Category: Android
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Saving and reading files in the internal storage
You can save and read files in the internal storage as private files which only your app can see except for other apps with root privileges.
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The class LruCache to manage a cache of bitmap objects
The intensive use of many images in an app can create difficulties to the responsiveness and to memory, shown by warnings like ANR (Application Not Responding) or errors like OutOfMemoryError.
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Avoiding too frequent updates to the views
In Android in order to avoid to do too work in the main thread, most of the operations should be carried out in a secondary thread or a class that extends AsyncTask; then the final results are reported in some view to be shown to the user using Activity.runOnUiThread(Runnable) or View.post(Runnable) (see Processes and Threads)…
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Golden Rolly
I published an app in Google Play Store named Golden Rolly, it is a game of the category puzzle and you can find a short video presentation here.
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Resetting the preferences on first launch of an app
If you want to reset or change preferences of an app at the first start here is an example of code you can put in an event as onCreate of the main activity:
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Restoring complex objects at restart of an activity
In an android app an activity is created and then destroyed, for example when the user open another activity or when the user presses the back button, later the user opens again the same activity that is is recreated using the data saved before the earlier destruction of the activity. The data are saved in…
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List of the sensors in a device
In December 2012 I wrote a post about an app that displays the sensor list in an android device, now after about a year and a half the API 19 have new sensor types and methods and I thought to update the app.
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Implementing the double tap on an ImageView
In this post I explain a simple example of an implementation of a double tap event on an ImageView that can be adapted with some changes for a TextView or an Activity.
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Padding and margin in DialogPreference
I implemented a Time Picker in the preference using the code found here where the class TimePreference extends the class DialogPreference but I found a lack of alignment with the other preference items because of a different setting of the margins and/or padding.
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Handling the multi-touch in a surface view
In the previous post Handling the multi-touch in a view I’ve used a class that extends a View to show the circles where the screen is touched, here I display the same example but using a SurfaceView.