Simple Animation Controller with Timeline
Document and Examples https://anseki.github.io/anim-sequence/
Simple lightweight library for high performance animation in a web page, makes preparations for each frame and calls the frames with optimized timeline for animation.
animId = AnimSequence.add(valueCallback, frameCallback, duration, count, timing, reverse, timeRatio)Add new animation, and return animId that is used to start and remove the animation.
For example:
animId = AnimSequence.add(
function(outputRatio) {
return 80 + (680 - 80) * outputRatio + 'px';
},
function(value) {
element.style.left = value;
},
3000, 0, 'ease-in-out');Arguments:
Type: function or undefined
Default: undefined
value = valueCallback(outputRatio)A function that returns a value that is used to draw each frame.
For high performance animation, the function is called for all frames before the animation starts. That is, it makes preparations for each value that is used to draw the frame.
outputRatio is a number ranging from 0 to 1 to calculate a value.
The function can return something that is used to draw an frame. The value can be an Object or Array that contains multiple values.
For example, move an element rightward, it changes a left CSS property, from 80px to 680px.
// Return `80px` when `outputRatio` is `0%` (0), `680px` when `outputRatio` is `100%` (1).
function(outputRatio) {
// This value is used by `frameCallback` to draw a frame.
return 80 + (680 - 80) * outputRatio + 'px';
}Type: function
toNext = frameCallback(value, finish, timeRatio, outputRatio)A function that draws a frame.
The function is called when it should draw a frame, it draws a frame with passed arguments.
valueis something that was returned byvalueCallback.finishistrueif the function should draw a last frame.timeRatiois a number ranging from0to1to indicate the progress time of the animation played. It means also the ratio of the progress time andduration.outputRatiois the same as an argument ofvalueCallback.
If the function returns false, stop the animation forcedly.
For example, move an element rightward, it changes a left CSS property.
function(value, finish, timeRatio, outputRatio) {
element.style.left = value; // It was already calculated by `valueCallback`.
if (finish) {
element.style.backgroundColor = 'red'; // Change the color to red at the right.
}
}Type: number
A number determining how long (milliseconds) the animation will run.
Type: number
Default: 0
A number of times the animation should repeat. The animation will repeat forever if 0 is specified.
Type: Array or string
An Array that is [x1, y1, x2, y2] as a "timing function" that indicates how to change the speed. It works same as that of CSS animation.
You can specify one of the following keywords also. These values mean keywords for common timing functions.
easelinearease-inease-outease-in-out
Type: boolean
Default: false
The animation plays backward if true is specified.
It can be specified by AnimSequence.start also.
Type: number or boolean
Default: 0
A number ranging from 0 to 1 to play from the midst or false that prevents it starting.
It can be specified by AnimSequence.start also.
AnimSequence.remove(animId)Remove an animation.
Arguments:
Type: number
The animId that was returned by AnimSequence.add.
AnimSequence.start(animId, reverse, timeRatio)Start an animation.
Arguments:
Type: number
The animId that was returned by AnimSequence.add.
Type: boolean
Default: false
The animation plays backward if true is specified.
Type: number
Default: 0
A number ranging from 0 to 1 to play from the midst.
timeRatio = AnimSequence.stop(animId, getTimeRatioByFrame)Stop an animation.
timeRatio is a number ranging from 0 to 1 for restarting the animation from the frame that was stopped.
Arguments:
Type: number
The animId that was returned by AnimSequence.add.
Type: boolean
Default: false
If true is specified, return timeRatio of the last played frame.
isValid = AnimSequence.validTiming(timing)Check whether an Array or string as timing is valid.