Table of Contents
XSetLineAttributes, XSetDashes
- GC convenience routines
- 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);
- 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.
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.
- 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.
XCreateGC(3)
,
XQueryBestSize(3)
, XSetArcMode(3)
, XSetClipOrigin(3)
, XSetFillStyle(3)
,
XSetFont(3)
, XSetState(3)
, XSetTile(3)
Xlib - C Language X Interface
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