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      1 /*
      2  * Copyright 2006 The Android Open Source Project
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #ifndef SkEvent_DEFINED
      9 #define SkEvent_DEFINED
     10 
     11 #include "SkMetaData.h"
     12 #include "SkString.h"
     13 
     14 class SkDOM;
     15 struct SkDOMNode;
     16 
     17 #include "../private/SkLeanWindows.h"
     18 
     19 /** Unique 32bit id used to identify an instance of SkEventSink. When events are
     20     posted, they are posted to a specific sinkID. When it is time to dispatch the
     21     event, the sinkID is used to find the specific SkEventSink object. If it is found,
     22     its doEvent() method is called with the event.
     23 */
     24 typedef uint32_t SkEventSinkID;
     25 
     26 /**
     27  *  \class SkEvent
     28  *
     29  *  When an event is dispatched from the event queue, it is either sent to
     30  *  the eventsink matching the target ID (if not 0), or the target proc is
     31  *  called (if not NULL).
     32  */
     33 class SkEvent {
     34 public:
     35     /**
     36      *  Function pointer that takes an event, returns true if it "handled" it.
     37      */
     38     typedef bool (*Proc)(const SkEvent& evt);
     39 
     40     SkEvent();
     41     explicit SkEvent(const SkString& type, SkEventSinkID = 0);
     42     explicit SkEvent(const char type[], SkEventSinkID = 0);
     43     SkEvent(const SkEvent& src);
     44     ~SkEvent();
     45 
     46     /** Copy the event's type into the specified SkString parameter */
     47     void getType(SkString* str) const;
     48 
     49     /** Returns true if the event's type matches exactly the specified type (case sensitive) */
     50     bool isType(const SkString& str) const;
     51 
     52     /** Returns true if the event's type matches exactly the specified type (case sensitive) */
     53     bool isType(const char type[], size_t len = 0) const;
     54 
     55     /**
     56      *  Set the event's type to the specified string.
     57      */
     58     void setType(const SkString&);
     59 
     60     /**
     61      *  Set the event's type to the specified string.
     62      */
     63     void setType(const char type[], size_t len = 0);
     64 
     65     /**
     66      *  Return the target ID, or 0 if there is none.
     67      *
     68      *  When an event is dispatched from the event queue, it is either sent to
     69      *  the eventsink matching the targetID (if not 0), or the target proc is
     70      *  called (if not NULL).
     71      */
     72     SkEventSinkID getTargetID() const { return fTargetID; }
     73 
     74     /**
     75      *  Set the target ID for this event. 0 means none. Calling this will
     76      *  automatically clear the targetProc to null.
     77      *
     78      *  When an event is dispatched from the event queue, it is either sent to
     79      *  the eventsink matching the targetID (if not 0), or the target proc is
     80      *  called (if not NULL).
     81      */
     82     SkEvent* setTargetID(SkEventSinkID targetID) {
     83         fTargetProc = NULL;
     84         fTargetID = targetID;
     85         return this;
     86     }
     87 
     88     /**
     89      *  Return the target proc, or NULL if it has none.
     90      *
     91      *  When an event is dispatched from the event queue, it is either sent to
     92      *  the eventsink matching the targetID (if not 0), or the target proc is
     93      *  called (if not NULL).
     94      */
     95     Proc getTargetProc() const { return fTargetProc; }
     96 
     97     /**
     98      *  Set the target ID for this event. NULL means none. Calling this will
     99      *  automatically clear the targetID to 0.
    100      *
    101      *  When an event is dispatched from the event queue, it is either sent to
    102      *  the eventsink matching the targetID (if not 0), or the target proc is
    103      *  called (if not NULL).
    104      */
    105     SkEvent* setTargetProc(Proc proc) {
    106         fTargetID = 0;
    107         fTargetProc = proc;
    108         return this;
    109     }
    110 
    111     /**
    112      *  Return the event's unnamed 32bit field. Default value is 0
    113      */
    114     uint32_t getFast32() const { return f32; }
    115 
    116     /**
    117      *  Set the event's unnamed 32bit field.
    118      */
    119     void setFast32(uint32_t x) { f32 = x; }
    120 
    121     /** Return true if the event contains the named 32bit field, and return the field
    122         in value (if value is non-null). If there is no matching named field, return false
    123         and ignore the value parameter.
