native_client_sdk/src/libraries/ppapi_simple/ps_event.h

   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_ */