1 // Copyright 2014 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_EVENTS_PLATFORM_PLATFORM_EVENT_DISPATCHER_H_ 6 #define UI_EVENTS_PLATFORM_PLATFORM_EVENT_DISPATCHER_H_ 7 8 #include "base/basictypes.h" 9 #include "ui/events/events_export.h" 10 #include "ui/events/platform/platform_event_types.h" 11 12 namespace ui { 13 14 // See documentation for |PlatformEventDispatcher::DispatchEvent()| for 15 // explanation of the meaning of the flags. 16 enum PostDispatchAction { 17 POST_DISPATCH_NONE = 0x0, 18 POST_DISPATCH_PERFORM_DEFAULT = 0x1, 19 POST_DISPATCH_STOP_PROPAGATION = 0x2, 20 }; 21 22 // PlatformEventDispatcher receives events from a PlatformEventSource and 23 // dispatches them. 24 class EVENTS_EXPORT PlatformEventDispatcher { 25 public: 26 // Returns whether this dispatcher wants to dispatch |event|. 27 virtual bool CanDispatchEvent(const PlatformEvent& event) = 0; 28 29 // Dispatches |event|. If this is not the default dispatcher, then the 30 // dispatcher can request that the default dispatcher gets a chance to 31 // dispatch the event by setting POST_DISPATCH_PERFORM_DEFAULT to the return 32 // value. If the dispatcher has processed the event, and no other dispatcher 33 // should be allowed to dispatch the event, then the dispatcher should set 34 // POST_DISPATCH_STOP_PROPAGATION flag on the return value. 35 virtual uint32_t DispatchEvent(const PlatformEvent& event) = 0; 36 37 protected: 38 virtual ~PlatformEventDispatcher() {} 39 }; 40 41 } // namespace ui 42 43 #endif // UI_EVENTS_PLATFORM_PLATFORM_EVENT_DISPATCHER_H_ 44
