Upstream Chrome on iOS source code [9/11].

ios/chrome/browser/ui/util/label_link_controller.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_LABEL_LINK_CONTROLLER_H_
+#define IOS_CHROME_BROWSER_UI_UTIL_LABEL_LINK_CONTROLLER_H_
+
+#import <UIKit/UIKit.h>
+#include "ios/chrome/browser/procedural_block_types.h"
+
+class GURL;
+
+// A LabelLinkController manages a UILabel instance that is to have tappable
+// substrings ("links"). The controller handles styling the link areas (if
+// desired), and installs a gesture recognizer on the label that will trigger if
+// the specified regions are tapped. Multiple regions of the label may be
+// defined as links, and they may trigger different actions.
+// Each LabelLinkController calls a single action (a block that takes a GURL
+// parameter) for all taps; different links are defined by having different
+// URLs associated with them.
+// The LabelLinkController observes (via KVO) changes in the label's size, style
+// and text. If the label's bounds or style change, the controller recomputes
+// the link areas. If the text changes, all of the defined links for the label
+// are cleared (since they are presumed to be meaningless).
+// To prevent spurious recomputation of link areas, it is best to apply any
+// text manipulations and styling to the label before initializing a
+// LabelLinkController with it.
+@interface LabelLinkController : NSObject
+
+// If |showTapAreas| is true in a debug build, the tappable regions of the label
+// will have colored rectangles around them, with different colors for each URL,
+// and a darker outline around the exact text that the tappable region is for.
+// In non-debug builds, setting this property has no effect.
+@property(nonatomic, assign) BOOL showTapAreas;
+
+// Sets the link color for any defined links, updating the controlled label's
+// attributed text accordingly.
+@property(nonatomic, assign) UIColor* linkColor;
+
+// Sets the link underline style for any defined links, updating the controlled
+// label's attributed text accordingly.
+@property(nonatomic, assign) NSUnderlineStyle linkUnderlineStyle;
+
+// Sets the link font for any defined links, updating the controlled label's
+// attributed text accordingly.
+@property(nonatomic, retain) UIFont* linkFont;
+
+// Creates a new controller for |label|, whose lifetime is expected to exceed
+// that of the receiver. |action| is the block called for any tapped link.
+- (instancetype)initWithLabel:(UILabel*)label
+                       action:(ProceduralBlockWithURL)action;
+
+// Adds a link to the controlled label at |range| in the label's text, which
+// will call the receiver's action block when tapped, passing in |url|.
+- (void)addLinkWithRange:(NSRange)range url:(GURL)url;
+
+@end
+
+@interface LabelLinkController (Testing)
+
+// Testing interface for LabelLinkController.
+
+// This is the class that will be instantiated to do text mapping; by default
+// it is CoreTextMapper, but tests can assign to this property to do dependency
+// injection.
+@property(nonatomic, assign) Class textMapperClass;
+// Returns the tap rects generated by the controller that are associated with
+// |url|.
+- (NSArray*)tapRectsForURL:(GURL)url;
+// Simulates a tap in the controlled label at |point|. No touch events are
+// generated, but |action| should be invoked if |point| is inside a tap rect.
+- (void)tapLabelAtPoint:(CGPoint)point;
+
+@end
+
+#endif  // IOS_CHROME_BROWSER_UI_UTIL_LABEL_LINK_CONTROLLER_H_