Upstream Chrome on iOS source code [10/11].

ios/chrome/browser/ui/util/text_frame.h

+// Copyright 2015 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_UTIL_TEXT_FRAME_H_
+#define IOS_CHROME_BROWSER_UI_UTIL_TEXT_FRAME_H_
+
+#import <CoreText/CoreText.h>
+#import <UIKit/UIKit.h>
+
+// An object encapsulating a line of text that has been framed within a bounding
+// rect.
+@interface FramedLine : NSObject
+
+// Designated initializer.
+- (instancetype)initWithLine:(CTLineRef)line
+                 stringRange:(NSRange)stringRange
+                      origin:(CGPoint)origin NS_DESIGNATED_INITIALIZER;
+- (instancetype)init NS_UNAVAILABLE;
+
+// The CTLine that was framed.
+@property(nonatomic, readonly) CTLineRef line;
+// The range within the original string that corresponds with |line|.  CTLines
+// created by ManualTextFramers report string ranges with 0 for their locations,
+// so the actual range is stored here separately.
+@property(nonatomic, readonly) NSRange stringRange;
+// The baseline origin (in Quartz coordinates) of the line within its bounds.
+@property(nonatomic, readonly) CGPoint origin;
+
+// Returns the offset into |line| of the glyph corresponding with the character
+// in the original string at |stringLocation|.  Returns kCFNotFound if
+// |stringLocation| is outside of |stringRange|.
+- (CFIndex)lineOffsetForStringLocation:(NSUInteger)stringLocation;
+
+@end
+
+// Protocol for objects that contain NSAttributedStrings laid out within a
+// bounding rect.
+@protocol TextFrame<NSObject>
+
+// The string that was framed within |bounds|.
+@property(nonatomic, readonly) NSAttributedString* string;
+// The range of |string| that was successfully framed.
+@property(nonatomic, readonly) NSRange framedRange;
+// An NSArray of FramedLines corresponding to |string| as laid out in |bounds|.
+@property(nonatomic, readonly) NSArray* lines;
+// The bounds in which |string| is laid out.
+@property(nonatomic, readonly) CGRect bounds;
+
+@end
+
+// A TextFrame implementation that is backed by a CTFrameRef.
+@interface CoreTextTextFrame : NSObject<TextFrame>
+
+// Designated initializer.
+- (instancetype)initWithString:(NSAttributedString*)string
+                        bounds:(CGRect)bounds
+                         frame:(CTFrameRef)frame NS_DESIGNATED_INITIALIZER;
+- (instancetype)init NS_UNAVAILABLE;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_UTIL_TEXT_FRAME_H_