From 915f1e2dd4a202fe0f0ccbf7857fa699d9aebb7f Mon Sep 17 00:00:00 2001
From: Robert Penner <robertpenner@microsoft.com>
Date: Fri, 27 Sep 2024 17:11:35 +0000
Subject: [PATCH] refactor(motion): simplify variant creation w/functional
 approach, starting with Collapse

---
 .../src/components/Collapse/Collapse.ts       | 104 +++++++++++-------
 .../library/src/types.ts                      |   7 ++
 .../react-motion/library/src/index.ts         |   1 +
 3 files changed, 70 insertions(+), 42 deletions(-)
 create mode 100644 packages/react-components/react-motion-components-preview/library/src/types.ts

diff --git a/packages/react-components/react-motion-components-preview/library/src/components/Collapse/Collapse.ts b/packages/react-components/react-motion-components-preview/library/src/components/Collapse/Collapse.ts
index 498884eb718f3..71244de0d3563 100644
--- a/packages/react-components/react-motion-components-preview/library/src/components/Collapse/Collapse.ts
+++ b/packages/react-components/react-motion-components-preview/library/src/components/Collapse/Collapse.ts
@@ -1,49 +1,69 @@
-import {
-  motionTokens,
-  type PresenceMotionFn,
-  createPresenceComponent,
-  createPresenceComponentVariant,
-} from '@fluentui/react-motion';
+import { motionTokens, createPresenceComponent } from '@fluentui/react-motion';
+import type { PresenceMotionFnCreator } from '../../types';
+
+const { durationNormal, durationSlower, durationFast, curveEasyEaseMax } = motionTokens;
+
+type CollapseVariantParams = {
+  /** Time (ms) for the enter transition (expand). Defaults to the `durationNormal` value (200 ms). */
+  enterDuration?: number;
+
+  /** Time (ms) for the exit transition (collapse). Defaults to the `durationNormal` value (200 ms). */
+  exitDuration?: number;
+
+  /** Easing curve for the enter transition (expand). Defaults to the `easeEaseMax` value.  */
+  enterEasing?: string;
+
+  /** Easing curve for the exit transition (expand). Defaults to the `easeEaseMax` value.  */
+  exitEasing?: string;
+};
+
+type CollapseRuntimeParams = {
+  /** Whether to animate the opacity. Defaults to `true`. */
+  animateOpacity?: boolean;
+};
 
 /** Define a presence motion for collapse/expand */
-const collapseMotion: PresenceMotionFn<{ animateOpacity?: boolean }> = ({ element, animateOpacity = true }) => {
-  const fromOpacity = animateOpacity ? 0 : 1;
-  const toOpacity = 1;
-  const fromHeight = '0'; // Could be a custom param in the future: start partially expanded
-  const toHeight = `${element.scrollHeight}px`;
-  const overflow = 'hidden';
-
-  const duration = motionTokens.durationNormal;
-  const easing = motionTokens.curveEasyEaseMax;
-
-  const enterKeyframes = [
-    { opacity: fromOpacity, maxHeight: fromHeight, overflow },
-    // Transition to the height of the content, at 99.99% of the duration.
-    { opacity: toOpacity, maxHeight: toHeight, offset: 0.9999, overflow },
-    // On completion, remove the maxHeight because the content might need to expand later.
-    // This extra keyframe is simpler than firing a callback on completion.
-    { opacity: toOpacity, maxHeight: 'unset', overflow },
-  ];
-
-  const exitKeyframes = [
-    { opacity: toOpacity, maxHeight: toHeight, overflow },
-    { opacity: fromOpacity, maxHeight: fromHeight, overflow },
-  ];
-
-  return {
-    enter: { duration, easing, keyframes: enterKeyframes },
-    exit: { duration, easing, keyframes: exitKeyframes },
+export const createCollapsePresence: PresenceMotionFnCreator<CollapseVariantParams, CollapseRuntimeParams> =
+  ({
+    enterDuration = durationNormal,
+    exitDuration = durationNormal,
+    enterEasing = curveEasyEaseMax,
+    exitEasing = curveEasyEaseMax,
+  } = {}) =>
+  ({ element, animateOpacity = true }) => {
+    const fromOpacity = animateOpacity ? 0 : 1;
+    const toOpacity = 1;
+    const fromHeight = '0'; // Could be a custom param in the future: start partially expanded
+    const toHeight = `${element.scrollHeight}px`;
+    const overflow = 'hidden';
+
+    const enterKeyframes = [
+      { opacity: fromOpacity, maxHeight: fromHeight, overflow },
+      // Transition to the height of the content, at 99.99% of the duration.
+      { opacity: toOpacity, maxHeight: toHeight, offset: 0.9999, overflow },
+      // On completion, remove the maxHeight because the content might need to expand later.
+      // This extra keyframe is simpler than firing a callback on completion.
+      { opacity: toOpacity, maxHeight: 'unset', overflow },
+    ];
+
+    const exitKeyframes = [
+      { opacity: toOpacity, maxHeight: toHeight, overflow },
+      { opacity: fromOpacity, maxHeight: fromHeight, overflow },
+    ];
+
+    return {
+      enter: { enterDuration, enterEasing, keyframes: enterKeyframes },
+      exit: { exitDuration, exitEasing, keyframes: exitKeyframes },
+    };
   };
-};
 
 /** A React component that applies collapse/expand transitions to its children. */
-export const Collapse = createPresenceComponent(collapseMotion);
+export const Collapse = createPresenceComponent(createCollapsePresence());
 
-export const CollapseSnappy = createPresenceComponentVariant(Collapse, {
-  all: { duration: motionTokens.durationUltraFast },
-});
+export const CollapseSnappy = createPresenceComponent(
+  createCollapsePresence({ enterDuration: durationFast, exitDuration: durationFast }),
+);
 
-export const CollapseExaggerated = createPresenceComponentVariant(Collapse, {
-  enter: { duration: motionTokens.durationSlow, easing: motionTokens.curveEasyEaseMax },
-  exit: { duration: motionTokens.durationNormal, easing: motionTokens.curveEasyEaseMax },
-});
+export const CollapseExaggerated = createPresenceComponent(
+  createCollapsePresence({ enterDuration: durationSlower, exitDuration: durationNormal }),
+);
diff --git a/packages/react-components/react-motion-components-preview/library/src/types.ts b/packages/react-components/react-motion-components-preview/library/src/types.ts
new file mode 100644
index 0000000000000..2cf74f7df01a0
--- /dev/null
+++ b/packages/react-components/react-motion-components-preview/library/src/types.ts
@@ -0,0 +1,7 @@
+import type { MotionParam, PresenceMotionFn } from '@fluentui/react-motion';
+
+// TODO: move to @fluentui/react-motion when stable
+export type PresenceMotionFnCreator<
+  MotionVariantParams extends Record<string, MotionParam> = {},
+  MotionRuntimeParams extends Record<string, MotionParam> = {},
+> = (variantParams?: MotionVariantParams) => PresenceMotionFn<MotionRuntimeParams>;
diff --git a/packages/react-components/react-motion/library/src/index.ts b/packages/react-components/react-motion/library/src/index.ts
index fe49b7011d977..74495e48de51a 100644
--- a/packages/react-components/react-motion/library/src/index.ts
+++ b/packages/react-components/react-motion/library/src/index.ts
@@ -19,6 +19,7 @@ export type {
   PresenceMotionFn,
   PresenceDirection,
   MotionImperativeRef,
+  MotionParam,
 } from './types';
 
 export { MotionBehaviourProvider } from './contexts/MotionBehaviourContext';