Ubuntu Manpage: m17nDraw_-_Dra - - Drawing M-texts on a window.

NAME

       m17nDraw_-_Dra -  - Drawing M-texts on a window.

SYNOPSIS

   Data Structures
       struct MDrawControl
           Type of a text drawing control.
       struct MDrawMetric
           Type of metric for glyphs and texts.
       struct MDrawGlyphInfo
           Type of information about a glyph.
       struct MDrawGlyph
           Type of information about a glyph metric and font.

   Typedefs
       typedef void * MDrawWindow
           Window system dependent type for a window.
       typedef void * MDrawRegion
           Window system dependent type for a region.

   Functions
       int mdraw_text (MFrame *frame, MDrawWindow win, int x, int y, MText *mt, int from, int to)
           Draw an M-text on a window.
       int mdraw_image_text (MFrame *frame, MDrawWindow win, int x, int y, MText *mt, int from,
           int to)
           Draw an M-text on a window as an image.
       int mdraw_text_with_control (MFrame *frame, MDrawWindow win, int x, int y, MText *mt, int
           from, int to, MDrawControl *control)
           Draw an M-text on a window with fine control.
       int mdraw_text_extents (MFrame *frame, MText *mt, int from, int to, MDrawControl *control,
           MDrawMetric *overall_ink_return, MDrawMetric *overall_logical_return, MDrawMetric
           *overall_line_return)
           Compute text pixel width.
       int mdraw_text_per_char_extents (MFrame *frame, MText *mt, int from, int to, MDrawControl
           *control, MDrawMetric *ink_array_return, MDrawMetric *logical_array_return, int
           array_size, int *num_chars_return, MDrawMetric *overall_ink_return, MDrawMetric
           *overall_logical_return)
           Compute the text dimensions of each character of M-text.
       int mdraw_coordinates_position (MFrame *frame, MText *mt, int from, int to, int x_offset,
           int y_offset, MDrawControl *control)
           Return the character position nearest to the coordinates.
       int mdraw_glyph_info (MFrame *frame, MText *mt, int from, int pos, MDrawControl *control,
           MDrawGlyphInfo *info)
           Compute information about a glyph.
       int mdraw_glyph_list (MFrame *frame, MText *mt, int from, int to, MDrawControl *control,
           MDrawGlyph *glyphs, int array_size, int *num_glyphs_return)
           Compute information about glyph sequence.
       void mdraw_text_items (MFrame *frame, MDrawWindow win, int x, int y, MDrawTextItem *items,
           int nitems)
           Draw one or more textitems.
       int mdraw_default_line_break (MText *mt, int pos, int from, int to, int line, int y)
           Calculate a line breaking position.
       void mdraw_per_char_extents (MFrame *frame, MText *mt, MDrawMetric *array_return,
           MDrawMetric *overall_return)
           Obtain per character dimension information.
       void mdraw_clear_cache (MText *mt)
           clear cached information.
            "

   Variables
       int mdraw_line_break_option
           Option of line breaking for drawing text.

Detailed Description

       Drawing M-texts on a window.

       The m17n GUI API provides functions to draw M-texts.

       The fonts used for drawing are selected automatically based on the fontset and the
       properties of a face. A face also specifies the appearance of M-texts, i.e. font size,
       color, underline, etc.

       The drawing format of M-texts can be controlled in a variety of ways, which provides
       powerful 2-dimensional layout facility.

Data Structure Documentation

MDrawControl
Type of a text drawing control.

FIELD DOCUMENTATION:

unsigned MDrawControl::as_image If nonzero, draw an M-text as image, i.e. with background
filled with background colors of faces put on the M-text. Otherwise, the background is not
changed.

unsigned MDrawControl::align_head If nonzero and the first glyph of each line has negative
lbearing, shift glyphs horizontally to right so that no pixel is drawn to the left of the
specified position.

unsigned MDrawControl::two_dimensional If nonzero, draw an M-text two-dimensionally, i.e.,
newlines in M-text breaks lines and the following characters are drawn in the next line.
If <format> is non-NULL, and the function returns nonzero line width, a line longer than
that width is also broken.

unsigned MDrawControl::orientation_reversed If nonzero, draw an M-text to the right of a
specified position.

unsigned MDrawControl::enable_bidi If nonzero, reorder glyphs correctly for bidi text.

