Files
2018-09-01 17:23:03 +02:00

363 lines
9.1 KiB
TypeScript

import { Component, Element, Event, EventEmitter, Listen, Method, Prop, QueueApi } from '@stencil/core';
import { Color, Config, Mode, ScrollBaseDetail, ScrollDetail } from '../../interface';
import { createColorClasses } from '../../utils/theme';
@Component({
tag: 'ion-content',
styleUrl: 'content.scss',
shadow: true
})
export class Content {
private watchDog: any;
private isScrolling = false;
private lastScroll = 0;
private queued = false;
private cTop = -1;
private cBottom = -1;
private scrollEl!: HTMLElement;
// Detail is used in a hot loop in the scroll event, by allocating it here
// V8 will be able to inline any read/write to it since it's a monomorphic class.
// https://mrale.ph/blog/2015/01/11/whats-up-with-monomorphism.html
private detail: ScrollDetail = {
scrollTop: 0,
scrollLeft: 0,
type: 'scroll',
event: undefined!,
startX: 0,
startY: 0,
startTimeStamp: 0,
currentX: 0,
currentY: 0,
velocityX: 0,
velocityY: 0,
deltaX: 0,
deltaY: 0,
timeStamp: 0,
data: undefined,
isScrolling: true,
};
mode!: Mode;
@Prop() color?: Color;
@Element() el!: HTMLStencilElement;
@Prop({ context: 'config' }) config!: Config;
@Prop({ context: 'queue' }) queue!: QueueApi;
@Prop({ context: 'window' }) win!: Window;
/**
* If true, the content will scroll behind the headers
* and footers. This effect can easily be seen by setting the toolbar
* to transparent.
*/
@Prop() fullscreen = false;
/**
* If true and the content does not cause an overflow scroll, the scroll interaction will cause a bounce.
* If the content exceeds the bounds of ionContent, nothing will change.
* Note, the does not disable the system bounce on iOS. That is an OS level setting.
*/
@Prop({ mutable: true }) forceOverscroll?: boolean;
/**
* If you want to enable the content scrolling in the X axis, set this property to `true`.
*/
@Prop() scrollX = false;
/**
* If you want to disable the content scrolling in the Y axis, set this property to `false`.
*/
@Prop() scrollY = true;
/**
* Because of performance reasons, ionScroll events are disabled by default, in order to enable them
* and start listening from (ionScroll), set this property to `true`.
*/
@Prop() scrollEvents = false;
/**
* Emitted when the scroll has started.
*/
@Event() ionScrollStart!: EventEmitter<ScrollBaseDetail>;
/**
* Emitted while scrolling. This event is disabled by default.
* Look at the property: `scrollEvents`
*/
@Event() ionScroll!: EventEmitter<ScrollDetail>;
/**
* Emitted when the scroll has ended.
*/
@Event() ionScrollEnd!: EventEmitter<ScrollBaseDetail>;
@Listen('body:ionNavDidChange')
onNavChanged() {
this.resize();
}
componentWillLoad() {
if (this.forceOverscroll === undefined) {
this.forceOverscroll = this.mode === 'ios' && ('ontouchstart' in this.win);
}
}
componentDidLoad() {
this.resize();
}
componentDidUnload() {
if (this.watchDog) {
clearInterval(this.watchDog);
}
}
private resize() {
if (this.fullscreen) {
this.queue.read(this.readDimensions.bind(this));
} else if (this.cTop !== 0 || this.cBottom !== 0) {
this.cTop = this.cBottom = 0;
this.el.forceUpdate();
}
}
private readDimensions() {
const page = getPageElement(this.el);
const top = Math.max(this.el.offsetTop, 0);
const bottom = Math.max(page.offsetHeight - top - this.el.offsetHeight, 0);
const dirty = top !== this.cTop || bottom !== this.cBottom;
if (dirty) {
this.cTop = top;
this.cBottom = bottom;
this.el.forceUpdate();
}
}
private onScroll(ev: UIEvent) {
const timeStamp = Date.now();
const shouldStart = !this.isScrolling;
this.lastScroll = timeStamp;
if (shouldStart) {
this.onScrollStart();
}
if (!this.queued && this.scrollEvents) {
this.queued = true;
this.queue.read(ts => {
this.queued = false;
this.detail.event = ev;
updateScrollDetail(this.detail, this.scrollEl, ts, shouldStart);
this.ionScroll.emit(this.detail);
});
}
}
@Method()
getScrollElement(): Promise<HTMLElement> {
return Promise.resolve(this.scrollEl);
}
/**
* Scroll to the top of the component
*/
@Method()
scrollToTop(duration = 0): Promise<void> {
return this.scrollToPoint(undefined, 0, duration);
