87fac4abd7
git-svn-id: http://skia.googlecode.com/svn/trunk@2041 2bbb7eff-a529-9590-31e7-b0007b416f81
110 lines
3.0 KiB
C++
110 lines
3.0 KiB
C++
|
|
/*
|
|
* Copyright 2006 The Android Open Source Project
|
|
*
|
|
* Use of this source code is governed by a BSD-style license that can be
|
|
* found in the LICENSE file.
|
|
*/
|
|
|
|
|
|
#ifndef SkEventSink_DEFINED
|
|
#define SkEventSink_DEFINED
|
|
|
|
#include "SkRefCnt.h"
|
|
#include "SkEvent.h"
|
|
|
|
struct SkTagList;
|
|
|
|
/** \class SkEventSink
|
|
|
|
SkEventSink is the base class for all objects that receive SkEvents.
|
|
*/
|
|
class SkEventSink : public SkRefCnt {
|
|
public:
|
|
SkEventSink();
|
|
virtual ~SkEventSink();
|
|
|
|
/**
|
|
* Returns this eventsink's unique ID. Use this to post SkEvents to
|
|
* this eventsink.
|
|
*/
|
|
SkEventSinkID getSinkID() const { return fID; }
|
|
|
|
/**
|
|
* Call this to pass an event to this object for processing. Returns true if the
|
|
* event was handled.
|
|
*/
|
|
bool doEvent(const SkEvent&);
|
|
|
|
/** Returns true if the sink (or one of its subclasses) understands the event as a query.
|
|
If so, the sink may modify the event to communicate its "answer".
|
|
*/
|
|
bool doQuery(SkEvent* query);
|
|
|
|
/**
|
|
* Add sinkID to the list of listeners, to receive events from calls to sendToListeners()
|
|
* and postToListeners(). If sinkID already exists in the listener list, no change is made.
|
|
*/
|
|
void addListenerID(SkEventSinkID sinkID);
|
|
|
|
/**
|
|
* Copy listeners from one event sink to another, typically from parent to child.
|
|
* @param from the event sink to copy the listeners from
|
|
*/
|
|
void copyListeners(const SkEventSink& from);
|
|
|
|
/**
|
|
* Remove sinkID from the list of listeners. If sinkID does not appear in the list,
|
|
* no change is made.
|
|
*/
|
|
void removeListenerID(SkEventSinkID);
|
|
|
|
/**
|
|
* Returns true if there are 1 or more listeners attached to this eventsink
|
|
*/
|
|
bool hasListeners() const;
|
|
|
|
/**
|
|
* Posts a copy of evt to each of the eventsinks in the lisener list.
|
|
* This ignores the targetID and target proc in evt.
|
|
*/
|
|
void postToListeners(const SkEvent& evt, SkMSec delay = 0);
|
|
|
|
enum EventResult {
|
|
kHandled_EventResult, //!< the eventsink returned true from its doEvent method
|
|
kNotHandled_EventResult, //!< the eventsink returned false from its doEvent method
|
|
kSinkNotFound_EventResult //!< no matching eventsink was found for the event's getSink().
|
|
};
|
|
|
|
/**
|
|
* DoEvent handles dispatching the event to its target ID or proc.
|
|
*/
|
|
static EventResult DoEvent(const SkEvent&);
|
|
|
|
/**
|
|
* Returns the matching eventsink, or null if not found
|
|
*/
|
|
static SkEventSink* FindSink(SkEventSinkID);
|
|
|
|
protected:
|
|
/** Override this to handle events in your subclass. Be sure to call the inherited version
|
|
for events that you don't handle.
|
|
*/
|
|
virtual bool onEvent(const SkEvent&);
|
|
virtual bool onQuery(SkEvent*);
|
|
|
|
SkTagList* findTagList(U8CPU tag) const;
|
|
void addTagList(SkTagList*);
|
|
void removeTagList(U8CPU tag);
|
|
|
|
private:
|
|
SkEventSinkID fID;
|
|
SkTagList* fTagHead;
|
|
|
|
// for our private link-list
|
|
SkEventSink* fNextSink;
|
|
};
|
|
|
|
#endif
|
|
|