| // Copyright 2018 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 "third_party/blink/renderer/core/display_lock/display_lock_context.h" |
| |
| #include <string> |
| |
| #include "base/auto_reset.h" |
| #include "base/memory/ptr_util.h" |
| #include "base/metrics/histogram_macros.h" |
| #include "third_party/blink/renderer/core/accessibility/ax_object_cache.h" |
| #include "third_party/blink/renderer/core/css/style_change_reason.h" |
| #include "third_party/blink/renderer/core/css/style_engine.h" |
| #include "third_party/blink/renderer/core/css/style_recalc.h" |
| #include "third_party/blink/renderer/core/display_lock/display_lock_document_state.h" |
| #include "third_party/blink/renderer/core/display_lock/display_lock_utilities.h" |
| #include "third_party/blink/renderer/core/dom/document.h" |
| #include "third_party/blink/renderer/core/dom/dom_exception.h" |
| #include "third_party/blink/renderer/core/dom/element.h" |
| #include "third_party/blink/renderer/core/dom/node_computed_style.h" |
| #include "third_party/blink/renderer/core/editing/frame_selection.h" |
| #include "third_party/blink/renderer/core/editing/selection_template.h" |
| #include "third_party/blink/renderer/core/frame/local_frame.h" |
| #include "third_party/blink/renderer/core/frame/local_frame_view.h" |
| #include "third_party/blink/renderer/core/html_element_type_helpers.h" |
| #include "third_party/blink/renderer/core/inspector/inspector_trace_events.h" |
| #include "third_party/blink/renderer/core/layout/layout_box.h" |
| #include "third_party/blink/renderer/core/layout/layout_object.h" |
| #include "third_party/blink/renderer/core/page/page.h" |
| #include "third_party/blink/renderer/core/paint/compositing/composited_layer_mapping.h" |
| #include "third_party/blink/renderer/core/paint/paint_layer.h" |
| #include "third_party/blink/renderer/core/paint/pre_paint_tree_walk.h" |
| #include "third_party/blink/renderer/platform/bindings/microtask.h" |
| #include "third_party/blink/renderer/platform/heap/heap.h" |
| #include "third_party/blink/renderer/platform/instrumentation/use_counter.h" |
| #include "third_party/blink/renderer/platform/wtf/text/string_builder.h" |
| |
| namespace blink { |
| |
| namespace { |
| namespace rejection_names { |
| const char* kContainmentNotSatisfied = |
| "Containment requirement is not satisfied."; |
| const char* kUnsupportedDisplay = |
| "Element has unsupported display type (display: contents)."; |
| } // namespace rejection_names |
| |
| void RecordActivationReason(Document* document, |
| DisplayLockActivationReason reason) { |
| int ordered_reason = -1; |
| |
| // IMPORTANT: This number needs to be bumped up when adding |
| // new reasons. |
| static const int number_of_reasons = 9; |
| |
| switch (reason) { |
| case DisplayLockActivationReason::kAccessibility: |
| ordered_reason = 0; |
| break; |
| case DisplayLockActivationReason::kFindInPage: |
| ordered_reason = 1; |
| break; |
| case DisplayLockActivationReason::kFragmentNavigation: |
| ordered_reason = 2; |
| break; |
| case DisplayLockActivationReason::kScriptFocus: |
| ordered_reason = 3; |
| break; |
| case DisplayLockActivationReason::kScrollIntoView: |
| ordered_reason = 4; |
| break; |
| case DisplayLockActivationReason::kSelection: |
| ordered_reason = 5; |
| break; |
| case DisplayLockActivationReason::kSimulatedClick: |
| ordered_reason = 6; |
| break; |
| case DisplayLockActivationReason::kUserFocus: |
| ordered_reason = 7; |
| break; |
| case DisplayLockActivationReason::kViewportIntersection: |
| ordered_reason = 8; |
| break; |
| case DisplayLockActivationReason::kViewport: |
| case DisplayLockActivationReason::kAny: |
| NOTREACHED(); |
| break; |
| } |
| UMA_HISTOGRAM_ENUMERATION("Blink.Render.DisplayLockActivationReason", |
| ordered_reason, number_of_reasons); |
| |
| if (document && reason == DisplayLockActivationReason::kFindInPage) |
| document->MarkHasFindInPageContentVisibilityActiveMatch(); |
| } |
| |
| ScrollableArea* GetScrollableArea(Node* node) { |
| if (!node) |
| return nullptr; |
| |
| LayoutBoxModelObject* object = |
| DynamicTo<LayoutBoxModelObject>(node->GetLayoutObject()); |
| if (!object) |
| return nullptr; |
| |
| return object->GetScrollableArea(); |
| } |
| |
| } // namespace |
| |
| DisplayLockContext::DisplayLockContext(Element* element) |
| : element_(element), document_(&element_->GetDocument()) { |
| document_->GetDisplayLockDocumentState().AddDisplayLockContext(this); |
| DetermineIfSubtreeHasFocus(); |
| DetermineIfSubtreeHasSelection(); |
| } |
| |
| void DisplayLockContext::SetRequestedState(EContentVisibility state) { |
| if (state_ == state) |
| return; |
| state_ = state; |
| base::AutoReset<bool> scope(&set_requested_state_scope_, true); |
| switch (state_) { |
| case EContentVisibility::kVisible: |
| RequestUnlock(); |
| break; |
| case EContentVisibility::kAuto: |
| UseCounter::Count(document_, WebFeature::kContentVisibilityAuto); |
| had_any_viewport_intersection_notifications_ = false; |
| RequestLock(static_cast<uint16_t>(DisplayLockActivationReason::kAny)); |
| break; |
| case EContentVisibility::kHidden: |
| UseCounter::Count(document_, WebFeature::kContentVisibilityHidden); |
| RequestLock(0u); |
| break; |
| case EContentVisibility::kHiddenMatchable: |
| UseCounter::Count(document_, |
| WebFeature::kContentVisibilityHiddenMatchable); |
| RequestLock( |
| static_cast<uint16_t>(DisplayLockActivationReason::kAny) & |
| ~static_cast<uint16_t>(DisplayLockActivationReason::kViewport)); |
| break; |
| } |
| // In a new state, we might need to either start or stop observing viewport |
| // intersections. |
| UpdateActivationObservationIfNeeded(); |
| |
| // If we needed a deferred not intersecting signal from 'auto' mode, we can |
| // set that to false, since the mode has switched to something else. If we're |
| // switching _to_ 'auto' mode, this should already be false and will be a |
| // no-op. |
| DCHECK(state_ != EContentVisibility::kAuto || |
| !needs_deferred_not_intersecting_signal_); |
| needs_deferred_not_intersecting_signal_ = false; |
