Merge branch 'master' into #4121

src/browser/AccessibilityManager.ts

@@ -8,16 +8,32 @@ import { ITerminal, IRenderDebouncer } from 'browser/Types';
 import { isMac } from 'common/Platform';
 import { TimeBasedDebouncer } from 'browser/TimeBasedDebouncer';
 import { Disposable, toDisposable } from 'common/Lifecycle';
+import { ScreenDprMonitor } from 'browser/ScreenDprMonitor';
+import { IRenderService } from 'browser/services/Services';
+import { addDisposableDomListener } from 'browser/Lifecycle';
 
 const MAX_ROWS_TO_READ = 20;
 
+const enum BoundaryPosition {
+  TOP,
+  BOTTOM
+}
+
 export class AccessibilityManager extends Disposable {
   private _accessibilityContainer: HTMLElement;
 
+  private _rowContainer: HTMLElement;
+  private _rowElements: HTMLElement[];
+
   private _liveRegion: HTMLElement;
   private _liveRegionLineCount: number = 0;
   private _liveRegionDebouncer: IRenderDebouncer;
 
+  private _screenDprMonitor: ScreenDprMonitor;
+
+  private _topBoundaryFocusListener: (e: FocusEvent) => void;
+  private _bottomBoundaryFocusListener: (e: FocusEvent) => void;
+
   /**
    * This queue has a character pushed to it for keys that are pressed, if the
    * next character added to the terminal is equal to the key char then it is
@@ -32,12 +48,30 @@ export class AccessibilityManager extends Disposable {
   private _charsToAnnounce: string = '';
 
   constructor(
-    private readonly _terminal: ITerminal
+    private readonly _terminal: ITerminal,
+    @IRenderService private readonly _renderService: IRenderService
   ) {
     super();
     this._accessibilityContainer = document.createElement('div');
     this._accessibilityContainer.classList.add('xterm-accessibility');
 
+    this._rowContainer = document.createElement('div');
+    this._rowContainer.setAttribute('role', 'list');
+    this._rowContainer.classList.add('xterm-accessibility-tree');
+    this._rowElements = [];
+    for (let i = 0; i < this._terminal.rows; i++) {
+      this._rowElements[i] = this._createAccessibilityTreeNode();
+      this._rowContainer.appendChild(this._rowElements[i]);
+    }
+
+    this._topBoundaryFocusListener = e => this._handleBoundaryFocus(e, BoundaryPosition.TOP);
+    this._bottomBoundaryFocusListener = e => this._handleBoundaryFocus(e, BoundaryPosition.BOTTOM);
+    this._rowElements[0].addEventListener('focus', this._topBoundaryFocusListener);
+    this._rowElements[this._rowElements.length - 1].addEventListener('focus', this._bottomBoundaryFocusListener);
+
+    this._refreshRowsDimensions();
+    this._accessibilityContainer.appendChild(this._rowContainer);
+
     this._liveRegion = document.createElement('div');
     this._liveRegion.classList.add('live-region');
     this._liveRegion.setAttribute('aria-live', 'assertive');
@@ -50,6 +84,7 @@ export class AccessibilityManager extends Disposable {
     this._terminal.element.insertAdjacentElement('afterbegin', this._accessibilityContainer);
 
     this.register(this._liveRegionDebouncer);
+    this.register(this._terminal.onResize(e => this._handleResize(e.rows)));
     this.register(this._terminal.onRender(e => this._refreshRows(e.start, e.end)));
     this.register(this._terminal.onScroll(() => this._refreshRows()));
     // Line feed is an issue as the prompt won't be read out after a command is run
@@ -58,7 +93,20 @@ export class AccessibilityManager extends Disposable {
     this.register(this._terminal.onA11yTab(spaceCount => this._handleTab(spaceCount)));
     this.register(this._terminal.onKey(e => this._handleKey(e.key)));
     this.register(this._terminal.onBlur(() => this._clearLiveRegion()));
-    this.register(toDisposable(() => this._accessibilityContainer.remove()));
+    this.register(this._renderService.onDimensionsChange(() => this._refreshRowsDimensions()));
+
+    this._screenDprMonitor = new ScreenDprMonitor(window);
+    this.register(this._screenDprMonitor);
+    this._screenDprMonitor.setListener(() => this._refreshRowsDimensions());
+    // This shouldn't be needed on modern browsers but is present in case the
+    // media query that drives the ScreenDprMonitor isn't supported
+    this.register(addDisposableDomListener(window, 'resize', () => this._refreshRowsDimensions()));
+
+    this._refreshRows();
+    this.register(toDisposable(() => {
+      this._accessibilityContainer.remove();
+      this._rowElements.length = 0;
+    }));
   }
 
