Posts Tagged ‘Java’
These posts contain code written in Java or are somehow related to Java.
Android: Obtaining the current orientation using a BroadcastReceiver
Posted by Dimitri | Filed under Programming
This Android tutorial explains how to create a Broadcast Receiver that detects screen orientation changes that are triggered by rotating the device. Since screen orientation changes don’t happen every second, it’s better to detect it using a BroadcastReceiver instead of a Service. Both can be used to execute tasks on the background, but the BroadcastReceiver execution will be triggered only when the desired Intent is filtered (in this case, a screen orientation change). Right after the execution, the background task is killed, which is ideal since a BroadcastReceiver can be created to obtain the new screen orientation only after it has changed.
Android: how to create a loading screen – Part 3
Posted by Dimitri | Filed under Featured, Programming
This is the third and final post of a series that explains how to code a loading screen for Android. The other two previous posts (which can be found here and here), used two distinct approaches to solve the problem of executing code on a background thread and update the progress back to the application’s UI thread. However, both of them relied on an instance of the ProgressDialog class to display the current progress. In the following paragraphs, instead of using this type of dialog, a custom View inflated from a layout XML file is going to be created to achieve that purpose.
As the other two previous posts, all the code in this article has been created and tested in Android 2.1. An example Eclipse project is available at the end of the post.
Android: how to create a loading screen – Part 2
Posted by Dimitri | Filed under Programming
This is the second tutorial from the post series that explains how to code a loading screen on Android. The first one can be found here. This post has a similar approach to the previous one, except this time, instead of using a AsyncTask to execute code on the background thread, a Thread and Handler objects are going to be used to achieve the same results.
The Activity featured below is somewhat similar to the first post, except this time, the UI rendering related functions calls will be more scattered throughout the Activity’s body. Additionally, the Runnable interface is going to be implemented multiple times in the below code. Not only that, but now it’s necessary to “kill” the thread manually after the code executes, a task that is handled automatically by the AsyncTask class (see this thread for more info).
All code has been developed and tested in Android 2.1, and is available for download at the end of the post.
Android: how to create a loading screen – Part 1
Posted by Dimitri | Filed under Programming
This is the first of three Android post in a series that explains how to code a simple loading screen that shows the progress of operation before the application’s View is loaded. This first tutorial objective is to create this loading screen in simplest way possible. The code featured in this tutorial has been developed and tested in Android 2.1, but it should work without much modification in later versions. All code featured in this tutorial is available for download at the end of the post.
Because of the nature of the Android operational system and the Activity stack, there’s no way to precisely determine the loading progress of an Activity. That’s why, in the below example, the Activity is going to be started, but instead of loading the standard View, it will load a ProgressDialog object and simulate a computationally heavy process on a background thread right on the beginning of the onCreate() method.
Android: Initialize View child class object from a XML file
Posted by Dimitri | Filed under Programming
This tutorial shows how to inherit from the View class to create your own customized View element, and how to initialize an object from this child class with parameters defined at a layout XML file. There are two major advantages in this approach over initializing the extended View object at the Activity.
The first is that the Java part of your code remains clean, without a lot of member variable assignments to set the View’s basic parameters. The second and most important, is the possibility to instantly preview the changes at the Graphical Layout tool in Eclipse without the need to execute the application. This means that the space this customized View element takes on the screen can be immediately be seen and adjusted, if necessary.