| UpdateLifecycleNotificationRegistration(); |
| |
| // Note that we call this here since the |state_| change is a render affecting |
| // state, but is tracked independently. |
| NotifyRenderAffectingStateChanged(); |
| |
| // Since our state changed, check if we need to create a scoped force update |
| // object. |
| element_->GetDocument().GetDisplayLockDocumentState().ForceLockIfNeeded( |
| element_.Get()); |
| } |
| |
| void DisplayLockContext::AdjustElementStyle(ComputedStyle* style) const { |
| if (state_ == EContentVisibility::kVisible) |
| return; |
| // If not visible, element gains style, layout, and paint containment. If |
| // skipped, it also gains size containment. |
| // https://wicg.github.io/display-locking/#content-visibility |
| auto contain = |
| style->Contain() | kContainsStyle | kContainsLayout | kContainsPaint; |
| if (IsLocked()) |
| contain |= kContainsSize; |
| style->SetContain(contain); |
| } |
| |
| void DisplayLockContext::RequestLock(uint16_t activation_mask) { |
| UpdateActivationMask(activation_mask); |
| SetRenderAffectingState(RenderAffectingState::kLockRequested, true); |
| } |
| |
| void DisplayLockContext::RequestUnlock() { |
| SetRenderAffectingState(RenderAffectingState::kLockRequested, false); |
| } |
| |
| void DisplayLockContext::UpdateActivationMask(uint16_t activatable_mask) { |
| if (activatable_mask == activatable_mask_) |
| return; |
| |
| bool all_activation_was_blocked = !activatable_mask_; |
| bool all_activation_is_blocked = !activatable_mask; |
| UpdateDocumentBookkeeping(IsLocked(), all_activation_was_blocked, IsLocked(), |
| all_activation_is_blocked); |
| |
| activatable_mask_ = activatable_mask; |
| } |
| |
| void DisplayLockContext::UpdateDocumentBookkeeping( |
| bool was_locked, |
| bool all_activation_was_blocked, |
| bool is_locked, |
| bool all_activation_is_blocked) { |
| if (!document_) |
| return; |
| |
| if (was_locked != is_locked) { |
| if (is_locked) |
| document_->GetDisplayLockDocumentState().AddLockedDisplayLock(); |
| else |
| document_->GetDisplayLockDocumentState().RemoveLockedDisplayLock(); |
| } |
| |
| bool was_locked_and_blocking = was_locked && all_activation_was_blocked; |
| bool is_locked_and_blocking = is_locked && all_activation_is_blocked; |
| if (was_locked_and_blocking != is_locked_and_blocking) { |
| if (is_locked_and_blocking) { |
| document_->GetDisplayLockDocumentState() |
| .IncrementDisplayLockBlockingAllActivation(); |
| } else { |
| document_->GetDisplayLockDocumentState() |
| .DecrementDisplayLockBlockingAllActivation(); |
| } |
| } |
| } |
| |
| void DisplayLockContext::UpdateActivationObservationIfNeeded() { |
| // If we don't have a document, then we don't have an observer so just make |
| // sure we're marked as not observing anything and early out. |
| if (!document_) { |
| is_observed_ = false; |
| return; |
| } |
| |
| // We require observation if we are in 'auto' mode and we're connected to a |
| // view. |
| bool should_observe = |
| state_ == EContentVisibility::kAuto && ConnectedToView(); |
| if (is_observed_ == should_observe) |
| return; |
| is_observed_ = should_observe; |
| |
| if (should_observe) { |
| document_->GetDisplayLockDocumentState() |
| .RegisterDisplayLockActivationObservation(element_); |
| } else { |
| document_->GetDisplayLockDocumentState() |
| .UnregisterDisplayLockActivationObservation(element_); |
| // If we're not listening to viewport intersections, then we can assume |
| // we're not intersecting: |
| // 1. We might not be connected, in which case we're not intersecting. |
| // 2. We might not be in 'auto' mode. which means that this doesn't affect |
| // anything consequential but acts as a reset should we switch back to |
| // the 'auto' mode. |
| SetRenderAffectingState(RenderAffectingState::kIntersectsViewport, false); |
| } |
| } |
| |
| bool DisplayLockContext::NeedsLifecycleNotifications() const { |
| return needs_deferred_not_intersecting_signal_ || |
| render_affecting_state_[static_cast<int>( |
| RenderAffectingState::kAutoStateUnlockedUntilLifecycle)]; |
| } |
| |
| void DisplayLockContext::UpdateLifecycleNotificationRegistration() { |
| if (!document_ || !document_->View()) { |
| is_registered_for_lifecycle_notifications_ = false; |
| return; |
| } |
| |
| bool needs_notifications = NeedsLifecycleNotifications(); |
| if (needs_notifications == is_registered_for_lifecycle_notifications_) |
| return; |
| |
| is_registered_for_lifecycle_notifications_ = needs_notifications; |
| if (needs_notifications) { |
| document_->View()->RegisterForLifecycleNotifications(this); |
| } else { |
| document_->View()->UnregisterFromLifecycleNotifications(this); |
| } |
| } |
| |
| void DisplayLockContext::Lock() { |
| DCHECK(!IsLocked()); |
| is_locked_ = true; |
| UpdateDocumentBookkeeping(false, !activatable_mask_, true, |
| !activatable_mask_); |
| |
| // If we're not connected, then we don't have to do anything else. Otherwise, |
| // we need to ensure that we update our style to check for containment later, |
| // layout size based on the options, and also clear the painted output. |
| if (!ConnectedToView()) |
| return; |
| |
| // There are two ways we can get locked: |
| // 1. A new content-visibility property needs us to be locked. |
| // 2. We're in 'auto' mode and we are not intersecting the viewport. |
| // In the first case, we are already in style processing, so we don't need to |
| // invalidate style. However, in the second case we invalidate style so that |
| // `AdjustElementStyle()` can be called. |
| if (CanDirtyStyle()) { |
| element_->SetNeedsStyleRecalc( |
| kLocalStyleChange, |
| StyleChangeReasonForTracing::Create(style_change_reason::kDisplayLock)); |
| |
| // TODO(vmpstr): Note when an 'auto' context gets locked, we should clear |
| // the ancestor scroll anchors. This is a workaround for a behavior that |
| // happens when the user quickly scrolls (e.g. scrollbar scrolls) into an |
| // area that only has locked content. We can get into a loop that will |
| // keep unlocking an element, which may shrink it to be out of the viewport, |