   private _handleTab(spaceCount: number): void {
@@ -126,4 +174,107 @@ export class AccessibilityManager extends Disposable {
     this._liveRegion.textContent += this._charsToAnnounce;
     this._charsToAnnounce = '';
   }
+
+  private _handleBoundaryFocus(e: FocusEvent, position: BoundaryPosition): void {
+    const boundaryElement = e.target as HTMLElement;
+    const beforeBoundaryElement = this._rowElements[position === BoundaryPosition.TOP ? 1 : this._rowElements.length - 2];
+
+    // Don't scroll if the buffer top has reached the end in that direction
+    const posInSet = boundaryElement.getAttribute('aria-posinset');
+    const lastRowPos = position === BoundaryPosition.TOP ? '1' : `${this._terminal.buffer.lines.length}`;
+    if (posInSet === lastRowPos) {
+      return;
+    }
+
+    // Don't scroll when the last focused item was not the second row (focus is going the other
+    // direction)
+    if (e.relatedTarget !== beforeBoundaryElement) {
+      return;
+    }
+
+    // Remove old boundary element from array
+    let topBoundaryElement: HTMLElement;
+    let bottomBoundaryElement: HTMLElement;
+    if (position === BoundaryPosition.TOP) {
+      topBoundaryElement = boundaryElement;
+      bottomBoundaryElement = this._rowElements.pop()!;
+      this._rowContainer.removeChild(bottomBoundaryElement);
+    } else {
+      topBoundaryElement = this._rowElements.shift()!;
+      bottomBoundaryElement = boundaryElement;
+      this._rowContainer.removeChild(topBoundaryElement);
+    }
+
+    // Remove listeners from old boundary elements
+    topBoundaryElement.removeEventListener('focus', this._topBoundaryFocusListener);
+    bottomBoundaryElement.removeEventListener('focus', this._bottomBoundaryFocusListener);
+
+    // Add new element to array/DOM
+    if (position === BoundaryPosition.TOP) {
+      const newElement = this._createAccessibilityTreeNode();
+      this._rowElements.unshift(newElement);
+      this._rowContainer.insertAdjacentElement('afterbegin', newElement);
+    } else {
+      const newElement = this._createAccessibilityTreeNode();
+      this._rowElements.push(newElement);
+      this._rowContainer.appendChild(newElement);
+    }
+
+    // Add listeners to new boundary elements
+    this._rowElements[0].addEventListener('focus', this._topBoundaryFocusListener);
+    this._rowElements[this._rowElements.length - 1].addEventListener('focus', this._bottomBoundaryFocusListener);
+
+    // Scroll up
+    this._terminal.scrollLines(position === BoundaryPosition.TOP ? -1 : 1);
+
+    // Focus new boundary before element
+    this._rowElements[position === BoundaryPosition.TOP ? 1 : this._rowElements.length - 2].focus();
+
+    // Prevent the standard behavior
+    e.preventDefault();
+    e.stopImmediatePropagation();
+  }
+
+  private _handleResize(rows: number): void {
+    // Remove bottom boundary listener
+    this._rowElements[this._rowElements.length - 1].removeEventListener('focus', this._bottomBoundaryFocusListener);
+
+    // Grow rows as required
+    for (let i = this._rowContainer.children.length; i < this._terminal.rows; i++) {
+      this._rowElements[i] = this._createAccessibilityTreeNode();
+      this._rowContainer.appendChild(this._rowElements[i]);
+    }
+    // Shrink rows as required
+    while (this._rowElements.length > rows) {
+      this._rowContainer.removeChild(this._rowElements.pop()!);
+    }
+
+    // Add bottom boundary listener
+    this._rowElements[this._rowElements.length - 1].addEventListener('focus', this._bottomBoundaryFocusListener);
+
+    this._refreshRowsDimensions();
+  }
+
+  private _createAccessibilityTreeNode(): HTMLElement {
+    const element = document.createElement('div');
+    element.setAttribute('role', 'listitem');
+    element.tabIndex = -1;
+    this._refreshRowDimensions(element);
+    return element;
+  }
+  private _refreshRowsDimensions(): void {
+    if (!this._renderService.dimensions.css.cell.height) {
+      return;
+    }
+    this._accessibilityContainer.style.width = `${this._renderService.dimensions.css.canvas.width}px`;
+    if (this._rowElements.length !== this._terminal.rows) {
+      this._handleResize(this._terminal.rows);
+    }
+    for (let i = 0; i < this._terminal.rows; i++) {
+      this._refreshRowDimensions(this._rowElements[i]);
+    }
+  }
+  private _refreshRowDimensions(element: HTMLElement): void {
+    element.style.height = `${this._renderService.dimensions.css.cell.height}px`;
+  }
 }