unsigned MDrawControl::ignore_formatting_char If nonzero, don't draw characters whose
general category (in Unicode) is Cf (Other, format).

unsigned MDrawControl::fixed_width If nonzero, draw glyphs suitable for a terminal. Not
yet implemented.

unsigned MDrawControl::anti_alias If nonzero, draw glyphs with anti-aliasing if a backend
font driver supports it.

unsigned MDrawControl::disable_overlapping_adjustment If nonzero, disable the adjustment
of glyph positions to avoid horizontal overlapping at font boundary.

unsigned int MDrawControl::min_line_ascent If nonzero, the values are minimum line ascent
pixels.

unsigned int MDrawControl::min_line_descent If nonzero, the values are minimum line
descent pixels.

unsigned int MDrawControl::max_line_ascent If nonzero, the values are maximum line ascent
pixels.

unsigned int MDrawControl::max_line_descent If nonzero, the values are maximum line
descent pixels.

unsigned int MDrawControl::max_line_width If nonzero, the value specifies how many pixels
each line can occupy on the display. The value zero means that there is no limit. It is
ignored if <format> is non-NULL.

unsigned int MDrawControl::tab_width If nonzero, the value specifies the distance between
tab stops in columns (the width of one column is the width of a space in the default font
of the frame). The value zero means

void(* MDrawControl::format) (int line, int y, int *indent, int *width) If non-NULL, the
value is a function that calculates the indentation and width limit of each line based on
the line number LINE and the coordinate Y. The function store the indentation and width
limit at the place pointed by INDENT and WIDTH respectively.

The indentation specifies how many pixels the first glyph of each line is shifted to the
right (if the member <orientation_reversed> is zero) or to the left (otherwise). If the
value is negative, each line is shifted to the reverse direction.

The width limit specifies how many pixels each line can occupy on the display. The value 0
means that there is no limit.

LINE and Y are reset to 0 when a line is broken by a newline character, and incremented
each time when a long line is broken because of the width limit.

This has an effect only when <two_dimensional> is nonzero.

int(* MDrawControl::line_break) (MText *mt, int pos, int from, int to, int line, int y) If
non-NULL, the value is a function that calculates a line breaking position when a line is
too long to fit within the width limit. POS is the position of the character next to the
last one that fits within the limit. FROM is the position of the first character of the
line, and TO is the position of the last character displayed on the line if there were not
width limit. LINE and Y are the same as the arguments to <format>.

The function must return a character position to break the line.

The function should not modify MT.

The mdraw_default_line_break() function is useful for such a script that uses SPACE as a
word separator.

int MDrawControl::with_cursor If nonzero, show the cursor according to <cursor_width>.

int MDrawControl::cursor_pos Specifies the character position to display a cursor. If it
is greater than the maximum character position, the cursor is displayed next to the last
character of an M-text. If the value is negative, even if <cursor_width> is nonzero,
cursor is not displayed.

int MDrawControl::cursor_width If nonzero, display a cursor at the character position
<cursor_pos>. If the value is positive, it is the pixel width of the cursor. If the value
is negative, the cursor width is the same as the underlining glyph(s).

int MDrawControl::cursor_bidi If nonzero and <cursor_width> is also nonzero, display
double bar cursors; at the character position <cursor_pos> and at the logically previous
character. Both cursors have one pixel width with horizontal fringes at upper or lower
positions.

int MDrawControl::partial_update If nonzero, on drawing partial text, pixels of
surrounding texts that intrude into the drawing area are also drawn. For instance, some
CVC sequence of Thai text (C is consonant, V is upper vowel) is drawn so that V is placed
over the middle of two Cs. If this CVC sequence is already drawn and only the last C is
drawn again (for instance by updating cursor position), the right half of V is erased if
this member is zero. By setting this member to nonzero, even with such a drawing, we can
keep this CVC sequence correctly displayed.

int MDrawControl::disable_caching If nonzero, don't cache the result of any drawing
information of an M-text.

MDrawRegion MDrawControl::clip_region If non-NULL, limit the drawing effect to the
specified region.

MDrawMetric
Type of metric for glyphs and texts.

FIELD DOCUMENTATION:

int MDrawMetric::x X coordinates of a glyph or a text.

int MDrawMetric::y Y coordinates of a glyph or a text.

unsigned int MDrawMetric::width Pixel width of a glyph or a text.

unsigned int MDrawMetric::height Pixel height of a glyph or a text.