| // and thus relocking it again. It is is also possible that we selected the |
| // scroller itself or one of the locked elements as the anchor, so we don't |
| // actually shift the scroll and the loop continues indefinitely. The user |
| // can easily get out of the loop by scrolling since that triggers a new |
| // scroll anchor selection. The work-around for us is also to pick a new |
| // scroll anchor for the scroller that has a newly-locked context. The |
| // reason it works is that it causes us to pick an anchor while the element |
| // is still unlocked, so when it gets relocked we shift the scroll to |
| // whatever visible content we had. The TODO here is to figure out if there |
| // is a better way to solve this. In either case, we have to select a new |
| // scroll anchor to get out of this behavior. |
| element_->NotifyPriorityScrollAnchorStatusChanged(); |
| } |
| |
| // We need to notify the AX cache (if it exists) to update |element_|'s |
| // children in the AX cache. |
| if (AXObjectCache* cache = element_->GetDocument().ExistingAXObjectCache()) |
| cache->ChildrenChanged(element_); |
| |
| if (!element_->GetLayoutObject()) |
| return; |
| |
| // If this element is a scroller, then stash its current scroll offset, so |
| // that we can restore it when needed. |
| // Note that this only applies if the element itself is a scroller. Any |
| // subtree scrollers' scroll offsets are not affected. |
| StashScrollOffsetIfAvailable(); |
| |
| MarkNeedsRepaintAndPaintArtifactCompositorUpdate(); |
| } |
| |
| // Should* and Did* function for the lifecycle phases. These functions control |
| // whether or not to process the lifecycle for self or for children. |
| // ============================================================================= |
| bool DisplayLockContext::ShouldStyleChildren() const { |
| return !is_locked_ || update_forced_ || |
| (document_->GetDisplayLockDocumentState() |
| .ActivatableDisplayLocksForced() && |
| IsActivatable(DisplayLockActivationReason::kAny)); |
| } |
| |
| void DisplayLockContext::DidStyleSelf() { |
| // TODO(vmpstr): This needs to be in the spec. |
| if (ForceUnlockIfNeeded()) |
| return; |
| |
| if (!IsLocked() && state_ != EContentVisibility::kVisible) { |
| UpdateActivationObservationIfNeeded(); |
| NotifyRenderAffectingStateChanged(); |
| } |
| |
| if (blocked_style_traversal_type_ == kStyleUpdateSelf) |
| blocked_style_traversal_type_ = kStyleUpdateNotRequired; |
| } |
| |
| void DisplayLockContext::DidStyleChildren() { |
| if (element_->ChildNeedsReattachLayoutTree()) |
| element_->MarkAncestorsWithChildNeedsReattachLayoutTree(); |
| blocked_style_traversal_type_ = kStyleUpdateNotRequired; |
| MarkElementsForWhitespaceReattachment(); |
| } |
| |
| bool DisplayLockContext::ShouldLayoutChildren() const { |
| return !is_locked_ || update_forced_ || |
| (document_->GetDisplayLockDocumentState() |
| .ActivatableDisplayLocksForced() && |
| IsActivatable(DisplayLockActivationReason::kAny)); |
| } |
| |
| void DisplayLockContext::DidLayoutChildren() { |
| // Since we did layout on children already, we'll clear this. |
| child_layout_was_blocked_ = false; |
| had_lifecycle_update_since_last_unlock_ = true; |
| |
| // If we're not locked and we laid out the children, then now is a good time |
| // to restore the scroll offset. |
| if (!is_locked_) |
| RestoreScrollOffsetIfStashed(); |
| } |
| |
| bool DisplayLockContext::ShouldPrePaintChildren() const { |
| return !is_locked_ || update_forced_; |
| } |
| |
| bool DisplayLockContext::ShouldPaintChildren() const { |
| // Note that forced updates should never require us to paint, so we don't |
| // check |update_forced_| here. In other words, although |update_forced_| |
| // could be true here, we still should not paint. |
| return !is_locked_; |
| } |
| // End Should* and Did* functions ============================================== |
| |
| bool DisplayLockContext::IsActivatable( |
| DisplayLockActivationReason reason) const { |
| return activatable_mask_ & static_cast<uint16_t>(reason); |
| } |
| |
| void DisplayLockContext::CommitForActivationWithSignal( |
| Element* activated_element, |
| DisplayLockActivationReason reason) { |
| DCHECK(activated_element); |
| DCHECK(element_); |
| DCHECK(ConnectedToView()); |
| DCHECK(IsLocked()); |
| DCHECK(ShouldCommitForActivation(DisplayLockActivationReason::kAny)); |
| |
| // The following actions (can) scroll content into view. However, if the |
| // position of the target is outside of the bounds that would cause the |
| // auto-context to unlock, then we can scroll into wrong content while the |
| // context remains lock. To avoid this, unlock it until the next lifecycle. |
| // If the scroll is successful, then we will gain visibility anyway so the |
| // context will be unlocked for other reasons. |
| if (reason == DisplayLockActivationReason::kAccessibility || |
| reason == DisplayLockActivationReason::kFindInPage || |
| reason == DisplayLockActivationReason::kFragmentNavigation || |
| reason == DisplayLockActivationReason::kScrollIntoView || |
| reason == DisplayLockActivationReason::kSimulatedClick) { |
| // Note that because the visibility is only determined at the _end_ of the |
| // next frame, we need to ensure that we stay unlocked for two frames. |
| SetKeepUnlockedUntilLifecycleCount(2); |
| } |
| |
| RecordActivationReason(document_, reason); |
| } |
| |
| void DisplayLockContext::SetKeepUnlockedUntilLifecycleCount(int count) { |
| DCHECK_GT(count, 0); |
| keep_unlocked_count_ = std::max(keep_unlocked_count_, count); |
| SetRenderAffectingState( |
| RenderAffectingState::kAutoStateUnlockedUntilLifecycle, true); |
| UpdateLifecycleNotificationRegistration(); |
| ScheduleAnimation(); |
| } |
| |
| void DisplayLockContext::NotifyIsIntersectingViewport() { |
| had_any_viewport_intersection_notifications_ = true; |
| // If we are now intersecting, then we are definitely not nested in a locked |
| // subtree and we don't need to lock as a result. |
| needs_deferred_not_intersecting_signal_ = false; |
| UpdateLifecycleNotificationRegistration(); |