src/browser/decorations/BufferDecorationRenderer.ts

@@ -72,6 +72,7 @@ export class BufferDecorationRenderer extends Disposable {
   private _createElement(decoration: IInternalDecoration): HTMLElement {
     const element = document.createElement('div');
     element.classList.add('xterm-decoration');
+    element.classList.toggle('xterm-decoration-top-layer', decoration?.options?.layer === 'top');
     element.style.width = `${Math.round((decoration.options.width || 1) * this._renderService.dimensions.css.cell.width)}px`;
     element.style.height = `${(decoration.options.height || 1) * this._renderService.dimensions.css.cell.height}px`;
     element.style.top = `${(decoration.marker.line - this._bufferService.buffers.active.ydisp) * this._renderService.dimensions.css.cell.height}px`;

src/browser/renderer/dom/DomRenderer.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { BOLD_CLASS, CURSOR_BLINK_CLASS, CURSOR_CLASS, CURSOR_STYLE_BAR_CLASS, CURSOR_STYLE_BLOCK_CLASS, CURSOR_STYLE_UNDERLINE_CLASS, DomRendererRowFactory, ITALIC_CLASS } from 'browser/renderer/dom/DomRendererRowFactory';
+import { BOLD_CLASS, CURSOR_BLINK_CLASS, CURSOR_CLASS, CURSOR_STYLE_BAR_CLASS, CURSOR_STYLE_BLOCK_CLASS, CURSOR_STYLE_UNDERLINE_CLASS, DIM_CLASS, DomRendererRowFactory, ITALIC_CLASS } from 'browser/renderer/dom/DomRendererRowFactory';
 import { INVERTED_DEFAULT_COLOR } from 'browser/renderer/shared/Constants';
 import { createRenderDimensions } from 'browser/renderer/shared/RendererUtils';
 import { IRenderDimensions, IRenderer, IRequestRedrawEvent } from 'browser/renderer/shared/Types';
@@ -53,7 +53,7 @@ export class DomRenderer extends Disposable implements IRenderer {
     @IOptionsService private readonly _optionsService: IOptionsService,
     @IBufferService private readonly _bufferService: IBufferService,
     @ICoreBrowserService private readonly _coreBrowserService: ICoreBrowserService,
-    @IThemeService themeService: IThemeService
+    @IThemeService private readonly _themeService: IThemeService
   ) {
     super();
     this._rowContainer = document.createElement('div');
@@ -69,8 +69,8 @@ export class DomRenderer extends Disposable implements IRenderer {
     this._updateDimensions();
     this.register(this._optionsService.onOptionChange(() => this._handleOptionsChanged()));
 
-    this.register(themeService.onChangeColors(e => this._injectCss(e)));
-    this._injectCss(themeService.colors);
+    this.register(this._themeService.onChangeColors(e => this._injectCss(e)));
+    this._injectCss(this._themeService.colors);
 
     this._rowFactory = instantiationService.createInstance(DomRendererRowFactory, document);
 
