Posts Tagged ‘Android’

Posts that contains tutorials and information about Google’s OS, Android.

Android: get String resource at another XML namespace

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This post shows the necessary steps to obtain the correct String resource outside the Android XML namespace. It has been written specifically for dealing with string resources associated with Preferences inflated from XML files, so this post assumes that the reader is familiar with writing customized preferences for Android. Altought, it can probably be used on other situations. This code has been tested on an emulator running Android 2.1 and also on real devices running Android 2.1, 2.2 and 4.0.4.

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Android: “reset to default” preference dialog

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This post explains how to create a DialogPreference that allows the user to reset all preference values to their defaults. This post has been created and tested in both the emulator and on a real device running Android 2.1. Therefore, some method calls used in this example may be deprecated on newer Android versions.

The best way to show how to reset all the preference values with a DialogPreference is by presenting an example featuring PreferenceActivity that sets some preferences, and them show how to revert them back to their default. This example project can be downloaded at the end of the post. So, the first thing needed for this example is a XML file that defines the contents of the preference screen: (more…)

Android: Changing image color saturation

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It’s the 100th post on 41 Post! This Android programming tutorial shows how to control the color saturation of an image using a SeekBar. The code featured in this post has been tested at an emulated and on a real device both running Android 2.1 . An example project with the code featured below is available at the end of the post.

As previously described, a SeekBar is going to be used to control the saturation of an Bitmap object that is rendered at the screen using a ImageView. Since a screenshot is far more descriptive then trying to explain how the application user interface will end up looking like, here’s a screenshot: (more…)

Android: how to rotate a View element

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Another Android programming tutorial, this time, explaining how to rotate a View element using two distinct approaches. Not only that, but this post also presents a brief explanation on the advantages and disadvantages of each approach. The code featured here has been tested on both the emulator and on a real device running Android 2.1 . Before going any further, please bear in mind that from Android 3.0 (API level 11), a setRotation() method has been added to the View class, therefore, it should be used instead of the code described in this article, which focuses on lower level APIs.

The first and perhaps most direct method of rotating a View element is to create a class that inherits from a View widget that needs to be rotated, for example, the TextView or the Button. Then, inside this class, the onDraw() method must be overridden. (more…)

Android: rendering a path with a Bitmap fill

Click here to read Android: rendering a path with a Bitmap fill

This Android tutorial shows how to render a Path that is filled by a Bitmap and displays stroke in a different color. It also explains how to manipulate the texture coordinates to make it independent of the position of the path, just like a mask, but without using any of the PorterDuff rendering modes. The code featured in this code was created and tested on Android 2.1, both on a real and at an emulated device.

Here’s a video of the example application in action:


If you can’t play the video, don’t worry: there is a screenshot of the application at the bottom of this post.

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