Cdk - Curses Development Kit Display Capabilities.
Cdk has a number of pre-defined display types which need
explaining. This manual page will explain all of the display
types and how to use them. The following lists which
display types will be outlined in this manual page.
o How To Use Colors
o How To Use Different Character Attributes
o How To Justify Strings
o How To Use Special Drawing Characters
Cdk has special formatting commands which can be included
in any string which add highlights, justification, or even
colors to a basic string. This manual page outlines and
demonstrates how they work.
How To Use Colors
Cdk has the capability to display colors in almost
every string type displayed in a Cdk widget. To turn on
colors, the function initCDKColor has to be called.
When this function is called 64 color pairs are created.
Normally the color pairs are accessed via the
COLOR_PAIR macro. You can still do this, but creating a
string with multiple colors gets terribly difficult.
That is why the color commands were created. The color
setting are stored directly in the string and when the
widget is created or activated, the string is converted
to take advantage of any color commands in the string.
To turn on a color pair insert </XX> into the string;
where XX is a numeric value from 0 to 64. Color pair 0
is the standard default color pair for the screen. To
turn off a color pair use the format command <!XX>
where XX is a numeric value from 0 to 64. The following
code segment demonstrates the use of the color commands.
----------------------------------------
#include <cdk.h>
void main()
{
CDKSCREEN *cdkscreen;
CDKLABEL *demo;
WINDOW *screen;
char *mesg[4];
/* Initialize the Cdk screen. */
screen = initscr();
cdkscreen = initCDKScreen (screen);
/* Set the labels up. */
mesg[0] = "</1>This line should have a yellow foreground and a blue background.<!1>";
mesg[1] = "</2>This line should have a white foreground and a blue background.<!2>";
mesg[2] = "</3>This line should have a yellow foreground and a red background.<!3>";
mesg[3] = "<C>This line should be set to whatever the screen default is.";
/* Declare the labels. */
demo = newCDKLabel (cdkscreen, CENTER, CENTER, mesg, 4, TRUE, TRUE);
/* Draw the label */
drawCDKLabel (demo, TRUE);
waitCDKLabel (demo, ' ');
/* Clean up */
destroyCDKLabel (demo);
destroyCDKScreen (cdkscreen);
endCDK();
exit (0);
}
----------------------------------------
This example uses the color pair 5 (which is white on
blue) for the label to the entry widget.
How To Use Different Character Attributes
Cdk also provides attribute commands which allow different
character attributes to be displayed in a Cdk
widget. To use a character attribute the format command
is </X> where X is one of several command characters.
To turn a attribute off use the command <!X>. The following
table outlines the command characters and what
they mean.
Command_Character Character_Attribute
B Bold
U Underline
K Blink
R Reverse
S Standout
D Dim
N Normal
The following code segment demonstrates the use of
character display attributes.
----------------------------------------
#include <cdk.h>
void main()
{
CDKSCREEN *cdkscreen;
CDKLABEL *demo;
WINDOW *screen;
char *mesg[4];
/* Initialize the Cdk screen. */
screen = initscr();
cdkscreen = initCDKScreen (screen);
/* Set the labels up. */
mesg[0] = "</B/1>This line should have a yellow foreground and a blue background.<!1>";
mesg[1] = "</U/2>This line should have a white foreground and a blue background.<!2>";
mesg[2] = "</K/3>This line should have a yellow foreground and a red background.<!3>";
mesg[3] = "<C>This line should be set to whatever the screen default is.";
/* Declare the labels. */
demo = newCDKLabel (cdkscreen, CENTER, CENTER, mesg, 4, TRUE, TRUE);
/* Draw the label */
drawCDKLabel (demo, TRUE);
waitCDKLabel (demo, ' ');
/* Clean up */
destroyCDKLabel (demo);
destroyCDKScreen (cdkscreen);
endCDK();
exit (0);
}
----------------------------------------
Notice that color commands and format commands can be
mixed inside the same format marker. The above example
underlines the label marker, which also sets color pair
number 5.
How To Justify Strings
Justification commands can left justify, right justify,
or center a string of text. To use a justification format
in a string the command <X> is used. The following
table lists all of the format commands available.
Justification_Command Action.
<L> Left Justified. Default if not stated.
<C> Centered text.
<R> Right justified.
<I=X> Indent the line X characters.
<B=X> Bullet. X is the bullet string to use.
<F=X> Links in a file where X is the filename.
