diff --git a/AsyncDisplayKit.xcodeproj/project.pbxproj b/AsyncDisplayKit.xcodeproj/project.pbxproj index 29c10b3ca5..83427c715c 100644 --- a/AsyncDisplayKit.xcodeproj/project.pbxproj +++ b/AsyncDisplayKit.xcodeproj/project.pbxproj @@ -217,6 +217,10 @@ 509E68651B3AEDC5009B9150 /* CGRect+ASConvenience.h in Headers */ = {isa = PBXBuildFile; fileRef = 205F0E1F1B376416007741D0 /* CGRect+ASConvenience.h */; }; 509E68661B3AEDD7009B9150 /* CGRect+ASConvenience.m in Sources */ = {isa = PBXBuildFile; fileRef = 205F0E201B376416007741D0 /* CGRect+ASConvenience.m */; }; 6BDC61F61979037800E50D21 /* AsyncDisplayKit.h in Headers */ = {isa = PBXBuildFile; fileRef = 6BDC61F51978FEA400E50D21 /* AsyncDisplayKit.h */; settings = {ATTRIBUTES = (Public, ); }; }; + 9C204A641B86349B00313849 /* ASStackTextPositionedLayout.h in Headers */ = {isa = PBXBuildFile; fileRef = 9C204A621B86349B00313849 /* ASStackTextPositionedLayout.h */; settings = {ATTRIBUTES = (Public, ); }; }; + 9C204A651B86349B00313849 /* ASStackTextPositionedLayout.h in Headers */ = {isa = PBXBuildFile; fileRef = 9C204A621B86349B00313849 /* ASStackTextPositionedLayout.h */; settings = {ATTRIBUTES = (Public, ); }; }; + 9C204A661B86349B00313849 /* ASStackTextPositionedLayout.mm in Sources */ = {isa = PBXBuildFile; fileRef = 9C204A631B86349B00313849 /* ASStackTextPositionedLayout.mm */; }; + 9C204A671B86349B00313849 /* ASStackTextPositionedLayout.mm in Sources */ = {isa = PBXBuildFile; fileRef = 9C204A631B86349B00313849 /* ASStackTextPositionedLayout.mm */; }; 9C3061061B857EC400D0530B /* ASStackTextLayoutSpec.h in Headers */ = {isa = PBXBuildFile; fileRef = 9C3061041B857EC400D0530B /* ASStackTextLayoutSpec.h */; settings = {ATTRIBUTES = (Public, ); }; }; 9C3061071B857EC400D0530B /* ASStackTextLayoutSpec.h in Headers */ = {isa = PBXBuildFile; fileRef = 9C3061041B857EC400D0530B /* ASStackTextLayoutSpec.h */; settings = {ATTRIBUTES = (Public, ); }; }; 9C3061081B857EC400D0530B /* ASStackTextLayoutSpec.mm in Sources */ = {isa = PBXBuildFile; fileRef = 9C3061051B857EC400D0530B /* ASStackTextLayoutSpec.mm */; }; @@ -562,6 +566,8 @@ 4640521E1A3F83C40061C0BA /* ASMultidimensionalArrayUtils.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASMultidimensionalArrayUtils.h; sourceTree = ""; }; 4640521F1A3F83C40061C0BA /* ASMultidimensionalArrayUtils.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASMultidimensionalArrayUtils.mm; sourceTree = ""; }; 6BDC61F51978FEA400E50D21 /* AsyncDisplayKit.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = AsyncDisplayKit.h; sourceTree = ""; }; + 9C204A621B86349B00313849 /* ASStackTextPositionedLayout.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ASStackTextPositionedLayout.h; sourceTree = ""; }; + 9C204A631B86349B00313849 /* ASStackTextPositionedLayout.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ASStackTextPositionedLayout.mm; sourceTree = ""; }; 9C3061041B857EC400D0530B /* ASStackTextLayoutSpec.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = ASStackTextLayoutSpec.h; path = AsyncDisplayKit/Layout/ASStackTextLayoutSpec.h; sourceTree = ""; }; 9C3061051B857EC400D0530B /* ASStackTextLayoutSpec.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; name = ASStackTextLayoutSpec.mm; path = AsyncDisplayKit/Layout/ASStackTextLayoutSpec.mm; sourceTree = ""; }; 9C49C36E1B853957000B0DD5 /* ASStackLayoutable.