1a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)// Copyright (c) 2013 The Chromium Authors. All rights reserved. 2a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 3a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)// found in the LICENSE file. 4a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 5a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)#ifndef UI_EVENTS_EVENT_TARGETER_H_ 6a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)#define UI_EVENTS_EVENT_TARGETER_H_ 7a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 8a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)#include "base/compiler_specific.h" 9a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)#include "ui/events/event.h" 10a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)#include "ui/events/events_export.h" 11a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 12a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)namespace ui { 13a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 14a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)class Event; 15a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)class EventTarget; 16a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)class LocatedEvent; 17a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 18a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)class EVENTS_EXPORT EventTargeter { 19a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) public: 20a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) virtual ~EventTargeter(); 21a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 22a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) // Returns the target |event| should be dispatched to. If there is no such 231320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // target, return NULL. If |event| is a located event, the location of |event| 241320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // is in the coordinate space of |root|. Furthermore, the targeter can mutate 251320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // the event (e.g., by changing the location of the event to be in the 261320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // returned target's coordinate space) so that it can be dispatched to the 271320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // target without any further modification. 28a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) virtual EventTarget* FindTargetForEvent(EventTarget* root, 29a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) Event* event); 30a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 31a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) // Same as FindTargetForEvent(), but used for positional events. The location 32a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) // etc. of |event| are in |root|'s coordinate system. When finding the target 33effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch // for the event, the targeter can mutate the |event| (e.g. change the 34effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch // coordinate to be in the returned target's coordinate system) so that it can 351320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // be dispatched to the target without any further modification. 361320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // TODO(tdanderson|sadrul): This should not be in the public API of 371320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // EventTargeter. 38a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) virtual EventTarget* FindTargetForLocatedEvent(EventTarget* root, 39a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) LocatedEvent* event); 40a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 41010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // Returns true if |target| or one of its descendants can be a target of 42010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // |event|. This requires that |target| and its descendants are not 43010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // prohibited from accepting the event, and that the event is within an 44010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // actionable region of the target's bounds. Note that the location etc. of 45010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // |event| is in |target|'s parent's coordinate system. 46010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // TODO(tdanderson|sadrul): This function should be made non-virtual and 47010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // non-public. 48a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) virtual bool SubtreeShouldBeExploredForEvent(EventTarget* target, 49a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) const LocatedEvent& event); 50effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch 51effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch // Returns the next best target for |event| as compared to |previous_target|. 521320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci // |event| is in the local coordinate space of |previous_target|. 53effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch // Also mutates |event| so that it can be dispatched to the returned target 54effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch // (e.g., by changing |event|'s location to be in the returned target's 55effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch // coordinate space). 56effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch virtual EventTarget* FindNextBestTarget(EventTarget* previous_target, 57effb81e5f8246d0db0270817048dc992db66e9fbBen Murdoch Event* event); 58010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) 59010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) protected: 60010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // Returns false if neither |target| nor any of its descendants are allowed 61010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // to accept |event| for reasons unrelated to the event's location or the 62010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // target's bounds. For example, overrides of this function may consider 63010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // attributes such as the visibility or enabledness of |target|. Note that 64010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // the location etc. of |event| is in |target|'s parent's coordinate system. 65010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) virtual bool SubtreeCanAcceptEvent(EventTarget* target, 66010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) const LocatedEvent& event) const; 67010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) 68010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // Returns whether the location of the event is in an actionable region of the 69010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // target. Note that the location etc. of |event| is in the |target|'s 70010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) // parent's coordinate system. 71010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) virtual bool EventLocationInsideBounds(EventTarget* target, 72010d83a9304c5a91596085d917d248abff47903aTorne (Richard Coles) const LocatedEvent& event) const; 73a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)}; 74a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 75a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)} // namespace ui 76a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 77a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles)#endif // UI_EVENTS_EVENT_TARGETER_H_ 78