1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef UI_BASE_COCOA_TRACKING_AREA_H_ 6 #define UI_BASE_COCOA_TRACKING_AREA_H_ 7 8 #import <AppKit/AppKit.h> 9 10 #include "base/mac/scoped_nsobject.h" 11 #include "ui/base/ui_base_export.h" 12 13 @class CrTrackingAreaOwnerProxy; 14 15 // The CrTrackingArea can be used in place of an NSTrackingArea to shut off 16 // messaging to the |owner| at a specific point in time. 17 UI_BASE_EXPORT 18 @interface CrTrackingArea : NSTrackingArea { 19 @private 20 base::scoped_nsobject<CrTrackingAreaOwnerProxy> ownerProxy_; 21 } 22 23 // Designated initializer. Forwards all arguments to the superclass, but wraps 24 // |owner| in a proxy object. 25 - (id)initWithRect:(NSRect)rect 26 options:(NSTrackingAreaOptions)options 27 owner:(id)owner 28 userInfo:(NSDictionary*)userInfo; 29 30 // Prevents any future messages from being delivered to the |owner|. 31 - (void)clearOwner; 32 33 // Watches |window| for its NSWindowWillCloseNotification and calls 34 // |-clearOwner| when the notification is observed. 35 - (void)clearOwnerWhenWindowWillClose:(NSWindow*)window; 36 37 @end 38 39 // Scoper ////////////////////////////////////////////////////////////////////// 40 41 namespace ui { 42 43 // Use an instance of this class to call |-clearOwner| on the |tracking_area_| 44 // when this goes out of scope. 45 class UI_BASE_EXPORT ScopedCrTrackingArea { 46 public: 47 // Takes ownership of |tracking_area| without retaining it. 48 explicit ScopedCrTrackingArea(CrTrackingArea* tracking_area = nil); 49 ~ScopedCrTrackingArea(); 50 51 // This will call |scoped_nsobject<>::reset()| to take ownership of the new 52 // tracking area. Note that -clearOwner is NOT called on the existing 53 // tracking area. 54 void reset(CrTrackingArea* tracking_area = nil); 55 56 CrTrackingArea* get() const; 57 58 private: 59 base::scoped_nsobject<CrTrackingArea> tracking_area_; 60 DISALLOW_COPY_AND_ASSIGN(ScopedCrTrackingArea); 61 }; 62 63 } // namespace ui 64 65 #endif // UI_BASE_COCOA_TRACKING_AREA_H_ 66