Unix and Linux Discussions Tagged with graphics |
|
Thread / Thread Starter |
Last Post |
Replies |
Views |
Forum |
|
|
|
9 |
3,828 |
UNIX for Beginners Questions & Answers |
|
|
|
2 |
1,569 |
Programming |
|
|
|
5 |
4,293 |
Programming |
|
|
|
4 |
2,459 |
UNIX for Advanced & Expert Users |
|
|
|
1 |
7,323 |
Hardware |
|
|
|
14 |
7,542 |
Shell Programming and Scripting |
|
|
|
3 |
2,104 |
Solaris |
|
|
|
0 |
3,626 |
Solaris |
|
|
|
12 |
21,264 |
Ubuntu |
|
|
|
1 |
3,942 |
Programming |
|
|
|
0 |
4,236 |
OS X Support RSS |
|
|
|
0 |
4,159 |
OS X Support RSS |
|
|
|
0 |
1,609 |
OS X Support RSS |
|
|
|
5 |
5,517 |
Solaris |
|
|
|
0 |
979 |
UNIX and Linux RSS News |
|
|
|
0 |
1,209 |
Software Releases - RSS News |
|
|
|
1 |
6,756 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
5,487 |
AIX |
|
|
|
0 |
2,895 |
Solaris |
|
|
|
0 |
1,141 |
Software Releases - RSS News |
|
|
|
2 |
4,063 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
6,682 |
Programming |
|
|
|
6 |
4,224 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
2,370 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
5,823 |
UNIX for Dummies Questions & Answers |
|
|
|
6 |
9,206 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
2,842 |
Post Here to Contact Site Administrators and Moderators |
|
|
|
3 |
3,270 |
UNIX for Dummies Questions & Answers |
|
|
|
5 |
6,190 |
UNIX for Dummies Questions & Answers |
|
|
|
12 |
9,063 |
UNIX for Dummies Questions & Answers |
|
|
|
0 |
10,792 |
OS X (Apple) |
|
|
|
2 |
2,515 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
5,018 |
UNIX for Dummies Questions & Answers |
|
|
|
3 |
6,973 |
UNIX for Dummies Questions & Answers |
|
|
|
1 |
5,494 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
3,904 |
UNIX for Dummies Questions & Answers |
|
|
|
5 |
3,508 |
UNIX for Dummies Questions & Answers |
Tk_GetGC(3) Tk Library Procedures Tk_GetGC(3)
__________________________________________________________________________________________________________________________________________________
NAME
Tk_GetGC, Tk_FreeGC - maintain database of read-only graphics contexts
SYNOPSIS
#include <tk.h>
GC
Tk_GetGC(tkwin, valueMask, valuePtr)
Tk_FreeGC(display, gc)
ARGUMENTS
Tk_Window tkwin (in) Token for window in which the graphics context will be used.
unsigned long valueMask (in) Mask of bits (such as GCForeground or GCStipple) indicating which fields of *valuePtr are valid.
XGCValues *valuePtr (in) Pointer to structure describing the desired values for the graphics context.
Display *display (in) Display for which gc was allocated.
GC gc (in) X identifier for graphics context that is no longer needed. Must have been allocated by Tk_GetGC.
_________________________________________________________________
DESCRIPTION
Tk_GetGC and Tk_FreeGC 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. Tk_GetGC 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 valueMask and valuePtr.
Tk_GetGC maintains a database of all the graphics contexts it has created. Whenever possible, a call to Tk_GetGC will return an existing
graphics context rather than creating a new one. This approach can substantially reduce server overhead, so Tk_GetGC should generally be
used in preference to the Xlib procedure XCreateGC, which creates a new graphics context on each call.
Since the return values of Tk_GetGC are shared, callers should never modify the graphics contexts returned by Tk_GetGC. If a graphics con-
text must be modified dynamically, then it should be created by calling XCreateGC instead of Tk_GetGC.
When a graphics context is no longer needed, Tk_FreeGC should be called to release it. There should be exactly one call to Tk_FreeGC for
each call to Tk_GetGC. When a graphics context is no longer in use anywhere (i.e. it has been freed as many times as it has been gotten)
Tk_FreeGC will release it to the X server and delete it from the database.
KEYWORDS
graphics context
Tk Tk_GetGC(3)