Maintenance script: UI Lua API import (WAR 1.4.8)

2026-10-16T19:51:48Z

UI Lua API import (WAR 1.4.8)

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{{LuaApi|group=Window}}
Sets a window's alpha (opacity).

<pre>
WindowSetAlpha(windowName, alpha)
</pre>

== Arguments ==
;windowName : <code>string</code> – Name of the window.
;alpha : <code>number</code> – New alpha, from 0 (invisible) to 1 (opaque).

== Returns ==
Nothing.

== Details ==
* Values below 0 are stored as 0 and values above 1 as 1.
* If the window already has this alpha, nothing happens.
* The alpha the window is drawn with is its own alpha multiplied by the alpha of its parents. Child windows are updated, so fading a parent fades all of its children. The children keep their own alpha values; [[API:WindowGetAlpha|WindowGetAlpha]] on a child still returns the child's own value.
* Only the window's alpha changes. Text alpha is a separate setting; see [[API:WindowSetFontAlpha|WindowSetFontAlpha]].
* A running alpha animation overwrites the value on its next frame. Stop it first with [[API:WindowStopAlphaAnimation|WindowStopAlphaAnimation]].
* The function needs at least two arguments and only reads the last two.

== Errors ==
* <code>Error in function call 'WindowSetAlpha': Window %s does not exist</code>

== Example ==
Fading a tooltip, window and text together, from <code>easystem_tooltips/source/tooltips.lua</code>:
<pre>
function Tooltips.SetTooltipAlpha( alpha )
WindowSetAlpha( Tooltips.curTooltipWindow, alpha )
WindowSetFontAlpha( Tooltips.curTooltipWindow, alpha )
end
</pre>

== See also ==
* [[API:WindowGetAlpha|WindowGetAlpha]]
* [[API:WindowSetFontAlpha|WindowSetFontAlpha]]
* [[API:WindowStartAlphaAnimation|WindowStartAlphaAnimation]]

API:WindowSetAlpha - Revision history

Maintenance script: UI Lua API import (WAR 1.4.8)