GSoC 2022 Final Report: Improving the Calendar Application

Blog post by HarshitSharma on Mon, 2022-09-12 15:04

Project Description

A Calendar application is a must have application for any operating system and is beneficial for end users as well as developers. Having a feature-rich Calendar might not sound like a big deal, but it can drastically impact your performance at work and personal life.

The basic idea of my project was to improve the Calendar Application, by implementing the the following features:

  • Filter Utility
  • Reminders Utility
  • Calendar Profiles (After some discussion, we decided not to work on this)

Hence, I ended up implementing the Filters and Reminders

My fork:

Tag to my last commit under GSoC:

Work Done

Filter Utility



In this PR, we implemented the Filter Feature. It’s UI and working can be seen here.

So, now we can filter out the events as per the keywords entered.

How to test?

I also have created a bash script to add demo events on any certain day, so that we can test out the filtering. Here is a link to it:

Just place the in the events directory (~/config/settings/Calendar/events) and open the terminal there. Then run ./ in the terminal you opened.



It was a more typical project and it required much more discussion, which we did on this thread and with my mentors on emails.

We created a separate background application (CalendarDaemon) which:

  • Searches for the events and stores them in a list, and keep the list updated with adding/removing the events.
  • Then sends off an alert for the event, at the specified time

We also did some changes in the UI of the main Calendar Application along with the existing data model. The new UI can be seen here:


Initially we started with only one PR, and did everthing in it. Not so surprisingly, the PR got way too big to handle. So, we broke the work into multiple PRs.

Here are the PRs:

PR Short Description Initial PR Code restructure for Daemon. Restructured the files, so there is a Calendar app and a separate Daemon Removed dependence of the DBManager on the Main Application Set up a basic daemon which node monitors the Events directory for events adding/removing. UI change in Calendar and data model changes Querying the DB for an updated list of events Getting alerts at the right time using BMessageRunner

What’s next?

The work for Daemon is (almost) complete. The daemon can start as a background application, fetches the events' list from the DBManager and monitors the events directory (~/config/settings/Calendar/events). It can also send the Alert for reminding for the event at the pre-specified time. What remains is: Automatically starting the CalendarDaemon with the help of launch_daemon. The issue for this: I would definitely complete this.

I’ve decided to continue to contribute to open source in my spare time. And I’ll continue to engage with the Haiku community as well. Projects here are really interesting!

Final Words

I had a great and very productive time working on this project. Thanks to this project, I have learnt many things about Haiku, git, Bash Scripting and even C++!

First of all about the Haiku API. I started as a noob in the Haiku API (everyone does :P). My first project was the Filter Utility, in which I used some C++ functions to implement the searching and the Haiku API for UI changes. The Be Book helped me a lot in this. You can also check it out here: I also got to know about some C++ Standard Library Functions, which I used to implement the filtering internally.

Now it came down to testing the filtering, and obviously we needed many events to filter them out! But creating events manually through the Calendar app was quite a drag. So I wrote a script which can add some events to the specified day.

For the next project, I needed to create a separate Daemon! Let me be honest, it was quite a task for a beginner! `:) But yes, we pulled this off. Again, the Haiku API along with the legacy docs helped a lot.

How did I created an appication with no previous knowledge at all? Here lessons from DarkWyrm were much useful (You can find them here) They really do contain a step by step explaination of how to create an application from scratch in Haiku. Recommended to every beginner contributer out there!

All these things, would not been completed if constant guidance from my mentors wasn’t there. So, a special thanks to my mentors Niels Sascha Reedijk and Humdinger. They mentored me really well and were always ready to help me out. Thanks for being patient with me and clarifying my doubts.

Finally, I would like to thank this amazing community!

Have a great day!