| // If we're not connected, then there is no need to change any state. |
| // This could be the case if we were disconnected while a viewport |
| // intersection notification was pending. |
| if (ConnectedToView()) |
| SetRenderAffectingState(RenderAffectingState::kIntersectsViewport, true); |
| } |
| |
| void DisplayLockContext::NotifyIsNotIntersectingViewport() { |
| had_any_viewport_intersection_notifications_ = true; |
| |
| if (IsLocked()) { |
| DCHECK(!needs_deferred_not_intersecting_signal_); |
| return; |
| } |
| |
| // We might have been disconnected while the intersection observation |
| // notification was pending. Ensure to unregister from lifecycle |
| // notifications if we're doing that, and early out. |
| if (!ConnectedToView()) { |
| needs_deferred_not_intersecting_signal_ = false; |
| UpdateLifecycleNotificationRegistration(); |
| return; |
| } |
| |
| // There are two situations we need to consider here: |
| // 1. We are off-screen but not nested in any other lock. This means we should |
| // re-lock (also verify that the reason we're in this state is that we're |
| // activated). |
| // 2. We are in a nested locked context. This means we don't actually know |
| // whether we should lock or not. In order to avoid needless dirty of the |
| // layout and style trees up to the nested context, we remain unlocked. |
| // However, we also need to ensure that we relock if we become unnested. |
| // So, we simply delay this check to the next frame (via LocalFrameView), |
| // which will call this function again and so we can perform the check |
| // again. |
| auto* locked_ancestor = |
| DisplayLockUtilities::NearestLockedExclusiveAncestor(*element_); |
| if (locked_ancestor) { |
| needs_deferred_not_intersecting_signal_ = true; |
| } else { |
| needs_deferred_not_intersecting_signal_ = false; |
| SetRenderAffectingState(RenderAffectingState::kIntersectsViewport, false); |
| } |
| UpdateLifecycleNotificationRegistration(); |
| } |
| |
| bool DisplayLockContext::ShouldCommitForActivation( |
| DisplayLockActivationReason reason) const { |
| return IsActivatable(reason) && IsLocked(); |
| } |
| |
| void DisplayLockContext::NotifyForcedUpdateScopeStarted() { |
| ++update_forced_; |
| if (update_forced_ == 1) { |
| TRACE_EVENT_NESTABLE_ASYNC_BEGIN0( |
| TRACE_DISABLED_BY_DEFAULT("blink.debug.display_lock"), "LockForced", |
| TRACE_ID_LOCAL(this)); |
| } |
| |
| if (IsLocked()) { |
| // Now that the update is forced, we should ensure that style layout, and |
| // prepaint code can reach it via dirty bits. Note that paint isn't a part |
| // of this, since |update_forced_| doesn't force paint to happen. See |
| // ShouldPaint(). Also, we could have forced a lock from SetRequestedState |
| // during a style update. If that's the case, don't mark style as dirty |
| // from within style recalc. We rely on `AdjustStyleRecalcChangeForChildren` |
| // instead. |
| if (CanDirtyStyle()) |
| MarkForStyleRecalcIfNeeded(); |
| MarkForLayoutIfNeeded(); |
| MarkAncestorsForPrePaintIfNeeded(); |
| } |
| } |
| |
| void DisplayLockContext::NotifyForcedUpdateScopeEnded() { |
| DCHECK(update_forced_); |
| --update_forced_; |
| if (update_forced_ == 0) { |
| TRACE_EVENT_NESTABLE_ASYNC_END0( |
| TRACE_DISABLED_BY_DEFAULT("blink.debug.display_lock"), "LockForced", |
| TRACE_ID_LOCAL(this)); |
| } |
| } |
| |
| void DisplayLockContext::Unlock() { |
| DCHECK(IsLocked()); |
| is_locked_ = false; |
| had_lifecycle_update_since_last_unlock_ = false; |
| UpdateDocumentBookkeeping(true, !activatable_mask_, false, |
| !activatable_mask_); |
| |
| if (!ConnectedToView()) |
| return; |
| |
| // There are a few ways we can get unlocked: |
| // 1. A new content-visibility property needs us to be ulocked. |
| // 2. We're in 'auto' mode and we are intersecting the viewport. |
| // In the first case, we are already in style processing, so we don't need to |
| // invalidate style. However, in the second case we invalidate style so that |
| // `AdjustElementStyle()` can be called. |
| if (CanDirtyStyle()) { |
| // Since size containment depends on the activatability state, we should |
| // invalidate the style for this element, so that the style adjuster can |
| // properly remove the containment. |
| element_->SetNeedsStyleRecalc( |
| kLocalStyleChange, |
| StyleChangeReasonForTracing::Create(style_change_reason::kDisplayLock)); |
| |
| // Also propagate any dirty bits that we have previously blocked. |
| // If we're in style recalc, this will be handled by |
| // `AdjustStyleRecalcChangeForChildren()`. |
| MarkForStyleRecalcIfNeeded(); |
| } |
| |
| // We also need to notify the AX cache (if it exists) to update the childrens |
| // of |element_| in the AX cache. |
| if (AXObjectCache* cache = element_->GetDocument().ExistingAXObjectCache()) |
| cache->ChildrenChanged(element_); |
| |
| auto* layout_object = element_->GetLayoutObject(); |
| // We might commit without connecting, so there is no layout object yet. |
| if (!layout_object) |
| return; |
| |
| // Now that we know we have a layout object, we should ensure that we can |
| // reach the rest of the phases as well. |
| MarkForLayoutIfNeeded(); |
| MarkAncestorsForPrePaintIfNeeded(); |
| MarkNeedsRepaintAndPaintArtifactCompositorUpdate(); |
| MarkNeedsCullRectUpdate(); |
| } |
| |
| void DisplayLockContext::AddToWhitespaceReattachSet(Element& element) { |
| whitespace_reattach_set_.insert(&element); |
| } |
| |
| void DisplayLockContext::MarkElementsForWhitespaceReattachment() { |
| for (auto element : whitespace_reattach_set_) { |
| if (!element || element->NeedsReattachLayoutTree() || |
| !element->GetLayoutObject()) |
| continue; |
| |
| if (Node* first_child = LayoutTreeBuilderTraversal::FirstChild(*element)) |
| first_child->MarkAncestorsWithChildNeedsReattachLayoutTree(); |
| } |
| whitespace_reattach_set_.clear(); |
| } |
| |
| StyleRecalcChange DisplayLockContext::AdjustStyleRecalcChangeForChildren( |
| StyleRecalcChange change) { |
| // This code is similar to MarkForStyleRecalcIfNeeded, except that it acts on |
| // |change| and not on |element_|. This is only called during style recalc. |
