollbar, position_in_widget)); |
| const gfx::Vector2dF clamped_scroll_offset( |
| layer_tree_host_impl_->ComputeScrollDelta( |
| *currently_scrolling_node, ScrollOffsetToVector2dF(scroll_offset))); |
| |
| if (clamped_scroll_offset.IsZero()) |
| return scroll_result; |
| |
| // Thumb drags have more granularity and are purely dependent on the pointer |
| // movement. Hence we use kPrecisePixel when dragging the thumb. |
| scroll_result.scroll_units = |
| ui::input_types::ScrollGranularity::kScrollByPrecisePixel; |
| scroll_result.scroll_offset = gfx::ScrollOffset(clamped_scroll_offset); |
| drag_processed_for_current_frame_ = true; |
| |
| return scroll_result; |
| } |
| |
| float ScrollbarController::GetScrollerToScrollbarRatio( |
| const ScrollbarLayerImplBase* scrollbar) { |
| // Calculating the delta by which the scroller layer should move when |
| // dragging the thumb depends on the following factors: |
| // - scrollbar_track_length |
| // - scrollbar_thumb_length |
| // - scroll_layer_length |
| // - viewport_length |
| // - position_in_widget |
| // |
| // When a thumb drag is in progress, for every pixel that the pointer moves, |
| // the delta for the corresponding scroll_layer needs to be scaled by the |
| // following ratio: |
| // scaled_scroller_to_scrollbar_ratio = |
| // (scroll_layer_length - viewport_length) / |
| // (scrollbar_track_length - scrollbar_thumb_length) |
| // |
| // PS: Note that since this is a "ratio", it need not be scaled by the DSF. |
| // |
| // |<--------------------- scroll_layer_length -------------------------->| |
| // |
| // +------------------------------------------------+...................... |
| // | | . |
| // |<-------------- viewport_length --------------->| . |
| // | | . |
| // | | . |
| // | | . |
| // | | . |
| // | | . |
| // | | . |
| // | | . |
| // | | . |
| // | | . |
| // | |<------- scrollbar_track_length --------->| | . |
| // | | . |
| // +--+-----+----------------------------+-------+--+...................... |
| // |<|| |############################| ||>| |
| // +--+-----+----------------------------+-------+--+ |
| // |
| // |<- scrollbar_thumb_length ->| |
| // |
| layer_tree_host_impl_->active_tree()->UpdateScrollbarGeometries(); |
| float scroll_layer_length = scrollbar->scroll_layer_length(); |
| float scrollbar_track_length = scrollbar->TrackLength(); |
| gfx::Rect thumb_rect(scrollbar->ComputeThumbQuadRect()); |
| float scrollbar_thumb_length = |
| scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? thumb_rect.height() |
| : thumb_rect.width(); |
| |
| const LayerImpl* owner_scroll_layer = |
| layer_tree_host_impl_->active_tree()->ScrollableLayerByElementId( |
| scrollbar->scroll_element_id()); |
| const float viewport_length = |
| scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? owner_scroll_layer->scroll_container_bounds().height() |
| : (owner_scroll_layer->scroll_container_bounds().width()); |
| |
| return ((scroll_layer_length - viewport_length) / |
| (scrollbar_track_length - scrollbar_thumb_length)); |
| } |
| |
| void ScrollbarController::ResetState() { |
| drag_processed_for_current_frame_ = false; |
| drag_state_ = base::nullopt; |
| autoscroll_state_ = base::nullopt; |
| captured_scrollbar_metadata_ = base::nullopt; |
| } |
| |
| void ScrollbarController::DidUnregisterScrollbar(ElementId element_id) { |
| if (captured_scrollbar_metadata_.has_value() && |
| captured_scrollbar_metadata_->scroll_element_id == element_id) |
| ResetState(); |
| } |
| |
| void ScrollbarController::RecomputeAutoscrollStateIfNeeded() { |
| if (!autoscroll_state_.has_value() || |
| !captured_scrollbar_metadata_.has_value()) |
| return; |
| |
| layer_tree_host_impl_->active_tree()->UpdateScrollbarGeometries(); |
| const ScrollbarLayerImplBase* scrollbar = ScrollbarLayer(); |
| const gfx::Rect thumb_quad = scrollbar->ComputeThumbQuadRect(); |
| |
| bool clipped; |
| gfx::PointF scroller_relative_position(GetScrollbarRelativePosition( |
| scrollbar, last_known_pointer_position_, &clipped)); |
| |
| if (clipped) |
| return; |
| |
| // Based on the orientation of the scrollbar and the direction of the |
