path: root/man/XDrawText.man

.\" Copyright \(co 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1994, 1996 X Consortium
.\"
.\" Permission is hereby granted, free of charge, to any person obtaining
.\" a copy of this software and associated documentation files (the
.\" "Software"), to deal in the Software without restriction, including
.\" without limitation the rights to use, copy, modify, merge, publish,
.\" distribute, sublicense, and/or sell copies of the Software, and to
.\" permit persons to whom the Software is furnished to do so, subject to
.\" the following conditions:
.\"
.\" The above copyright notice and this permission notice shall be included
.\" in all copies or substantial portions of the Software.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
.\" IN NO EVENT SHALL THE X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR
.\" OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
.\" ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
.\" OTHER DEALINGS IN THE SOFTWARE.
.\"
.\" Except as contained in this notice, the name of the X Consortium shall
.\" not be used in advertising or otherwise to promote the sale, use or
.\" other dealings in this Software without prior written authorization
.\" from the X Consortium.
.\"
.\" Copyright \(co 1985, 1986, 1987, 1988, 1989, 1990, 1991 by
.\" Digital Equipment Corporation
.\"
.\" Portions Copyright \(co 1990, 1991 by
.\" Tektronix, Inc.
.\"
.\" Permission to use, copy, modify and distribute this documentation for
.\" any purpose and without fee is hereby granted, provided that the above
.\" copyright notice appears in all copies and that both that copyright notice
.\" and this permission notice appear in all copies, and that the names of
.\" Digital and Tektronix not be used in in advertising or publicity pertaining
.\" to this documentation without specific, written prior permission.
.\" Digital and Tektronix makes no representations about the suitability
.\" of this documentation for any purpose.
.\" It is provided ``as is'' without express or implied warranty.
.\" 
.\"
.ds xT X Toolkit Intrinsics \- C Language Interface
.ds xW Athena X Widgets \- C Language X Toolkit Interface
.ds xL Xlib \- C Language X Interface
.ds xC Inter-Client Communication Conventions Manual
.na
.de Ds
.nf
.\\$1D \\$2 \\$1
.ft CW
.\".ps \\n(PS
.\".if \\n(VS>=40 .vs \\n(VSu
.\".if \\n(VS<=39 .vs \\n(VSp
..
.de De
.ce 0
.if \\n(BD .DF
.nr BD 0
.in \\n(OIu
.if \\n(TM .ls 2
.sp \\n(DDu
.fi
..
.de IN		\" send an index entry to the stderr
..
.de Pn
.ie t \\$1\fB\^\\$2\^\fR\\$3
.el \\$1\fI\^\\$2\^\fP\\$3
..
.de ZN
.ie t \fB\^\\$1\^\fR\\$2
.el \fI\^\\$1\^\fP\\$2
..
.de hN
.ie t <\fB\\$1\fR>\\$2
.el <\fI\\$1\fP>\\$2
..
.de NT
.ne 7
.ds NO Note
.if \\n(.$>$1 .if !'\\$2'C' .ds NO \\$2
.if \\n(.$ .if !'\\$1'C' .ds NO \\$1
.ie n .sp
.el .sp 10p
.TB
.ce
\\*(NO
.ie n .sp
.el .sp 5p
.if '\\$1'C' .ce 99
.if '\\$2'C' .ce 99
.in +5n
.ll -5n
.R
..
.		\" Note End -- doug kraft 3/85
.de NE
.ce 0
.in -5n
.ll +5n
.ie n .sp
.el .sp 10p
..
.ny0
.TH XDrawText __libmansuffix__ __xorgversion__ "XLIB FUNCTIONS"
.SH NAME
XDrawText, XDrawText16, XTextItem, XTextItem16 \- draw polytext text and text drawing structures
.SH SYNTAX
.HP
int XDrawText\^(\^Display *\fIdisplay\fP\^, Drawable \fId\fP\^, GC \fIgc\fP\^,
int \fIx\fP\^, int \fIy\fP\^, XTextItem *\fIitems\fP\^, int \fInitems\fP\^); 
.HP
int XDrawText16\^(\^Display *\fIdisplay\fP\^, Drawable \fId\fP\^, GC
\fIgc\fP\^, int \fIx\fP\^, int \fIy\fP\^, XTextItem16 *\fIitems\fP\^, int
\fInitems\fP\^); 
.SH ARGUMENTS
.IP \fId\fP 1i
Specifies the drawable. 
