[GSoC 2017] Calendar Application

Blog post by AkshayAgarwal007 on Mon, 2017-05-08 06:51


Hello I'm Akshay (IRC/Trac: akshay, GitHub: AkshayAgarwal007) from Kolkata, India. I would be working on developing a native Calendar Application for Haiku as a part of Google Summer of Code 2017. My mentors for the project are Scott McCreary and Kacper Kasper. I am very excited for this project.

Why a Calendar Application? Isn't there already one?

A Calendar application is a must have application for any operating system and would be beneficial for end users as well as developers. Haiku doesn't have a calendar application yet. There are a few existing 3rd party Calendar apps out there, but none are close to a simple and elegant Calendar app that an end user would like to use, with all the necessary features a modern Calendar app should have.

Also the existing ones (Borg, A-Book, Organizer, Eventual) have issues of their own and hence I would be writing one completely from scratch, referring them wherever required.

Features the Calendar app would have

I reviewed a bunch of Calendar apps on other platforms and came up with a subset of necessary features to be implemented:

  • Create, modify and synchronise events.
  • Set event reminders.
  • Display Day, Month Calendar views.
  • Set event color.
  • All day long events, recurring events.
  • Google Calendar integration.
  • A minimal look with intuitive UI design.

Future features

These are the features that I plan to work upon after GSoC:

  • Support for alternate calendars.
  • Categorize events.
  • Search for events.
  • Week, Year View.
  • Timeline view for a single day/week.

Google Calendar Integration

This is one of the most important feature the Calendar app would have. It is a must have so that the users can get their events synchronised between devices and other platforms they use. Since almost all the calendar apps have a Google Calendar integration, this would be the best way to achieve event synchronisation.

A Google Calendar API client would be written using Haiku APIs and would be integrated into the application.


These are some tentative designs for the Calendar application.

Add Event

  • I would be coming up with a final design for this, incorporating all the options required for supporting recurring events and an event color picker.

Add Event

Day View

  • All day long events would be pinned to the top.
  • Right click on an event will open a context menu with three options (View, Modify, Delete)
  • View will open the entire event details in read only mode. Modify and Delete options would also be available inside View mode.
  • Using the calendar widget in the side panel, user can navigate through months. Buttons to navigate one month at a time can be replaced by a dropdown to simply select month+year for user's ease.

Day View

Month View

  • Clicking on a particular day in month view will show events of that day in side panel.
  • Again the buttons to navigate one month/year at a time can be replaced by a dropdown to simply select month+year for user's ease.

Month View

I would be finalising the user interface design in the upcoming week and suggestions from you all would be highly valuable for the same.


I plan to use the following icons in the application (icons be Michele Frau [Zumi] are really cool):

  • Main Application icon:
  • Add Event toolbar icon:
  • I would be needing a Calendar toolbar icon similar to one in the wireframes.

Apart from this I would also be working on to improve date/time classes in Haiku as required for the application.