    124     */
    125     bool findS32(const char name[], int32_t* value = NULL) const { return fMeta.findS32(name, value); }
    126     /** Return true if the event contains the named SkScalar field, and return the field
    127         in value (if value is non-null). If there is no matching named field, return false
    128         and ignore the value parameter.
    129     */
    130     bool findScalar(const char name[], SkScalar* value = NULL) const { return fMeta.findScalar(name, value); }
    131     /** Return true if the event contains the named SkScalar field, and return the fields
    132         in value[] (if value is non-null), and return the number of SkScalars in count (if count is non-null).
    133         If there is no matching named field, return false and ignore the value and count parameters.
    134     */
    135     const SkScalar* findScalars(const char name[], int* count, SkScalar values[] = NULL) const { return fMeta.findScalars(name, count, values); }
    136     /** Return the value of the named string field, or if no matching named field exists, return null.
    137     */
    138     const char* findString(const char name[]) const { return fMeta.findString(name); }
    139     /** Return true if the event contains the named pointer field, and return the field
    140         in value (if value is non-null). If there is no matching named field, return false
    141         and ignore the value parameter.
    142     */
    143     bool findPtr(const char name[], void** value) const { return fMeta.findPtr(name, value); }
    144     bool findBool(const char name[], bool* value) const { return fMeta.findBool(name, value); }
    145     const void* findData(const char name[], size_t* byteCount = NULL) const {
    146         return fMeta.findData(name, byteCount);
    147     }
    148 
    149     /** Returns true if ethe event contains the named 32bit field, and if it equals the specified value */
    150     bool hasS32(const char name[], int32_t value) const { return fMeta.hasS32(name, value); }
    151     /** Returns true if ethe event contains the named SkScalar field, and if it equals the specified value */
    152     bool hasScalar(const char name[], SkScalar value) const { return fMeta.hasScalar(name, value); }
    153     /** Returns true if ethe event contains the named string field, and if it equals (using strcmp) the specified value */
    154     bool hasString(const char name[], const char value[]) const { return fMeta.hasString(name, value); }
    155     /** Returns true if ethe event contains the named pointer field, and if it equals the specified value */
    156     bool hasPtr(const char name[], void* value) const { return fMeta.hasPtr(name, value); }
    157     bool hasBool(const char name[], bool value) const { return fMeta.hasBool(name, value); }
    158     bool hasData(const char name[], const void* data, size_t byteCount) const {
    159         return fMeta.hasData(name, data, byteCount);
    160     }
    161 
    162     /** Add/replace the named 32bit field to the event. In XML use the subelement <data name=... s32=... /> */
    163     void setS32(const char name[], int32_t value) { fMeta.setS32(name, value); }
    164     /** Add/replace the named SkScalar field to the event. In XML use the subelement <data name=... scalar=... /> */
    165     void setScalar(const char name[], SkScalar value) { fMeta.setScalar(name, value); }
    166     /** Add/replace the named SkScalar[] field to the event. */
    167     SkScalar* setScalars(const char name[], int count, const SkScalar values[] = NULL) { return fMeta.setScalars(name, count, values); }
    168     /** Add/replace the named string field to the event. In XML use the subelement <data name=... string=... */
    169     void setString(const char name[], const SkString& value) { fMeta.setString(name, value.c_str()); }
    170     /** Add/replace the named string field to the event. In XML use the subelement <data name=... string=... */
    171     void setString(const char name[], const char value[]) { fMeta.setString(name, value); }
    172     /** Add/replace the named pointer field to the event. There is no XML equivalent for this call */
    173     void setPtr(const char name[], void* value) { fMeta.setPtr(name, value); }
    174     void setBool(const char name[], bool value) { fMeta.setBool(name, value); }
    175     void setData(const char name[], const void* data, size_t byteCount) {
    176         fMeta.setData(name, data, byteCount);
    177     }
    178 
    179     /** Return the underlying metadata object */
    180     SkMetaData& getMetaData() { return fMeta; }
    181     /** Return the underlying metadata object */
    182     const SkMetaData& getMetaData() const { return fMeta; }
    183 
    184     /** Call this to initialize the event from the specified XML node */
    185     void inflate(const SkDOM&, const SkDOMNode*);
    186 
    187     SkDEBUGCODE(void dump(const char title[] = NULL);)
    188 
    189     ///////////////////////////////////////////////////////////////////////////
    190 
    191     /**
    192      *  Post to the event queue using the event's targetID or target-proc.
