backdrop
Type
property
Summary
Places a solid or patterned background behind the application's windows, hiding any other applications.
Syntax
set the backdrop to {<colorName> | <RGBColor> | <patternNumber> | <imageID> | none}
Description
Use the backdrop property to create a kiosk mode, or to limit distractions during a movie or similar presentation.
Hiding other applications from the user is usually not recommended, since users may need or want to see other windows on their system. However, the ability to do this can be very useful for some applications (such as kiosk systems or games) or at times when you want to reduce distractions (such as during the playing of a movie).
Setting the backdrop property to "none" eliminates the backdrop and lets other windows be seen.
Pattern images can be color or black-and-white.
To be used as a pattern on Mac OS systems, an image must be 128x128 pixels or less, and both its height and width must be a power of 2. To be used on Windows and Unix systems, height and width must be divisible by 8. To be used as a fully cross-platform pattern, both an image's dimensions should be one of 8, 16, 32, 64, or 128.
On Mac OS systems, if you use the launch or open process commands to start up another application, or if the user brings another application to the front, its windows appear in front of the backdrop. (The backdrop remains visible even if the application is in the background.) Bringing the application to the front again hides the other application behind the backdrop. On Unix and Windows systems, any windows you open after setting the backdrop property remain in front of the backdrop, even if they belong to an application that is in the background.
If the system has multiple screens connected, the backdrop property affects only the main screen.
Examples
set the backdrop to "black"
set the backdrop to "140,30,30"
set the backdrop to none -- removes the backdrop
Value
| Name | Type | Description |
|---|---|---|
value | The backdrop is a color reference or a pattern specifier. The colorName is any standard color name. The RGBColor consists of three comma-separated integers between zero and 255, specifying the level of each of red, green, and blue; or an HTML-style color consisting of a hash mark (#) followed by three hexadecimal numbers, one for each of red, green, and blue. A patternNumber is a built-in pattern number between 1 and 164. These patterns are provided for compatability with patterns available in MetaCard and correspond to LiveCode's built in image id 137 to 300. As with MetaCard pattern numbers 105 to 114 and 146 and above are unavailable. An imageID is the ID of an image to use for a pattern. LiveCode looks for the specified image first in the current stack, then in other open stacks. By default, the backdrop is "none". |
Related
function: clickStack, stacks
glossary: property, command, hexadecimal, current stack, Windows, color reference, Mac OS, Unix, integer, background, application
keyword: image
message: mouseUpInBackdrop
property: raiseWindows, height, pixels, width
command: launch, open process
Compatibility and Support
Introduced
LiveCode 1.0
OS
mac
windows
linux
Platforms
desktop