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = ASStackLayoutable.h; path = AsyncDisplayKit/Layout/ASStackLayoutable.h; sourceTree = ""; }; @@ -696,7 +702,9 @@ 058D09AD195D04C000B7D73C /* Products */, FD40E2760492F0CAAEAD552D /* Pods */, ); + indentWidth = 2; sourceTree = ""; + tabWidth = 2; }; 058D09AD195D04C000B7D73C /* Products */ = { isa = PBXGroup; @@ -928,6 +936,8 @@ ACF6ED481B17847A00DA7C62 /* ASStackPositionedLayout.mm */, ACF6ED491B17847A00DA7C62 /* ASStackUnpositionedLayout.h */, ACF6ED4A1B17847A00DA7C62 /* ASStackUnpositionedLayout.mm */, + 9C204A621B86349B00313849 /* ASStackTextPositionedLayout.h */, + 9C204A631B86349B00313849 /* ASStackTextPositionedLayout.mm */, ); path = Private; sourceTree = ""; @@ -1056,6 +1066,7 @@ 0574D5E219C110940097DC25 /* ASTableViewProtocols.h in Headers */, 055F1A3C19ABD43F004DAFF1 /* ASCellNode.h in Headers */, 058D0A53195D05DC00B7D73C /* _ASDisplayLayer.h in Headers */, + 9C204A641B86349B00313849 /* ASStackTextPositionedLayout.h in Headers */, 058D0A54195D05DC00B7D73C /* _ASDisplayLayer.mm in Headers */, 058D0A55195D05DC00B7D73C /* _ASDisplayView.h in Headers */, 058D0A56195D05DC00B7D73C /* _ASDisplayView.mm in Headers */, @@ -1148,6 +1159,7 @@ B35061FA1B010EFD0018CF92 /* ASControlNode+Subclasses.h in Headers */, B35062371B010EFD0018CF92 /* ASTextNodeWordKerner.h in Headers */, B35062261B010EFD0018CF92 /* ASRangeController.h in Headers */, + 9C204A651B86349B00313849 /* ASStackTextPositionedLayout.h in Headers */, B35062111B010EFD0018CF92 /* _ASDisplayView.h in Headers */, B35061F81B010EFD0018CF92 /* ASControlNode.h in Headers */, 430E7C901B4C23F100697A4C /* ASIndexPath.h in Headers */, @@ -1423,6 +1435,7 @@ 058D0A26195D050800B7D73C /* _ASCoreAnimationExtras.mm in Sources */, 058D0A23195D050800B7D73C /* _ASAsyncTransactionContainer.m in Sources */, 058D0A1E195D050800B7D73C /* ASTextNodeShadower.m in Sources */, + 9C204A661B86349B00313849 /* ASStackTextPositionedLayout.mm in Sources */, ACF6ED2E1B17843500DA7C62 /* ASRatioLayoutSpec.mm in Sources */, 058D0A18195D050800B7D73C /* _ASDisplayLayer.mm in Sources */, ACF6ED321B17843500DA7C62 /* ASStaticLayoutSpec.mm in Sources */, @@ -1526,6 +1539,7 @@ 9C3061091B857EC400D0530B /* ASStackTextLayoutSpec.mm in Sources */, 34EFC7641B701CC600AD841F /* ASCenterLayoutSpec.mm in Sources */, B350623B1B010EFD0018CF92 /* NSMutableAttributedString+TextKitAdditions.m in Sources */, + 9C204A671B86349B00313849 /* ASStackTextPositionedLayout.mm in Sources */, B35062401B010EFD0018CF92 /* _ASAsyncTransactionContainer.m in Sources */, B35062311B010EFD0018CF92 /* ASTextNodeRenderer.mm in Sources */, B35062051B010EFD0018CF92 /* ASMultiplexImageNode.mm in Sources */, diff --git a/AsyncDisplayKit/Layout/ASStackLayoutDefines.h b/AsyncDisplayKit/Layout/ASStackLayoutDefines.h index 39e51b65c8..d7737f7eab 100644 --- a/AsyncDisplayKit/Layout/ASStackLayoutDefines.h +++ b/AsyncDisplayKit/Layout/ASStackLayoutDefines.h @@ -44,11 +44,7 @@ typedef NS_ENUM(NSUInteger, ASStackLayoutAlignItems) { /** Center children on cross axis */ ASStackLayoutAlignItemsCenter, /** Expand children to fill cross axis */ - ASStackLayoutAlignItemsStretch, - /** Children align along the first baseline of the stack. Only available for horizontal stack nodes */ - ASStackLayoutAlignItemsFirstBaseline, - /** Children