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. \(bu How To Use Colors 5 \(bu How To Use Different Character Attributes 5 \(bu How To Justify Strings 5 \(bu How To Use Special Drawing Characters 5

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.

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#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.

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#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(1)>

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(2)><#UR>"; mesg[1] = "<C><#VL></R>This text should be boxed.<!R><#VL>"; mesg[2] = "<C><#LL><#HL(2)><#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?n"); 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>.