🚀 Features

• The minimum contrast ratio feature will now change luminance in the opposite direction if the contrast ratio isn't met (#3806, #3808) via @Tyriar. For example a red foreground on a slightly darker red background will try lighten the color and if the minimumContrastRatio option isn't met when #FFFFFF is reached it will try moving it towards #000000. This can cause somewhat unexpected results by changing explicitly styled whites to blacks for example but it's really good for accessibility.
• The library now supports parsing #rgb, #rgba, rgb(r, g, b) and rgba(r, g, b, a) color formats (#3815, #3819, #3823) via @ChaseKnowlden, @Tyriar
• Opaque selectionBackground is now supported in the DOM renderer (#3839) via @Tyriar
• The symbol powerline font glyphs now use custom rendering when ITerminalOptions.customGlyphs is enabled (#3856, #3862, #3866) via @Tyriar This has multiple benefits:
  • A patched powerlines font doesn't need to be installed to render the most common characters
  • Ugly lines due to anti-aliasing that can appear no longer do
  • The glyphs always use greyscale anti-aliasing (not sub-pixel)
  • ITerminalOptions.lineHeight is taken into account when rendering the glyph

📦 API

• The overview ruler is a companion feature to the decorations introduced in 4.18.0 which shows little indicators on the scroll bar (#3676, #3687, #3688, #3689, #3693, #3694, #3695, #3697, #3702, #3711, #3723, #3730, #3733, #3738, #3788, #3791, #3792, #3841) via @meganrogge, @Tyriar. To use it, add the overviewRulerOptions property to a decoration's IDecorationOptions and it will automatically show up in the overview ruler.

  const marker = term.addMarker(1);
  const decoration = term.registerDecoration({
    marker,
    x: 5,
    overviewRulerOptions: {
      color: '#FF0000',
      position: 'left'
    }
  });
  decoration.onRender(() => {
    decoration.element.style.backgroundColor = 'red';
  });
  

  The width of the resulting overview ruler is controlled by ITerminalOptions.overviewRulerWidth.
• Decorations can now change a cell's background and foreground colors (#3775, #3782) via @Tyriar. When this is set, the minimum contrast ratio feature will also be in effect.

  const decoration = term.registerDecoration({
    marker,
    backgroundColor: '#ff0000',
    foregroundColor: '#ffffff'
  });
  

• Decorations can now specify the layer property to allow rendering above the selection (#3785, #3800) via @Tyriar

  const decoration = term.registerDecoration({
    marker,
    layer: 'top'
  });
  

• There's a new selectionForeground theme color, when set this will use a static color for selections (#3813) via @Tyriar

  const term = new Terminal({
    theme: {
      selectionBackground: '#000000',
      selectionForeground: '#FFFFFF'
    }
  });
  

🐞 Bug fixes

• Fix triple click selection edge case where initial line was getting unselected (#3669) via @silamon
• Fixing edge cases when clearing decorations via Terminal.clear (#3671, #3868) via @meganrogge
• Handle missing compositionend events for Sogou IME (#3680) via @Eugeny
• Fix a bug when running emacs by preferring ST over BEL (#3704) via @meganrogge
• Fix Alt-N/E/U handling in macOS, handle Alt-Shift-Letter (#3726) via @Eugeny
• Fix caps lock while IMEs are being used preventing lowercase input (#3728) via @serkodev
• Exclude powerline characters from the minimum contrast ratio feature (#3740, #3742) via @meganrogge
• Send ctrl modifier for page up/down sequences (#3761) via @Tyriar
• Send record separator on ctrl+@ (#3763) via @robinfai
• Switching from webgl to dom renderer will now correctly reposition decorations (#3779) via @Tyriar
• Decorations are now rendered in the same frame as the buffer, ensuring they stay in sync (#3796, #3818) via @meganrogge
• Fire onSelectionChange when Terminal.select is called (#3805) via @Tyriar
• Padding is now taken into account when converting mouse coordinates to cell positions (#3826) via @Tyriar
• Exclude box drawing and block glyphs from the minimum contrast ratio as they are typically used to blend with background colors (#3844) via @meganrogge
• Fix a minimum contrast ratio edge case with inverted text in the DOM renderer (#3846) via @meganrogge
• Only send the wheel mouse event when scrolling a line or more (#3869) via @pfitzseb

📝 Documentation and internal improvements

• Replace internal use of getOption/setOption with options (#3667) via @childrentime
• Lint code using putout (#3674) via @coderaiser
• Improve the way the scroll bar is hidden when scrollback is 0 (#3678) via @silamon
• Remove unwanted console.log (#3685) via @Tyriar
• Replace deprecated String.prototype.substr (#3713) via @CommanderRoot
• Dependency updates (#3714, #3715) via @dependabot
• Consolidate powerline glyph detection (#3743, #3756) via @meganrogge
• Speed up decoration rendering (#3769) via @Tyriar
• Enable the search highlight all matches feature in the demo by default (#3786) via @Tyriar
• Simplify CSS rules (#3787) via @Tyriar
• Add a warning in the demo's implementation calling out the importance of flow control (#3789) via @Tyriar
• Deflake link provider tests (#3822) via @Tyriar
• Standardize internal handling of colors for simplicity (#3824) via @Tyriar
• Add convenient powerline symbol test button to demo (#3828) via @Tyriar
• Organize demo test buttons (#3852) via @umaxyon
• Re-enable webgl minimum contrast ratio tests (#3863) via @Tyriar
• Fix a typo in serialize addon test (#3865) via @mmis1000

🎉 New real-world use cases

• hack.courses (#3837) via @lp1dev
• Render (#3871) via @crcastle
• CloudTTY (#3876) via yankay

📥 Addons

xterm-addon-search

• Support showing all find matches by leveraging decorations (#3698, #3707, #3708, #3709, #3710, #3736, #3750, #3757, #3767, #3768, #3811, #3835) via @meganrogge, @Tyriar
• Return the number of results when searching (#3716, #3731, #3745, #3752, #3793, #3831, #3874) via @meganrogge
• Allow external styling of the active result decoration via .xterm-find-active-result-decoration (#3802) via @Tyriar

xterm-addon-serialize

• Restore cursor style during serialize (#3682) via @Tyriar

xterm-addon-web-links

• Expose urlRegex in public API (#3719) via @LuckyGeck
• Handle wrapped lines properly (#3718) via @LuckyGeck

xterm-addon-webgl

• Simplified and sped up selection rendering by leveraging the decorations feature (#3782, #3860) via @Tyriar

🤝 Compatible addon versions

• xterm-addon-attach@0.6.0
• xterm-addon-fit@0.5.0
• xterm-addon-ligatures@0.5.3
• xterm-addon-search@0.9.0
• xterm-addon-serialize@0.7.0
• xterm-addon-unicode11@0.3.0
• xterm-addon-web-links@0.6.0
• xterm-addon-webgl@0.12.0

🌐 Website

• Add decorations to the demo (https://github.com/xtermjs/xtermjs.org/pull/170) via @meganrogge
• Fix a typo in hooks guide (https://github.com/xtermjs/xtermjs.org/pull/171) via @fixator10
• Fix handling of }, | and ~ in the demo (https://github.com/xtermjs/xtermjs.org/pull/175) via @MOBUMIN