@@ -149,6 +149,10 @@ export class DomRenderer extends Disposable implements IRenderer {
       ` font-family: ${this._optionsService.rawOptions.fontFamily};` +
       ` font-size: ${this._optionsService.rawOptions.fontSize}px;` +
       `}`;
+    styles +=
+      `${this._terminalSelector} .${ROW_CONTAINER_CLASS} .xterm-dim {` +
+      ` color: ${color.multiplyOpacity(colors.foreground, 0.5).css};` +
+      `}`;
     // Text styles
     styles +=
       `${this._terminalSelector} span:not(.${BOLD_CLASS}) {` +
@@ -224,10 +228,12 @@ export class DomRenderer extends Disposable implements IRenderer {
     for (const [i, c] of colors.ansi.entries()) {
       styles +=
         `${this._terminalSelector} .${FG_CLASS_PREFIX}${i} { color: ${c.css}; }` +
+        `${this._terminalSelector} .${FG_CLASS_PREFIX}${i}.${DIM_CLASS} { color: ${color.multiplyOpacity(c, 0.5).css}; }` +
         `${this._terminalSelector} .${BG_CLASS_PREFIX}${i} { background-color: ${c.css}; }`;
     }
     styles +=
       `${this._terminalSelector} .${FG_CLASS_PREFIX}${INVERTED_DEFAULT_COLOR} { color: ${color.opaque(colors.background).css}; }` +
+      `${this._terminalSelector} .${FG_CLASS_PREFIX}${INVERTED_DEFAULT_COLOR}.${DIM_CLASS} { color: ${color.multiplyOpacity(color.opaque(colors.background), 0.5).css}; }` +
       `${this._terminalSelector} .${BG_CLASS_PREFIX}${INVERTED_DEFAULT_COLOR} { background-color: ${colors.foreground.css}; }`;
 
     this._themeStyleElement.textContent = styles;
@@ -340,6 +346,8 @@ export class DomRenderer extends Disposable implements IRenderer {
   private _handleOptionsChanged(): void {
     // Force a refresh
     this._updateDimensions();
+    // Refresh CSS
+    this._injectCss(this._themeService.colors);
   }
 
   public clear(): void {
@@ -385,8 +393,37 @@ export class DomRenderer extends Disposable implements IRenderer {
   }
 
   private _setCellUnderline(x: number, x2: number, y: number, y2: number, cols: number, enabled: boolean): void {
-    x = this._cellToRowElements[y][x];
-    x2 = this._cellToRowElements[y2][x2];
+    /**
+     * NOTE: The linkifier may send out of viewport y-values if:
+     * - negative y-value: the link started at a higher line
+     * - y-value >= maxY: the link ends at a line below viewport
+     *
+     * For negative y-values we can simply adjust x = 0,
+     * as higher up link start means, that everything from
+     * (0,0) is a link under top-down-left-right char progression
+     *
+     * Additionally there might be a small chance of out-of-sync x|y-values
+     * from a race condition of render updates vs. link event handler execution:
+     * - (sync) resize: chances terminal buffer in sync, schedules render update async
+     * - (async) link handler race condition: new buffer metrics, but still on old render state
+     * - (async) render update: brings term metrics and render state back in sync
+     */
+    if (y < 0) x = 0;
+    if (y2 < 0) x2 = 0;
+
+    // avoid out-of-sync y-values, simply clamp into valid area
+    const maxY = this._cellToRowElements.length - 1;
+    y = Math.max(Math.min(y, maxY), 0);
+    y2 = Math.max(Math.min(y2, maxY), 0);
+    const elemY = this._cellToRowElements[y];
+    const elemY2 = this._cellToRowElements[y2];
+    if (x >= elemY.length || x2 >= elemY2.length) {
+      // avoid out-of-sync x-values
+      // simply exit early, gets fixed by the next render update
+      return;
+    }
+    x = elemY[x];
+    x2 = elemY2[x2];
 
     if (x === -1 || x2 === -1) {
       return;

src/browser/renderer/dom/DomRendererRowFactory.test.ts

@@ -167,6 +167,16 @@ describe('DomRendererRowFactory', () => {
         });
       });
 
