Code Folding

TSynEdit can collapse and expand blocks of text (procedures, classes, comments, regions...) with the markers in the gutter, like the IDEs do.

Unit: SynEdit.CodeFolding.

Enabling the folding

SynEdit1.UseCodeFolding := True;
SynEdit1.Highlighter := SynPasSyn1;   // a highlighter that supports folding

The folding ranges are computed by the highlighter. The highlighters that support it derive from TSynCustomCodeFoldingHighlighter: Object Pascal, C/C++, C#, Java, JavaScript, PHP, Perl, Python, Visual Basic, VBScript, COBOL, DWScript, FoxPro, INI, JSON, YAML and Omni. For the other ones, or for special rules, write the ranges with the event OnScanForFoldRanges of the editor.

The CodeFolding property

CodeFolding (TSynCodeFolding) controls the appearance:

Property	Description
GutterShapeSize	Size of the collapse/expand shape in the gutter (default 9, scaled with the DPI).
CollapsedLineColor	Color of the line shown under a collapsed block.
FolderBarLinesColor	Color of the lines of the folding bar in the gutter.
ShowCollapsedLine	Shows a line under the collapsed blocks.
ShowHintMark	Shows a hint mark on the collapsed lines (default True).
IndentGuides	Shows the indent guides.
IndentGuidesColor	Color of the indent guides.

Commands

SynEdit1.CollapseAll collapses all the blocks. The other operations are editor commands that can be bound to keys with Keystrokes, or executed with ExecuteCommand:

Command	Effect
ecFoldAll, ecUnfoldAll	Collapses / expands all the blocks.
ecFoldNearest, ecUnfoldNearest	Collapses / expands the block nearest to the caret.
ecFoldLevel1, ecFoldLevel2, ecFoldLevel3	Collapses the blocks of that nesting level.
ecUnfoldLevel1, ecUnfoldLevel2, ecUnfoldLevel3	Expands the blocks of that nesting level.

Demo

See the Code Folding demo: it opens a C++, a JavaScript and a Python file with the folding enabled.