This is a plugin for the Glyphs font editor that draws colored lines to indicate the presence of zero-width glyphs in Edit View.

Install the plugin using the button above or search for “Show Zero-Width Glyphs” in the Plugin Manager. Relaunch Glyphs for the plugin to be loaded.

Show Zero-Width Glyphs offers a range of configurable preferences.

The ShowZeroWidthGlyphsLineColor preference controls the color of the indicator line. Set the preference to 8 for the default purple color or one of the following numbers: 0: red, 1: orange, 2: brown, 3: yellow, 4: green, 7: blue, 8: purple, 9: pink, 10: gray.

Run the following line in the Macro panel to set the color (or set it to None to reset it):

Glyphs.defaults["ShowZeroWidthGlyphsLineColor"] = 1

The ShowZeroWidthGlyphsLineAlphaValue preference controls the transparency of the indicator line. Set the preference to 0.5 for the default transparency. 1.0 makes the line fully opaque, and 0.0 hides the line (full transparency).

If there are multiple zero-width glyphs next to each other, transparent colors will overlay, resulting in a more prominent line.

Run the following line in the Macro panel to set the alpha value (or set it to None to reset it):

Glyphs.defaults["ShowZeroWidthGlyphsLineAlphaValue"] = 0.25

The ShowZeroWidthGlyphsLineThickness preference controls the thickness of the indicator line. This thickness is added on all four sides of the layer box. The default value is 1.0.

Run the following line in the Macro panel to set the thickness (or set it to None to reset it):

Glyphs.defaults["ShowZeroWidthGlyphsLineThickness"] = 5.0

The ShowZeroWidthGlyphsMaximumWidth preference controls the maximum layer width for which the highlighting is applied. The default value is 0 (only zero-width glyphs are highlighted). Set it to a small value like 5 or 10 to also catch other very narrow glyphs.

Run the following line in the Macro panel to set the maximum width (or set it to None to reset it):

Glyphs.defaults["ShowZeroWidthGlyphsMaximumWidth"] = 10

Licensed under the Apache License, Version 2.0.