+      it('should add class for overline', () => {
+        const cell = CellData.fromCharData([0, 'a', 1, 'a'.charCodeAt(0)]);
+        cell.bg = DEFAULT_ATTR_DATA.bg | BgFlags.OVERLINE;
+        lineData.setCell(0, cell);
+        const fragment = rowFactory.createRow(lineData, 0, false, undefined, 0, false, 5, 20, EMPTY_ELEM_MAPPING);
+        assert.equal(getFragmentHtml(fragment),
+          '<span class="xterm-overline">a</span>'
+        );
+      });
+
       it('should add class for strikethrough', () => {
         const cell = CellData.fromCharData([0, 'a', 1, 'a'.charCodeAt(0)]);
         cell.fg = DEFAULT_ATTR_DATA.fg | FgFlags.STRIKETHROUGH;

src/browser/renderer/dom/DomRendererRowFactory.ts

@@ -9,7 +9,6 @@ import { NULL_CELL_CODE, WHITESPACE_CELL_CHAR, Attributes } from 'common/buffer/
 import { CellData } from 'common/buffer/CellData';
 import { ICoreService, IDecorationService, IOptionsService } from 'common/services/Services';
 import { color, rgba } from 'common/Color';
-import { IColorSet, ReadonlyColorSet } from 'browser/Types';
 import { ICharacterJoinerService, ICoreBrowserService, IThemeService } from 'browser/services/Services';
 import { JoinedCellData } from 'browser/services/CharacterJoinerService';
 import { excludeFromContrastRatioDemands } from 'browser/renderer/shared/RendererUtils';
@@ -19,6 +18,7 @@ export const BOLD_CLASS = 'xterm-bold';
 export const DIM_CLASS = 'xterm-dim';
 export const ITALIC_CLASS = 'xterm-italic';
 export const UNDERLINE_CLASS = 'xterm-underline';
+export const OVERLINE_CLASS = 'xterm-overline';
 export const STRIKETHROUGH_CLASS = 'xterm-strikethrough';
 export const CURSOR_CLASS = 'xterm-cursor';
 export const CURSOR_BLINK_CLASS = 'xterm-cursor-blink';
@@ -186,6 +186,13 @@ export class DomRendererRowFactory {
         }
       }
 
+      if (cell.isOverline()) {
+        charElement.classList.add(OVERLINE_CLASS);
+        if (charElement.textContent === ' ') {
+          charElement.textContent = '\xa0'; // =  
+        }
+      }
+
       if (cell.isStrikethrough()) {
         charElement.classList.add(STRIKETHROUGH_CLASS);
       }

src/browser/renderer/shared/TextureAtlas.ts

@@ -304,12 +304,6 @@ export class TextureAtlas implements ITextureAtlas {
         break;
     }
 
-    if (dim) {
-      // Blend here instead of using opacity because transparent colors mess with clipping the
-      // glyph's bounding box
-      result = color.blend(this._config.colors.background, color.multiplyOpacity(result, DIM_OPACITY));
-    }
-
     return result;
   }
 
@@ -429,12 +423,12 @@ export class TextureAtlas implements ITextureAtlas {
     // Allow 1 cell width per character, with a minimum of 2 (CJK), plus some padding. This is used
     // to draw the glyph to the canvas as well as to restrict the bounding box search to ensure
     // giant ligatures (eg. =====>) don't impact overall performance.
-    const allowedWidth = this._config.deviceCellWidth * Math.max(chars.length, 2) + TMP_CANVAS_GLYPH_PADDING * 2;
+    const allowedWidth = Math.min(this._config.deviceCellWidth * Math.max(chars.length, 2) + TMP_CANVAS_GLYPH_PADDING * 2, this._textureSize);
     if (this._tmpCanvas.width < allowedWidth) {
       this._tmpCanvas.width = allowedWidth;
     }
     // Include line height when drawing glyphs
-    const allowedHeight = this._config.deviceCellHeight + TMP_CANVAS_GLYPH_PADDING * 4;
+    const allowedHeight = Math.min(this._config.deviceCellHeight + TMP_CANVAS_GLYPH_PADDING * 4, this._textureSize);
     if (this._tmpCanvas.height < allowedHeight) {
       this._tmpCanvas.height = allowedHeight;
     }
@@ -455,6 +449,7 @@ export class TextureAtlas implements ITextureAtlas {
     const italic = !!this._workAttributeData.isItalic();
     const underline = !!this._workAttributeData.isUnderline();
     const strikethrough = !!this._workAttributeData.isStrikethrough();
+    const overline = !!this._workAttributeData.isOverline();
     let fgColor = this._workAttributeData.getFgColor();
     let fgColorMode = this._workAttributeData.getFgColorMode();
     let bgColor = this._workAttributeData.getBgColor();
@@ -638,12 +633,24 @@ export class TextureAtlas implements ITextureAtlas {
       }
     }
 
