From 7bd44128895b9fa4992142c0cc30cf75092cb794 Mon Sep 17 00:00:00 2001
From: Liam DeBeasi <liamdebeasi@users.noreply.github.com>
Date: Thu, 31 Oct 2019 12:50:54 -0400
Subject: [PATCH] fix(animation): track correctly when updating CSS Animation
 (#19813)

* fix bug

* update menu

* fix
---
 core/src/components/menu/menu.tsx             | 17 +++++++----
 .../utils/animation/animation-interface.ts    |  2 +-
 core/src/utils/animation/animation.ts         | 30 ++++++++++---------
 3 files changed, 28 insertions(+), 21 deletions(-)

diff --git a/core/src/components/menu/menu.tsx b/core/src/components/menu/menu.tsx
index 42cb233717..b632a935da 100644
--- a/core/src/components/menu/menu.tsx
+++ b/core/src/components/menu/menu.tsx
@@ -337,7 +337,12 @@ AFTER:
     const isReversed = !shouldOpen;
     const ani = (this.animation as Animation)!
       .direction((isReversed) ? 'reverse' : 'normal')
-      .easing((isReversed) ? this.easingReverse : this.easing);
+      .easing((isReversed) ? this.easingReverse : this.easing)
+      .onFinish(() => {
+        if (ani.getDirection() === 'reverse') {
+          ani.direction('normal');
+        }
+      });
 
     if (animated) {
       await ani.play();
@@ -384,9 +389,7 @@ AFTER:
     }
 
     // the cloned animation should not use an easing curve during seek
-    (this.animation as Animation)
-      .direction((this._isOpen) ? 'reverse' : 'normal')
-      .progressStart(true);
+    (this.animation as Animation).progressStart(true, (this._isOpen) ? 1 : 0);
   }
 
   private onMove(detail: GestureDetail) {
@@ -398,7 +401,7 @@ AFTER:
     const delta = computeDelta(detail.deltaX, this._isOpen, this.isEndSide);
     const stepValue = delta / this.width;
 
-    this.animation.progressStep(stepValue);
+    this.animation.progressStep((this._isOpen) ? 1 - stepValue : stepValue);
   }
 
   private onEnd(detail: GestureDetail) {
@@ -451,12 +454,14 @@ AFTER:
      */
     newStepValue += getTimeGivenProgression([0, 0], [0.4, 0], [0.6, 1], [1, 1], clamp(0, adjustedStepValue, 1))[0];
 
+    const playTo = (this._isOpen) ? !shouldComplete : shouldComplete;
+
     this.animation
       .easing('cubic-bezier(0.4, 0.0, 0.6, 1)')
       .onFinish(
         () => this.afterAnimation(shouldOpen),
         { oneTimeCallback: true })
-      .progressEnd(shouldComplete ? 1 : 0, newStepValue, 300);
+      .progressEnd((playTo) ? 1 : 0, (this._isOpen) ? 1 - newStepValue : newStepValue, 300);
   }
 
   private beforeAnimation(shouldOpen: boolean) {
diff --git a/core/src/utils/animation/animation-interface.ts b/core/src/utils/animation/animation-interface.ts
index 3ed04870b1..f856d2f261 100644
--- a/core/src/utils/animation/animation-interface.ts
+++ b/core/src/utils/animation/animation-interface.ts
@@ -29,7 +29,7 @@ export interface Animation {
    */
   destroy(): void;
 
-  progressStart(forceLinearEasing: boolean): void;
+  progressStart(forceLinearEasing: boolean, step?: number): void;
   progressStep(step: number): void;
   progressEnd(playTo: 0 | 1 | undefined, step: number, dur?: number): void;
 
diff --git a/core/src/utils/animation/animation.ts b/core/src/utils/animation/animation.ts
index e065119a23..baf677f838 100644
--- a/core/src/utils/animation/animation.ts
+++ b/core/src/utils/animation/animation.ts
@@ -19,7 +19,7 @@ interface AnimationInternal extends Animation {
   /**
    * Updates any existing animations.
    */
-  update(deep: boolean): Animation;
+  update(deep: boolean, toggleAnimationName: boolean, step?: number): Animation;
 
   animationFinish(): void;
 }
@@ -611,8 +611,7 @@ export const createAnimation = (animationId?: string): Animation => {
       });
 
     } else {
-      const animationDelay = getDelay() || 0;
-      const animationDuration = `-${animationDelay + (getDuration()! * step)}ms`;
+      const animationDuration = `-${getDuration()! * step}ms`;
 
       elements.forEach(element => {
         if (_keyframes.length > 0) {
@@ -623,7 +622,7 @@ export const createAnimation = (animationId?: string): Animation => {
     }
   };
 
-  const updateWebAnimation = () => {
+  const updateWebAnimation = (step?: number) => {
     webAnimations.forEach(animation => {
       animation.effect.updateTiming({
         delay: getDelay(),
@@ -634,15 +633,19 @@ export const createAnimation = (animationId?: string): Animation => {
         direction: getDirection()
       });
     });
+
+    if (step !== undefined) {
+      setAnimationStep(step);
+    }
   };
 
-  const updateCSSAnimation = (toggleAnimationName = true) => {
+  const updateCSSAnimation = (toggleAnimationName = true, step?: number) => {
     raf(() => {
       elements.forEach(element => {
         setStyleProperty(element, 'animation-name', keyframeName || null);
         setStyleProperty(element, 'animation-duration', `${getDuration()}ms`);
         setStyleProperty(element, 'animation-timing-function', getEasing());
-        setStyleProperty(element, 'animation-delay', `${getDelay()}ms`);
+        setStyleProperty(element, 'animation-delay', (step !== undefined) ? `-${step! * getDuration()}ms` : `${getDelay()}ms`);
         setStyleProperty(element, 'animation-fill-mode', getFill() || null);
         setStyleProperty(element, 'animation-direction', getDirection() || null);
 
@@ -663,25 +666,25 @@ export const createAnimation = (animationId?: string): Animation => {
     });
   };
 
-  const update = (deep = false, toggleAnimationName = true) => {
+  const update = (deep = false, toggleAnimationName = true, step?: number) => {
     if (deep) {
       childAnimations.forEach(animation => {
-        animation.update(deep);
+        animation.update(deep, toggleAnimationName, step);
       });
     }
 
     if (supportsWebAnimations) {
-      updateWebAnimation();
+      updateWebAnimation(step);
     } else {
-      updateCSSAnimation(toggleAnimationName);
+      updateCSSAnimation(toggleAnimationName, step);
     }
 
     return ani;
   };
 
-  const progressStart = (forceLinearEasing = false) => {
+  const progressStart = (forceLinearEasing = false, step?: number) => {
     childAnimations.forEach(animation => {
-      animation.progressStart(forceLinearEasing);
+      animation.progressStart(forceLinearEasing, step);
     });
 
     pauseAnimation();
@@ -690,8 +693,7 @@ export const createAnimation = (animationId?: string): Animation => {
     if (!initialized) {
       initializeAnimation();
     } else {
-      update();
-      setAnimationStep(0);
+      update(false, true, step);
     }
 
     return ani;