Currently only works with the viewer
widget.
The following code segment demonstrates how to use the
justification commands in a Cdk widget.
----------------------------------------
#include <cdk.h>
void main()
{
CDKSCREEN *cdkscreen;
CDKLABEL *demo;
WINDOW *screen;
char *mesg[4];
/* Initialize the Cdk screen. */
screen = initscr();
cdkscreen = initCDKScreen (screen);
/* Set the labels up. */
mesg[0] = "<R></B/1>This line should have a yellow foreground and a blue background.<!1>";
mesg[1] = "</U/2>This line should have a white foreground and a blue background.<!2>";
mesg[2] = "<B=+>This is a bullet.";
mesg[3] = "<I=10>This is indented 10 characters.";
mesg[4] = "<C>This line should be set to whatever the screen default is.";
/* Declare the labels. */
demo = newCDKLabel (cdkscreen, CENTER, CENTER, mesg, 5, TRUE, TRUE);
/* Draw the label */
drawCDKLabel (demo, TRUE);
waitCDKLabel (demo, ' ');
/* Clean up */
destroyCDKLabel (demo);
destroyCDKScreen (cdkscreen);
endCDK();
exit (0);
}
----------------------------------------
The bullet format command can take either a single
character or a string. The bullet in the the above
example would look like
+ This is a bullet.
but if we were to use the following command instead
<B=***>This is a bullet.
it would look like
*** This is a bullet.
The only restriction that a format command has is that
it must be at the beginning of the string.
How To Use Special Drawing Characters
Cdk has a set of special drawing characters which can
be inserted into any ASCII file. In order to use a special
character the format command <#XXX> is used. The
following table lists all of the special character commands
available.
Special_Character Character
<#UL> Upper Left Corner
<#UR> Upper Right Corner
<#LL> Lower Left Corner
<#LR> Lower Right Corner
<#LT> Left Tee
<#RT> Right Tee
<#TT> Top Tee
<#BT> Bottom Tee
<#HL> Horizontal Line
<#VL> Vertical Line
<#PL> Plus Sign
<#PM> Plus/Minus Sign
<#DG> Degree Sign
<#CB> Checker Board
<#DI> Diamond
<#BU> Bullet
The character formats can be repeated using an optional
numeric repeat value. To repeat a character add (XXX)
to the end of the character format. The following example,
draws 10 horizontal lines.
<#HL(10)>
The following code segment draws a box within a label
window.
----------------------------------------
#include "cdk.h"
void main()
{
/* Declare variables. */
CDKSCREEN *cdkscreen;
CDKLABEL *demo;
WINDOW *cursesWin;
char *mesg[4];
/* Set up CDK */
cursesWin = initscr();
cdkscreen = initCDKScreen (cursesWin);
/* Start CDK Colors */
initCDKColor();
/* Set the labels up. */
mesg[0] = "<C><#UL><#HL(25)><#UR>";
mesg[1] = "<C><#VL></R>This text should be boxed.<!R><#VL>";
mesg[2] = "<C><#LL><#HL(25)><#LR>";
mesg[3] = "<C>While this is not.";
/* Declare the labels. */
demo = newCDKLabel (cdkscreen, CENTER, CENTER, mesg, 4, TRUE, TRUE);
/* Is the label NULL??? */
if (demo == (CDKLABEL *)NULL)
{
/* Clean up the memory. */
destroyCDKScreen (cdkscreen);
/* End curses... */
endCDK();
/* Spit out a message. */
printf ("Oops. Can't seem to create the label. Is the window too small?0);
exit (1);
}
/* Draw the CDK screen. */
refreshCDKScreen (cdkscreen);
waitCDKLabel (demo, ' ');
/* Clean up */
destroyCDKLabel (demo);
destroyCDKScreen (cdkscreen);
delwin (cursesWin);
endCDK();
exit (0);
}
----------------------------------------
Notice that drawn text can also be justified.
cdk(3), cdk_binding(3), cdk_screen(3)
The header file <cdk.h> automatically includes the header
files <curses.h>, <stdlib.h>, <string.h>, <ctype.h>,
<unistd.h>, <dirent.h>, <time.h>, <errno.h>, <pwd.h>,
<grp.h>, <sys/stat.h>, and <sys/types.h>. The <curses.h>
header file includes <stdio.h> and <unctrl.h>.
05 Dec 1995 cdk_display(3)
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