| // Note that since we're already in self style recalc, this code is shorter |
| // since it doesn't have to deal with dirtying self-style. |
| DCHECK(!CanDirtyStyle()); |
| |
| if (reattach_layout_tree_was_blocked_) { |
| change = change.ForceReattachLayoutTree(); |
| reattach_layout_tree_was_blocked_ = false; |
| } |
| |
| if (blocked_style_traversal_type_ == kStyleUpdateDescendants) |
| change = change.ForceRecalcDescendants(); |
| else if (blocked_style_traversal_type_ == kStyleUpdateChildren) |
| change = change.EnsureAtLeast(StyleRecalcChange::kRecalcChildren); |
| blocked_style_traversal_type_ = kStyleUpdateNotRequired; |
| return change; |
| } |
| |
| bool DisplayLockContext::CanDirtyStyle() const { |
| return !set_requested_state_scope_ && !document_->InStyleRecalc(); |
| } |
| |
| bool DisplayLockContext::MarkForStyleRecalcIfNeeded() { |
| if (reattach_layout_tree_was_blocked_) { |
| // We previously blocked a layout tree reattachment on |element_|'s |
| // descendants, so we should mark it for layout tree reattachment now. |
| element_->SetForceReattachLayoutTree(); |
| reattach_layout_tree_was_blocked_ = false; |
| } |
| if (IsElementDirtyForStyleRecalc()) { |
| if (blocked_style_traversal_type_ > kStyleUpdateNotRequired) { |
| // We blocked a traversal going to the element previously. |
| // Make sure we will traverse this element and maybe its subtree if we |
| // previously blocked a style traversal that should've done that. |
| element_->SetNeedsStyleRecalc( |
| blocked_style_traversal_type_ == kStyleUpdateDescendants |
| ? kSubtreeStyleChange |
| : kLocalStyleChange, |
| StyleChangeReasonForTracing::Create( |
| style_change_reason::kDisplayLock)); |
| if (blocked_style_traversal_type_ == kStyleUpdateChildren) |
| element_->SetChildNeedsStyleRecalc(); |
| blocked_style_traversal_type_ = kStyleUpdateNotRequired; |
| } else if (element_->ChildNeedsReattachLayoutTree()) { |
| // Mark |element_| as style dirty, as we can't mark for child reattachment |
| // before style. |
| element_->SetNeedsStyleRecalc(kLocalStyleChange, |
| StyleChangeReasonForTracing::Create( |
| style_change_reason::kDisplayLock)); |
| } |
| // Propagate to the ancestors, since the dirty bit in a locked subtree is |
| // stopped at the locked ancestor. |
| // See comment in IsElementDirtyForStyleRecalc. |
| element_->MarkAncestorsWithChildNeedsStyleRecalc(); |
| return true; |
| } |
| return false; |
| } |
| |
| bool DisplayLockContext::MarkForLayoutIfNeeded() { |
| if (IsElementDirtyForLayout()) { |
| // Forces the marking of ancestors to happen, even if |
| // |DisplayLockContext::ShouldLayout()| returns false. |
| base::AutoReset<int> scoped_force(&update_forced_, update_forced_ + 1); |
| if (child_layout_was_blocked_ || HasStashedScrollOffset()) { |
| // We've previously blocked a child traversal when doing self-layout for |
| // the locked element, so we're marking it with child-needs-layout so that |
| // it will traverse to the locked element and do the child traversal |
| // again. We don't need to mark it for self-layout (by calling |
| // |LayoutObject::SetNeedsLayout()|) because the locked element itself |
| // doesn't need to relayout. |
| // |
| // Note that we also make sure to visit the children when we have a |
| // stashed scroll offset. This is so that we can restore the offset after |
| // laying out the children. If we try to restore it before the layout, it |
| // will be ignored since the scroll area may think that it doesn't have |
| // enough contents. |
| // TODO(vmpstr): In the scroll offset case, we're doing this just so we |
| // can reach DisplayLockContext::DidLayoutChildren where we restore the |
| // offset. If performance becomes an issue, then we should think of a |
| // different time / opportunity to restore the offset. |
| element_->GetLayoutObject()->SetChildNeedsLayout(); |
| child_layout_was_blocked_ = false; |
| } else { |
| // Since the dirty layout propagation stops at the locked element, we need |
| // to mark its ancestors as dirty here so that it will be traversed to on |
| // the next layout. |
| element_->GetLayoutObject()->MarkContainerChainForLayout(); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| bool DisplayLockContext::MarkAncestorsForPrePaintIfNeeded() { |
| // TODO(vmpstr): We should add a compositing phase for proper bookkeeping. |
| bool compositing_dirtied = MarkForCompositingUpdatesIfNeeded(); |
| |
| if (IsElementDirtyForPrePaint()) { |
| auto* layout_object = element_->GetLayoutObject(); |
| if (auto* parent = layout_object->Parent()) |
| parent->SetSubtreeShouldCheckForPaintInvalidation(); |
| |
| // Note that if either we or our descendants are marked as needing this |
| // update, then ensure to mark self as needing the update. This sets up the |
| // correct flags for PrePaint to recompute the necessary values and |
| // propagate the information into the subtree. |
| if (needs_effective_allowed_touch_action_update_ || |
| layout_object->EffectiveAllowedTouchActionChanged() || |
| layout_object->DescendantEffectiveAllowedTouchActionChanged()) { |
| // Note that although the object itself should have up to date value, in |
| // order to force recalc of the whole subtree, we mark it as needing an |
| // update. |
| layout_object->MarkEffectiveAllowedTouchActionChanged(); |
| } |
| if (needs_blocking_wheel_event_handler_update_ || |
| layout_object->BlockingWheelEventHandlerChanged() || |
| layout_object->DescendantBlockingWheelEventHandlerChanged()) { |
| // Note that although the object itself should have up to date value, in |
| // order to force recalc of the whole subtree, we mark it as needing an |
| // update. |
| layout_object->MarkBlockingWheelEventHandlerChanged(); |
| } |
| return true; |
| } |
| return compositing_dirtied; |
| } |
| |
| bool DisplayLockContext::MarkNeedsRepaintAndPaintArtifactCompositorUpdate() { |
| DCHECK(ConnectedToView()); |
| if (auto* layout_object = element_->GetLayoutObject()) { |
| layout_object->PaintingLayer()->SetNeedsRepaint(); |