.IP \fIdisplay\fP 1i
Specifies the connection to the X server.
.IP \fIgc\fP 1i
Specifies the GC.
.IP \fIitems\fP 1i
Specifies an array of text items.
.IP \fInitems\fP 1i
Specifies the number of text items in the array.
.ds Xy , which are relative to the origin of the specified drawable \
and define the origin of the first character
.IP \fIx\fP 1i
.br
.ns
.IP \fIy\fP 1i
Specify the x and y coordinates\*(Xy.
.SH DESCRIPTION
The
.ZN XDrawText16
function is similar to
.ZN XDrawText 
except that it uses 2-byte or 16-bit characters.
Both functions allow complex spacing and font shifts between counted strings.
.LP
Each text item is processed in turn.
A font member other than 
.ZN None
in an item causes the font to be stored in the GC
and used for subsequent text.  
A text element delta specifies an additional change
in the position along the x axis before the string is drawn. 
The delta is always added to the character origin
and is not dependent on any characteristics of the font.
Each character image, as defined by the font in the GC, is treated as an
additional mask for a fill operation on the drawable.
The drawable is modified only where the font character has a bit set to 1.
If a text item generates a
.ZN BadFont
error, the previous text items may have been drawn.
.LP
For fonts defined with linear indexing rather than 2-byte matrix indexing,
each 
.ZN XChar2b
structure is interpreted as a 16-bit number with byte1 as the 
most significant byte.
.LP
Both functions use these GC components:
function, plane-mask, fill-style, font, subwindow-mode, 
clip-x-origin, clip-y-origin, and clip-mask.
They also use these GC mode-dependent components: 
foreground, background, tile, stipple, tile-stipple-x-origin, 
and tile-stipple-y-origin.
.LP
.ZN XDrawText
and
.ZN XDrawText16
can generate
.ZN BadDrawable ,
.ZN BadFont ,
.ZN BadGC ,
and
.ZN BadMatch 
errors.
.SH STRUCTURES
The
.ZN XTextItem
and
.ZN XTextItem16
structures contain:
.LP
.Ds 0
typedef struct {
        char *chars;    /\&* pointer to string */
        int nchars;     /\&* number of characters */
        int delta;      /\&* delta between strings */
        Font font;      /\&* Font to print it in, None don't change */
} XTextItem;
.De
.LP
.Ds 0
typedef struct {
        XChar2b *chars; /\&* pointer to two-byte characters */
        int nchars;     /\&* number of characters */
        int delta;      /\&* delta between strings */
        Font font;      /\&* font to print it in, None don't change */
} XTextItem16;
.De
.LP
If the font member is not
.ZN None ,
the font is changed before printing and also is stored in the GC.
If an error was generated during text drawing,
the previous items may have been drawn.
The baseline of the characters are drawn starting at the x and y
coordinates that you pass in the text drawing functions.
.LP
For example, consider the background rectangle drawn by
.ZN XDrawImageString .
If you want the upper-left corner of the background rectangle
to be at pixel coordinate (x,y), pass the (x,y + ascent)
as the baseline origin coordinates to the text functions.
The ascent is the font ascent, as given in the
.ZN XFontStruct
structure.
If you want the lower-left corner of the background rectangle
to be at pixel coordinate (x,y), pass the (x,y \- descent + 1)
as the baseline origin coordinates to the text functions.
The descent is the font descent, as given in the
.ZN XFontStruct
structure.
.SH DIAGNOSTICS
.TP 1i
.ZN BadDrawable
A value for a Drawable argument does not name a defined Window or Pixmap.
.TP 1i
.ZN BadFont
A value for a Font or GContext argument does not name a defined Font.
.TP 1i
.ZN BadGC
A value for a GContext argument does not name a defined GContext.
.TP 1i
.ZN BadMatch
An
.ZN InputOnly
window is used as a Drawable.
.SH "SEE ALSO"
XDrawImageString(__libmansuffix__),
XDrawString(__libmansuffix__),
XLoadFont(__libmansuffix__)
.br
\fI\*(xL\fP