GtkChart - a chart widget for GTK4

Introduction

The beginnings of a small chart widget library for GTK4.

This is a spinoff from the lxi-tools project.

Much can be improved but it is better than nothing.

Looking for maintainer/contributors to help improve this library.

Motivation

Couldn't find a chart widget library for GTK4 so created one.

Features

Various chart types
- Line
- Scatter
- Linear gauge
- Angular gauge
- Number
Dimensionally scalable
Plot and render data live
Save rendered chart to PNG
Save plotted data to CSV

Todo

Optimize Cairo/snapshot code
Make charts handle negative axis ranges
- Introduce gtk_chart_set_x_min()
- Introduce gtk_chart_set_y_min()
Make charts zoomable
Make chart axes autoscale depending on plot value
Make colours configurable
Etc.

Usage

// Required for GtkChart to be recognized by builder
gtk_chart_get_type();
...
GtkWidget *chart = gtk_chart_new();
gtk_chart_set_type(chart, GTK_CHART_TYPE_LINE);
gtk_chart_set_title(chart, "Title");
gtk_chart_set_label(chart, "Label");
gtk_chart_set_x_label(chart, "X label [ ]");
gtk_chart_set_y_label(chart, "Y label [ ]");
gtk_chart_set_x_max(chart, 100);
gtk_chart_set_y_max(chart, 10);
gtk_chart_set_width(chart, 800);
...
gtk_chart_plot_point(chart, 0.0, 0.0);
gtk_chart_plot_point(chart, 1.0, 1.0);
gtk_chart_plot_point(chart, 2.0, 2.0);
gtk_chart_plot_point(chart, 3.0, 3.0);
...
gtk_chart_save_csv(chart, "chart0.csv");
gtk_chart_save_png(chart, "chart0.png");