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Text File  |  2002-10-03  |  7.3 KB  |  199 lines
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  4. iiiillllCCCCaaaallllllllbbbbaaaacccckkkk((((3333))))      IIIImmmmaaaaggggeeeeVVVViiiissssiiiioooonnnn LLLLiiiibbbbrrrraaaarrrryyyy CCCC++++++++ RRRReeeeffffeeeerrrreeeennnncccceeee MMMMaaaannnnuuuuaaaallll      iiiillllCCCCaaaallllllllbbbbaaaacccckkkk((((3333))))
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  8. NNNNAAAAMMMMEEEE
  9.      iiiillllCCCCaaaallllllllbbbbaaaacccckkkk - generic call back mechanism
  10.  
  11. IIIINNNNHHHHEEEERRRRIIIITTTTSSSS FFFFRRRROOOOMMMM
  12.      ilCacheBase
  13.  
  14. HHHHEEEEAAAADDDDEEEERRRR FFFFIIIILLLLEEEE
  15.      #include <il/ilCallback.h>
  16.  
  17. CCCCLLLLAAAASSSSSSSS DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  18.      This class provide a generic call back mechanism.  There are two derived
  19.      class templates, ilFunctionCallback and ilMethodCallback, that provide
  20.      either normal function callbacks or callbacks to a method on some object,
  21.      repectively.
  22.  
  23.      The ilFunctionCallback template is used to create a callback to a
  24.      function that takes an argument, _u_s_e_r_A_r_g, that is supplied when the
  25.      callback is created and a second argument, _c_a_l_l_e_r_A_r_g that is passed from
  26.      the callsite of the callback (i.e. when ddddooooiiiitttt() is called). A callback
  27.      function, 'func', thus has the prototype:
  28.  
  29.           ilStatus func(UserArgType userArg, CallerArgType callerArg);
  30.  
  31.  
  32.      The ilMethodCallback template is used to create a callback to a method on
  33.      an object of type UserClass that takes an argument, _u_s_e_r_A_r_g, that is
  34.      supplied when the callback is created and a second argument, _c_a_l_l_e_r_A_r_g,
  35.      that is passed from the callsite of the callback (i.e. when ddddooooiiiitttt() is
  36.      called). Thus a callback 'method' would have the prototype:
  37.  
  38.           ilStatus UserClass::method(UserArgType userArg, CallerArgType callerArg);
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  41. CCCCLLLLAAAASSSSSSSS MMMMEEEEMMMMBBBBEEEERRRR FFFFUUUUNNNNCCCCTTTTIIIIOOOONNNN SSSSUUUUMMMMMMMMAAAARRRRYYYY
  42.      CCCCoooonnnnssssttttrrrruuuuccccttttoooorrrrssss
  43.  
  44.           ilFunctionCallback(ilStatus (*func)(UserArgType userArg,
  45.                                               CallerArgType callerArg),
  46.                              UserArgType userArg)
  47.           ilMethodCallback(UserClass* object,
  48.                            ilStatus (UserClass::*method)(UserArgType userArg,
  49.                                                          CallerArgType callerArg),
  50.                            UserArgType userArg)
  51.           ilNullCallback()
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  53.      CCCCaaaallllllllbbbbaaaacccckkkk aaaaccccttttiiiioooonnnn
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  55.           virtual ilStatus doit(void* callerArg)
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  57.      SSSSeeeetttt mmmmeeeetttthhhhooooddddssss
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  63.                                                                         PPPPaaaaggggeeee 1111
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  70. iiiillllCCCCaaaallllllllbbbbaaaacccckkkk((((3333))))      IIIImmmmaaaaggggeeeeVVVViiiissssiiiioooonnnn LLLLiiiibbbbrrrraaaarrrryyyy CCCC++++++++ RRRReeeeffffeeeerrrreeeennnncccceeee MMMMaaaannnnuuuuaaaallll      iiiillllCCCCaaaallllllllbbbbaaaacccckkkk((((3333))))
  71.  