align along the last baseline of the stack. Only available for horizontal stack nodes */ - ASStackLayoutAlignItemsLastBaseline, + ASStackLayoutAlignItemsStretch }; /** @@ -66,6 +62,4 @@ typedef NS_ENUM(NSUInteger, ASStackLayoutAlignSelf) { ASStackLayoutAlignSelfCenter, /** Expand to fill cross axis */ ASStackLayoutAlignSelfStretch, - - /** Note: All children in a stack must have the same baseline align type */ }; diff --git a/AsyncDisplayKit/Layout/ASStackTextLayoutSpec.h b/AsyncDisplayKit/Layout/ASStackTextLayoutSpec.h index ab5b80db19..a7b94da03b 100644 --- a/AsyncDisplayKit/Layout/ASStackTextLayoutSpec.h +++ b/AsyncDisplayKit/Layout/ASStackTextLayoutSpec.h @@ -1,35 +1,48 @@ -// -// ASStackTextLayoutSpec.h -// AsyncDisplayKit -// -// Created by ricky cancro on 8/19/15. -// Copyright (c) 2015 Facebook. All rights reserved. -// +/* + * Copyright (c) 2014-present, Facebook, Inc. + * All rights reserved. + * + * This source code is licensed under the BSD-style license found in the + * LICENSE file in the root directory of this source tree. An additional grant + * of patent rights can be found in the PATENTS file in the same directory. + * + */ #import -/** Orientation of children along cross axis */ typedef NS_ENUM(NSUInteger, ASStackTextLayoutBaselineAlignment) { - ASStackTextLayoutBaselineAlignmentNone, - /** Children align along the first baseline of the stack. Only available for horizontal stack nodes */ - ASStackTextLayoutBaselineAlignmentFirst, - /** Children align along the last baseline of the stack. Only available for horizontal stack nodes */ - ASStackTextLayoutBaselineAlignmentLast, + /** No baseline alignment. This is only valid for a vertical stack */ + ASStackTextLayoutBaselineAlignmentNone, + /** Align all children to the first baseline. This is only valid for a horizontal stack */ + ASStackTextLayoutBaselineAlignmentFirst, + /** Align all children to the last baseline. This is useful when a text node wraps and you want to align + to the bottom baseline. This is only valid for a horizontal stack */ + ASStackTextLayoutBaselineAlignmentLast, }; typedef struct { - /** Specifies the direction children are stacked in. */ - ASStackLayoutSpecStyle stackLayoutStyle; - - ASStackTextLayoutBaselineAlignment baselineAlignment; + /** Describes how the stack will be laid out */ + ASStackLayoutSpecStyle stackLayoutStyle; + + /** The type of baseline alignment */ + ASStackTextLayoutBaselineAlignment baselineAlignment; } ASStackTextLayoutSpecStyle; -@interface ASStackTextLayoutSpec : ASLayoutSpec + +/** + A specialized version of a stack layout that aligns its children on a baseline. This spec only works with + ASStackTextLayoutable children. + + If the spec is created with a horizontal direction, the children will be laid on a common baseline. + If the spec is created with a vertical direction, a child's vertical spacing will be measured from its + baseline instead of from the child's bounding box. +*/ +@interface ASStackTextLayoutSpec : ASLayoutSpec /** @param style Specifies how children are laid out. - @param children ASLayoutable children to be positioned. + @param children ASTextLayoutable children to be positioned. */ + (instancetype)newWithStyle:(ASStackTextLayoutSpecStyle)style children:(NSArray *)children; diff --git