Underline links on hover

src/renderer/LinkRenderLayer.ts

@@ -0,0 +1,44 @@
+import { IColorSet } from './Interfaces';
+import { IBuffer, ICharMeasure, ITerminal, ILinkifierAccessor } from '../Interfaces';
+import { CHAR_DATA_ATTR_INDEX } from '../Buffer';
+import { GridCache } from './GridCache';
+import { FLAGS } from './Types';
+import { BaseRenderLayer, INVERTED_DEFAULT_COLOR } from './BaseRenderLayer';
+import { LinkHoverEvent, LinkHoverEventTypes } from '../Types';
+
+export class LinkRenderLayer extends BaseRenderLayer {
+  private _state: LinkHoverEvent = null;
+
+  constructor(container: HTMLElement, zIndex: number, colors: IColorSet, terminal: ILinkifierAccessor) {
+    super(container, 'link', zIndex, colors);
+    terminal.linkifier.on(LinkHoverEventTypes.HOVER, (e: LinkHoverEvent) => this._onLinkHover(e));
+    terminal.linkifier.on(LinkHoverEventTypes.LEAVE, (e: LinkHoverEvent) => this._onLinkLeave(e));
+  }
+
+  public resize(terminal: ITerminal, canvasWidth: number, canvasHeight: number, charSizeChanged: boolean): void {
+    super.resize(terminal, canvasWidth, canvasHeight, charSizeChanged);
+    // Resizing the canvas discards the contents of the canvas so clear state
+    this._state = null;
+  }
+
+  public reset(terminal: ITerminal): void {
+    this._clearCurrentLink();
+  }
+
+  private _clearCurrentLink(): void {
+    if (this._state) {
+      this.clearCells(this._state.x, this._state.y, this._state.length, 1);
+      this._state = null;
+    }
+  }
+
+  private _onLinkHover(e: LinkHoverEvent): void {
+    this._ctx.fillStyle = this.colors.foreground;
+    this.fillBottomLineAtCells(e.x, e.y, e.length);
+    this._state = e;
+  }
+
+  private _onLinkLeave(e: LinkHoverEvent): void {
+    this._clearCurrentLink();
+  }
+}