+    // Overline
+    if (overline) {
+      const lineWidth = Math.max(1, Math.floor(this._config.fontSize * this._config.devicePixelRatio / 15));
+      const yOffset = lineWidth % 2 === 1 ? 0.5 : 0;
+      this._tmpCtx.lineWidth = lineWidth;
+      this._tmpCtx.strokeStyle = this._tmpCtx.fillStyle;
+      this._tmpCtx.beginPath();
+      this._tmpCtx.moveTo(padding, padding + yOffset);
+      this._tmpCtx.lineTo(padding + this._config.deviceCharWidth * chWidth, padding + yOffset);
+      this._tmpCtx.stroke();
+    }
+
     // Draw the character
     if (!customGlyph) {
       this._tmpCtx.fillText(chars, padding, padding + this._config.deviceCharHeight);
     }
 
-    // If this charcater is underscore and beyond the cell bounds, shift it up until it is visible
+    // If this character is underscore and beyond the cell bounds, shift it up until it is visible
     // even on the bottom row, try for a maximum of 5 pixels.
     if (chars === '_' && !this._config.allowTransparency) {
       let isBeyondCellBounds = clearColor(this._tmpCtx.getImageData(padding, padding, this._config.deviceCellWidth, this._config.deviceCellHeight), backgroundColor, foregroundColor, enableClearThresholdCheck);

src/common/InputHandler.test.ts

@@ -2222,7 +2222,7 @@ describe('InputHandler', () => {
     });
     it('ANSI 2 (keyboard action mode)', async () => {
       await inputHandler.parseP('\x1b[2$p');
-      assert.deepEqual(reportStack.pop(), '\x1b[2;3$y');    // always set
+      assert.deepEqual(reportStack.pop(), '\x1b[2;4$y');    // always reset
     });
     it('ANSI 4 (insert mode)', async () => {
       await inputHandler.parseP('\x1b[4$p');
@@ -2236,7 +2236,7 @@ describe('InputHandler', () => {
     });
     it('ANSI 12 (send/receive)', async () => {
       await inputHandler.parseP('\x1b[12$p');
-      assert.deepEqual(reportStack.pop(), '\x1b[12;4$y');   // always reset
+      assert.deepEqual(reportStack.pop(), '\x1b[12;3$y');   // always set
     });
     it('ANSI 20 (newline mode)', async () => {
       await inputHandler.parseP('\x1b[20$p');
@@ -2280,7 +2280,7 @@ describe('InputHandler', () => {
     });
     it('DEC privates perma modes', async () => {
       // [mode number, state value]
-      const perma = [[3, 0], [8, 3], [1005, 4], [1015, 4], [1048, 1]];
+      const perma = [[3, 0], [8, 3], [67, 4], [1005, 4], [1015, 4], [1048, 1]];
       for (const [mode, value] of perma) {
         await inputHandler.parseP(`\x1b[?${mode}$p`);
         assert.deepEqual(reportStack.pop(), `\x1b[?${mode};${value}$y`);

src/common/InputHandler.ts

@@ -2223,9 +2223,9 @@ export class InputHandler extends Disposable implements IInputHandler {
     const p = params.params[0];
 