a/AsyncDisplayKit/Layout/ASStackTextLayoutSpec.mm b/AsyncDisplayKit/Layout/ASStackTextLayoutSpec.mm index a15f4c6686..67c6942696 100644 --- a/AsyncDisplayKit/Layout/ASStackTextLayoutSpec.mm +++ b/AsyncDisplayKit/Layout/ASStackTextLayoutSpec.mm @@ -1,10 +1,12 @@ -// -// ASStackTextLayoutSpec.m -// AsyncDisplayKit -// -// Created by ricky cancro on 8/19/15. -// Copyright (c) 2015 Facebook. All rights reserved. -// +/* + * Copyright (c) 2014-present, Facebook, Inc. + * All rights reserved. + * + * This source code is licensed under the BSD-style license found in the + * LICENSE file in the root directory of this source tree. An additional grant + * of patent rights can be found in the PATENTS file in the same directory. + * + */ #import "ASStackTextLayoutSpec.h" #import "ASStackLayoutable.h" @@ -19,109 +21,61 @@ #import "ASStackLayoutSpecUtilities.h" #import "ASStackPositionedLayout.h" #import "ASStackUnpositionedLayout.h" +#import "ASStackTextPositionedLayout.h" #import "ASThread.h" -static CGFloat baselineForItem(const ASStackTextLayoutSpecStyle &style, - const ASLayout *layout) { - - __weak id textChild = (id) layout.layoutableObject; - switch (style.baselineAlignment) { - case ASStackTextLayoutBaselineAlignmentNone: - return 0; - case ASStackTextLayoutBaselineAlignmentFirst: - return textChild.ascender; - case ASStackTextLayoutBaselineAlignmentLast: - return textChild.descender; - } - -} - -static CGFloat baselineOffset(const ASStackTextLayoutSpecStyle &style, - const ASLayout *l, - const CGFloat maxBaseline) -{ - switch (style.baselineAlignment) { - case ASStackTextLayoutBaselineAlignmentFirst: - case ASStackTextLayoutBaselineAlignmentLast: - return maxBaseline - baselineForItem(style, l); - case ASStackTextLayoutBaselineAlignmentNone: - return 0; - } -} - @implementation ASStackTextLayoutSpec { - ASStackTextLayoutSpecStyle _textStyle; - std::vector> _children; - std::vector> _stackChildren; - ASDN::RecursiveMutex _propertyLock; + ASStackTextLayoutSpecStyle _textStyle; + std::vector> _stackChildren; + ASDN::RecursiveMutex _propertyLock; } +@synthesize ascender = _ascender; +@synthesize descender = _descender; + + (instancetype)newWithStyle:(ASStackTextLayoutSpecStyle)style children:(NSArray *)children { - ASDisplayNodeAssert(style.stackLayoutStyle.direction == ASStackLayoutDirectionHorizontal && style.baselineAlignment != ASStackTextLayoutBaselineAlignmentNone, @"if you don't need baseline alignment, use ASStackLayoutSpec"); - - ASStackTextLayoutSpec *spec = [super new]; - if (spec) { - spec->_textStyle = style; - spec->_children = std::vector>(); - for (id child in children) { - ASDisplayNodeAssert([child conformsToProtocol:@protocol(ASStackTextLayoutable)], @"child must conform to ASStackLayoutable"); - - spec->_children.push_back(child); - spec->_stackChildren.push_back(child); - } + ASDisplayNodeAssert((style.stackLayoutStyle.direction == ASStackLayoutDirectionHorizontal && style.baselineAlignment != ASStackTextLayoutBaselineAlignmentNone) || style.stackLayoutStyle.direction == ASStackLayoutDirectionVertical, @"baselineAlignment is set to none. If you don't need baseline alignment please use ASStackLayoutSpec"); + + ASStackTextLayoutSpec *spec = [super new]; + if (spec) { + spec->_textStyle = style; + spec->_stackChildren = std::vector>(); + for (id child in