fix: type improve

src/Animation.ts

@@ -3,7 +3,7 @@ import { Layer } from './Layer';
 import { IFrame, AnimationFn } from './types';
 import { Util } from './Util';
 
-var now = (function (): () => number {
+const now = (function (): () => number {
   if (glob.performance && glob.performance.now) {
     return function () {
       return glob.performance.now();
@@ -61,21 +61,12 @@ export class Animation {
    * @param {Konva.Layer|Array} [layers] layer(s) to be redrawn. Can be a layer, an array of layers, or null.  Not specifying a node will result in no redraw.
    * @return {Konva.Animation} this
    */
-  setLayers(layers) {
-    var lays = [];
+  setLayers(layers:null | Layer | Layer[]) {
+    let lays: Layer[] = [];
     // if passing in no layers
-    if (!layers) {
-      lays = [];
-    } else if (layers.length > 0) {
-      // if passing in an array of Layers
-      // NOTE: layers could be an array.  for simplicity, I'm just inspecting
-      // the length property to check for both cases
-      lays = layers;
-    } else {
-      // if passing in a Layer
-      lays = [layers];
+    if (layers) {
+      lays = Array.isArray(layers)? layers : [layers]
     }
-
     this.layers = lays;
     return this;
   }
@@ -95,13 +86,12 @@ export class Animation {
    * @param {Konva.Layer} layer to add
    * @return {Bool} true if layer is added to animation, otherwise false
    */
-  addLayer(layer) {
-    var layers = this.layers,
-      len = layers.length,
-      n;
+  addLayer(layer: Layer) {
+    const layers = this.layers
+    const len = layers.length
 
     // don't add the layer if it already exists
-    for (n = 0; n < len; n++) {
+    for (let n = 0; n < len; n++) {
       if (layers[n]._id === layer._id) {
         return false;
       }
@@ -117,12 +107,11 @@ export class Animation {
    * @return {Bool} is animation running?
    */
   isRunning() {
-    var a = Animation,
-      animations = a.animations,
-      len = animations.length,
-      n;
+    const a = Animation
+    const animations = a.animations
+    const len = animations.length
 
-    for (n = 0; n < len; n++) {
+    for (let n = 0; n < len; n++) {
       if (animations[n].id === this.id) {
         return true;
       }
@@ -152,7 +141,7 @@ export class Animation {
     Animation._removeAnimation(this);
     return this;
   }
-  _updateFrameObject(time) {
+  _updateFrameObject(time: number) {
     this.frame.timeDiff = time - this.frame.lastTime;
     this.frame.lastTime = time;
     this.frame.time += this.frame.timeDiff;
@@ -168,12 +157,11 @@ export class Animation {
     this._handleAnimation();
   }
   static _removeAnimation(anim) {
-    var id = anim.id,
-      animations = this.animations,
-      len = animations.length,
-      n;
+    const id = anim.id
+    const animations = this.animations
+    const len = animations.length
 
-    for (n = 0; n < len; n++) {
+    for (let n = 0; n < len; n++) {
       if (animations[n].id === id) {
         this.animations.splice(n, 1);
         break;
@@ -182,17 +170,8 @@ export class Animation {
   }
 
   static _runFrames() {
-    var layerHash = {},
-      animations = this.animations,
-      anim,
-      layers,
-      func,
-      n,
-      i,
-      layersLen,
-      layer,
-      key,
-      needRedraw;
+    const layerHash = {}
+    const animations = this.animations
     /*
      * loop through all animations and execute animation
      *  function.  if the animation object has specified node,
@@ -205,15 +184,16 @@ export class Animation {
      * the for loop is running, causing a JS error
      */
 
-    for (n = 0; n < animations.length; n++) {
-      anim = animations[n];
-      layers = anim.layers;
-      func = anim.func;
+    for (let n = 0; n < animations.length; n++) {
+      const anim = animations[n];
+      const layers = anim.layers;
+      const func = anim.func;
 
       anim._updateFrameObject(now());
-      layersLen = layers.length;
+      const layersLen = layers.length;
 
       // if animation object has a function, execute it
+      let needRedraw
       if (func) {
         // allow anim bypassing drawing
         needRedraw = func.call(anim, anim.frame) !== false;
@@ -223,24 +203,24 @@ export class Animation {
       if (!needRedraw) {
         continue;
       }
-      for (i = 0; i < layersLen; i++) {
-        layer = layers[i];
+      for (let i = 0; i < layersLen; i++) {
+        const layer = layers[i];
 
         if (layer._id !== undefined) {
           layerHash[layer._id] = layer;
         }
       }
     }
 
-    for (key in layerHash) {
+    for (let key in layerHash) {
       if (!layerHash.hasOwnProperty(key)) {
         continue;
       }
       layerHash[key].batchDraw();
     }
   }
   static _animationLoop() {
-    var Anim = Animation;
+    const Anim = Animation;
     if (Anim.animations.length) {
       Anim._runFrames();
       Util.requestAnimFrame(Anim._animationLoop);