Grokking Android

Getting Down to the Nitty Gritty of Android Development

Adding ActionBarSherlock to Your Project

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In my last post I had a look at how to set up a Fragment project that uses a master detail view. This week I am going to show you the necessary steps to make this project use the ActionBarSherlock library. ActionBarSherlock is a library by Jake Wharton, that enables you to use action bars […]  Continue Reading  “Adding ActionBarSherlock to Your Project”

Getting Started With Fragments and the Support Library

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Fragments are modular building blocks for creating a responsive Android UI. They help you to target different devices and screen sizes while at the same time avoiding code duplication. This post starts with the Android Developers Tools generating a project for you. I then explain some of the generated code and will show you how […]  Continue Reading  “Getting Started With Fragments and the Support Library”

Android: How to Use Two Data Sources in ListViews?

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Sometimes in our apps we have the need to link to data of other sources. You have a database of your own for your app, but some records also point to the MediaStore content provider to calendar entries or to contacts. For all detail pages this is not much of a problem. You get the […]  Continue Reading  “Android: How to Use Two Data Sources in ListViews?”

Use Android’s ContentObserver in Your Code to Listen to Data Changes

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When you are using a content provider as a client, chances are that you want to know whenever the data changes. That’s what Android’s class ContentObserver is for. To use the ContentObserver you have to take two steps: Implement a subclass of ContentObserver Register your content observer to listen for changes Implement a subclass of […]  Continue Reading  “Use Android’s ContentObserver in Your Code to Listen to Data Changes”

What You Need to Know About the Intents of Android’s Calendar App

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When your app needs to access calendar data you have to choose whether to use the CalendarContract content provider or whether to use Intents to start specific Activities of the Calendar app. This post covers the intents offered by the official Calendar app. While with using Intents your possibilities are limited compared to those of […]  Continue Reading  “What You Need to Know About the Intents of Android’s Calendar App”

Half a Year of Blogging About Android Development

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Exactly six months ago I published my “Hello World” post. And one week later my first post with serious content followed: Android: Checking Connectivity. Over the last half year I have continuously blogged and there were only two weeks in which I didn’t publish any posts. According my general feeling my blog progresses nicely. And […]  Continue Reading  “Half a Year of Blogging About Android Development”

iCal’s Recurrence Rule and Duration Formats

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If you create repeating events in Android using the CalendarContract content provider, the fields for recurrence rules (RRULE) and durations (DURATION) follow the iCal format (RFC 5545). Here I cover the basics of these formats to create valid field values. This post is somewhat of an oddity on this blog as most of its content […]  Continue Reading  “iCal’s Recurrence Rule and Duration Formats”

Android’s CalendarContract Content Provider

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Android developers have been longing for an official Calendar app and content provider since Android has been released. With the release of Ice Cream Sandwich Google has finally added this feature to our tools list. Now we developers can use the Calendar app from within our Activities using Intents or we can access the data […]  Continue Reading  “Android’s CalendarContract Content Provider”

Useful Android Libraries: Crouton

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One way to notify users is to use Toasts. But Toasts have the problem that they might pop up in totally unrelated contexts. They are displayed for a defined duration on the screen no matter what the user does. The user might even have changed the app, with the result, that your Toast simply confuses […]  Continue Reading  “Useful Android Libraries: Crouton”

Take These Steps to Make your Android App Accessible

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Accessibility in an app helps users with disabilities to use your app with the help of the Android system. Android’s accessibility system tools as well as third-party developer’s tools provide features to help with visual impairment. In this post I outline why you should care about accessibility and what steps to take to make your […]  Continue Reading  “Take These Steps to Make your Android App Accessible”