diff --git a/Source/ASDisplayNode+Layout.mm b/Source/ASDisplayNode+Layout.mm index 2ec4a9bff6..e77c354ab9 100644 --- a/Source/ASDisplayNode+Layout.mm +++ b/Source/ASDisplayNode+Layout.mm @@ -296,113 +296,118 @@ ASLayoutElementStyleExtensibilityForwarding - (void)_u_measureNodeWithBoundsIfNecessary:(CGRect)bounds { ASDisplayNodeAssertLockUnownedByCurrentThread(__instanceLock); - ASDN::MutexLocker l(__instanceLock__); - // Check if we are a subnode in a layout transition. - // In this case no measurement is needed as it's part of the layout transition - if ([self _isLayoutTransitionInvalid]) { - return; - } - CGSize boundsSizeForLayout = ASCeilSizeValues(bounds.size); - - // Prefer a newer and not yet applied _pendingDisplayNodeLayout over _calculatedDisplayNodeLayout - // If there is no such _pending, check if _calculated is valid to reuse (avoiding recalculation below). - BOOL pendingLayoutIsPreferred = NO; - if (_pendingDisplayNodeLayout != nullptr && _pendingDisplayNodeLayout->isValid(_layoutVersion)) { - NSUInteger calculatedVersion = _calculatedDisplayNodeLayout->version; - NSUInteger pendingVersion = _pendingDisplayNodeLayout->version; - if (pendingVersion > calculatedVersion) { - pendingLayoutIsPreferred = YES; // Newer _pending - } else if (pendingVersion == calculatedVersion - && !ASSizeRangeEqualToSizeRange(_pendingDisplayNodeLayout->constrainedSize, - _calculatedDisplayNodeLayout->constrainedSize)) { - pendingLayoutIsPreferred = YES; // _pending with a different constrained size + BOOL isInLayoutPendingState = NO; + { + ASDN::MutexLocker l(__instanceLock__); + // Check if we are a subnode in a layout transition. + // In this case no measurement is needed as it's part of the layout transition + if ([self _isLayoutTransitionInvalid]) { + return; } - } - BOOL calculatedLayoutIsReusable = (_calculatedDisplayNodeLayout->isValid(_layoutVersion) - && (_calculatedDisplayNodeLayout->requestedLayoutFromAbove - || CGSizeEqualToSize(_calculatedDisplayNodeLayout->layout.size, boundsSizeForLayout))); - if (!pendingLayoutIsPreferred && calculatedLayoutIsReusable) { - return; + + CGSize boundsSizeForLayout = ASCeilSizeValues(bounds.size); + + // Prefer a newer and not yet applied _pendingDisplayNodeLayout over _calculatedDisplayNodeLayout + // If there is no such _pending, check if _calculated is valid to reuse (avoiding recalculation below). + BOOL pendingLayoutIsPreferred = NO; + if (_pendingDisplayNodeLayout != nullptr && _pendingDisplayNodeLayout->isValid(_layoutVersion)) { + NSUInteger calculatedVersion = _calculatedDisplayNodeLayout->version; + NSUInteger pendingVersion = _pendingDisplayNodeLayout->version; + if (pendingVersion > calculatedVersion) { + pendingLayoutIsPreferred = YES; // Newer _pending + } else if (pendingVersion == calculatedVersion + && !ASSizeRangeEqualToSizeRange(_pendingDisplayNodeLayout->constrainedSize, + _calculatedDisplayNodeLayout->constrainedSize)) { + pendingLayoutIsPreferred = YES; // _pending with a different constrained size + } + } + BOOL calculatedLayoutIsReusable = (_calculatedDisplayNodeLayout->isValid(_layoutVersion) + && (_calculatedDisplayNodeLayout->requestedLayoutFromAbove + || CGSizeEqualToSize(_calculatedDisplayNodeLayout->layout.size, boundsSizeForLayout))); + if (!pendingLayoutIsPreferred && calculatedLayoutIsReusable) { + return; + } + + as_activity_create_for_scope("Update node layout for current bounds"); + as_log_verbose(ASLayoutLog(), "Node %@, bounds size %@, calculatedSize %@, calculatedIsDirty %d", self, NSStringFromCGSize(boundsSizeForLayout), NSStringFromCGSize(_calculatedDisplayNodeLayout->layout.size), _calculatedDisplayNodeLayout->version < _layoutVersion.load()); + // _calculatedDisplayNodeLayout is not reusable we need to transition to a new one + [self cancelLayoutTransition]; + + BOOL didCreateNewContext = NO; + ASLayoutElementContext *context = ASLayoutElementGetCurrentContext(); + if (context == nil) { + context = [[ASLayoutElementContext alloc] init]; + ASLayoutElementPushContext(context); + didCreateNewContext = YES; + } + + // Figure out previous and pending layouts for layout transition + std::shared_ptr nextLayout = _pendingDisplayNodeLayout; +#define layoutSizeDifferentFromBounds !CGSizeEqualToSize(nextLayout->layout.size, boundsSizeForLayout) + + // nextLayout was likely