draw

package module
v0.34.0 Latest Latest
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 Go to latest Published: Dec 21, 2025 License: MIT Imports: 6 Imported by: 0

README

ARCHIVED! Moved to https://sogvin.com/draw

draw - package for writing software design diagrams

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Documentation

Overview

Package draw provides SVG writing features.

Example (Inline) 
package main

import (
	"fmt"

	"sogvin.com/draw/design"
)

func main() {
	d := design.NewSequenceDiagram()
	fmt.Println(d.Inline())
}

Output:
<svg
  xmlns="http://www.w3.org/2000/svg"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  font-family="Arial,Helvetica,sans-serif" width="1" height="1"></svg>
Example (Overview)

The overview is used as social preview in github. Transform to png with e.g. inkscape -z -w 890 -h 356 overview.svg -e overview.png 

package main

import (
	"database/sql"

	"sogvin.com/draw/design"
	"sogvin.com/draw/internal/app"
	"sogvin.com/draw/shape"
)

func main() {
	var (
		d   = design.NewSequenceDiagram()
		cli = d.AddStruct(app.Client{})
		srv = d.AddStruct(app.Server{})
		db  = d.AddStruct(sql.DB{})
	)
	d.Link(cli, srv, "connect()")
	d.Link(srv, db, "...")

	// Flow part
	var (
		start = shape.NewDot()
		run   = shape.NewState("Run")
		end   = shape.NewExitDot()
	)
	d.Place(start).At(100, 140)
	d.Place(run, end).Below(start)
	d.VAlignCenter(start, run, end)
	d.LinkAll(start, run, end)

	// Class diagram (manual)
	var (
		circle = design.NewVRecord(shape.Circle{})
		shp    = design.NewVRecord((*shape.Shape)(nil))
	)
	circle.HideMethods()
	d.Place(shp).RightOf(start, 100)
	d.Place(circle).RightOf(shp, 100)
	d.HAlignBottom(shp, circle)
	lnk := shape.NewArrowBetween(circle, shp)
	lnk.SetClass("implements-arrow")
	d.Place(lnk)

	// Actors and notes
	var (
		note  = shape.NewNote("Anything is possible!\nGo draw your next design")
		actor = shape.NewActor()
	)
	d.Place(note).Above(circle, 60)
	shape.Move(note, 50, 0)
	d.Place(actor).Above(note)
	d.VAlignLeft(note, actor)
	d.Place(shape.NewArrowBetween(actor, note))

	// components
	var (
		dbcomp  = shape.NewDatabase("database")
		inet    = shape.NewInternet()
		service = shape.NewComponent("Service")
		browser = shape.NewComponent("Browser")
	)
	browser.SetClass("external")
	d.Place(service).RightOf(note, 70)
	shape.Move(service, 0, -70)
	d.Place(dbcomp).RightOf(service)
	d.Place(inet).Below(service)
	d.Place(browser).Below(inet)
	d.VAlignCenter(service, inet, browser)

	d.SetCaption("gregoryv/draw provided shapes and diagrams")
	d.SaveAs("overview.svg")
}

Index

Examples

Constants

This section is empty.

Variables

View Source 
var (
	DefaultFont    = Font{Height: 12, LineHeight: 16, /* contains filtered or unexported fields */}
	DefaultTextPad = Padding{Left: 6, Top: 4, Bottom: 6, Right: 10}
	DefaultPad     = Padding{Left: 10, Top: 2, Bottom: 7, Right: 10}
	DefaultSpacing = 30 // between elements

	DefaultFontFamily = `font-family="Arial,Helvetica,sans-serif"`

	DefaultClassAttributes = ClassAttributes{
		"area-red-label":   `font-style="italic" ` + DefaultFontFamily,
		"area-green-label": `font-style="italic" ` + DefaultFontFamily,
		"area-blue-label":  `font-style="italic" ` + DefaultFontFamily,
		"area-red":         `stroke="black" stroke-width="0" fill="#ff9999" fill-opacity="0.1"`,
		"area-green":       `stroke="black" stroke-width="0" fill="#ccff99" fill-opacity="0.1"`,
		"area-blue":        `stroke="black" stroke-width="0" fill="#99e6ff" fill-opacity="0.1"`,

