home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
IRIX Base Documentation 1998 November
/
IRIX 6.5.2 Base Documentation November 1998.img
/
usr
/
share
/
catman
/
u_man
/
cat3
/
Tk
/
getgc.z
/
getgc
Wrap
Text File
|
1998-10-30
|
5KB
|
133 lines
TTTTkkkk____GGGGeeeettttGGGGCCCC((((3333TTTTkkkk)))) TTTTkkkk____GGGGeeeettttGGGGCCCC((((3333TTTTkkkk))))
NNNNAAAAMMMMEEEE
Tk_GetGC, Tk_FreeGC - maintain database of read-only graphics contexts
SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
####iiiinnnncccclllluuuuddddeeee <<<<ttttkkkk....hhhh>>>>
GC
TTTTkkkk____GGGGeeeettttGGGGCCCC(_t_k_w_i_n, _v_a_l_u_e_M_a_s_k, _v_a_l_u_e_P_t_r)
TTTTkkkk____FFFFrrrreeeeeeeeGGGGCCCC((((_d_i_s_p_l_a_y, _g_c)
AAAARRRRGGGGUUUUMMMMEEEENNNNTTTTSSSS
Tk_Window _t_k_w_i_n (in) Token for window in which the
graphics context will be used.
unsigned long _v_a_l_u_e_M_a_s_k (in) Mask of bits (such as GGGGCCCCFFFFoooorrrreeeeggggrrrroooouuuunnnndddd
or GGGGCCCCSSSSttttiiiipppppppplllleeee) indicating which
fields of *_v_a_l_u_e_P_t_r are valid.
XGCValues *_v_a_l_u_e_P_t_r (in) Pointer to structure describing the
desired values for the graphics
context.
Display *_d_i_s_p_l_a_y (in) Display for which _g_c was allocated.
GC _g_c (in) X identifier for graphics context
that is no longer needed. Must
have been allocated by TTTTkkkk____GGGGeeeettttGGGGCCCC.
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
TTTTkkkk____GGGGeeeettttGGGGCCCC and TTTTkkkk____FFFFrrrreeeeeeeeGGGGCCCC manage a collection of graphics contexts being
used by an application. The procedures allow graphics contexts to be
shared, thereby avoiding the server overhead that would be incurred if a
separate GC were created for each use. TTTTkkkk____GGGGeeeettttGGGGCCCC takes arguments
describing the desired graphics context and returns an X identifier for a
GC that fits the description. The graphics context that is returned will
have default values in all of the fields not specified explicitly by
_v_a_l_u_e_M_a_s_k and _v_a_l_u_e_P_t_r.
TTTTkkkk____GGGGeeeettttGGGGCCCC maintains a database of all the graphics contexts it has
created. Whenever possible, a call to TTTTkkkk____GGGGeeeettttGGGGCCCC will return an existing
graphics context rather than creating a new one. This approach can
substantially reduce server overhead, so TTTTkkkk____GGGGeeeettttGGGGCCCC should generally be
used in preference to the Xlib procedure XXXXCCCCrrrreeeeaaaatttteeeeGGGGCCCC, which creates a new
graphics context on each call.
Since the return values of TTTTkkkk____GGGGeeeettttGGGGCCCC are shared, callers should never
modify the graphics contexts returned by TTTTkkkk____GGGGeeeettttGGGGCCCC. If a graphics context
must be modified dynamically, then it should be created by calling
XXXXCCCCrrrreeeeaaaatttteeeeGGGGCCCC instead of TTTTkkkk____GGGGeeeettttGGGGCCCC.
PPPPaaaaggggeeee 1111
TTTTkkkk____GGGGeeeettttGGGGCCCC((((3333TTTTkkkk)))) TTTTkkkk____GGGGeeeettttGGGGCCCC((((3333TTTTkkkk))))
When a graphics context is no longer needed, TTTTkkkk____FFFFrrrreeeeeeeeGGGGCCCC should be called
to release it. There should be exactly one call to TTTTkkkk____FFFFrrrreeeeeeeeGGGGCCCC for each
call to TTTTkkkk____GGGGeeeettttGGGGCCCC. When a graphics context is no longer in use anywhere
(i.e. it has been freed as many times as it has been gotten) TTTTkkkk____FFFFrrrreeeeeeeeGGGGCCCC
will release it to the X server and delete it from the database.
KKKKEEEEYYYYWWWWOOOORRRRDDDDSSSS
graphics context
PPPPaaaaggggeeee 2222