schmelczer-dev/src/page/background/background.ts
Schmelczer András 0429ea7f72 Add final touches
2020-01-10 20:11:10 +01:00

80 lines
2.3 KiB
TypeScript

import { PageElement } from '../../framework/page-element';
import { PageEvent, PageEventType } from '../../framework/events/page-event';
import { Blob } from './blob';
import { Random } from '../../framework/helper/random';
import { getHeight } from '../../framework/helper/get-height';
import { sum } from '../../framework/helper/sum';
export class PageBackground extends PageElement {
private readonly blobs: Array<Blob> = [];
private readonly blobSpacing = 350;
public constructor(private start: PageElement, private end: PageElement) {
super();
Blob.initialize(10, 30, 5);
}
protected handleEvent(event: PageEvent, parent: PageElement) {
switch (event.type) {
case PageEventType.onLoad:
this.bindListeners(parent);
break;
case PageEventType.onBodyDimensionsChanged:
this.resize(parent, event.data?.deltaHeight);
break;
case PageEventType.pageThemeChanged:
Blob.changeTheme(event.data);
this.blobs.forEach(b => b.decideColor());
break;
}
}
private bindListeners(parent: PageElement) {
window.addEventListener('resize', () => this.resize(parent));
window.addEventListener('load', () => this.resize(parent));
}
private resize(parent: PageElement, heightChange?: number) {
const siblings: Array<HTMLElement> = PageBackground.getSiblings(parent);
const width = document.body.clientWidth;
let height = sum(siblings.map(getHeight));
if (heightChange) {
height += heightChange;
}
const requiredBlobCount = Math.round(
(width * height) / this.blobSpacing ** 2
);
while (requiredBlobCount > this.blobs.length) {
const blob = new Blob();
parent.element.appendChild(blob.htmlElement);
this.blobs.push(blob);
}
const random = new Random(2662);
this.blobs.forEach((b, i) => {
if (i >= requiredBlobCount) {
b.hide();
} else {
b.transform(
random,
width,
parent.element.clientHeight,
height,
getHeight(this.start.element),
getHeight(this.end.element)
);
b.show();
}
});
}
private static getSiblings(parent: PageElement): Array<HTMLElement> {
return Array.prototype.slice
.call(parent.element.children)
.filter((e: HTMLElement) => !e.classList.contains('background-element'));
}
}