1 /* Copyright 2013 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 PPAPI_SIMPLE_PS_EVENT_H_
6 #define PPAPI_SIMPLE_PS_EVENT_H_
7 
8 #include "ppapi/c/pp_bool.h"
9 #include "ppapi/c/pp_resource.h"
10 #include "ppapi/c/pp_var.h"
11 
12 #include "sdk_util/macros.h"
13 
14 EXTERN_C_BEGIN
15 
16 /**
17  * PSEvent
18  *
19  * The PSEvent system provides an in-order event processing mechanism.
20  * As Pepper events such as input, or focus and view changes arrive on the
21  * main pepper thread, they are placed on various FIFOs based on event type.
22  * For any given event type, only a single thread will process those events.
23  *
24  * By default, the "EventThread" will receive all messages.  However any thread
25  * can call PSRequestEventsType to request that all new events of that type
26  * are placed on that particular thread's queue.
27  *
28  * This allows the developer to choose which threads handle which event types
29  * while keeping all events belonging to a particular thread in order.  This
30  * is useful, for example, in the case of graphics to synchronize the size
31  * of the graphics context, with mouse clicks to correctly interpret location.
32  */
33 
34 
35 typedef enum {
36   /* Mask off all events. */
37   PSE_NONE = 0,
38 
39   /* From HandleInputEvent, conatins an input resource. */
40   PSE_INSTANCE_HANDLEINPUT = 1,
41 
42   /* From HandleMessage, contains a PP_Var. */
43   PSE_INSTANCE_HANDLEMESSAGE = 2,
44 
45   /* From DidChangeView, contains a view resource */
46   PSE_INSTANCE_DIDCHANGEVIEW = 4,
47 
48   /* From DidChangeFocus, contains a PP_Bool with the current focus state. */
49   PSE_INSTANCE_DIDCHANGEFOCUS = 8,
50 
51   /* When the 3D context is lost, no resource. */
52   PSE_GRAPHICS3D_GRAPHICS3DCONTEXTLOST = 16,
53 
54   /* When the mouse lock is lost. */
55   PSE_MOUSELOCK_MOUSELOCKLOST = 32,
56 
57   /* Enable all events. */
58   PSE_ALL = -1,
59 } PSEventType;
60 
61 typedef uint32_t PSEventTypeMask;
62 
63 // Generic Event
64 typedef struct PSEvent {
65   PSEventType type;
66   union {
67     PP_Bool as_bool;
68     PP_Resource as_resource;
69     struct PP_Var as_var;
70   };
71 
72   /* Internal */
73   struct PSEvent* next;
74 } PSEvent;
75 
76 typedef void (*PSMessageHandler_t)(struct PP_Var key,
77                                    struct PP_Var value,
78                                    void* user_data);
79 
80 /**
81  * Function for queuing, acquiring, and releasing events.
82  */
83 PSEvent* PSEventTryAcquire();
84 PSEvent* PSEventWaitAcquire();
85 void PSEventRelease(PSEvent* event);
86 void PSEventSetFilter(PSEventTypeMask mask);
87 
88 /**
89  * Creates and adds an event of the specified type to the event queue if
90  * that event type is not currently filtered.
91  */
92 void PSEventPost(PSEventType type);
93 void PSEventPostBool(PSEventType type, PP_Bool state);
94 void PSEventPostVar(PSEventType type, struct PP_Var var);
95 void PSEventPostResource(PSEventType type, PP_Resource resource);
96 
97 
98 /* Register a message handler for messages that arrive from JavaScript with a
99  * give names.
100  * Messages are of the form:  { message_name : <value> }.
101  *
102  * PSInstance will then not generate events but instead cause the handler to be
103  * called upon message arrival.  If handler is NULL then the current handler
104  * will be removed. Example usage:
105  *
106  * JavaScript:
107  *   nacl_module.postMessage({'foo': 123});
108  *
109  * C:
110  *   void MyMessageHandler(struct PP_Var key,
111  *                         struct PP_Var value,
112  *                         void* user_data) {
113  *     assert(key.type == PP_VARTYPE_STRING);
114  *     assert(value.type == PP_VARTYPE_INT32));
115  *     assert(value.value.as_int == 123);
116  *   }
117  *   ...
118  *   PSInstanceRegisterMessageHandler("foo", &MyMessageHandler, NULL); */
119 void PSEventRegisterMessageHandler(const char* message_name,
120                                    PSMessageHandler_t handler,
121                                    void* user_data);
122 
123 EXTERN_C_END
124 
125 #endif  /* PPAPI_SIMPLE_PS_EVENT_H_ */
126