Rename CK classes to AS classes

AsyncDisplayKit/TextKit/ASTextKitRenderer+Positioning.h

@@ -0,0 +1,103 @@
+/*
+ *  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 "ASTextKitRenderer.h"
+
+typedef void (^ck_text_component_index_block_t)(NSUInteger characterIndex,
+                                                CGRect glyphBoundingRect,
+                                                BOOL *stop);
+
+/**
+ Measure options are used to specify which type of line height measurement to use.
+
+ ASTextNodeRendererMeasureOptionLineHeight is faster and will give the height from the baseline to the next line.
+
+ ASTextNodeRendererMeasureOptionCapHeight is a more nuanced measure of the glyphs in the given range that attempts to
+ produce a visually balanced rectangle above and below the glyphs to produce nice looking text highlights.
+
+ ASTextNodeRendererMeasureOptionBlock uses the cap height option to generate each glyph index, but combines all but the
+ first and last line rect into a single block.  Looks nice for multiline selection.
+ */
+typedef NS_ENUM(NSUInteger, ASTextKitRendererMeasureOption) {
+  ASTextKitRendererMeasureOptionLineHeight,
+  ASTextKitRendererMeasureOptionCapHeight,
+  ASTextKitRendererMeasureOptionBlock
+};
+
+@interface ASTextKitRenderer (Positioning)
+
+/**
+ Returns the bounding rect for the given character range.
+
+ @param textRange The character range for which the bounding rect will be computed.  Should be within the range of the
+ attributedString of this renderer.
+
+ @discussion In the external, shadowed coordinate space.
+ */
+- (CGRect)frameForTextRange:(NSRange)textRange;
+
+/**
+ Returns an array of rects representing the lines in the given character range
+
+ @param textRange The character range for which the rects will be computed. Should be within the range of the
+ attributedString of this renderer.
+ @param measureOption The measure option to use for construction of the rects. See ASTextKitRendererMeasureOption
+ docs for usage.
+
+ @discussion This method is useful for providing highlighting text.  Returned rects are in the coordinate space of the
+ renderer.
+
+ Triggers initialization of textkit components, truncation, and sizing.
+ */
+- (NSArray *)rectsForTextRange:(NSRange)textRange
+                 measureOption:(ASTextKitRendererMeasureOption)measureOption;
+
+/**
+ Enumerate the text character indexes at a position within the coordinate space of the renderer.
+
+ @param position The point in the shadowed coordinate space at which text indexes will be enumerated.
+ @param block The block that will be executed for each index identified that may correspond to the given position.  The
+ block is given the character index that corresponds to the glyph at each index in question, as well as the bounding
+ rect for that glyph.
+
+ @discussion Glyph location based on a touch point is not an exact science because user touches are not well-represented
+ by a simple point, especially in the context of link-heavy text.  So we have this method to make it a bit easier.  This
+ method checks a grid of candidate positions around the touch point you give it, and computes the bounding rect of the
+ glyph corresponding to the character index given.
+
+ The bounding rect of the glyph can be used to identify the best glyph index that corresponds to your touch.  For
+ instance, comparing centroidal distance from the glyph bounding rect to the touch center is useful for identifying
+ which link a user actually intended to select.
+
+ Triggers initialization of textkit components, truncation, and sizing.
+ */
+- (void)enumerateTextIndexesAtPosition:(CGPoint)position
+                            usingBlock:(ck_text_component_index_block_t)block;
+
+/**
+ Returns the single text index whose glyph's centroid is closest to the given position.
+
+ @param position The point in the shadowed coordinate space that should be checked.
+
+ @discussion This will use the grid enumeration function above, `enumerateTextIndexesAtPosition...`, in order to find
+ the closest glyph, so it is possible that a glyph could be missed, but ultimately unlikely.
+ */
+- (NSUInteger)nearestTextIndexAtPosition:(CGPoint)position;
+
+/**
+ Returns the trailing rect unused by the renderer in the last rendered line.
+
+ @discussion In the external shadowed coordinate space.
+
+ Triggers initialization of textkit components, truncation, and sizing.
+ */
+- (CGRect)trailingRect;
+
+@end