		"actor":                 `stroke="black" stroke-width="2" fill="#ffffff"`,
		"circle":                `stroke="#d3d3d3" stroke-width="2" fill="#ffffff"`,
		"container":             `stroke="#737373" stroke-dasharray="5,5,5" fill="transparent"`,
		"cylinder":              `stroke="#d3d3d3" stroke-width="1" fill="#ffffff"`,
		"card":                  `stroke="#d3d3d3" stroke-width="1" fill="#ffffff"`,
		"card-external":         `stroke="#d3d3d3" stroke-width="1" fill="#f8f9fa"`,
		"card-title":            DefaultFontFamily + ` font-weight="bold"`,
		"database":              `stroke="#d3d3d3" stroke-width="1" fill="#ffffff"`,
		"dot":                   `stroke="black"`,
		"exit":                  `stroke="black" stroke-width="2" fill="#ffffff"`,
		"exit-dot":              `stroke="black"`,
		"note":                  DefaultFontFamily,
		"note-box":              `stroke="#d3d3d3" fill="#ffffcc"`,
		"highlight":             `stroke="red"`,
		"highlight-head":        `stroke="red" fill="#ffffff"`,
		"implements-arrow":      `stroke="black" stroke-dasharray="5,5,5"`,
		"implements-arrow-head": `stroke="black" fill="#ffffff"`,
		"arrow":                 `stroke="black"`,
		"arrow-head":            `stroke="black" fill="#ffffff"`,
		"arrow-tail":            `stroke="black" fill="#777777"`,
		"dashed-arrow":          `stroke="black"`,
		"dashed-arrow-head":     `stroke="black" fill="#ffffff"`,
		"dashed-arrow-tail":     `stroke="black" fill="#777777"`,
		"activity-arrow":        `stroke="black"`,
		"activity-arrow-head":   `stroke="black" fill="#ffffff"`,
		"activity-arrow-tail":   `stroke="black" fill="#777777"`,
		"compose-arrow":         `stroke="black"`,
		"compose-arrow-head":    `stroke="black" fill="#ffffff"`,
		"compose-arrow-tail":    `stroke="black" fill="#777777"`,
		"aggregate-arrow":       `stroke="black"`,
		"aggregate-arrow-head":  `stroke="black" fill="#ffffff"`,
		"aggregate-arrow-tail":  `stroke="black" fill="#ffffff"`,
		"external":              `stroke="#d3d3d3" fill="#e2e2e2"`,
		"dim":                   `stroke="#d3d3d3" fill="#e2e2e2"`,
		"hexagon":               `stroke="#d3d3d3" fill="#ffffff"`,
		"hexagon-title":         DefaultFontFamily,
		"internet":              `stroke="#d3d3d3" fill="#e2e2e2"`,
		"internet-title":        DefaultFontFamily,
		"line":                  `stroke="black"`,
		"triangle":              `stroke="black"`,
		"column-line":           `stroke="#d3d3d3"`,
		"process":               `stroke="#d3d3d3" fill="#ffffff"`,
		"process-title":         DefaultFontFamily,
		"record":                `stroke="#d3d3d3" fill="#ffffff"`,
		"record-line":           `stroke="#d3d3d3"`,
		"record-title":          DefaultFontFamily,
		"rect":                  `stroke="#d3d3d3" fill="#ffffff"`,
		"rect-title":            DefaultFontFamily,
		"root":                  DefaultFontFamily,
		"skip":                  `stroke="#ffffff" stroke-dasharray="2,2,2"`,
		"span-green":            `stroke="#d3d3d3" fill="#ccff99" rx="5" ry="5"`,
		"span-green-title":      DefaultFontFamily,
		"span-blue":             `stroke="#d3d3d3" fill="#99e6ff" rx="5" ry="5"`,
		"span-blue-title":       DefaultFontFamily,
		"span-red":              `stroke="#d3d3d3" fill="#ff9999" rx="5" ry="5"`,
		"span-red-title":        DefaultFontFamily,
		"state-title":           DefaultFontFamily,
		"state":                 `stroke="#d3d3d3" fill="#ffffff" rx="10" ry="10"`,
		"store":                 `stroke="#d3d3d3" fill="#ffffff"`,
		"store-title":           DefaultFontFamily,
		"component":             `stroke="#d3d3d3" fill="#ffffff"`,
		"component-title":       DefaultFontFamily,
		"field":                 DefaultFontFamily,
		"method":                DefaultFontFamily,
		"record-label":          DefaultFontFamily,
		"label":                 DefaultFontFamily,
		"weekend":               DefaultFontFamily + ` fill="#f3f3f3"`,
		"weekend-title":         DefaultFontFamily,
		"caption":               DefaultFontFamily,
		"diamond":               `stroke="#d3d3d3" fill="#333333"`,
		"decision":              `stroke="#d3d3d3" fill="#ffffff"`,
	}
)

