ng2-fittext/src/ng2fittext.directive.ts
2017-06-19 11:42:53 +02:00

86 lines
2.8 KiB
TypeScript

import {Directive, ElementRef, Renderer, Input, AfterViewInit, HostListener, OnInit} from '@angular/core';
@Directive({
selector: '[fittext]'
})
export class Ng2FittextDirective implements AfterViewInit, OnInit {
@Input('fittext') fittext: any;
@Input('activateOnResize') activateOnResize: boolean;
@Input('container') container: any;
@Input('activateOnInputEvents') activateOnInputEvents: boolean;
@Input('useMaxFontSize') useMaxFontSize: boolean;
private maxFontSize: number = 1000;
private fontSize: number = 0;
private speed: number = 1.05;
constructor(public el: ElementRef, public renderer: Renderer) {
}
setFontSize(fontSize) {
this.fontSize = fontSize;
return this.el.nativeElement.style.setProperty('font-size', (fontSize).toString() + 'px');
}
calculateFontSize(fontSize, speed) {
// TODO Do with Gauss
return Math.floor(fontSize / speed);
}
checkOverflow(parent: any, children: any) {
let overflowX = children.scrollWidth - parent.clientWidth;
let overflowY = children.clientHeight - parent.clientHeight;
return (overflowX > 1 || overflowY > 1);
}
@HostListener('window:resize', ['$event'])
onResize() {
if (this.activateOnResize && this.fittext) {
if (this.activateOnInputEvents && this.fittext) {
this.setFontSize(this.container ? this.container.clientHeight : this.el.nativeElement.parentElement.clientHeight);
} else {
this.setFontSize(this.container ? this.container.clientWidth : this.el.nativeElement.parentElement.clientWidth);
}
this.ngAfterViewInit();
}
}
@HostListener('input', ['$event'])
onInputEvents() {
if (this.activateOnInputEvents && this.fittext) {
this.setFontSize(this.container ? this.container.clientHeight : this.el.nativeElement.parentElement.clientHeight);
this.ngAfterViewInit();
}
}
ngOnInit() {
if (this.useMaxFontSize) {
this.maxFontSize = parseInt(window.getComputedStyle(this.el.nativeElement).fontSize, null);
}
if (this.fittext) {
this.setFontSize(this.maxFontSize);
}
this.el.nativeElement.style.setProperty('will-change', 'content');
}
ngAfterViewInit() {
if (this.fittext) {
let overflow = this.container ? this.checkOverflow(this.container, this.el.nativeElement)
: this.checkOverflow(this.el.nativeElement.parentElement, this.el.nativeElement);
if (overflow) {
this.setFontSize(this.calculateFontSize(this.fontSize, this.speed));
if (this.useMaxFontSize) {
if(this.fontSize > this.maxFontSize){
this.maxFontSize = parseInt(window.getComputedStyle(this.el.nativeElement).fontSize, null);
this.setFontSize(this.maxFontSize);
}
}
this.ngAfterViewInit();
}
}
}
}