     if (ansi) {
-      if (p === 2) return f(p, V.PERMANENTLY_SET);
+      if (p === 2) return f(p, V.PERMANENTLY_RESET);
       if (p === 4) return f(p, b2v(cs.modes.insertMode));
-      if (p === 12) return f(p, V.PERMANENTLY_RESET);
+      if (p === 12) return f(p, V.PERMANENTLY_SET);
       if (p === 20) return f(p, b2v(opts.convertEol));
       return f(p, V.NOT_RECOGNIZED);
     }
@@ -2240,6 +2240,7 @@ export class InputHandler extends Disposable implements IInputHandler {
     if (p === 25) return f(p, b2v(!cs.isCursorHidden));
     if (p === 45) return f(p, b2v(dm.reverseWraparound));
     if (p === 66) return f(p, b2v(dm.applicationKeypad));
+    if (p === 67) return f(p, V.PERMANENTLY_RESET);
     if (p === 1000) return f(p, b2v(mouseProtocol === 'VT200'));
     if (p === 1002) return f(p, b2v(mouseProtocol === 'DRAG'));
     if (p === 1003) return f(p, b2v(mouseProtocol === 'ANY'));
@@ -2425,6 +2426,8 @@ export class InputHandler extends Disposable implements IInputHandler {
    * | 47        | Background color: White.                                 | #Y      |
    * | 48        | Background color: Extended color.                        | #P[Support for RGB and indexed colors, see below.] |
    * | 49        | Background color: Default (original).                    | #Y      |
+   * | 53        | Overlined.                                               | #Y      |
+   * | 55        | Not Overlined.                                           | #Y      |
    * | 58        | Underline color: Extended color.                         | #P[Support for RGB and indexed colors, see below.] |
    * | 90 - 97   | Bright foreground color (analogous to 30 - 37).          | #Y      |
    * | 100 - 107 | Bright background color (analogous to 40 - 47).          | #Y      |
@@ -2551,6 +2554,12 @@ export class InputHandler extends Disposable implements IInputHandler {
       } else if (p === 38 || p === 48 || p === 58) {
         // fg color 256 and RGB
         i += this._extractColor(params, i, attr);
+      } else if (p === 53) {
+        // overline
+        attr.bg |= BgFlags.OVERLINE;
+      } else if (p === 55) {
+        // not overline
+        attr.bg &= ~BgFlags.OVERLINE;
       } else if (p === 59) {
         attr.extended = attr.extended.clone();
         attr.extended.underlineColor = -1;

src/common/Types.d.ts

@@ -165,6 +165,7 @@ export interface IAttributeData {
   isDim(): number;
   isStrikethrough(): number;
   isProtected(): number;
+  isOverline(): number;
 
   /**
    * The color mode of the foreground color which determines how to decode {@link getFgColor},

src/common/buffer/AttributeData.ts

@@ -47,6 +47,7 @@ export class AttributeData implements IAttributeData {
   public isDim(): number           { return this.bg & BgFlags.DIM; }
   public isStrikethrough(): number { return this.fg & FgFlags.STRIKETHROUGH; }
   public isProtected(): number     { return this.bg & BgFlags.PROTECTED; }
+  public isOverline(): number      { return this.bg & BgFlags.OVERLINE; }
 
   // color modes
   public getFgColorMode(): number { return this.fg & Attributes.CM_MASK; }

src/common/buffer/Constants.ts

@@ -128,7 +128,8 @@ export const enum BgFlags {
   ITALIC = 0x4000000,
   DIM = 0x8000000,
   HAS_EXTENDED = 0x10000000,
-  PROTECTED = 0x20000000
+  PROTECTED = 0x20000000,
+  OVERLINE = 0x40000000
 }
 
 export const enum ExtFlags {

src/headless/public/Terminal.test.ts

@@ -22,7 +22,7 @@ describe('Headless API Tests', function (): void {
 
   it('Proposed API check', async () => {
     term = new Terminal({ allowProposedApi: false });
-    throws(() => term.markers, (error) => error.message === 'You must set the allowProposedApi option to true to use proposed API');
+    throws(() => term.markers, (error: any) => error.message === 'You must set the allowProposedApi option to true to use proposed API');
   });
 
   it('write', async () => {