Start SelectionRenderLayer

src/renderer/SelectionRenderLayer.ts

@@ -0,0 +1,83 @@
+import { IRenderLayer } from './Interfaces';
+import { IBuffer, ICharMeasure, ITerminal } from '../Interfaces';
+import { CHAR_DATA_ATTR_INDEX } from '../Buffer';
+import { TANGO_COLORS } from './Color';
+import { GridCache } from './GridCache';
+import { FLAGS } from './Types';
+
+export class BackgroundRenderLayer implements IRenderLayer {
+  private _canvas: HTMLCanvasElement;
+  private _ctx: CanvasRenderingContext2D;
+  private _state: {start: [number, number], end: [number, number]};
+
+  constructor(container: HTMLElement) {
+    this._canvas = document.createElement('canvas');
+    this._canvas.classList.add('xterm-bg-layer');
+    this._ctx = this._canvas.getContext('2d');
+    this._ctx.scale(window.devicePixelRatio, window.devicePixelRatio);
+    this._ctx.fillStyle = 'rgba(255, 255, 255, 0.5)';
+    container.appendChild(this._canvas);
+    this._state = {
+      start: null,
+      end: null
+    };
+  }
+
+  public resize(terminal: ITerminal, canvasWidth: number, canvasHeight: number, charSizeChanged: boolean): void {
+    this._canvas.width = canvasWidth * window.devicePixelRatio;
+    this._canvas.height = canvasHeight * window.devicePixelRatio;
+    this._canvas.style.width = `${canvasWidth}px`;
+    this._canvas.style.height = `${canvasHeight}px`;
+  }
+
+  public render(terminal: ITerminal, startRow: number, endRow: number): void {
+    const scaledCharWidth = Math.ceil(terminal.charMeasure.width) * window.devicePixelRatio;
+    const scaledCharHeight = Math.ceil(terminal.charMeasure.height) * window.devicePixelRatio;
+
+    const start = terminal.selectionManager.selectionStart;
+    const end = terminal.selectionManager.selectionEnd;
+
+    // TODO: Need to redraw selection if the viewport has moved
+
+    // Selection has not changed
+    if (this._state.start === start || this._state.end === end) {
+      return;
+    }
+
+    // Remove all selections
+    this._ctx.clearRect(0, 0, this._canvas.width, this._canvas.height);
+
+    // Selection does not exist
+    if (!start || !end) {
+      return;
+    }
+
+    // Translate from buffer position to viewport position
+    const viewportStartRow = start[1] - terminal.buffer.ydisp;
+    const viewportEndRow = end[1] - terminal.buffer.ydisp;
+    const viewportCappedStartRow = Math.max(viewportStartRow, 0);
+    const viewportCappedEndRow = Math.min(viewportEndRow, terminal.rows - 1);
+
+    // No need to draw the selection
+    if (viewportCappedStartRow >= terminal.rows || viewportCappedEndRow < 0) {
+      return;
+    }
+
+    // Create the selections
+    // Draw first row
+    const startCol = viewportStartRow === viewportCappedStartRow ? start[0] : 0;
+    const endCol = viewportCappedStartRow === viewportCappedEndRow ? end[0] : terminal.cols;
+    this._ctx.fillRect(startCol * scaledCharWidth, viewportCappedStartRow * scaledCharHeight, (endCol - startCol) * scaledCharWidth, scaledCharHeight);
+    // documentFragment.appendChild(this._createSelectionElement(viewportCappedStartRow, startCol, endCol));
+    // Draw middle rows
+    // const middleRowsCount = viewportCappedEndRow - viewportCappedStartRow - 1;
+    // documentFragment.appendChild(this._createSelectionElement(viewportCappedStartRow + 1, 0, this._terminal.cols, middleRowsCount));
+    // // Draw final row
+    // if (viewportCappedStartRow !== viewportCappedEndRow) {
+    //   // Only draw viewportEndRow if it's not the same as viewporttartRow
+    //   const endCol = viewportEndRow === viewportCappedEndRow ? end[0] : this._terminal.cols;
+    //   documentFragment.appendChild(this._createSelectionElement(viewportCappedEndRow, 0, endCol));
+    // }
+    // this._terminal.selectionContainer.appendChild(documentFragment);
+  }
+}