Maintenance script: UI Lua API import (WAR 1.4.8)

2026-10-16T19:52:07Z

UI Lua API import (WAR 1.4.8)

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{{LuaApi|group=Window}}
Starts an animation of a window's alpha (opacity).

<pre>
WindowStartAlphaAnimation(windowName, animationType, startAlpha, endAlpha, duration, setStartBeforeDelay, delay, loopCount)
</pre>

== Arguments ==
;windowName : <code>string</code> – Name of the window.
;animationType : <code>number</code> – How the value changes over time. Use a <code>Window.AnimationType</code> constant (see below).
;startAlpha : <code>number</code> – Alpha at the start of the animation.
;endAlpha : <code>number</code> – Alpha at the end of the animation.
;duration : <code>number</code> – Length of one pass from <code>startAlpha</code> to <code>endAlpha</code>, in seconds.
;setStartBeforeDelay : <code>boolean</code> – <code>true</code> to apply <code>startAlpha</code> straight away, during the delay. With <code>false</code>, the window keeps its current alpha until the delay is over.
;delay : <code>number</code> – Seconds to wait before the animation starts.
;loopCount : <code>number</code> – For <code>LOOP</code> and <code>REPEAT</code>: how many passes to run before the animation ends. 0 runs until it is stopped. Ignored by the other types.

== Returns ==
Nothing.

== Details ==
* Animation types:
{| class="wikitable"
! Constant !! Value !! Behaviour
|-
| <code>Window.AnimationType.SINGLE</code> || 1 || Linear change from start to end, once. Then the window's alpha goes back to the value it had before the animation.
|-
| <code>Window.AnimationType.SINGLE_NO_RESET</code> || 2 || Linear change from start to end, once. The end value stays.
|-
| <code>Window.AnimationType.SINGLE_NO_RESET_HIDE</code> || 3 || Like <code>SINGLE_NO_RESET</code>, and the window is hidden when the animation finishes.
|-
| <code>Window.AnimationType.EASE_OUT</code> || 4 || Change from start to end along (time / duration)², so slow at first and fast at the end, once. The end value stays.
|-
| <code>Window.AnimationType.EASE_OUT_HIDE</code> || 5 || Like <code>EASE_OUT</code>, and the window is hidden when the animation finishes.
|-
| <code>Window.AnimationType.LOOP</code> || 6 || Linear back and forth: start to end, then back to start. One loop takes twice <code>duration</code>. When it ends, the original alpha is restored.
|-
| <code>Window.AnimationType.REPEAT</code> || 7 || Linear from start to end, then jumps back to start and repeats. When it ends, the original alpha is restored.
|-
| <code>Window.AnimationType.POP</code> || 8 || A special curve. When it ends, the original alpha is restored.
|-
| <code>Window.AnimationType.POP_AND_EASE</code> || 9 || A special curve. When it ends, the original alpha is restored.
|}
* Each frame the animated value is written to both the window's alpha and its font alpha, so the text fades too. Child windows follow as with [[API:WindowSetAlpha|WindowSetAlpha]] and [[API:WindowSetFontAlpha|WindowSetFontAlpha]].
* "Original alpha" means the window's alpha and font alpha at the moment the animation was started. Types 1 and 6–9 restore them both when they finish and when they are stopped with [[API:WindowStopAlphaAnimation|WindowStopAlphaAnimation]]. Types 2–5 leave the current value in place.
* The hiding of types 3 and 5 happens only when the animation finishes by itself, not when it is stopped.
* A window has at most one alpha animation. Starting a new one stops the old one first, including its reset.
* If both <code>duration</code> and <code>delay</code> are 0, the animation is finished immediately without applying <code>endAlpha</code>.
* <code>animationType</code> and <code>loopCount</code> are truncated to whole numbers.
* <code>easystem_windowutils/source/frame.lua</code> passes <code>false</code> for <code>setStartBeforeDelay</code> in a variable named <code>unsupportedParameter</code>, with the comment that it "does not appear to be used". The client does use it as described above.
* There is no lock check in this function.

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

== Example ==
A pulsing buff icon, from <code>eatemplate_unitframes/source/bufftracker.lua</code>:
<pre>
WindowStartAlphaAnimation( self:GetName(), Window.AnimationType.LOOP, 1, 0.5, 1, true, 0, 0 )
</pre>

Fading out combat text after a delay, from <code>easystem_eventtext/source/system_eventtext.lua</code>:
<pre>
WindowStartAlphaAnimation( newEventFrame:GetName(), Window.AnimationType.EASE_OUT,
1, 0,
animationData.fadeDuration, false, animationData.fadeDelay, 0 )
</pre>

== See also ==
* [[API:WindowStopAlphaAnimation|WindowStopAlphaAnimation]]
* [[API:WindowStartPositionAnimation|WindowStartPositionAnimation]]
* [[API:WindowStartScaleAnimation|WindowStartScaleAnimation]]
* [[API:WindowSetAlpha|WindowSetAlpha]]

API:WindowStartAlphaAnimation - Revision history

Maintenance script: UI Lua API import (WAR 1.4.8)