children) { + ASDisplayNodeAssert([child conformsToProtocol:@protocol(ASStackTextLayoutable)], @"child must conform to ASStackLayoutable"); + + spec->_stackChildren.push_back(child); } - return spec; + } + return spec; } + (instancetype)new { - ASDISPLAYNODE_NOT_DESIGNATED_INITIALIZER(); + ASDISPLAYNODE_NOT_DESIGNATED_INITIALIZER(); } - (ASLayout *)measureWithSizeRange:(ASSizeRange)constrainedSize { - ASStackLayoutSpecStyle stackStyle = _textStyle.stackLayoutStyle; - - - const auto unpositionedLayout = ASStackUnpositionedLayout::compute(_stackChildren, stackStyle, constrainedSize); - const auto positionedLayout = ASStackPositionedLayout::compute(unpositionedLayout, stackStyle, constrainedSize); - - // Alter the positioned layouts to include baselines - const auto baselineIt = std::max_element(positionedLayout.sublayouts.begin(), positionedLayout.sublayouts.end(), [&](const ASLayout *a, const ASLayout *b){ - return baselineForItem(_textStyle, a) < baselineForItem(_textStyle, b); - }); - const CGFloat maxBaseline = baselineIt == positionedLayout.sublayouts.end() ? 0 : baselineForItem(_textStyle, *baselineIt); - - CGPoint p = CGPointZero; - BOOL first = YES; - auto stackedChildren = AS::map(positionedLayout.sublayouts, [&](ASLayout *l) -> ASLayout *{ - __weak id textChild = (id) l.layoutableObject; - if (first) { - p = l.position; - } - first = NO; - - if (stackStyle.direction == ASStackLayoutDirectionHorizontal) { - l.position = p + CGPointMake(0, baselineOffset(_textStyle, l, maxBaseline)); - } - - CGFloat spacingAfterBaseline = (stackStyle.direction == ASStackLayoutDirectionVertical) ? textChild.descender : 0; - p = p + directionPoint(stackStyle.direction, stackDimension(stackStyle.direction, l.size) + [(id)l.layoutableObject spacingAfter] + spacingAfterBaseline, 0); - - return l; - }); - - const ASStackPositionedLayout alteredPositionedLayouts = {stackedChildren, positionedLayout.crossSize}; - const CGSize finalSize = directionSize(stackStyle.direction, unpositionedLayout.stackDimensionSum, alteredPositionedLayouts.crossSize); - - NSArray *sublayouts = [NSArray arrayWithObjects:&alteredPositionedLayouts.sublayouts[0] count:alteredPositionedLayouts.sublayouts.size()]; - - - return [ASLayout newWithLayoutableObject:self - size:ASSizeRangeClamp(constrainedSize, finalSize) - sublayouts:sublayouts]; + ASStackLayoutSpecStyle stackStyle = _textStyle.stackLayoutStyle; + + const auto unpositionedLayout = ASStackUnpositionedLayout::compute(_stackChildren, stackStyle, constrainedSize); + const auto positionedLayout = ASStackPositionedLayout::compute(unpositionedLayout, stackStyle, constrainedSize); + const auto baselinePositionedLayout = ASStackTextPositionedLayout::compute(positionedLayout, _textStyle, constrainedSize); + + const CGSize finalSize = directionSize(stackStyle.direction, unpositionedLayout.stackDimensionSum, baselinePositionedLayout.crossSize); + + NSArray *sublayouts = [NSArray arrayWithObjects:&baselinePositionedLayout.sublayouts[0] count:baselinePositionedLayout.sublayouts.size()]; + + ASDN::MutexLocker l(_propertyLock); + _ascender = baselinePositionedLayout.ascender; + _descender = baselinePositionedLayout.descender; + + + return [ASLayout newWithLayoutableObject:self + size:ASSizeRangeClamp(constrainedSize, finalSize) + sublayouts:sublayouts]; } @end diff --git