Daniel Imms
13175976d0
Bunch of types needed changing in this version, also the IOffscreenCanvas "support" in the canvas renderer was removed as we're moving away from that.
63 lines
2.0 KiB
TypeScript
63 lines
2.0 KiB
TypeScript
/**
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* Copyright (c) 2017 The xterm.js authors. All rights reserved.
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* @license MIT
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*/
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import { Disposable } from '../common/Lifecycle';
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export type ScreenDprListener = (newDevicePixelRatio?: number, oldDevicePixelRatio?: number) => void;
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/**
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* The screen device pixel ratio monitor allows listening for when the
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* window.devicePixelRatio value changes. This is done not with polling but with
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* the use of window.matchMedia to watch media queries. When the event fires,
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* the listener will be reattached using a different media query to ensure that
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* any further changes will register.
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*
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* The listener should fire on both window zoom changes and switching to a
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* monitor with a different DPI.
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*/
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export class ScreenDprMonitor extends Disposable {
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private _currentDevicePixelRatio: number;
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private _outerListener: (this: MediaQueryList, ev: MediaQueryListEvent) => any;
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private _listener: ScreenDprListener;
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private _resolutionMediaMatchList: MediaQueryList;
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public setListener(listener: ScreenDprListener): void {
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if (this._listener) {
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this.clearListener();
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}
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this._listener = listener;
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this._outerListener = () => {
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this._listener(window.devicePixelRatio, this._currentDevicePixelRatio);
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this._updateDpr();
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};
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this._updateDpr();
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}
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public dispose(): void {
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super.dispose();
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this.clearListener();
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}
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private _updateDpr(): void {
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// Clear listeners for old DPR
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if (this._resolutionMediaMatchList) {
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this._resolutionMediaMatchList.removeListener(this._outerListener);
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}
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// Add listeners for new DPR
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this._currentDevicePixelRatio = window.devicePixelRatio;
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this._resolutionMediaMatchList = window.matchMedia(`screen and (resolution: ${window.devicePixelRatio}dppx)`);
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this._resolutionMediaMatchList.addListener(this._outerListener);
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}
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public clearListener(): void {
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if (!this._listener) {
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return;
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}
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this._resolutionMediaMatchList.removeListener(this._outerListener);
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this._listener = null;
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this._outerListener = null;
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}
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}
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