| // autoscroll, the code below makes a decision of whether the track autoscroll |
| // should be canceled or not. |
| int thumb_start = 0; |
| int thumb_end = 0; |
| int pointer_position = 0; |
| if (scrollbar->orientation() == ScrollbarOrientation::VERTICAL) { |
| thumb_start = thumb_quad.y(); |
| thumb_end = thumb_quad.y() + thumb_quad.height(); |
| pointer_position = scroller_relative_position.y(); |
| } else { |
| thumb_start = thumb_quad.x(); |
| thumb_end = thumb_quad.x() + thumb_quad.width(); |
| pointer_position = scroller_relative_position.x(); |
| } |
| |
| // If the thumb reaches the pointer while autoscrolling, abort. |
| if ((autoscroll_state_->direction == |
| AutoScrollDirection::AUTOSCROLL_FORWARD && |
| thumb_end > pointer_position) || |
| (autoscroll_state_->direction == |
| AutoScrollDirection::AUTOSCROLL_BACKWARD && |
| thumb_start < pointer_position)) |
| layer_tree_host_impl_->mutator_host()->ScrollAnimationAbort(); |
| |
| // When the scroller is autoscrolling forward, its dimensions need to be |
| // monitored. If the length of the scroller layer increases, the old one needs |
| // to be aborted and a new autoscroll animation needs to start. This needs to |
| // be done only for the "autoscroll forward" case. Autoscrolling backward |
| // always has a constant value to animate to (which is '0'. See the function |
| // ScrollbarController::StartAutoScrollAnimation). |
| if (autoscroll_state_->direction == AutoScrollDirection::AUTOSCROLL_FORWARD) { |
| const float scroll_layer_length = scrollbar->scroll_layer_length(); |
| if (autoscroll_state_->scroll_layer_length != scroll_layer_length) { |
| layer_tree_host_impl_->mutator_host()->ScrollAnimationAbort(); |
| StartAutoScrollAnimation(autoscroll_state_->velocity, scrollbar, |
| autoscroll_state_->pressed_scrollbar_part); |
| } |
| } |
| |
| // The animations need to be aborted/restarted based on the pointer location |
| // (i.e leaving/entering the track/arrows, reaching the track end etc). The |
| // autoscroll_state_ however, needs to be reset on pointer changes. |
| const gfx::RectF scrollbar_part_rect(GetRectForScrollbarPart( |
| scrollbar, autoscroll_state_->pressed_scrollbar_part)); |
| if (!scrollbar_part_rect.Contains(scroller_relative_position)) { |
| // Stop animating if pointer moves outside the rect bounds. |
| layer_tree_host_impl_->mutator_host()->ScrollAnimationAbort(); |
| } else if (scrollbar_part_rect.Contains(scroller_relative_position) && |
| !layer_tree_host_impl_->mutator_host()->IsElementAnimating( |
| scrollbar->scroll_element_id())) { |
| // Start animating if pointer re-enters the bounds. |
| StartAutoScrollAnimation(autoscroll_state_->velocity, scrollbar, |
| autoscroll_state_->pressed_scrollbar_part); |
| } |
| } |
| |
| // Helper to calculate the autoscroll velocity. |
| float ScrollbarController::InitialDeltaToAutoscrollVelocity( |
| const ScrollbarLayerImplBase* scrollbar, |
| gfx::ScrollOffset scroll_offset) const { |
| const float scroll_delta = |
| scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? scroll_offset.y() |
| : scroll_offset.x(); |
| return scroll_delta * kAutoscrollMultiplier; |
| } |
| |
| void ScrollbarController::StartAutoScrollAnimation( |
| const float velocity, |
| const ScrollbarLayerImplBase* scrollbar, |
| ScrollbarPart pressed_scrollbar_part) { |
| // Autoscroll and thumb drag are mutually exclusive. Both can't be active at |
| // the same time. |
| DCHECK(!drag_state_.has_value()); |
| DCHECK_NE(velocity, 0); |
| |
| // scroll_node is set up while handling GSB. If there's no node to scroll, we |
| // don't need to create any animation for it. |
| ScrollTree& scroll_tree = |
| layer_tree_host_impl_->active_tree()->property_trees()->scroll_tree; |
| ScrollNode* scroll_node = |
| scroll_tree.FindNodeFromElementId(scrollbar->scroll_element_id()); |
| |
| if (!(scroll_node && scrollbar_scroll_is_active_)) |
| return; |
| |
| layer_tree_host_impl_->active_tree()->UpdateScrollbarGeometries(); |
| float scroll_layer_length = scrollbar->scroll_layer_length(); |
| |
| gfx::ScrollOffset current_offset = |