MDrawGlyphInfo
Type of information about a glyph.

FIELD DOCUMENTATION:

int MDrawGlyphInfo::from Start position of character range corresponding to the glyph.

int MDrawGlyphInfo::to End position of character range corresponding to the glyph.

int MDrawGlyphInfo::line_from Start position of character range corresponding to the line
of the glyph.

int MDrawGlyphInfo::line_to End position of character range corresponding to the line of
the glyph.

int MDrawGlyphInfo::x X coordinates of the glyph.

int MDrawGlyphInfo::y Y coordinates of the glyph.

MDrawMetric MDrawGlyphInfo::metrics Metric of the glyph.

MFont* MDrawGlyphInfo::font Font used for the glyph. Set to NULL if no font is found for
the glyph.

int MDrawGlyphInfo::prev_from Character ranges corresponding to logically previous glyphs.
Note that we do not need the members prev_to because it must be the same as the member
<from>.

int MDrawGlyphInfo::next_to Character ranges corresponding to logically next glyphs. Note
that we do not need the members next_from because it must be the same as the member <to>
respectively.

int MDrawGlyphInfo::left_from Start position of character ranges corresponding to visually
left glyphs.

int MDrawGlyphInfo::left_to End position of character ranges corresponding to visually
left glyphs.

int MDrawGlyphInfo::right_from Start position of character ranges corresponding to
visually right glyphs.

int MDrawGlyphInfo::right_to End position of character ranges corresponding to visually
left glyphs.

int MDrawGlyphInfo::logical_width Logical width of the glyph. Nominal distance to the next
glyph.

MDrawGlyph
Type of information about a glyph metric and font.

FIELD DOCUMENTATION:

int MDrawGlyph::from Character range corresponding to the glyph.

int MDrawGlyph::to

int MDrawGlyph::glyph_code Font glyph code of the glyph.

int MDrawGlyph::x_advance Logical width of the glyph. Nominal distance to the next glyph.

int MDrawGlyph::y_advance Logical height of the glyph. Nominal distance to the next glyph.

int MDrawGlyph::x_off X offset relative to the glyph position.

int MDrawGlyph::y_off Y offset relative to the glyph position.

int MDrawGlyph::lbearing Metric of the glyph (left-bearing).

int MDrawGlyph::rbearing Metric of the glyph (right-bearing).

int MDrawGlyph::ascent Metric of the glyph (ascent).

int MDrawGlyph::descent Metric of the glyph (descent).

MFont* MDrawGlyph::font Font used for the glyph. Set to NULL if no font is found for the
glyph.

MSymbol MDrawGlyph::font_type Type of the font. One of Mx, Mfreetype, Mxft.

void* MDrawGlyph::fontp Pointer to the font structure. The actual type is (XFontStruct *)
if <font_type> member is Mx, FT_Face if <font_type> member is Mfreetype, and (XftFont *)
if <font_type> member is Mxft.

Typedef Documentation

   typedef void* MDrawWindow
       Window system dependent type for a window. The type MDrawWindow is for a window; a
       rectangular area that works in several ways like a miniature screen.

       What it actually points depends on a window system. A program that uses the m17n-X library
       must coerce the type Drawable to this type.

   typedef void* MDrawRegion
       Window system dependent type for a region. The type MDrawRegion is for a region; an
       arbitrary set of pixels on the screen (typically a rectangular area).

       What it actually points depends on a window system. A program that uses the m17n-X library
       must coerce the type Region to this type.

Variable Documentation

   int mdraw_line_break_option
       Option of line breaking for drawing text. The variable mdraw_line_break_option specifies
       line breaking options by logical-or of the members of MTextLineBreakOption. It controls
       the line breaking algorithm of the function mdraw_default_line_break().

Author

       Generated automatically by Doxygen for The m17n Library from the source code.

COPYRIGHT

       Copyright (C) 2001 Information-technology Promotion Agency (IPA)
       Copyright (C) 2001-2011 National Institute of Advanced Industrial Science and Technology
       (AIST)
       Permission is granted to copy, distribute and/or modify this document under the terms of
       the GNU Free Documentation License <http://www.gnu.org/licenses/fdl.html>.