Environment Declaration

Define the screen coordinate system.

screen size {X Y|dialog units|device units}

X Y

Integer values representing the number of horizontal and vertical co-ordinates on the screen. These units are device-independent.

dialog units

Express the screen coordinate system in dialog units. Dialog units are proportional to the size of the Windows system font. A dialog unit is defined to be one-quarter of the average character width of the system font in the horizontal direction, and one-eighth of the maximum baseline extent (e.g., the maximum height) of the system font. You can override the system font size by using the -u runtime option.

device units

The screen co-ordinate system should correspond to the resolution of the display device. One co-ordinate in either dimension corresponds to one pixel on the display device. This is the default for windowed applications.

Description

The screen size environment declaration should be the first statement in an ESL program. You cannot use the screen size declaration inside a response.

Any object or drawing statement positioned outside of the specified co-ordinates will not be displayed.

Dialog units are useful for programs that make extensive use of the Windows system font. Dialog boxes and controls are always defined in dialog units.

Example

 

screen size 640 350 # Typical screen size for EGA

# in high resolution.

screen size 640 480 # Typical screen size for VGA.

screen size 1024 768 # Typical screen size for 8514.