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Text File  |  1995-07-26  |  6.8 KB  |  133 lines
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  4.      TTTTkkkk____CCCCrrrreeeeaaaatttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr((((3333))))     TTTTkkkk (((( ))))      TTTTkkkk____CCCCrrrreeeeaaaatttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr((((3333))))
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  8.      _________________________________________________________________
  9.  
  10.      NNNNAAAAMMMMEEEE
  11.           Tk_CreateEventHandler,  Tk_DeleteEventHandler  -   associate
  12.           procedure callback with an X event
  13.  
  14.      SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
  15.           ####iiiinnnncccclllluuuuddddeeee <<<<ttttkkkk....hhhh>>>>
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  17.           TTTTkkkk____CCCCrrrreeeeaaaatttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr(_t_k_w_i_n, _m_a_s_k, _p_r_o_c, _c_l_i_e_n_t_D_a_t_a)
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  19.           TTTTkkkk____DDDDeeeelllleeeetttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr(_t_k_w_i_n, _m_a_s_k, _p_r_o_c, _c_l_i_e_n_t_D_a_t_a)
  20.  
  21.      AAAARRRRGGGGUUUUMMMMEEEENNNNTTTTSSSS
  22.           Tk_Window       _t_k_w_i_n        (in)      Token for  window  in
  23.                                                  which    events   may
  24.                                                  occur.
  25.  
  26.           unsigned long   _m_a_s_k         (in)      Bit-mask  of   events
  27.                                                  (such              as
  28.                                                  BBBBuuuuttttttttoooonnnnPPPPrrrreeeessssssssMMMMaaaasssskkkk)  for
  29.                                                  which  _p_r_o_c should be
  30.                                                  called.
  31.  
  32.           Tk_EventProc    *_p_r_o_c        (in)      Procedure  to  invoke
  33.                                                  whenever  an event in
  34.                                                  _m_a_s_k  occurs  in  the
  35.                                                  window    given    by
  36.                                                  _t_k_w_i_n.
  37.  
  38.           ClientData      _c_l_i_e_n_t_D_a_t_a   (in)      Arbitrary    one-word
  39.                                                  value   to   pass  to
  40.                                                  _p_r_o_c.
  41.      _________________________________________________________________
  42.  
  43.  
  44.      DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  45.           TTTTkkkk____CCCCrrrreeeeaaaatttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr arranges for _p_r_o_c to be invoked in the
  46.           future  whenever  one  of  the event types specified by _m_a_s_k
  47.           occurs in the window specified by _t_k_w_i_n.   The  callback  to
  48.           _p_r_o_c  will  be  made  by TTTTkkkk____HHHHaaaannnnddddlllleeeeEEEEvvvveeeennnntttt; this mechanism only
  49.           works   in   programs   that   dispatch    events    through
  50.           TTTTkkkk____HHHHaaaannnnddddlllleeeeEEEEvvvveeeennnntttt  (or  through  other  Tk procedures that call
  51.           TTTTkkkk____HHHHaaaannnnddddlllleeeeEEEEvvvveeeennnntttt, such as TTTTkkkk____DDDDooooOOOOnnnneeeeEEEEvvvveeeennnntttt or TTTTkkkk____MMMMaaaaiiiinnnnLLLLoooooooopppp).
  52.  
  53.           _P_r_o_c should have arguments and result that  match  the  type
  54.           TTTTkkkk____EEEEvvvveeeennnnttttPPPPrrrroooocccc:
  55.                typedef void Tk_EventProc(
  56.                     ClientData _c_l_i_e_n_t_D_a_t_a,
  57.                     XEvent *_e_v_e_n_t_P_t_r);
  58.           The _c_l_i_e_n_t_D_a_t_a parameter to _p_r_o_c is a copy of the _c_l_i_e_n_t_D_a_t_a
  59.           argument  given  to  TTTTkkkk____CCCCrrrreeeeaaaatttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr when the callback
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  63.      Page 1                                          (printed 7/23/95)
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  70.      TTTTkkkk____CCCCrrrreeeeaaaatttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr((((3333))))     TTTTkkkk (((( ))))      TTTTkkkk____CCCCrrrreeeeaaaatttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr((((3333))))
  71.  
  72.  
  73.  
  74.           was  created.   Typically,  _c_l_i_e_n_t_D_a_t_a  points  to  a   data
  75.           structure  containing application-specific information about
  76.           the window in which  the  event  occurred.   _E_v_e_n_t_P_t_r  is  a
  77.           pointer  to  the  X  event,  which  will  be one of the ones
  78.           specified in the _m_a_s_k argument to TTTTkkkk____CCCCrrrreeeeaaaatttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr.
  79.  
  80.           TTTTkkkk____DDDDeeeelllleeeetttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr may be called to delete a  previously-
  81.           created  event  handler:   it  deletes  the first handler it
  82.           finds that is associated with _t_k_w_i_n and  matches  the  _m_a_s_k,
  83.           _p_r_o_c,  and _c_l_i_e_n_t_D_a_t_a arguments.  If no such handler exists,
  84.           then  TTTTkkkk____EEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr  returns   without   doing   anything.
  85.           Although  Tk  supports  it, it's probably a bad idea to have
  86.           more than  one  callback  with  the  same  _m_a_s_k,  _p_r_o_c,  and
  87.           _c_l_i_e_n_t_D_a_t_a  arguments.   When a window is deleted all of its
  88.           handlers will be deleted automatically;  in this case  there
  89.           is no need to call TTTTkkkk____DDDDeeeelllleeeetttteeeeEEEEvvvveeeennnnttttHHHHaaaannnnddddlllleeeerrrr.
  90.  
  91.           If mutliple handlers are declared for the  same  type  of  X
  92.           event  on the same window, then the handlers will be invoked
  93.           in the order they were created.
  94.  
  95.  
  96.      KKKKEEEEYYYYWWWWOOOORRRRDDDDSSSS
  97.           bind, callback, event, handler
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  129.      Page 2                                          (printed 7/23/95)
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