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xterm.js/addons/xterm-addon-webgl/src/renderLayer/BaseRenderLayer.ts
T

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8.9 KiB
TypeScript

/**
* Copyright (c) 2017 The xterm.js authors. All rights reserved.
* @license MIT
*/
import { IRenderLayer } from './Types';
import { acquireCharAtlas } from '../atlas/CharAtlasCache';
import { Terminal } from 'xterm';
import { IColorSet } from 'browser/Types';
import { IRenderDimensions } from 'browser/renderer/Types';
import { CellData } from 'common/buffer/CellData';
import { WebglCharAtlas } from 'atlas/WebglCharAtlas';
import { throwIfFalsy } from '../WebglUtils';
export abstract class BaseRenderLayer implements IRenderLayer {
private _canvas: HTMLCanvasElement;
protected _ctx!: CanvasRenderingContext2D;
private _scaledCharWidth: number = 0;
private _scaledCharHeight: number = 0;
private _scaledCellWidth: number = 0;
private _scaledCellHeight: number = 0;
private _scaledCharLeft: number = 0;
private _scaledCharTop: number = 0;
protected _charAtlas: WebglCharAtlas | undefined;
constructor(
private _container: HTMLElement,
id: string,
zIndex: number,
private _alpha: boolean,
protected _colors: IColorSet
) {
this._canvas = document.createElement('canvas');
this._canvas.classList.add(`xterm-${id}-layer`);
this._canvas.style.zIndex = zIndex.toString();
this._initCanvas();
this._container.appendChild(this._canvas);
}
public dispose(): void {
this._container.removeChild(this._canvas);
if (this._charAtlas) {
this._charAtlas.dispose();
}
}
private _initCanvas(): void {
this._ctx = throwIfFalsy(this._canvas.getContext('2d', {alpha: this._alpha}));
// Draw the background if this is an opaque layer
if (!this._alpha) {
this._clearAll();
}
}
public onOptionsChanged(terminal: Terminal): void {}
public onBlur(terminal: Terminal): void {}
public onFocus(terminal: Terminal): void {}
public onCursorMove(terminal: Terminal): void {}
public onGridChanged(terminal: Terminal, startRow: number, endRow: number): void {}
public onSelectionChanged(terminal: Terminal, start: [number, number], end: [number, number], columnSelectMode: boolean = false): void {}
public setColors(terminal: Terminal, colorSet: IColorSet): void {
this._refreshCharAtlas(terminal, colorSet);
}
protected _setTransparency(terminal: Terminal, alpha: boolean): void {
// Do nothing when alpha doesn't change
if (alpha === this._alpha) {
return;
}
// Create new canvas and replace old one
const oldCanvas = this._canvas;
this._alpha = alpha;
// Cloning preserves properties
this._canvas = this._canvas.cloneNode() as HTMLCanvasElement;
this._initCanvas();
this._container.replaceChild(this._canvas, oldCanvas);
// Regenerate char atlas and force a full redraw
this._refreshCharAtlas(terminal, this._colors);
this.onGridChanged(terminal, 0, terminal.rows - 1);
}
/**
* Refreshes the char atlas, aquiring a new one if necessary.
* @param terminal The terminal.
* @param colorSet The color set to use for the char atlas.
*/
private _refreshCharAtlas(terminal: Terminal, colorSet: IColorSet): void {
if (this._scaledCharWidth <= 0 && this._scaledCharHeight <= 0) {
return;
}
this._charAtlas = acquireCharAtlas(terminal, colorSet, this._scaledCharWidth, this._scaledCharHeight);
this._charAtlas.warmUp();
}
public resize(terminal: Terminal, dim: IRenderDimensions): void {
this._scaledCellWidth = dim.scaledCellWidth;
this._scaledCellHeight = dim.scaledCellHeight;
this._scaledCharWidth = dim.scaledCharWidth;
this._scaledCharHeight = dim.scaledCharHeight;
this._scaledCharLeft = dim.scaledCharLeft;
this._scaledCharTop = dim.scaledCharTop;
this._canvas.width = dim.scaledCanvasWidth;
this._canvas.height = dim.scaledCanvasHeight;
this._canvas.style.width = `${dim.canvasWidth}px`;
this._canvas.style.height = `${dim.canvasHeight}px`;
// Draw the background if this is an opaque layer
if (!this._alpha) {
this._clearAll();
}
this._refreshCharAtlas(terminal, this._colors);
}
public abstract reset(terminal: Terminal): void;
/**
* Fills 1+ cells completely. This uses the existing fillStyle on the context.
* @param x The column to start at.
* @param y The row to start at
* @param width The number of columns to fill.
