The StyleReader populates a store with records representing the rules of a Style or the entries of a ColorMap, so they can easily be shown in a grid.
The js is not minified so it is readable. See style-grid.js.
This grid shows the rules of a Style for a vector layer. Drag&Drop is enabled, labels are editable and filters can be edited inline using CQL syntax:
This grid shows the entries of the ColorMap of a RasterSymbolizer. The column configuration is the same as for the vector grid above. Label and filter (quantity) are editable, and the quantities will always be sorted in ascending order: