COLOR WHERE Attribute

The COLOR WHERE attribute defines a condition to set the foreground color dynamically.

Syntax

COLOR = color-spec [...] WHERE bool-expr
  1. color-spec can be: BLACK, BLUE, CYAN, GREEN, MAGENTA, RED, WHITE, and YELLOW.
  2. color-spec can also be one of: REVERSE, LEFT, BLINK, and UNDERLINE, and it can be combined with a color name (COLOR = RED REVERSE).
  3. bool-expr defines a boolean expression with a restricted syntax. This expression can only reference the current form field item tag.

Usage

The attribute COLOR WHERE defines a conditional color. The color will be applied if the condition is true.

The fglform compiler ignores COLOR=WHITE and COLOR=BLACK: These colors can be specified in the .per file, but will not be written in the .42f file.

A color name like RED, BLUE can be combined with an secondary keyword that must be one of: REVERSE, LEFT, BLINK, and UNDERLINE. The secondary keyword can also be used without a color name.

Note:

For backward compatibility, the color can be specified as a number: 0=WHITE, 1=YELLOW, 2=MAGENTA, 3=RED, 4=CYAN, 5=GREEN, 6=BLUE, 7=BLACK. Note that fglform ignores COLOR=0 or COLOR=7: like COLOR=WHITE and COLOR=BLACK.

The condition in COLOR WHERE can only reference the field for which the attribute is set,using its item tag. See Boolean expressions in forms for more details.

With form fields such as EDIT, BUTTONEDIT the color will be applied when leaving the field. The color will not change while editing the value.

Several COLOR ... WHERE attributes can be specified, to get different colors depending on the field value.

When setting the color by program with DISPLAY BY NAME varname ATTRIBUTES(RED), the COLOR … WHERE rules will take precedence over the DISPLAY BY NAME instruction.

Important:

In GUI mode, form elements can also be decorated with presentation styles. Pay attention to the specific rules that apply when combining TTY attributes and presentation styles.

Example

EDIT f001 = item.price,
    COLOR = RED   WHERE f001 < 0,
    COLOR = BLUE  WHERE f001 = 0,
    COLOR = GREEN WHERE f001 > 0,
    ;