XDrawText(3X11) MIT X11R4 XDrawText(3X11)
Name
XDrawText, XDrawText16, XTextItem, XTextItem16 - draw polytext text and text drawing structures
Syntax
XDrawText(display, d, gc, x, y, items, nitems)
Display *display;
Drawable d;
GC gc;
int x, y;
XTextItem *items;
int nitems;
XDrawText16(display, d, gc, x, y, items, nitems)
Display *display;
Drawable d;
GC gc;
int x, y;
XTextItem16 *items;
int nitems;
Arguments
d Specifies the drawable.
display Specifies the connection to the X server.
gc Specifies the GC.
items Specifies a pointer to an array of text items.
nitems Specifies the number of text items in the array.
x
y Specify the x and y coordinates, which are relative to the origin of the specified drawable and define the origin of the first
character.
Description
The function is similar to except that it uses 2-byte or 16-bit characters. Both functions allow complex spacing and font shifts between
counted strings.
Each text item is processed in turn. A font member other than 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 error, the previous text items may have been drawn.
For fonts defined with linear indexing rather than 2-byte matrix indexing, each structure is interpreted as a 16-bit number with byte1 as
the most-significant byte.
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.
and can generate and errors.
Structures
The and structures contain:
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 do not change */
} XTextItem;
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 do not change */
} XTextItem16;
If the font member is not 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.
For example, consider the background rectangle drawn by If you want the upper-left corner of the background rectangle to be at pixel coor-
dinate (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 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 structure.
Diagnostics
A value for a Drawable argument does not name a defined Window or Pixmap.
A value for a Font or GContext argument does not name a defined Font.
A value for a GContext argument does not name a defined GContext.
An window is used as a Drawable.
See Also
XDrawImageString(3X11), XDrawString(3X11), XLoadFont(3X11)
X Window System: The Complete Reference, Second Edition, Robert W. Scheifler and James Gettys
XDrawText(3X11)