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