a/AsyncDisplayKit/Private/ASStackPositionedLayout.mm b/AsyncDisplayKit/Private/ASStackPositionedLayout.mm index b567be3ef7..d106d0618b 100644 --- a/AsyncDisplayKit/Private/ASStackPositionedLayout.mm +++ b/AsyncDisplayKit/Private/ASStackPositionedLayout.mm @@ -15,21 +15,9 @@ #import "ASStackLayoutSpecUtilities.h" #import "ASLayoutable.h" -static CGFloat baselineForItem(const ASStackLayoutSpecStyle &style, - const ASStackUnpositionedItem &item) { - const ASStackLayoutAlignItems alignItems = alignment(item.child.alignSelf, style.alignItems); - if (alignItems == ASStackLayoutAlignItemsFirstBaseline) { - return item.child.layoutInsets.top; - } else if (alignItems == ASStackLayoutAlignItemsLastBaseline) { - return item.child.layoutInsets.bottom; - } - return 0; -} - static CGFloat crossOffset(const ASStackLayoutSpecStyle &style, const ASStackUnpositionedItem &l, - const CGFloat crossSize, - const CGFloat maxBaseline) + const CGFloat crossSize) { switch (alignment(l.child.alignSelf, style.alignItems)) { case ASStackLayoutAlignItemsEnd: @@ -39,9 +27,8 @@ static CGFloat crossOffset(const ASStackLayoutSpecStyle &style, case ASStackLayoutAlignItemsStart: case ASStackLayoutAlignItemsStretch: return 0; - case ASStackLayoutAlignItemsLastBaseline: - case ASStackLayoutAlignItemsFirstBaseline: - return maxBaseline - baselineForItem(style, l); + default: + return 0; } } @@ -61,12 +48,6 @@ static ASStackPositionedLayout stackedLayout(const ASStackLayoutSpecStyle &style const auto maxCrossSize = crossDimension(style.direction, constrainedSize.max); const CGFloat crossSize = MIN(MAX(minCrossSize, largestChildCrossSize), maxCrossSize); - // Find the maximum height for the baseline - const auto baselineIt = std::max_element(unpositionedLayout.items.begin(), unpositionedLayout.items.end(), [&](const ASStackUnpositionedItem &a, const ASStackUnpositionedItem &b){ - return baselineForItem(style, a) < baselineForItem(style, b); - }); - const CGFloat maxBaseline = baselineIt == unpositionedLayout.items.end() ? 0 : baselineForItem(style, *baselineIt); - CGPoint p = directionPoint(style.direction, offset, 0); BOOL first = YES; auto stackedChildren = AS::map(unpositionedLayout.items, [&](const ASStackUnpositionedItem &l) -> ASLayout *{ @@ -75,10 +56,9 @@ static ASStackPositionedLayout stackedLayout(const ASStackLayoutSpecStyle &style p = p + directionPoint(style.direction, style.spacing, 0); } first = NO; - l.layout.position = p + directionPoint(style.direction, 0, crossOffset(style, l, crossSize, maxBaseline)); + l.layout.position = p + directionPoint(style.direction, 0, crossOffset(style, l, crossSize)); - CGFloat spacingAfterBaseline = (style.direction == ASStackLayoutDirectionVertical && style.baselineRelativeArrangement) ? l.child.layoutInsets.bottom : 0; - p = p + directionPoint(style.direction, stackDimension(style.direction, l.layout.size) + l.child.spacingAfter + spacingAfterBaseline, 0); + p = p + directionPoint(style.direction, stackDimension(style.direction, l.layout.size) + l.child.spacingAfter, 0); return l.layout; }); return {stackedChildren, crossSize}; diff --git a/AsyncDisplayKit/Private/ASStackTextPositionedLayout.h b/AsyncDisplayKit/Private/ASStackTextPositionedLayout.h new file mode 100644 index 0000000000..9794e9b807 --- /dev/null +++ b/AsyncDisplayKit/Private/ASStackTextPositionedLayout.h @@ -0,0 +1,26 @@ +/* + * Copyright (c) 2014-present, Facebook, Inc. + * All rights reserved. + * + * This source code is licensed under the BSD-style license found in the + * LICENSE file in the root directory of this source tree. An additional grant + * of patent rights can be found in the PATENTS file in the same directory. + * + */ + +#import "ASLayout.h" +#import "ASDimension.h" +#import "ASStackTextLayoutSpec.h" +#import "ASStackPositionedLayout.h" + +struct ASStackTextPositionedLayout { + const std::vector sublayouts; + const CGFloat crossSize; + const CGFloat ascender; + const CGFloat descender; + + /** Given a positioned layout, computes each child position using baseline alignment. */ + static ASStackTextPositionedLayout compute(const ASStackPositionedLayout &positionedLayout, + const ASStackTextLayoutSpecStyle &textStyle, + const ASSizeRange &constrainedSize); +}; diff --git a/AsyncDisplayKit/Private/ASStackTextPositionedLayout.mm b/AsyncDisplayKit/Private/ASStackTextPositionedLayout.mm new file mode 100644 index 0000000000..c694a379b0 --- /dev/null +++ b/AsyncDisplayKit/Private/ASStackTextPositionedLayout.mm @@ -0,0 +1,118 @@ +/* + * Copyright (c) 2014-present, Facebook, Inc. + * All rights reserved. + * + * This source code is licensed under the BSD-style license found in the + * LICENSE file in the root directory of this source tree. An additional grant + * of patent rights can be found in the PATENTS file in the same directory. + * + */ + +#import "ASStackTextPositionedLayout.h" + +#import "ASLayoutSpecUtilities.h" +#import "ASStackLayoutSpecUtilities.h" + +static CGFloat baselineForItem(const ASStackTextLayoutSpecStyle &style, + const ASLayout *layout) { + + __weak id textChild = (id) layout.layoutableObject; + switch (style.baselineAlignment) { + case ASStackTextLayoutBaselineAlignmentNone: + return 0; + case ASStackTextLayoutBaselineAlignmentFirst: + return textChild.ascender; + case ASStackTextLayoutBaselineAlignmentLast: + return layout.size.height + textChild.descender; + } + +} + +static CGFloat baselineOffset(const ASStackTextLayoutSpecStyle &style, + const ASLayout *l, + const CGFloat maxAscender, + const CGFloat maxBaseline) +{ + if (style.stackLayoutStyle.direction == ASStackLayoutDirectionHorizontal) { + __weak id textChild = (id)l.layoutableObject; + switch (style.baselineAlignment) { + case ASStackTextLayoutBaselineAlignmentFirst: + return maxAscender - textChild.ascender; + case ASStackTextLayoutBaselineAlignmentLast: + return maxBaseline + textChild.descender - textChild.ascender; + case ASStackTextLayoutBaselineAlignmentNone: + return 0; + } + } + return 0; +} + +static CGFloat maxDimensionForLayout(const ASLayout *l, + const ASStackLayoutSpecStyle &style) +{ + CGFloat maxDimension = crossDimension(style.direction, l.size); + style.direction == ASStackLayoutDirectionVertical ? maxDimension += l.position.x : maxDimension += l.position.y; + return maxDimension; +} + +ASStackTextPositionedLayout ASStackTextPositionedLayout::compute(const ASStackPositionedLayout &positionedLayout, + const ASStackTextLayoutSpecStyle &textStyle, + const ASSizeRange &constrainedSize) +{ + ASStackLayoutSpecStyle stackStyle = textStyle.stackLayoutStyle; + + + // Get the largest distance from the top of the stack to a baseline. This is the baseline we will align to. + const auto baselineIt = std::max_element(positionedLayout.sublayouts.begin(), positionedLayout.sublayouts.end(), [&](const ASLayout *a, const ASLayout *b){ + return baselineForItem(textStyle, a) < baselineForItem(textStyle, b); + }); + const CGFloat maxBaseline = baselineIt == positionedLayout.sublayouts.end() ? 