New tutorials

As we have seen in the previous animations tutorial it is easy to create some funny animations defined by XML.

Unfortunately in some cases we face troublesome limitations. Lest see them through an example:
We will create a simple animation that moves a buttom from the top left corner of the screen to the center when it is clicked, then remains there, and when clicked again it moves back to its original...

The first tutorial, we went through the steps to create a simple layer.
In this tutorial, we are going to explain how to include actions in this layer

In my previous article I showed how to create a simple class that handles the basic gesture events such as ACTION_DOWN, ACTION_MOVE, ACTION_POINTER_DOWN, ACTION_POINTER_UP, ACTION_UP. Combinations of these, you can implement all of touch gesture stuffs thats you need in your work with a touch screen phone.

Handling multitouch
Create a boolean member...

Our goal is to start the users gallery application, allow him to select an image, and use the chosen image in our application.

API Level 3 required!

We will start the operation on a buttons onclick event, implemented as follows:

Sometimes you may need to display short animations in your applications like funny GIFs. The problem with GIFs is that they have only 256 colors and poor transparency. You can consider using PNGs, but basically that type of image doesn't support animations. So what can you do to push the advantage of PNGs (great lossless compression, alpha channels, various coloring schemes, etc.)?

Last week, in spite of the winter the weather was very mild. The beams of the winter sun brought forward the memories of the summer: hot weather, girls in bikinis, mojitos! We have already gotten a promise for the first two in a certain form here in Helloandroid HQ (the heating system will be repaired, and we 'll have some women colleagues), but it is our task to make coctails.

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In this tutorial I'll show you a simple time meter example. It can be used for checking the running time of your algorithms. It's useful when you need to decide wich solution is faster/better than an other. It just a simple helper code, but if you made some changes on it, can be a part of any final project, like benchmarking or testing workarounds.

This demo shows how to speed up the original autocomplete textview assuming that we can work with ordered data.

Let's prepare a simple test environment, which demostrate the difference between the two versions. Then let's generate a few thousand test data, and create two textviews from which we will speed up the second one.

In this tutorial, I show you how to encrypt a string with public key in Android.

First we make a 2048-bit RSA private key in linux:

Then convert private Key to PKCS#8 format, what Java can read: (in...