XDrawText(3X11)     RISC/os Reference Manual      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 rela-
               tive to the origin of the specified drawable and
               define the origin of the first character.

DESCRIPTION
     The XDrawText16 function is similar to XDrawText 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 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 char-
     acter 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 opera-
     tion on the drawable.  The drawable is modified only where
     the font character has a bit set to 1.  If a text item



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XDrawText(3X11)     RISC/os Reference Manual      XDrawText(3X11)



     generates a BadFont error, the previous text items may have
     been drawn.

     For fonts defined with linear indexing rather than 2-byte
     matrix indexing, each XChar2b 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.

     XDrawText and XDrawText16 can generate BadDrawable, BadFont,
     BadGC, and BadMatch errors.

STRUCTURES
     The XTextItem and XTextItem16 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 don't 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 don't change */
     } XTextItem16;

     If the font member is not None, the font is changed before
     printing and also is stored in the GC.  If an error was gen-
     erated 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
     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 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 XFontStruct structure.





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XDrawText(3X11)     RISC/os Reference Manual      XDrawText(3X11)



DIAGNOSTICS
     BadDrawable
               A value for a Drawable argument does not name a
               defined Window or Pixmap.

     BadFont   A value for a Font or GContext argument does not
               name a defined Font.

     BadGC     A value for a GContext argument does not name a
               defined GContext.

     BadMatch  An InputOnly window is used as a Drawable.

SEE ALSO
     XDrawImageString(3X11), XDrawString(3X11), XLoadFont(3X11)
     Xlib - C Language X Interface







































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