| scroll_tree.current_scroll_offset(scroll_node->element_id); |
| |
| // Determine the max offset for the scroll based on the scrolling direction. |
| // Negative scroll velocity indicates backwards scrolling whereas a positive |
| // value indicates forwards scrolling. |
| const float target_offset = velocity < 0 ? 0 : scroll_layer_length; |
| const gfx::Vector2dF target_offset_vector = |
| scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? gfx::Vector2dF(current_offset.x(), target_offset) |
| : gfx::Vector2dF(target_offset, current_offset.y()); |
| |
| autoscroll_state_ = AutoScrollState(); |
| autoscroll_state_->velocity = velocity; |
| autoscroll_state_->scroll_layer_length = scroll_layer_length; |
| autoscroll_state_->pressed_scrollbar_part = pressed_scrollbar_part; |
| autoscroll_state_->direction = velocity < 0 |
| ? AutoScrollDirection::AUTOSCROLL_BACKWARD |
| : AutoScrollDirection::AUTOSCROLL_FORWARD; |
| |
| layer_tree_host_impl_->AutoScrollAnimationCreate( |
| scroll_node, target_offset_vector, std::abs(velocity)); |
| } |
| |
| // Performs hit test and prepares scroll deltas that will be used by GSE. |
| InputHandlerPointerResult ScrollbarController::HandlePointerUp( |
| const gfx::PointF position_in_widget) { |
| InputHandlerPointerResult scroll_result; |
| if (scrollbar_scroll_is_active_) { |
| scrollbar_scroll_is_active_ = false; |
| scroll_result.type = PointerResultType::kScrollbarScroll; |
| } |
| |
| // TODO(arakeri): This needs to be moved to ScrollOffsetAnimationsImpl as it |
| // has knowledge about what type of animation is running. crbug.com/976353 |
| // Only abort the animation if it is an "autoscroll" animation. |
| if (autoscroll_state_.has_value()) |
| layer_tree_host_impl_->mutator_host()->ScrollAnimationAbort(); |
| |
| if (cancelable_autoscroll_task_) { |
| cancelable_autoscroll_task_->Cancel(); |
| cancelable_autoscroll_task_.reset(); |
| } |
| |
| ResetState(); |
| return scroll_result; |
| } |
| |
| // Returns the layer that is hit by the position_in_widget. |
| LayerImpl* ScrollbarController::GetLayerHitByPoint( |
| const gfx::PointF position_in_widget) { |
| LayerTreeImpl* active_tree = layer_tree_host_impl_->active_tree(); |
| gfx::Point viewport_point(position_in_widget.x(), position_in_widget.y()); |
| |
| gfx::PointF device_viewport_point = gfx::ScalePoint( |
| gfx::PointF(viewport_point), active_tree->device_scale_factor()); |
| LayerImpl* layer_impl = |
| active_tree->FindLayerThatIsHitByPoint(device_viewport_point); |
| |
| return layer_impl; |
| } |
| |
| int ScrollbarController::GetScrollDeltaForScrollbarPart( |
| const ScrollbarLayerImplBase* scrollbar, |
| const ScrollbarPart scrollbar_part, |
| const bool shift_modifier) { |
| int scroll_delta = 0; |
| int viewport_length = 0; |
| LayerImpl* owner_scroll_layer = nullptr; |
| |
| switch (scrollbar_part) { |
| case ScrollbarPart::BACK_BUTTON: |
| case ScrollbarPart::FORWARD_BUTTON: |
| scroll_delta = kPixelsPerLineStep * ScreenSpaceScaleFactor(); |
| break; |
| case ScrollbarPart::BACK_TRACK: |
| case ScrollbarPart::FORWARD_TRACK: |
| if (shift_modifier) { |
| scroll_delta = GetScrollDeltaForAbsoluteJump(scrollbar); |
| break; |
| } |
| owner_scroll_layer = |
| layer_tree_host_impl_->active_tree()->ScrollableLayerByElementId( |
| scrollbar->scroll_element_id()); |
| viewport_length = |
| scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? owner_scroll_layer->scroll_container_bounds().height() |
| : (owner_scroll_layer->scroll_container_bounds().width()); |
| scroll_delta = viewport_length * kMinFractionToStepWhenPaging; |
| break; |
| default: |
| scroll_delta = 0; |
| } |
| |
| return scroll_delta; |
| } |
| |
| float ScrollbarController::ScreenSpaceScaleFactor() const { |
| // TODO(arakeri): When crbug.com/716231 is fixed, this needs to be updated. |
| // If use_zoom_for_dsf is false, the click deltas and thumb drag ratios |
| // shouldn't be scaled. For example: On Mac, when the use_zoom_for_dsf is |
| // false and the device_scale_factor is 2, the scroll delta for pointer clicks |
| // on arrows would be incorrectly calculated as 80px instead of 40px. This is |