| document_->View()->SetPaintArtifactCompositorNeedsUpdate(); |
| return true; |
| } |
| return false; |
| } |
| |
| bool DisplayLockContext::MarkNeedsCullRectUpdate() { |
| DCHECK(ConnectedToView()); |
| if (!RuntimeEnabledFeatures::CullRectUpdateEnabled()) |
| return false; |
| |
| if (auto* layout_object = element_->GetLayoutObject()) { |
| layout_object->PaintingLayer()->SetForcesChildrenCullRectUpdate(); |
| return true; |
| } |
| return false; |
| } |
| |
| bool DisplayLockContext::MarkForCompositingUpdatesIfNeeded() { |
| if (!ConnectedToView()) |
| return false; |
| |
| auto* layout_object = element_->GetLayoutObject(); |
| if (!layout_object) |
| return false; |
| |
| auto* layout_box = DynamicTo<LayoutBoxModelObject>(layout_object); |
| if (layout_box && layout_box->HasSelfPaintingLayer()) { |
| if (layout_box->Layer()->ChildNeedsCompositingInputsUpdate() && |
| layout_box->Layer()->Parent()) { |
| // Note that if the layer's child needs compositing inputs update, then |
| // that layer itself also needs compositing inputs update. In order to |
| // propagate the dirty bit, we need to mark this layer's _parent_ as a |
| // needing an update. |
| layout_box->Layer()->Parent()->SetNeedsCompositingInputsUpdate(); |
| } |
| if (needs_compositing_requirements_update_) |
| layout_box->Layer()->SetNeedsCompositingRequirementsUpdate(); |
| needs_compositing_requirements_update_ = false; |
| |
| if (needs_compositing_dependent_flag_update_) |
| layout_box->Layer()->SetNeedsCompositingInputsUpdate(); |
| needs_compositing_dependent_flag_update_ = false; |
| |
| if (needs_graphics_layer_rebuild_) |
| layout_box->Layer()->SetNeedsGraphicsLayerRebuild(); |
| needs_graphics_layer_rebuild_ = false; |
| |
| if (forced_graphics_layer_update_blocked_) { |
| // We only add an extra dirty bit to the compositing state, which is safe |
| // since we do this before updating the compositing state. |
| DisableCompositingQueryAsserts disabler; |
| |
| auto* compositing_parent = |
| layout_box->Layer()->EnclosingLayerWithCompositedLayerMapping( |
| kIncludeSelf); |
| compositing_parent->GetCompositedLayerMapping() |
| ->SetNeedsGraphicsLayerUpdate(kGraphicsLayerUpdateSubtree); |
| } |
| forced_graphics_layer_update_blocked_ = false; |
| |
| return true; |
| } |
| return false; |
| } |
| |
| bool DisplayLockContext::IsElementDirtyForStyleRecalc() const { |
| // The |element_| checks could be true even if |blocked_style_traversal_type_| |
| // is not required. The reason for this is that the |
| // blocked_style_traversal_type_ is set during the style walk that this |
| // display lock blocked. However, we could dirty element style and commit |
| // before ever having gone through the style calc that would have been |
| // blocked, meaning we never blocked style during a walk. Instead we might |
| // have not propagated the dirty bits up the tree. |
| return element_->NeedsStyleRecalc() || element_->ChildNeedsStyleRecalc() || |
| element_->ChildNeedsReattachLayoutTree() || |
| blocked_style_traversal_type_ > kStyleUpdateNotRequired; |
| } |
| |
| bool DisplayLockContext::IsElementDirtyForLayout() const { |
| if (auto* layout_object = element_->GetLayoutObject()) { |
| return layout_object->NeedsLayout() || child_layout_was_blocked_ || |
| HasStashedScrollOffset(); |
| } |
| return false; |
| } |
| |
| bool DisplayLockContext::IsElementDirtyForPrePaint() const { |
| if (auto* layout_object = element_->GetLayoutObject()) { |
| auto* layout_box = DynamicTo<LayoutBoxModelObject>(layout_object); |
| return PrePaintTreeWalk::ObjectRequiresPrePaint(*layout_object) || |
| PrePaintTreeWalk::ObjectRequiresTreeBuilderContext(*layout_object) || |
| needs_prepaint_subtree_walk_ || |
| needs_effective_allowed_touch_action_update_ || |
| needs_blocking_wheel_event_handler_update_ || |
| needs_compositing_requirements_update_ || |
| (layout_box && layout_box->HasSelfPaintingLayer() && |
| layout_box->Layer()->ChildNeedsCompositingInputsUpdate()); |
| } |
| return false; |
| } |
| |
| void DisplayLockContext::DidMoveToNewDocument(Document& old_document) { |
| DCHECK(element_); |
| document_ = &element_->GetDocument(); |
| |
| old_document.GetDisplayLockDocumentState().RemoveDisplayLockContext(this); |
| document_->GetDisplayLockDocumentState().AddDisplayLockContext(this); |
| |
| if (is_observed_) { |
| old_document.GetDisplayLockDocumentState() |
| .UnregisterDisplayLockActivationObservation(element_); |
| document_->GetDisplayLockDocumentState() |
| .RegisterDisplayLockActivationObservation(element_); |
| } |
| |
| // Since we're observing the lifecycle updates, ensure that we listen to the |
| // right document's view. |
| if (is_registered_for_lifecycle_notifications_) { |
| if (old_document.View()) |
| old_document.View()->UnregisterFromLifecycleNotifications(this); |
| |
| if (document_->View()) |
| document_->View()->RegisterForLifecycleNotifications(this); |
| else |
| is_registered_for_lifecycle_notifications_ = false; |
| } |
| |
| if (IsLocked()) { |
| old_document.GetDisplayLockDocumentState().RemoveLockedDisplayLock(); |
| document_->GetDisplayLockDocumentState().AddLockedDisplayLock(); |
| if (!IsActivatable(DisplayLockActivationReason::kAny)) { |
| old_document.GetDisplayLockDocumentState() |
| .DecrementDisplayLockBlockingAllActivation(); |
| document_->GetDisplayLockDocumentState() |
| .IncrementDisplayLockBlockingAllActivation(); |
| } |
| } |
| |
| DetermineIfSubtreeHasFocus(); |
| DetermineIfSubtreeHasSelection(); |
| } |
| |
| void DisplayLockContext::WillStartLifecycleUpdate(const LocalFrameView& view) { |
| DCHECK(NeedsLifecycleNotifications()); |
| // We might have delayed processing intersection observation update (signal |
| // that we were not intersecting) because this context was nested in another |
| // locked context. At the start of the lifecycle, we should check whether |
| // that is still true. In other words, this call will check if we're still |
| // nested. If we are, we won't do anything. If we're not, then we will lock |
| // this context. |
| // |
| // Note that when we are no longer nested and and we have not received any |
