Merge pull request #3219 from mempool/mononaut/momentum-scrolling

blockchain momentum scrolling
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softsimon 2023-03-04 15:09:14 +09:00 committed by GitHub
commit 0c8636c803
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@ -38,6 +38,9 @@ export class StartComponent implements OnInit, OnDestroy {
pageIndex: number = 0;
pages: any[] = [];
pendingMark: number | void = null;
lastUpdate: number = 0;
lastMouseX: number;
velocity: number = 0;
constructor(
private stateService: StateService,
@ -136,6 +139,7 @@ export class StartComponent implements OnInit, OnDestroy {
onMouseDown(event: MouseEvent) {
this.mouseDragStartX = event.clientX;
this.resetMomentum(event.clientX);
this.blockchainScrollLeftInit = this.blockchainContainer.nativeElement.scrollLeft;
}
onPointerDown(event: PointerEvent) {
@ -159,6 +163,7 @@ export class StartComponent implements OnInit, OnDestroy {
@HostListener('document:mousemove', ['$event'])
onMouseMove(event: MouseEvent): void {
if (this.mouseDragStartX != null) {
this.updateVelocity(event.clientX);
this.stateService.setBlockScrollingInProgress(true);
this.blockchainContainer.nativeElement.scrollLeft =
this.blockchainScrollLeftInit + this.mouseDragStartX - event.clientX;
@ -167,7 +172,7 @@ export class StartComponent implements OnInit, OnDestroy {
@HostListener('document:mouseup', [])
onMouseUp() {
this.mouseDragStartX = null;
this.stateService.setBlockScrollingInProgress(false);
this.animateMomentum();
}
@HostListener('document:pointermove', ['$event'])
onPointerMove(event: PointerEvent): void {
@ -183,6 +188,45 @@ export class StartComponent implements OnInit, OnDestroy {
}
}
resetMomentum(x: number) {
this.lastUpdate = performance.now();
this.lastMouseX = x;
this.velocity = 0;
}
updateVelocity(x: number) {
const now = performance.now();
let dt = now - this.lastUpdate;
if (dt > 0) {
this.lastUpdate = now;
const velocity = (x - this.lastMouseX) / dt;
this.velocity = (0.8 * this.velocity) + (0.2 * velocity);
this.lastMouseX = x;
}
}
animateMomentum() {
this.lastUpdate = performance.now();
requestAnimationFrame(() => {
const now = performance.now();
const dt = now - this.lastUpdate;
this.lastUpdate = now;
if (Math.abs(this.velocity) < 0.005) {
this.stateService.setBlockScrollingInProgress(false);
} else {
const deceleration = Math.max(0.0025, 0.001 * this.velocity * this.velocity) * (this.velocity > 0 ? -1 : 1);
const displacement = (this.velocity * dt) - (0.5 * (deceleration * dt * dt));
const dv = (deceleration * dt);
if ((this.velocity < 0 && dv + this.velocity > 0) || (this.velocity > 0 && dv + this.velocity < 0)) {
this.velocity = 0;
} else {
this.velocity += dv;
}
this.blockchainContainer.nativeElement.scrollLeft -= displacement;
this.animateMomentum();
}
});
}
onScroll(e) {
const middlePage = this.pageIndex === 0 ? this.pages[0] : this.pages[1];