created by a call to layoutThatFits:, check if it is valid and can be applied. + // If our bounds size is different than it, or invalid, recalculate. Use #define to avoid nullptr-> + BOOL pendingLayoutApplicable = NO; + if (nextLayout == nullptr) { + as_log_verbose(ASLayoutLog(), "No pending layout."); + } else if (nextLayout->version < _layoutVersion) { + as_log_verbose(ASLayoutLog(), "Pending layout is stale."); + } else if (layoutSizeDifferentFromBounds) { + as_log_verbose(ASLayoutLog(), "Pending layout size %@ doesn't match bounds size.", NSStringFromCGSize(nextLayout->layout.size)); + } else { + as_log_verbose(ASLayoutLog(), "Using pending layout %@.", nextLayout->layout); + pendingLayoutApplicable = YES; + } + + if (!pendingLayoutApplicable) { + as_log_verbose(ASLayoutLog(), "Measuring with previous constrained size."); + // Use the last known constrainedSize passed from a parent during layout (if never, use bounds). + NSUInteger version = _layoutVersion; + ASSizeRange constrainedSize = [self _locked_constrainedSizeForLayoutPass]; + ASLayout *layout = [self calculateLayoutThatFits:constrainedSize + restrictedToSize:self.style.size + relativeToParentSize:boundsSizeForLayout]; + nextLayout = std::make_shared(layout, constrainedSize, boundsSizeForLayout, version); + // Now that the constrained size of pending layout might have been reused, the layout is useless + // Release it and any orphaned subnodes it retains + _pendingDisplayNodeLayout = nullptr; + } + + if (didCreateNewContext) { + ASLayoutElementPopContext(); + } + + // If our new layout's desired size for self doesn't match current size, ask our parent to update it. + // This can occur for either pre-calculated or newly-calculated layouts. + if (nextLayout->requestedLayoutFromAbove == NO + && CGSizeEqualToSize(boundsSizeForLayout, nextLayout->layout.size) == NO) { + as_log_verbose(ASLayoutLog(), "Layout size doesn't match bounds size. Requesting layout from above."); + // The layout that we have specifies that this node (self) would like to be a different size + // than it currently is. Because that size has been computed within the constrainedSize, we + // expect that calling setNeedsLayoutFromAbove will result in our parent resizing us to this. + // However, in some cases apps may manually interfere with this (setting a different bounds). + // In this case, we need to detect that we've already asked to be resized to match this + // particular ASLayout object, and shouldn't loop asking again unless we have a different ASLayout. + nextLayout->requestedLayoutFromAbove = YES; + __instanceLock__.unlock(); + [self _u_setNeedsLayoutFromAbove]; + __instanceLock__.lock(); + // Update the layout's version here because _u_setNeedsLayoutFromAbove calls __setNeedsLayout which in turn increases _layoutVersion + // Failing to do this will cause the layout to be invalid immediately + nextLayout->version = _layoutVersion; + } + + // Prepare to transition to nextLayout + ASDisplayNodeAssertNotNil(nextLayout->layout, @"nextLayout->layout should not be nil! %@", self); + _pendingLayoutTransition = [[ASLayoutTransition alloc] initWithNode:self + pendingLayout:nextLayout + previousLayout:_calculatedDisplayNodeLayout]; + isInLayoutPendingState = ASHierarchyStateIncludesLayoutPending(_hierarchyState); } - as_activity_create_for_scope("Update node layout for current bounds"); - as_log_verbose(ASLayoutLog(), "Node %@, bounds size %@, calculatedSize %@, calculatedIsDirty %d", self, NSStringFromCGSize(boundsSizeForLayout), NSStringFromCGSize(_calculatedDisplayNodeLayout->layout.size), _calculatedDisplayNodeLayout->version < _layoutVersion.load()); - // _calculatedDisplayNodeLayout is not reusable we need to transition to a new one - [self cancelLayoutTransition]; - - BOOL didCreateNewContext = NO; - ASLayoutElementContext *context = ASLayoutElementGetCurrentContext(); - if (context == nil) { - context = [[ASLayoutElementContext alloc] init]; - ASLayoutElementPushContext(context); - didCreateNewContext = YES; - } - - // Figure out previous and pending layouts for layout transition - std::shared_ptr nextLayout = _pendingDisplayNodeLayout; - #define layoutSizeDifferentFromBounds !CGSizeEqualToSize(nextLayout->layout.size, boundsSizeForLayout) - - // nextLayout was likely created by a call to layoutThatFits:, check