bionic (3) XSetLineAttributes.3.gz
NAME
XSetLineAttributes, XSetDashes - GC convenience routines
SYNTAX
int XSetLineAttributes(Display *display, GC gc, unsigned int line_width, int line_style, int cap_style,
int join_style);
int XSetDashes(Display *display, GC gc, int dash_offset, char dash_list[], int n);
ARGUMENTS
cap_style Specifies the line-style and cap-style you want to set for the specified GC. You can pass
CapNotLast, CapButt, CapRound, or CapProjecting.
dash_list Specifies the dash-list for the dashed line-style you want to set for the specified GC.
dash_offset
Specifies the phase of the pattern for the dashed line-style you want to set for the specified
GC.
display Specifies the connection to the X server.
gc Specifies the GC.
join_style
Specifies the line join-style you want to set for the specified GC. You can pass JoinMiter,
JoinRound, or JoinBevel.
line_style
Specifies the line-style you want to set for the specified GC. You can pass LineSolid,
LineOnOffDash, or LineDoubleDash.
line_width
Specifies the line-width you want to set for the specified GC.
n Specifies the number of elements in dash_list.
DESCRIPTION
The XSetLineAttributes function sets the line drawing components in the specified GC.
XSetLineAttributes can generate BadAlloc, BadGC, and BadValue errors.
The XSetDashes function sets the dash-offset and dash-list attributes for dashed line styles in the
specified GC. There must be at least one element in the specified dash_list, or a BadValue error
results. The initial and alternating elements (second, fourth, and so on) of the dash_list are the even
dashes, and the others are the odd dashes. Each element specifies a dash length in pixels. All of the
elements must be nonzero, or a BadValue error results. Specifying an odd-length list is equivalent to
specifying the same list concatenated with itself to produce an even-length list.
The dash-offset defines the phase of the pattern, specifying how many pixels into the dash-list the
pattern should actually begin in any single graphics request. Dashing is continuous through path
elements combined with a join-style but is reset to the dash-offset between each sequence of joined
lines.
The unit of measure for dashes is the same for the ordinary coordinate system. Ideally, a dash length is
measured along the slope of the line, but implementations are only required to match this ideal for
horizontal and vertical lines. Failing the ideal semantics, it is suggested that the length be measured
along the major axis of the line. The major axis is defined as the x axis for lines drawn at an angle of
between -45 and +45 degrees or between 135 and 225 degrees from the x axis. For all other lines, the
major axis is the y axis.
XSetDashes can generate BadAlloc, BadGC, and BadValue errors.
DIAGNOSTICS
BadAlloc The server failed to allocate the requested resource or server memory.
BadGC A value for a GContext argument does not name a defined GContext.
BadValue Some numeric value falls outside the range of values accepted by the request. Unless a
specific range is specified for an argument, the full range defined by the argument's type is
accepted. Any argument defined as a set of alternatives can generate this error.
SEE ALSO
XCreateGC(3), XQueryBestSize(3), XSetArcMode(3), XSetClipOrigin(3), XSetFillStyle(3), XSetFont(3), XSetState(3), XSetTile(3) Xlib - C Language X Interface