| // notifications from the intersection observer, it means that we are not |
| // visible. |
| if (needs_deferred_not_intersecting_signal_) |
| NotifyIsNotIntersectingViewport(); |
| |
| // If we're keeping this context unlocked, update the values. |
| if (keep_unlocked_count_) { |
| if (--keep_unlocked_count_) { |
| ScheduleAnimation(); |
| } else { |
| SetRenderAffectingState( |
| RenderAffectingState::kAutoStateUnlockedUntilLifecycle, false); |
| UpdateLifecycleNotificationRegistration(); |
| } |
| } else { |
| DCHECK(!render_affecting_state_[static_cast<int>( |
| RenderAffectingState::kAutoStateUnlockedUntilLifecycle)]); |
| } |
| } |
| |
| void DisplayLockContext::NotifyWillDisconnect() { |
| if (!IsLocked() || !element_ || !element_->GetLayoutObject()) |
| return; |
| // If we're locked while being disconnected, we need to layout the parent. |
| // The reason for this is that we might skip the layout if we're empty while |
| // locked, but it's important to update IsSelfCollapsingBlock property on |
| // the parent so that it's up to date. This property is updated during |
| // layout. |
| if (auto* parent = element_->GetLayoutObject()->Parent()) |
| parent->SetNeedsLayout(layout_invalidation_reason::kDisplayLock); |
| } |
| |
| void DisplayLockContext::ElementDisconnected() { |
| UpdateActivationObservationIfNeeded(); |
| } |
| |
| void DisplayLockContext::ElementConnected() { |
| UpdateActivationObservationIfNeeded(); |
| DetermineIfSubtreeHasFocus(); |
| DetermineIfSubtreeHasSelection(); |
| } |
| |
| void DisplayLockContext::ScheduleAnimation() { |
| DCHECK(element_); |
| if (!ConnectedToView() || !document_ || !document_->GetPage()) |
| return; |
| |
| // Schedule an animation to perform the lifecycle phases. |
| document_->GetPage()->Animator().ScheduleVisualUpdate(document_->GetFrame()); |
| } |
| |
| const char* DisplayLockContext::ShouldForceUnlock() const { |
| DCHECK(element_); |
| // This function is only called after style, layout tree, or lifecycle |
| // updates, so the style should be up-to-date, except in the case of nested |
| // locks, where the style recalc will never actually get to |element_|. |
| // TODO(vmpstr): We need to figure out what to do here, since we don't know |
| // what the style is and whether this element has proper containment. However, |
| // forcing an update from the ancestor locks seems inefficient. For now, we |
| // just optimistically assume that we have all of the right containment in |
| // place. See crbug.com/926276 for more information. |
| if (element_->NeedsStyleRecalc()) { |
| DCHECK(DisplayLockUtilities::LockedAncestorPreventingStyle(*element_)); |
| return nullptr; |
| } |
| |
| if (element_->HasDisplayContentsStyle()) |
| return rejection_names::kUnsupportedDisplay; |
| |
| auto* style = element_->GetComputedStyle(); |
| // Note that if for whatever reason we don't have computed style, then |
| // optimistically assume that we have containment. |
| if (!style) |
| return nullptr; |
| if (!style->ContainsStyle() || !style->ContainsLayout()) |
| return rejection_names::kContainmentNotSatisfied; |
| |
| // We allow replaced elements to be locked. This check is similar to the check |
| // in DefinitelyNewFormattingContext() in element.cc, but in this case we |
| // allow object element to get locked. |
| if (IsA<HTMLObjectElement>(*element_) || IsA<HTMLImageElement>(*element_) || |
| element_->IsFormControlElement() || element_->IsMediaElement() || |
| element_->IsFrameOwnerElement() || element_->IsSVGElement()) { |
| return nullptr; |
| } |
| |
| // From https://www.w3.org/TR/css-contain-1/#containment-layout |
| // If the element does not generate a principal box (as is the case with |
| // display: contents or display: none), or if the element is an internal |
| // table element other than display: table-cell, if the element is an |
| // internal ruby element, or if the element’s principal box is a |
| // non-atomic inline-level box, layout containment has no effect. |
| // (Note we're allowing display:none for display locked elements, and a bit |
| // more restrictive on ruby - banning <ruby> elements entirely). |
| auto* html_element = DynamicTo<HTMLElement>(element_.Get()); |
| if ((style->IsDisplayTableType() && |
| style->Display() != EDisplay::kTableCell) || |
| (!html_element || IsA<HTMLRubyElement>(html_element)) || |
| (style->IsDisplayInlineType() && !style->IsDisplayReplacedType())) { |
| return rejection_names::kContainmentNotSatisfied; |
| } |
| return nullptr; |
| } |
| |
| bool DisplayLockContext::ForceUnlockIfNeeded() { |
| // We must have "contain: style layout", and disallow display:contents |
| // for display locking. Note that we should always guarantee this after |
| // every style or layout tree update. Otherwise, proceeding with layout may |
| // cause unexpected behavior. By rejecting the promise, the behavior can be |
| // detected by script. |
| // TODO(rakina): If this is after acquire's promise is resolved and update() |
| // commit() isn't in progress, the web author won't know that the element |
| // got unlocked. Figure out how to notify the author. |
| if (auto* reason = ShouldForceUnlock()) { |
| if (IsLocked()) |
| Unlock(); |
| return true; |
| } |
| return false; |
| } |
| |
| bool DisplayLockContext::ConnectedToView() const { |
| return element_ && document_ && element_->isConnected() && document_->View(); |
| } |
| |
| void DisplayLockContext::NotifySubtreeLostFocus() { |
| SetRenderAffectingState(RenderAffectingState::kSubtreeHasFocus, false); |
| } |
| |
| void DisplayLockContext::NotifySubtreeGainedFocus() { |
| SetRenderAffectingState(RenderAffectingState::kSubtreeHasFocus, true); |
| } |
| |
| void DisplayLockContext::DetermineIfSubtreeHasFocus() { |
| if (!ConnectedToView()) { |
| SetRenderAffectingState(RenderAffectingState::kSubtreeHasFocus, false); |
| return; |
| } |
| |
| bool subtree_has_focus = false; |
| // Iterate up the ancestor chain from the currently focused element. If at any |
| // time we find our element, then our subtree is focused. |