0 : baselineForItem(textStyle, *baselineIt); + + // find the largest ascender for all children. This value will be used in offset computation as well as sent back to the ASStackTextLayoutSpec as its ascender. + const auto ascenderIt = std::max_element(positionedLayout.sublayouts.begin(), positionedLayout.sublayouts.end(), [&](const ASLayout *a, const ASLayout *b){ + return ((id)a.layoutableObject).ascender < ((id)b.layoutableObject).ascender; + }); + const CGFloat maxAscender = baselineIt == positionedLayout.sublayouts.end() ? 0 : ((id)(*ascenderIt).layoutableObject).ascender; + + CGPoint p = CGPointZero; + BOOL first = YES; + auto stackedChildren = AS::map(positionedLayout.sublayouts, [&](ASLayout *l) -> ASLayout *{ + __weak id textChild = (id) l.layoutableObject; + p = p + directionPoint(stackStyle.direction, textChild.spacingBefore, 0); + if (first) { + // if this is the first item use the previously computed start point + p = l.position; + } else { + // otherwise add the stack spacing + p = p + directionPoint(stackStyle.direction, stackStyle.spacing, 0); + } + first = NO; + + // add the baseline offset. baselineOffset is only valid in the horizontal direction, so we always add to y + l.position = p + CGPointMake(0, baselineOffset(textStyle, l, maxAscender, maxBaseline)); + + // If we are a vertical stack, add the minDescender (it is negative) to the spacing after. This will alter the stack spacing to be on baselines instead of bounding boxes + CGFloat spacingAfterBaseline = (stackStyle.direction == ASStackLayoutDirectionVertical) ? textChild.descender : 0; + p = p + directionPoint(stackStyle.direction, stackDimension(stackStyle.direction, l.size) + textChild.spacingAfter + spacingAfterBaseline, 0); + + return l; + }); + + // The cross dimension is the max of the childrens' cross dimensions (clamped to our constraint below). + const auto it = std::max_element(stackedChildren.begin(), stackedChildren.end(), + [&](ASLayout *a, ASLayout *b) { + return maxDimensionForLayout(a, stackStyle) < maxDimensionForLayout(b, stackStyle); + }); + const auto largestChildCrossSize = it == stackedChildren.end() ? 0 : maxDimensionForLayout(*it, stackStyle); + const auto minCrossSize = crossDimension(stackStyle.direction, constrainedSize.min); + const auto maxCrossSize = crossDimension(stackStyle.direction, constrainedSize.max); + const CGFloat crossSize = MIN(MAX(minCrossSize, largestChildCrossSize), maxCrossSize); + + // find the child with the largest height. Use that child's descender as the descender to pass back to the ASStackTextLayoutSpec. + const auto descenderIt = std::max_element(stackedChildren.begin(), stackedChildren.end(), [&](const ASLayout *a, const ASLayout *b){ + return a.position.y + a.size.height < b.position.y + b.size.height; + }); + const CGFloat minDescender = descenderIt == stackedChildren.end() ? 0 : ((id)(*descenderIt).layoutableObject).descender; + + return {stackedChildren, crossSize, maxAscender, minDescender}; +}