| // also necessary to ensure that hit testing works as intended. |
| return layer_tree_host_impl_->settings().use_zoom_for_dsf |
| ? layer_tree_host_impl_->active_tree() |
| ->painted_device_scale_factor() |
| : 1.f; |
| } |
| |
| gfx::PointF ScrollbarController::GetScrollbarRelativePosition( |
| const ScrollbarLayerImplBase* scrollbar, |
| const gfx::PointF position_in_widget, |
| bool* clipped) { |
| gfx::Transform inverse_screen_space_transform( |
| gfx::Transform::kSkipInitialization); |
| |
| // If use_zoom_for_dsf is false, the ScreenSpaceTransform needs to be scaled |
| // down by the DSF to ensure that position_in_widget is transformed correctly. |
| const float scale = |
| !layer_tree_host_impl_->settings().use_zoom_for_dsf |
| ? 1.f / layer_tree_host_impl_->active_tree()->device_scale_factor() |
| : 1.f; |
| gfx::Transform scaled_screen_space_transform( |
| scrollbar->ScreenSpaceTransform()); |
| scaled_screen_space_transform.PostScale(scale, scale); |
| if (!scaled_screen_space_transform.GetInverse( |
| &inverse_screen_space_transform)) |
| return gfx::PointF(0, 0); |
| |
| return gfx::PointF(MathUtil::ProjectPoint(inverse_screen_space_transform, |
| position_in_widget, clipped)); |
| } |
| |
| // Determines the ScrollbarPart based on the position_in_widget. |
| ScrollbarPart ScrollbarController::GetScrollbarPartFromPointerDown( |
| const ScrollbarLayerImplBase* scrollbar, |
| const gfx::PointF position_in_widget) { |
| // position_in_widget needs to be transformed and made relative to the |
| // scrollbar layer because hit testing assumes layer relative coordinates. |
| bool clipped = false; |
| |
| const gfx::PointF scroller_relative_position( |
| GetScrollbarRelativePosition(scrollbar, position_in_widget, &clipped)); |
| |
| if (clipped) |
| return ScrollbarPart::NO_PART; |
| |
| return scrollbar->IdentifyScrollbarPart(scroller_relative_position); |
| } |
| |
| // Determines the corresponding rect for the given scrollbar part. |
| gfx::Rect ScrollbarController::GetRectForScrollbarPart( |
| const ScrollbarLayerImplBase* scrollbar, |
| const ScrollbarPart scrollbar_part) { |
| if (scrollbar_part == ScrollbarPart::BACK_BUTTON) |
| return scrollbar->BackButtonRect(); |
| if (scrollbar_part == ScrollbarPart::FORWARD_BUTTON) |
| return scrollbar->ForwardButtonRect(); |
| if (scrollbar_part == ScrollbarPart::BACK_TRACK) |
| return scrollbar->BackTrackRect(); |
| if (scrollbar_part == ScrollbarPart::FORWARD_TRACK) |
| return scrollbar->ForwardTrackRect(); |
| return gfx::Rect(0, 0); |
| } |
| |
| // Determines the scroll offsets based on the ScrollbarPart and the scrollbar |
| // orientation. |
| gfx::ScrollOffset ScrollbarController::GetScrollOffsetForScrollbarPart( |
| const ScrollbarLayerImplBase* scrollbar, |
| const ScrollbarPart scrollbar_part, |
| const bool shift_modifier) { |
| float scroll_delta = |
| GetScrollDeltaForScrollbarPart(scrollbar, scrollbar_part, shift_modifier); |
| |
| // See CreateScrollStateForGesture for more information on how these values |
| // will be interpreted. |
| if (scrollbar_part == ScrollbarPart::BACK_BUTTON) { |
| return scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? gfx::ScrollOffset(0, -scroll_delta) // Up arrow |
| : gfx::ScrollOffset(-scroll_delta, 0); // Left arrow |
| } else if (scrollbar_part == ScrollbarPart::FORWARD_BUTTON) { |
| return scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? gfx::ScrollOffset(0, scroll_delta) // Down arrow |
| : gfx::ScrollOffset(scroll_delta, 0); // Right arrow |
| } else if (scrollbar_part == ScrollbarPart::BACK_TRACK) { |
| return scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? gfx::ScrollOffset(0, -scroll_delta) // Track click up |
| : gfx::ScrollOffset(-scroll_delta, 0); // Track click left |
| } else if (scrollbar_part == ScrollbarPart::FORWARD_TRACK) { |
| return scrollbar->orientation() == ScrollbarOrientation::VERTICAL |
| ? gfx::ScrollOffset(0, scroll_delta) // Track click down |
| : gfx::ScrollOffset(scroll_delta, 0); // Track click right |
| } |
| |
| return gfx::ScrollOffset(0, 0); |
| } |
| |
| } // namespace cc |