| for (auto* focused = document_->FocusedElement(); focused; |
| focused = FlatTreeTraversal::ParentElement(*focused)) { |
| if (focused == element_.Get()) { |
| subtree_has_focus = true; |
| break; |
| } |
| } |
| SetRenderAffectingState(RenderAffectingState::kSubtreeHasFocus, |
| subtree_has_focus); |
| } |
| |
| void DisplayLockContext::NotifySubtreeGainedSelection() { |
| SetRenderAffectingState(RenderAffectingState::kSubtreeHasSelection, true); |
| } |
| |
| void DisplayLockContext::NotifySubtreeLostSelection() { |
| SetRenderAffectingState(RenderAffectingState::kSubtreeHasSelection, false); |
| } |
| |
| void DisplayLockContext::DetermineIfSubtreeHasSelection() { |
| if (!ConnectedToView() || !document_->GetFrame()) { |
| SetRenderAffectingState(RenderAffectingState::kSubtreeHasSelection, false); |
| return; |
| } |
| |
| auto range = ToEphemeralRangeInFlatTree(document_->GetFrame() |
| ->Selection() |
| .GetSelectionInDOMTree() |
| .ComputeRange()); |
| bool subtree_has_selection = false; |
| for (auto& node : range.Nodes()) { |
| for (auto& ancestor : FlatTreeTraversal::InclusiveAncestorsOf(node)) { |
| if (&ancestor == element_.Get()) { |
| subtree_has_selection = true; |
| break; |
| } |
| } |
| if (subtree_has_selection) |
| break; |
| } |
| SetRenderAffectingState(RenderAffectingState::kSubtreeHasSelection, |
| subtree_has_selection); |
| } |
| |
| void DisplayLockContext::SetRenderAffectingState(RenderAffectingState state, |
| bool new_flag) { |
| // If we have forced activatable locks, it is possible that we're within |
| // find-in-page. We cannot lock an object while doing this, since it may |
| // invalidate layout and in turn prevent find-in-page from properly finding |
| // text (and DCHECK). Since layout is clean for this lock (we're unlocked), |
| // keep the context unlocked until the next lifecycle starts. |
| if (state == RenderAffectingState::kSubtreeHasSelection && !new_flag && |
| document_->GetDisplayLockDocumentState() |
| .ActivatableDisplayLocksForced()) { |
| SetKeepUnlockedUntilLifecycleCount(1); |
| } |
| |
| render_affecting_state_[static_cast<int>(state)] = new_flag; |
| NotifyRenderAffectingStateChanged(); |
| } |
| |
| void DisplayLockContext::NotifyRenderAffectingStateChanged() { |
| auto state = [this](RenderAffectingState state) { |
| return render_affecting_state_[static_cast<int>(state)]; |
| }; |
| |
| // Check that we're visible if and only if lock has not been requested. |
| DCHECK(state_ == EContentVisibility::kVisible || |
| state(RenderAffectingState::kLockRequested)); |
| DCHECK(state_ != EContentVisibility::kVisible || |
| !state(RenderAffectingState::kLockRequested)); |
| |
| // We should be locked if the lock has been requested (the above DCHECKs |
| // verify that this means that we are not 'visible'), and any of the |
| // following is true: |
| // - We are not in 'auto' mode (meaning 'hidden') or |
| // - We are in 'auto' mode and nothing blocks locking: viewport is |
| // not intersecting, subtree doesn't have focus, and subtree doesn't have |
| // selection. |
| bool should_be_locked = |
| state(RenderAffectingState::kLockRequested) && |
| (state_ != EContentVisibility::kAuto || |
| (!state(RenderAffectingState::kIntersectsViewport) && |
| !state(RenderAffectingState::kSubtreeHasFocus) && |
| !state(RenderAffectingState::kSubtreeHasSelection) && |
| !state(RenderAffectingState::kAutoStateUnlockedUntilLifecycle) && |
| !state(RenderAffectingState::kAutoUnlockedForPrint))); |
| |
| if (should_be_locked && !IsLocked()) |
| Lock(); |
| else if (!should_be_locked && IsLocked()) |
| Unlock(); |
| } |
| |
| void DisplayLockContext::Trace(Visitor* visitor) const { |
| visitor->Trace(element_); |
| visitor->Trace(document_); |
| visitor->Trace(whitespace_reattach_set_); |
| } |
| |
| void DisplayLockContext::SetShouldUnlockAutoForPrint(bool flag) { |
| SetRenderAffectingState(RenderAffectingState::kAutoUnlockedForPrint, flag); |
| } |
| |
| const char* DisplayLockContext::RenderAffectingStateName(int state) const { |
| switch (static_cast<RenderAffectingState>(state)) { |
| case RenderAffectingState::kLockRequested: |
| return "LockRequested"; |
| case RenderAffectingState::kIntersectsViewport: |
| return "IntersectsViewport"; |
| case RenderAffectingState::kSubtreeHasFocus: |
| return "SubtreeHasFocus"; |
| case RenderAffectingState::kSubtreeHasSelection: |
| return "SubtreeHasSelection"; |
| case RenderAffectingState::kAutoStateUnlockedUntilLifecycle: |
| return "AutoStateUnlockedUntilLifecycle"; |
| case RenderAffectingState::kAutoUnlockedForPrint: |
| return "AutoUnlockedForPrint"; |
| case RenderAffectingState::kNumRenderAffectingStates: |
| break; |
| } |
| return "<Invalid State>"; |
| } |
| |
| String DisplayLockContext::RenderAffectingStateToString() const { |
| StringBuilder builder; |
| for (int i = 0; |
| i < static_cast<int>(RenderAffectingState::kNumRenderAffectingStates); |
| ++i) { |
| builder.Append(RenderAffectingStateName(i)); |
| builder.Append(": "); |
| builder.Append(render_affecting_state_[i] ? "true" : "false"); |
| builder.Append("\n"); |
| } |
| return builder.ToString(); |
| } |
| |
| void DisplayLockContext::StashScrollOffsetIfAvailable() { |
| if (auto* area = GetScrollableArea(element_)) { |
| const ScrollOffset& offset = area->GetScrollOffset(); |
| // Only store the offset if it's non-zero. This is because scroll |
| // restoration has a small performance implication and restoring to a zero |
| // offset is the same as not restoring it. |
| if (!offset.IsZero()) |
| stashed_scroll_offset_.emplace(offset); |
| } |
| } |
| |
| void DisplayLockContext::RestoreScrollOffsetIfStashed() { |
| if (!stashed_scroll_offset_.has_value()) |
| return; |
| |
| // Restore the offset and reset the value. |
| if (auto* area = GetScrollableArea(element_)) { |
| area->SetScrollOffset(*stashed_scroll_offset_, |
| mojom::blink::ScrollType::kAnchoring); |
| stashed_scroll_offset_.reset(); |
| } |
| } |
| |
| bool DisplayLockContext::HasStashedScrollOffset() const { |
| return stashed_scroll_offset_.has_value(); |
| } |
| |
| } // namespace blink |