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  73.  
  74.           void setUserArg(UserArgType userArg)
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  76.  
  77. FFFFUUUUNNNNCCCCTTTTIIIIOOOONNNN DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNNSSSS
  78.      iiiillllFFFFuuuunnnnccccttttiiiioooonnnnCCCCaaaallllllllbbbbaaaacccckkkk(((())))
  79.  
  80.           ilFunctionCallback(ilStatus (*func)(UserArgType userArg,
  81.                                               CallerArgType callerArg),
  82.                              UserArgType userArg)
  83.  
  84.  
  85.           This constructor creates a callback to function, _f_u_n_c, with user
  86.           argument, _u_s_e_r_A_r_g.
  87.  
  88.           To define a callback to a simple function rrrreeeeaaaaddddyyyy() you might do
  89.           something like:
  90.  
  91.               ...
  92.               ilStatus ready(UserType*, CallerType*) { ... }
  93.               ...
  94.               typedef ilFunctionCallback<UserType*,CallerType*> UserCallback;
  95.  
  96.               Bar bar;
  97.               UserType userArg;
  98.               UserCallback doneCb(ready, &userArg);
  99.  
  100.  
  101.           and to invoke it from the callsite you would write something like:
  102.  
  103.               CallerType callerArg;
  104.               donecb.doit(&callerArg);
  105.  
  106.  
  107.      iiiillllMMMMeeeetttthhhhooooddddCCCCaaaallllllllbbbbaaaacccckkkk(((())))
  108.  
  109.           ilMethodCallback(UserClass* object,
  110.                            ilStatus (UserClass::*method)(UserArgType userArg,
  111.                                                          CallerArgType callerArg),
  112.                            UserArgType userArg)
  113.  
  114.  
  115.           This constructor creates a callback to _U_s_e_r_C_l_a_s_s::_m_e_t_h_o_d, with user
  116.           argument, _u_s_e_r_A_r_g.
  117.  
  118.           To define a callback to a member function BBBBaaaarrrr::::::::ddddoooonnnneeee() you might do
  119.           something like:
  120.  
  121.               ...
  122.               ilStatus Bar::done(UserType*, CallerType*) { ... }
  123.               ...
  124.               typedef ilMethodCallback<Bar,UserType*,CallerType*> UserCallback;
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  129.                                                                         PPPPaaaaggggeeee 2222
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  136. iiiillllCCCCaaaallllllllbbbbaaaacccckkkk((((3333))))      IIIImmmmaaaaggggeeeeVVVViiiissssiiiioooonnnn LLLLiiiibbbbrrrraaaarrrryyyy CCCC++++++++ RRRReeeeffffeeeerrrreeeennnncccceeee MMMMaaaannnnuuuuaaaallll      iiiillllCCCCaaaallllllllbbbbaaaacccckkkk((((3333))))
  137.  
  138.  
  139.  
  140.               Bar bar;
  141.               UserType userArg;
  142.               UserCallback doneCb(&bar, Bar::done, &userArg);
  143.  
  144.  
  145.           and to invoke it from the callsite you would write something like:
  146.  
  147.               CallerType callerArg;
  148.               donecb.doit(&callerArg);
  149.  
  150.  
  151.      iiiillllNNNNuuuullllllllCCCCaaaallllllllbbbbaaaacccckkkk(((())))
  152.  
  153.           ilNullCallback()
  154.  
  155.  
  156.           This constructor creates a callback that does nothing.
  157.  
  158.      ddddooooiiiitttt(((())))
  159.  
  160.           virtual ilStatus doit(void* callerArg)
  161.  
  162.  
  163.           This method is called to trigger the callback; the semantics of this
  164.           are defined by one of two derived classes: either ilFunctionCallback
  165.           or ilMethodCallback.  The returned value is the value returned from
  166.           the callback function or method.
  167.  
  168. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  169.      ilCallbackList(3)
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  195.                                                                         PPPPaaaaggggeeee 3333
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