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| <H1 class="no-header">default_colors 3x</H1> |
| <PRE> |
| <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG> <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG> |
| |
| |
| |
| |
| </PRE><H2><a name="h2-NAME">NAME</a></H2><PRE> |
| <STRONG>use_default_colors</STRONG>, <STRONG>assume_default_colors</STRONG> - use terminal's default col- |
| ors |
| |
| |
| </PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE> |
| <STRONG>#include</STRONG> <STRONG><curses.h></STRONG> |
| |
| <STRONG>int</STRONG> <STRONG>use_default_colors(void);</STRONG> |
| <STRONG>int</STRONG> <STRONG>assume_default_colors(int</STRONG> <STRONG>fg,</STRONG> <STRONG>int</STRONG> <STRONG>bg);</STRONG> |
| |
| |
| </PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE> |
| The <STRONG>use_default_colors</STRONG> and <STRONG>assume_default_colors</STRONG> functions are exten- |
| sions to the curses library. They are used with terminals that support |
| ISO 6429 color, or equivalent. These terminals allow the application |
| to reset color to an unspecified default value (e.g., with SGR 39 or |
| SGR 49). |
| |
| Applications that paint a colored background over the whole screen do |
| not take advantage of SGR 39 and SGR 49. Some applications are |
| designed to work with the default background, using colors only for |
| text. For example, there are several implementations of the <STRONG>ls</STRONG> program |
| which use colors to denote different file types or permissions. These |
| "color ls" programs do not necessarily modify the background color, |
| typically using only the <STRONG>setaf</STRONG> terminfo capability to set the fore- |
| ground color. Full-screen applications that use default colors can |
| achieve similar visual effects. |
| |
| The first function, <STRONG>use_default_colors</STRONG> tells the curses library to |
| assign terminal default foreground/background colors to color number |
| -1. So init_pair(x,COLOR_RED,-1) will initialize pair x as red on |
| default background and init_pair(x,-1,COLOR_BLUE) will initialize pair |
| x as default foreground on blue. |
| |
| The other, <STRONG>assume_default_colors</STRONG> is a refinement which tells which col- |
| ors to paint for color pair 0. This function recognizes a special |
| color number -1, which denotes the default terminal color. |
| |
| The following are equivalent: |
| <EM>use</EM><STRONG>_</STRONG><EM>default</EM><STRONG>_</STRONG><EM>colors();</EM> |
| <EM>assume</EM><STRONG>_</STRONG><EM>default</EM><STRONG>_</STRONG><EM>colors(-1,-1);</EM> |
| |
| These are ncurses extensions. For other curses implementations, color |
| number -1 does not mean anything, just as for ncurses before a success- |
| ful call of <STRONG>use_default_colors</STRONG> or <STRONG>assume_default_colors</STRONG>. |
| |
| Other curses implementations do not allow an application to modify |
| color pair 0. They assume that the background is COLOR_BLACK, but do |
| not ensure that the color pair 0 is painted to match the assumption. |
| If your application does not use either <STRONG>use_default_colors</STRONG> or |
| <STRONG>assume_default_colors</STRONG> ncurses will paint a white foreground (text) with |
| black background for color pair 0. |
| |
| |
| </PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE> |
| These functions return the integer <STRONG>ERR</STRONG> upon failure and <STRONG>OK</STRONG> on success. |
| They will fail if either the terminal does not support the <STRONG>orig_pair</STRONG> or |
| <STRONG>orig_colors</STRONG> capability. If the <STRONG>initialize_pair</STRONG> capability is not |
| found, this causes an error as well. |
| |
| |
| </PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE> |
| Associated with this extension, the <STRONG>init_pair</STRONG> function accepts negative |
| arguments to specify default foreground or background colors. |
| |
| The <STRONG>use_default_colors</STRONG> function was added to support <EM>ded</EM>. This is a |
| full-screen application which uses curses to manage only part of the |
| screen. The bottom portion of the screen, which is of adjustable size, |
| is left uncolored to display the results from shell commands. The top |
| portion of the screen colors filenames using a scheme like the "color |
| ls" programs. Attempting to manage the background color of the screen |
| for this application would give unsatisfactory results for a variety of |
| reasons. This extension was devised after noting that color xterm (and |
| similar programs) provides a background color which does not necessar- |
| ily correspond to any of the ANSI colors. While a special terminfo |
| entry could be constructed using nine colors, there was no mechanism |
| provided within curses to account for the related <STRONG>orig_pair</STRONG> and |
| <STRONG>back_color_erase</STRONG> capabilities. |
| |
| The <STRONG>assume_default_colors</STRONG> function was added to solve a different prob- |
| lem: support for applications which would use environment variables and |
| other configuration to bypass curses' notion of the terminal's default |
| colors, setting specific values. |
| |
| |
| </PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE> |
| These routines are specific to ncurses. They were not supported on |
| Version 7, BSD or System V implementations. It is recommended that any |
| code depending on them be conditioned using NCURSES_VERSION. |
| |
| |
| </PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE> |
| <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>, <STRONG>ded(1)</STRONG>. |
| |
| |
| </PRE><H2><a name="h2-AUTHOR">AUTHOR</a></H2><PRE> |
| Thomas Dickey (from an analysis of the requirements for color xterm for |
| XFree86 3.1.2C, February 1996). |
| |
| |
| |
| <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG> |
| </PRE> |
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| <ul> |
| <li><a href="#h2-NAME">NAME</a></li> |
| <li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li> |
| <li><a href="#h2-DESCRIPTION">DESCRIPTION</a></li> |
| <li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li> |
| <li><a href="#h2-NOTES">NOTES</a></li> |
| <li><a href="#h2-PORTABILITY">PORTABILITY</a></li> |
| <li><a href="#h2-SEE-ALSO">SEE ALSO</a></li> |
| <li><a href="#h2-AUTHOR">AUTHOR</a></li> |
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