gvcode

README

gvcode

gvcode is a Gio based text editor for code editing.

Key Features:

• Uses a PieceTable backed text buffer for efficient text editing.
• Optimized undo/redo operations with built-in support in the PieceTable.
• Supports tabs and tab stops, with soft tabs coming soon.
• Lines can be unwrapped, with horizontal scrolling supported.
• Syntax highlighting is available by applying text styles.
• Built-in line numbers for better readability.
• Expanded shortcut support (Work in Progress).
• Large file rendering(Planned).

Why another code editor?

I ported Gio's editor component to gioview and added a few features to support basic code editing, but it is far from a good code editor. Keep expanding the original editor seems a wise decision, but the design of the original editor makes it hard to adding more features. And it is also not performant enough for large file editing/rendering. Most importantly it lacks tab/tab stop support. When I tried to add tab stop support to it, I found it needs a new overall design, so there is gvcode.

Key Design

Gio's text shaper layout the whole document in one pass, although internally the document is processed by paragraphs. After the shaping flow, there is a iterator style API to get the shaped glyphs one by one. This is what Gio's editor does when layouting the texts.

Gvcode has chosen another way. gvcode read and layout in a paragraph by paragrah manner. The outcomes are joined together to assemble the final document view. This gives up the oppertunity to process the text only visible in the viewport, making incremental shaping possible. Besides that we can also process tab expanding & tab stops at line level, because we have full control of the paragraph layout. To achive that goal, gvcode implemented its own line wrapper.

How To Use

Gvcode exports simple APIs to ease the integration with your project. Here is a basic example:

    state := &editor.Editor{}
	var ops op.Ops

	for {
		e := ed.window.Event()

		switch e := e.(type) {
		case app.DestroyEvent:
			return e.Err
		case app.FrameEvent:
			gtx := app.NewContext(&ops, e)
			
            es := gvcode.NewEditor(th, state)
            es.Font.Typeface = "monospace"
            es.TextSize = unit.Sp(12)
            es.LineHeightScale = 1.5
			es.Layout(gtx)

			e.Frame(gtx.Ops)
		}
	}

For a full working example, please see code in the folder ./example.

Cautions

gvcode is not intended to be a drop-in replacement for the official Editor widget as it dropped some features such as single line mode, truncator and max lines limit.

This project is a work in progress, and the APIs may change as development continues. Please use it at your own risk.

Acknowledgments

This project uses code from the Gio project, which is licensed under the Unlicense OR MIT License.

Documentation

Index

• type EditorStyle
  • func NewEditor(th *material.Theme, editor *editor.Editor) EditorStyle
  • func (e EditorStyle) Layout(gtx layout.Context) layout.Dimensions

Types

type EditorStyle

type EditorStyle struct {
	Font font.Font
	// LineHeight controls the distance between the baselines of lines of text.
	// If zero, a sensible default will be used.
	LineHeight unit.Sp
	// LineHeightScale applies a scaling factor to the LineHeight. If zero, a
	// sensible default will be used.
	LineHeightScale float32
	// TabWidth set how many spaces to represent a tab character.
	TabWidth int
	// TextSize set the text size.
	TextSize unit.Sp
	// TextWeight set the text weight.
	TextWeight font.Weight
	// Color is the text color.
	Color color.NRGBA
	// SelectionColor is the color of the background for selected text.
	SelectionColor color.NRGBA
	//LineHighlightColor is the color used to highlight the clicked logical line.
	// If not set, line will not be highlighted.
	LineHighlightColor color.NRGBA
	// TextHighlightColor use the color used to highlight the interested substring.
	TextHighlightColor color.NRGBA
	// Gap size between the line number bar and the main text area.
	LineNumberGutter unit.Dp
	LineNumberColor  color.NRGBA

	Editor *editor.Editor
	// contains filtered or unexported fields
}

func NewEditor

func NewEditor(th *material.Theme, editor *editor.Editor) EditorStyle

func (EditorStyle) Layout

func (e EditorStyle) Layout(gtx layout.Context) layout.Dimensions