* @param height The number of rows to fill.
*/
protected _fillCells(x: number, y: number, width: number, height: number): void {
this._ctx.fillRect(
x * this._scaledCellWidth,
y * this._scaledCellHeight,
width * this._scaledCellWidth,
height * this._scaledCellHeight);
}
/**
* Fills a 1px line (2px on HDPI) at the bottom of the cell. This uses the
* existing fillStyle on the context.
* @param x The column to fill.
* @param y The row to fill.
*/
protected _fillBottomLineAtCells(x: number, y: number, width: number = 1): void {
this._ctx.fillRect(
x * this._scaledCellWidth,
(y + 1) * this._scaledCellHeight - window.devicePixelRatio - 1 /* Ensure it's drawn within the cell */,
width * this._scaledCellWidth,
window.devicePixelRatio);
}
/**
* Fills a 1px line (2px on HDPI) at the left of the cell. This uses the
* existing fillStyle on the context.
* @param x The column to fill.
* @param y The row to fill.
*/
protected _fillLeftLineAtCell(x: number, y: number, width: number): void {
this._ctx.fillRect(
x * this._scaledCellWidth,
y * this._scaledCellHeight,
window.devicePixelRatio * width,
this._scaledCellHeight);
}
/**
* Strokes a 1px rectangle (2px on HDPI) around a cell. This uses the existing
* strokeStyle on the context.
* @param x The column to fill.
* @param y The row to fill.
*/
protected _strokeRectAtCell(x: number, y: number, width: number, height: number): void {
this._ctx.lineWidth = window.devicePixelRatio;
this._ctx.strokeRect(
x * this._scaledCellWidth + window.devicePixelRatio / 2,
y * this._scaledCellHeight + (window.devicePixelRatio / 2),
width * this._scaledCellWidth - window.devicePixelRatio,
(height * this._scaledCellHeight) - window.devicePixelRatio);
}
/**
* Clears the entire canvas.
*/
protected _clearAll(): void {
if (this._alpha) {
this._ctx.clearRect(0, 0, this._canvas.width, this._canvas.height);
} else {
this._ctx.fillStyle = this._colors.background.css;
this._ctx.fillRect(0, 0, this._canvas.width, this._canvas.height);
}
}
/**
* Clears 1+ cells completely.
* @param x The column to start at.
* @param y The row to start at.
* @param width The number of columns to clear.
* @param height The number of rows to clear.
*/
protected _clearCells(x: number, y: number, width: number, height: number): void {
if (this._alpha) {
this._ctx.clearRect(
x * this._scaledCellWidth,
y * this._scaledCellHeight,
width * this._scaledCellWidth,
height * this._scaledCellHeight);
} else {
this._ctx.fillStyle = this._colors.background.css;
this._ctx.fillRect(
x * this._scaledCellWidth,
y * this._scaledCellHeight,
width * this._scaledCellWidth,
height * this._scaledCellHeight);
}
}
/**
* Draws a truecolor character at the cell. The character will be clipped to
* ensure that it fits with the cell, including the cell to the right if it's
* a wide character. This uses the existing fillStyle on the context.
* @param terminal The terminal.
* @param cell The cell data for the character to draw.
* @param x The column to draw at.
* @param y The row to draw at.
* @param color The color of the character.
*/
protected _fillCharTrueColor(terminal: Terminal, cell: CellData, x: number, y: number): void {
this._ctx.font = this._getFont(terminal, false, false);
this._ctx.textBaseline = 'middle';
this._clipRow(terminal, y);
this._ctx.fillText(
cell.getChars(),
x * this._scaledCellWidth + this._scaledCharLeft,
y * this._scaledCellHeight + this._scaledCharTop + this._scaledCharHeight / 2);
}
/**
* Clips a row to ensure no pixels will be drawn outside the cells in the row.
* @param terminal The terminal.
* @param y The row to clip.
*/
private _clipRow(terminal: Terminal, y: number): void {
this._ctx.beginPath();
this._ctx.rect(
0,
y * this._scaledCellHeight,
terminal.cols * this._scaledCellWidth,
this._scaledCellHeight);
this._ctx.clip();
}
/**
* Gets the current font.
* @param terminal The terminal.
* @param isBold If we should use the bold fontWeight.
*/
protected _getFont(terminal: Terminal, isBold: boolean, isItalic: boolean): string {
const fontWeight = isBold ? terminal.getOption('fontWeightBold') : terminal.getOption('fontWeight');
const fontStyle = isItalic ? 'italic' : '';
return `${fontStyle} ${fontWeight} ${terminal.getOption('fontSize') * window.devicePixelRatio}px ${terminal.getOption('fontFamily')}`;
}
}