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/ IRIX Base Documentation 2001 May / SGI IRIX Base Documentation 2001 May.iso / usr / share / catman / p_man / cat3 / Vk / VkBackground.z / VkBackground
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Text File  |  1998-10-20  |  5.3 KB  |  133 lines
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  4. VVVVkkkkBBBBaaaacccckkkkggggrrrroooouuuunnnndddd((((3333xxxx))))                                              VVVVkkkkBBBBaaaacccckkkkggggrrrroooouuuunnnndddd((((3333xxxx))))
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  9.      VkBackground - Support for simple work procedure-based background tasks
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  11. IIIINNNNHHHHEEEERRRRIIIITTTTSSSS FFFFRRRROOOOMMMM
  12.      VkCallbackObject
  13.  
  14. HHHHEEEEAAAADDDDEEEERRRR FFFFIIIILLLLEEEE
  15.      #include <Vk/VkBackground.h>
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  18.    CCCCoooonnnnssssttttrrrruuuuccccttttoooorrrr////DDDDeeeessssttttrrrruuuuccccttttoooorrrr
  19.            VkBackground(void);
  20.            void ~VkBackground(void);
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  23.    SSSSttttaaaarrrrttttiiiinnnngggg aaaannnndddd SSSSttttooooppppppppiiiinnnngggg
  24.            void start(void);
  25.            void stop(void);
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  28. PPPPRRRROOOOTTTTEEEECCCCTTTTEEEEDDDD PPPPRRRROOOOTTTTOOOOCCCCOOOOLLLL SSSSUUUUMMMMMMMMAAAARRRRYYYY
  29.            virtual Boolean timeSlice(void);
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  32. CCCCLLLLAAAASSSSSSSS DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  33.           VkBackground is an abstract class that provides a simple C++
  34.           interface to handling background tasks based on Xt work procedures
  35.           (functions that are called whenever there are no events pending in
  36.           the application's event queue).  VkBackground handles the details of
  37.           registering a work procedure and provides a convenient way to
  38.           maintain state between calls to the work procedure.
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  42. DDDDEEEERRRRIIIIVVVVIIIINNNNGGGG SSSSUUUUBBBBCCCCLLLLAAAASSSSSSSSEEEESSSS
  43.           The VkBackground class is intended to be subclassed. Derived classes
  44.           must override the _t_i_m_e_S_l_i_c_e() member function which behaves just
  45.           like an Xt work procedure. This member function is called whenever
  46.           no events are pending in the application's event queue. It is
  47.           expected to perform a small amount of work and return quickly. The
  48.           function must return TRUE if the class has completed its task is
  49.           done, or FALSE if the member function should be called again.
  50.  
  51.           The primary for using this class instead of using a work procedure
  52.           directly is the ability to store state in class data members between
  53.           calls to the _t_i_m_e_S_l_i_c_e() function.
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  70. VVVVkkkkBBBBaaaacccckkkkggggrrrroooouuuunnnndddd((((3333xxxx))))                                              VVVVkkkkBBBBaaaacccckkkkggggrrrroooouuuunnnndddd((((3333xxxx))))
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  73.  
  74. FUNCTION DESCRIPTIONS
  75.    ttttiiiimmmmeeeeSSSSlllliiiicccceeee(((())))
  76.            virtual Boolean timeSlice(void);
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  78.  
  79.           Called whenever no events are pending in the application's event
  80.           queue.  This function must return quickly and return a value of TRUE
  81.           if the class has completed its task and the member function should
  82.           not be called again, or FALSE if it should be called again at the
  83.           next possible time.
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  85.    VVVVkkkkBBBBaaaacccckkkkggggrrrroooouuuunnnndddd(((())))
  86.            VkBackground(void);
  87.  
  88.  
  89.           Initialize a VkBackground object. The constructor does _n_o_t start the
  90.           work procedure.
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  92.    ~~~~VVVVkkkkBBBBaaaacccckkkkggggrrrroooouuuunnnndddd(((())))
  93.            void ~VkBackground(void);
  94.  
  95.  
  96.           Free all storage associated with a VkBackground object. If this
  97.           object's work procedure is currently active, the destructor removes
  98.           it.
  99.  
  100.    ssssttttaaaarrrrtttt(((())))
  101.            void start(void);
  102.  
  103.  
  104.           Start the background task by installing a work procedure.
  105.  
  106.    ssssttttoooopppp(((())))
  107.            void stop(void);
  108.  
  109.  
  110.           Stop the background task by removing any currently installed work
  111.           procedure.
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  113. IIIINNNNHHHHEEEERRRRIIIITTTTEEEEDDDD MMMMEEEEMMMMBBBBEEEERRRR FFFFUUUUNNNNCCCCTTTTIIIIOOOONNNNSSSS
  114. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  115.      _V_i_e_w_K_i_t _P_r_o_g_r_a_m_m_e_r'_s _G_u_i_d_e
  116.      _T_h_e _X _W_i_n_d_o_w _S_y_s_t_e_m, DEC Press, Bob Sheifler and Jim Gettys
  117.      _T_h_e _X _W_i_n_d_o_w _S_y_s_t_e_m _T_o_o_l_k_i_t, DEC Press, Paul Asente and Ralph Swick
  118.      _T_h_e _O_S_F/_M_o_t_i_f _P_r_o_g_r_a_m_m_e_r_s _R_e_f_e_r_e_n_c_e, Prentice Hall, OSF
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