Unix and Linux Discussions Tagged with graphics |
|
Thread / Thread Starter |
Last Post |
Replies |
Views |
Forum |
|
|
|
9 |
2,859 |
UNIX for Beginners Questions & Answers |
|
|
|
2 |
1,394 |
Programming |
|
|
|
5 |
3,972 |
Programming |
|
|
|
4 |
2,208 |
UNIX for Advanced & Expert Users |
|
|
|
1 |
7,008 |
Hardware |
|
|
|
14 |
7,226 |
Shell Programming and Scripting |
|
|
|
3 |
2,014 |
Solaris |
|
|
|
0 |
3,539 |
Solaris |
|
|
|
12 |
20,771 |
Ubuntu |
|
|
|
1 |
3,696 |
Programming |
|
|
|
0 |
4,133 |
OS X Support RSS |
|
|
|
0 |
4,034 |
OS X Support RSS |
|
|
|
0 |
1,578 |
OS X Support RSS |
|
|
|
5 |
5,404 |
Solaris |
|
|
|
0 |
939 |
UNIX and Linux RSS News |
|
|
|
0 |
1,167 |
Software Releases - RSS News |
|
|
|
1 |
6,633 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
5,325 |
AIX |
|
|
|
0 |
2,764 |
Solaris |
|
|
|
0 |
1,089 |
Software Releases - RSS News |
|
|
|
2 |
3,697 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
6,488 |
Programming |
|
|
|
6 |
3,929 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
2,236 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
5,664 |
UNIX for Dummies Questions & Answers |
|
|
|
6 |
9,054 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
2,669 |
Post Here to Contact Site Administrators and Moderators |
|
|
|
3 |
2,984 |
UNIX for Dummies Questions & Answers |
|
|
|
5 |
5,962 |
UNIX for Dummies Questions & Answers |
|
|
|
12 |
8,733 |
UNIX for Dummies Questions & Answers |
|
|
|
0 |
10,504 |
OS X (Apple) |
|
|
|
2 |
2,447 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
4,748 |
UNIX for Dummies Questions & Answers |
|
|
|
3 |
6,658 |
UNIX for Dummies Questions & Answers |
|
|
|
1 |
5,346 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
3,523 |
UNIX for Dummies Questions & Answers |
|
|
|
5 |
3,396 |
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)