Functions

This section is empty.

Types

type ClassAttributes 

type ClassAttributes map[string]string

ClassAttributes define mapping between classes and svg attributes. Setting attributes that modify size or position is not advised.

func (ClassAttributes) CSS 

func (me ClassAttributes) CSS() string

CSS returns cascading rules for embedding in html

type Font 

type Font struct {
	Height int

	// It is allowed to have a smaller line height than height.
	LineHeight int
	// contains filtered or unexported fields
}

func (*Font) SetScale 

func (f *Font) SetScale(v float64)

func (Font) TextWidth 

func (f Font) TextWidth(txt string) int

TextWidth returns the width of the given text based on a 12px arial font.

type Padding 

type Padding struct {
	Left, Top, Right, Bottom int
}

func (*Padding) SetScale 

func (p *Padding) SetScale(v float64)

type SVG 

type SVG struct {
	Content []SVGWriter
	// contains filtered or unexported fields
}

func NewSVG 

func NewSVG() *SVG

NewSVG returns an empty SVG of size 100x100

Example 
package main

import (
	"os"

	"sogvin.com/draw"
)

func main() {
	s := draw.NewSVG()
	s.WriteSVG(os.Stdout)
}

Output:
<svg
  xmlns="http://www.w3.org/2000/svg"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  class="root" width="100" height="100"></svg>

func (*SVG) Append 

func (s *SVG) Append(w ...SVGWriter)

func (*SVG) Height 

func (s *SVG) Height() int

func (*SVG) Prepend 

func (s *SVG) Prepend(w ...SVGWriter)

func (*SVG) SetHeight 

func (s *SVG) SetHeight(h int)

SetHeight sets the SVG height in pixels.

func (*SVG) SetSize 

func (s *SVG) SetSize(width, height int)

SetSize sets the SVG size in pixels

func (*SVG) SetWidth 

func (s *SVG) SetWidth(w int)

SetWidth sets the SVG width in pixels.

func (*SVG) Width 

func (s *SVG) Width() int

func (*SVG) WriteSVG 

func (s *SVG) WriteSVG(w io.Writer) error

WriteSVG writes <svg> </svg> tags and it's content to the given writer.

type SVGWriter 

type SVGWriter interface {
	WriteSVG(io.Writer) error
}

type Style 

type Style struct {
	Font
	TextPad Padding // Surrounding text
	Pad     Padding // E.g. records
	Spacing int     // Between shapes in e.g. diagrams
	// contains filtered or unexported fields
}

func NewStyle 

func NewStyle() Style

NewStyle returns a style based on the default values, eg. draw.DefaultFont in this package.

func (*Style) SetOutput 

func (s *Style) SetOutput(w io.Writer)

SetOutput sets the destination of calls to Write.

func (*Style) SetScale 

func (s *Style) SetScale(v float64)

func (*Style) Write 

func (s *Style) Write(p []byte) (int, error)

Write adds a style attribute based on class. Limited to 1 class only and assumes the entire classname attribute is found.

Source Files

  • font.go
  • padding.go
  • style.go
  • svg.go

Directories

Path Synopsis
Package design provides diagram creators
 Package design provides diagram creators
Package docs provides the content of github pages at https://gregoryv.github.io/draw/
 Package docs provides the content of github pages at https://gregoryv.github.io/draw/
Package goviz provides means to generate Go diagrams.
 Package goviz provides means to generate Go diagrams.
internal
app
date
Package shape provides various SVG shapes
 Package shape provides various SVG shapes
Package xy provides xy Position
 Package xy provides xy Position

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