gopie

README

gopie

Package gopie renders pie charts to SVG.

Installation

To install gopie package run:

go get -u github.com/eugenezinovyev/gopie

Dependencies

This package depends on the following packages:

• github.com/golang/freetype/truetype
• golang.org/x/image/font
• github.com/satori/go.uuid

These package are used for chart label dimensions measure. Check limitations of github.com/golang/freetype package if you plan to use label font different than the default one.

Defaults

• Font used for label size measurement: Roboto Medium
• Default slice colors: Material Design palette 400 (see: https://material.io/color)
• Stroke color: white
• Label font family: Roboto Medium
• Label font size: 12
• Label line length: 10px
• Label line width: 2px
• Label text padding: 4px
• DPI ued for label size measurement: 92
• Chart width: 200px
• Chart height: 200px
• Font: Roboto Medium
• Embed font: false
• Inner raduis: 0px

Usage

	chart := gopie.PieChart{
		Values: []gopie.Value{
			gopie.Value{Value: 1, Label: "One"},
			gopie.Value{Value: 2, Label: "Two"},
			gopie.Value{Value: 5, Label: "Five"},
		},
	}

	svgBytes, err := chart.SVG()

Custom slice colors

Check example in ./_examples/custom_colors

	chart := gopie.PieChart{
		...
		SliceColors:    []string{"firebrick", "sandybrown", "mediumseagreen", "deepskyblue"},
		...
	}

Embed font

Check example in ./_examples/font

	robotoRegular, err := ioutil.ReadFile("Roboto-Regular.ttf")
	check(err)
	chart.SetFont(robotoRegular)

Donut

Check example in ./_examples/donut

	chart := gopie.PieChart{
		...
		InnerRadius:    90, // Forces chart to leave empty circle with 90px radius at center
		...
	}

You can also check ./_examples folder for more examples of usage.

Licence

MIT

Documentation

Overview

Package gopie renders pie charts to SVG.

Index

• type PieChart
  • func (o PieChart) SVG() (svgBytes []byte, err error)
  • func (c *PieChart) SetFont(ttf []byte) (err error)
• type Value

Types

type PieChart

type PieChart struct {
	Width          float64  // SVG Width. Default is 200.
	Height         float64  // SVG Height. Default is 200.
	Values         []Value  // Chart values.
	SliceColors    []string // Colors to be used for pie slices and label lines.
	StrokeColor    string   // Slice stroke color. Default is "#ffffff".
	StrokeWidth    float64  // Slice stroke width. Default is 0 px.
	FontSize       float64  // Label font size. Default is 12 px.
	FontFamily     string   // Label font family. Default is "Roboto Medium".
	LabelLine      float64  // Label line length. Default is 10 px.
	LabelLineWidth float64  // Label line width. Default is 2 px.
	LabelPadding   float64  // Label text padding. Default is 4 px.
	DPI            float64  // DPI. Default is 92.

	EmbedFont   bool    // Whether embed font or not. Default is false.
	InnerRadius float64 // Inner radius or donut chart. Default is 0 which means by default pie chart will be rendered.
	// contains filtered or unexported fields
}

PieChart struct represents a pie chart rendering options.

func (PieChart) SVG

func (o PieChart) SVG() (svgBytes []byte, err error)

SVG function renders pie chart to SVG

func (*PieChart) SetFont

func (c *PieChart) SetFont(ttf []byte) (err error)

SetFont function sets font for the chart. The parameter should contain bytes of TTF font.

type Value

type Value struct {
	Value float64 // Value.
	Label string  // Label of value.
}

Value represents chart value.