    193      *
    194      *  The event must be dynamically allocated, as ownership is transferred to
    195      *  the event queue. It cannot be allocated on the stack or in a global.
    196      */
    197     void post() {
    198         return this->postDelay(0);
    199     }
    200 
    201     /**
    202      *  Post to the event queue using the event's targetID or target-proc and
    203      *  the specifed millisecond delay.
    204      *
    205      *  The event must be dynamically allocated, as ownership is transferred to
    206      *  the event queue. It cannot be allocated on the stack or in a global.
    207      */
    208     void postDelay(SkMSec delay);
    209 
    210     /**
    211      *  Post to the event queue using the event's targetID or target-proc.
    212      *  The event will be delivered no sooner than the specified millisecond
    213      *  time, as measured by GetMSecsSinceStartup().
    214      *
    215      *  The event must be dynamically allocated, as ownership is transferred to
    216      *  the event queue. It cannot be allocated on the stack or in a global.
    217      */
    218     void postTime(SkMSec time);
    219 
    220     /**
    221      *  Returns ~zero the first time it's called, then returns the number of
    222      *  milliseconds since the first call. Behavior is undefined if the program
    223      *  runs more than ~25 days.
    224      */
    225     static SkMSec GetMSecsSinceStartup();
    226 
    227     ///////////////////////////////////////////////
    228     /** Porting layer must call these functions **/
    229     ///////////////////////////////////////////////
    230 
    231     /** Global initialization function for the SkEvent system. Should be called exactly
    232         once before any other event method is called, and should be called after the
    233         call to SkGraphics::Init().
    234     */
    235     static void Init();
    236     /** Global cleanup function for the SkEvent system. Should be called exactly once after
    237         all event methods have been called.
    238     */
    239     static void Term();
    240 
    241     /** Call this to process one event from the queue. If it returns true, there are more events
    242         to process.
    243     */
    244     static bool ProcessEvent();
    245     /** Call this whenever the requested timer has expired (requested by a call to SetQueueTimer).
    246         It will post any delayed events whose time as "expired" onto the event queue.
    247         It may also call SignalQueueTimer() and SignalNonEmptyQueue().
    248     */
    249     static void ServiceQueueTimer();
    250 
    251     /** Return the number of queued events. note that this value may be obsolete
    252         upon return, since another thread may have called ProcessEvent() or
    253         Post() after the count was made.
    254      */
    255     static int CountEventsOnQueue();
    256 
    257     ////////////////////////////////////////////////////
    258     /** Porting layer must implement these functions **/
    259     ////////////////////////////////////////////////////
    260 
    261     /** Called whenever an SkEvent is posted to an empty queue, so that the OS
    262         can be told to later call Dequeue().
    263     */
    264     static void SignalNonEmptyQueue();
    265     /** Called whenever the delay until the next delayed event changes. If zero is
    266         passed, then there are no more queued delay events.
    267     */
    268     static void SignalQueueTimer(SkMSec delay);
    269 
    270 #if defined(SK_BUILD_FOR_WIN)
    271     static bool WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
    272 #endif
    273 
    274 private:
    275     SkMetaData      fMeta;
    276     mutable char*   fType;  // may be characters with low bit set to know that it is not a pointer
    277     uint32_t        f32;
    278 
    279     // 'there can be only one' (non-zero) between target-id and target-proc
    280     SkEventSinkID   fTargetID;
    281     Proc            fTargetProc;
    282 
    283     // these are for our implementation of the event queue
    284     SkMSec          fTime;
    285     SkEvent*        fNextEvent; // either in the delay or normal event queue
    286 
    287     void initialize(const char* type, size_t typeLen, SkEventSinkID);
    288 
    289     static bool Enqueue(SkEvent* evt);
    290     static SkMSec EnqueueTime(SkEvent* evt, SkMSec time);
    291     static SkEvent* Dequeue();
    292     static bool     QHasEvents();
    293 };
    294 
    295 #endif
    296