}
/**
* Scroll to the bottom of the component
*/
@Method()
scrollToBottom(duration = 0): Promise<void> {
const y = this.scrollEl.scrollHeight - this.scrollEl.clientHeight;
return this.scrollToPoint(undefined, y, duration);
}
/**
* Scroll by a specified X/Y distance in the component
*/
@Method()
scrollByPoint(x: number, y: number, duration: number): Promise<void> {
return this.scrollToPoint(x + this.scrollEl.scrollLeft, y + this.scrollEl.scrollTop, duration);
}
/**
* Scroll to a specified X/Y location in the component
*/
@Method()
async scrollToPoint(x: number | undefined | null, y: number | undefined | null, duration = 0): Promise<void> {
const el = this.scrollEl;
if (duration < 32) {
if (y != null) {
el.scrollTop = y;
}
if (x != null) {
el.scrollLeft = x;
}
return;
}
let resolve!: () => void;
let startTime = 0;
const promise = new Promise<void>(r => resolve = r);
const fromY = el.scrollTop;
const fromX = el.scrollLeft;
const deltaY = y != null ? y - fromY : 0;
const deltaX = x != null ? x - fromX : 0;
// scroll loop
const step = (timeStamp: number) => {
const linearTime = Math.min(1, ((timeStamp - startTime) / duration)) - 1;
const easedT = Math.pow(linearTime, 3) + 1;
if (deltaY !== 0) {
el.scrollTop = Math.floor((easedT * deltaY) + fromY);
}
if (deltaX !== 0) {
el.scrollLeft = Math.floor((easedT * deltaX) + fromX);
}
if (easedT < 1) {
// do not use DomController here
// must use nativeRaf in order to fire in the next frame
// TODO: remove as any
requestAnimationFrame(step);
} else {
resolve();
}
};
// chill out for a frame first
requestAnimationFrame(ts => {
startTime = ts;
step(ts);
});
return promise;
}
private onScrollStart() {
this.isScrolling = true;
this.ionScrollStart.emit({
isScrolling: true
});
if (this.watchDog) {
clearInterval(this.watchDog);
}
// watchdog
this.watchDog = setInterval(() => {
if (this.lastScroll < Date.now() - 120) {
this.onScrollEnd();
}
}, 100);
}
private onScrollEnd() {
clearInterval(this.watchDog);
this.watchDog = null;
this.isScrolling = false;
this.ionScrollEnd.emit({
isScrolling: false
});
}
hostData() {
return {
class: {
...createColorClasses(this.color),
'overscroll': this.forceOverscroll,
},
style: {
'--offset-top': `${this.cTop}px`,
'--offset-bottom': `${this.cBottom}px`,
}
};
}
render() {
const { scrollX, scrollY, forceOverscroll } = this;
this.resize();
return [
<div
class={{
'inner-scroll': true,
'scroll-x': scrollX,
'scroll-y': scrollY,
'overscroll': (scrollX || scrollY) && !!forceOverscroll
}}
ref={el => this.scrollEl = el!}
onScroll={ev => this.onScroll(ev)}>
<slot></slot>
</div>,
<slot name="fixed"></slot>
];
}
}
function getParentElement(el: any) {
if (el.parentElement) {
// normal element with a parent element
return el.parentElement;
}
if (el.parentNode && el.parentNode.host) {
// shadow dom's document fragment
return el.parentNode.host;
}
return null;
}
function getPageElement(el: HTMLElement) {
const tabs = el.closest('ion-tabs');
if (tabs) {
return tabs;
}
const page = el.closest('ion-app,ion-page,.ion-page,page-inner');
if (page) {
return page;
}
return getParentElement(el);
}
// ******** DOM READ ****************
function updateScrollDetail(
detail: ScrollDetail,
el: Element,
timestamp: number,
shouldStart: boolean
) {
const prevX = detail.currentX;
const prevY = detail.currentY;
const prevT = detail.timeStamp;
const currentX = el.scrollLeft;
const currentY = el.scrollTop;
if (shouldStart) {
// remember the start positions
detail.startTimeStamp = timestamp;
detail.startX = currentX;
detail.startY = currentY;
detail.velocityX = detail.velocityY = 0;
}
detail.timeStamp = timestamp;
detail.currentX = detail.scrollLeft = currentX;
detail.currentY = detail.scrollTop = currentY;
detail.deltaX = currentX - detail.startX;
detail.deltaY = currentY - detail.startY;
const timeDelta = timestamp - prevT;
if (timeDelta > 0 && timeDelta < 100) {
const velocityX = (currentX - prevX) / timeDelta;
const velocityY = (currentY - prevY) / timeDelta;
detail.velocityX = velocityX * 0.7 + detail.velocityX * 0.3;
detail.velocityY = velocityY * 0.7 + detail.velocityY * 0.3;
}
}