if it is valid and can be applied. - // If our bounds size is different than it, or invalid, recalculate. Use #define to avoid nullptr-> - BOOL pendingLayoutApplicable = NO; - if (nextLayout == nullptr) { - as_log_verbose(ASLayoutLog(), "No pending layout."); - } else if (nextLayout->version < _layoutVersion) { - as_log_verbose(ASLayoutLog(), "Pending layout is stale."); - } else if (layoutSizeDifferentFromBounds) { - as_log_verbose(ASLayoutLog(), "Pending layout size %@ doesn't match bounds size.", NSStringFromCGSize(nextLayout->layout.size)); - } else { - as_log_verbose(ASLayoutLog(), "Using pending layout %@.", nextLayout->layout); - pendingLayoutApplicable = YES; - } - - if (!pendingLayoutApplicable) { - as_log_verbose(ASLayoutLog(), "Measuring with previous constrained size."); - // Use the last known constrainedSize passed from a parent during layout (if never, use bounds). - NSUInteger version = _layoutVersion; - ASSizeRange constrainedSize = [self _locked_constrainedSizeForLayoutPass]; - ASLayout *layout = [self calculateLayoutThatFits:constrainedSize - restrictedToSize:self.style.size - relativeToParentSize:boundsSizeForLayout]; - nextLayout = std::make_shared(layout, constrainedSize, boundsSizeForLayout, version); - // Now that the constrained size of pending layout might have been reused, the layout is useless - // Release it and any orphaned subnodes it retains - _pendingDisplayNodeLayout = nullptr; - } - - if (didCreateNewContext) { - ASLayoutElementPopContext(); - } - - // If our new layout's desired size for self doesn't match current size, ask our parent to update it. - // This can occur for either pre-calculated or newly-calculated layouts. - if (nextLayout->requestedLayoutFromAbove == NO - && CGSizeEqualToSize(boundsSizeForLayout, nextLayout->layout.size) == NO) { - as_log_verbose(ASLayoutLog(), "Layout size doesn't match bounds size. Requesting layout from above."); - // The layout that we have specifies that this node (self) would like to be a different size - // than it currently is. Because that size has been computed within the constrainedSize, we - // expect that calling setNeedsLayoutFromAbove will result in our parent resizing us to this. - // However, in some cases apps may manually interfere with this (setting a different bounds). - // In this case, we need to detect that we've already asked to be resized to match this - // particular ASLayout object, and shouldn't loop asking again unless we have a different ASLayout. - nextLayout->requestedLayoutFromAbove = YES; - __instanceLock__.unlock(); - [self _u_setNeedsLayoutFromAbove]; - __instanceLock__.lock(); - // Update the layout's version here because _u_setNeedsLayoutFromAbove calls __setNeedsLayout which in turn increases _layoutVersion - // Failing to do this will cause the layout to be invalid immediately - nextLayout->version = _layoutVersion; - } - - // Prepare to transition to nextLayout - ASDisplayNodeAssertNotNil(nextLayout->layout, @"nextLayout->layout should not be nil! %@", self); - _pendingLayoutTransition = [[ASLayoutTransition alloc] initWithNode:self - pendingLayout:nextLayout - previousLayout:_calculatedDisplayNodeLayout]; - // If a parent is currently executing a layout transition, perform our layout application after it. - if (ASHierarchyStateIncludesLayoutPending(_hierarchyState) == NO) { + if (isInLayoutPendingState == NO) { // If no transition, apply our new layout immediately (common case). [self _completePendingLayoutTransition]; } @@ -860,12 +865,18 @@ ASLayoutElementStyleExtensibilityForwarding */ - (void)_completePendingLayoutTransition { - __instanceLock__.lock(); - ASLayoutTransition *pendingLayoutTransition = _pendingLayoutTransition; - __instanceLock__.unlock(); - + ASDisplayNodeAssertLockUnownedByCurrentThread(__instanceLock); + + ASLayoutTransition *pendingLayoutTransition = nil; + { + ASDN::MutexLocker l(__instanceLock__); + pendingLayoutTransition = _pendingLayoutTransition; + if (pendingLayoutTransition != nil) { + [self _locked_setCalculatedDisplayNodeLayout:pendingLayoutTransition.pendingLayout]; + } + } + if (pendingLayoutTransition != nil) { - [self _setCalculatedDisplayNodeLayout:pendingLayoutTransition.pendingLayout]; [self _completeLayoutTransition:pendingLayoutTransition]; [self _pendingLayoutTransitionDidComplete]; }