For my new assignment, I wanted to use some library that can provide a "Posterize effect". I found many library like Aviary SDK and jhlabs, Yes, these are easy to use, but these making the code heavier. SO I keep searching for Android's API itself which can do the similar task. And after a lot of RnD, I finally found one my time saver class EffectsFactory which provides the same as I wanted. I applied it in my assignment also. But the bad thing it was added in API level 14, And my app should be compatible with at least API level 8.
So, My question is,
Can I use EffectsFactory class for lower version? If Yes then How?
Or, If No, Then Do we have any API in Android SDK itself which do similar to effectfactory ?
Please avoid referencing any library or NDK's open cv library.
No, there is not an Android API that will posterize an image below API 14. Even above API 14 EffectsFactory may not work, as it says in the Android documentation:
Some effects may not be available on all platforms, so before creating a certain effect, the application should confirm that the effect is supported on this platform by calling isEffectSupported(String).
However, you could easily make a lightweight solution yourself. Posterization is a simple process. For example, the code behind JHlabs' posterize filter is less than 50 lines (and most of them are sugar). In your shoes, if using a 3rd party library was out of the question, I wouldn't hesitate to write my own.
Edit: If you happen to be posterizing images your app takes from the camera, there is also Camera.Parameters.setColorEffect(), but again this is not supported on all devices, as it says in the documentation:
For example, the application should call getSupportedColorEffects() before calling setColorEffect(String).
Related
First off, I know very little about android development, I am just getting started.
What is the Minimum SDK choice that you get when creating a project in android studio? Is there a downside to using an older one? And if I follow a tutorial is it essential that I use the same one so I can follow along?
Thanks.
What is the Minimum SDK choice that you get when creating a project in android studio?
That is the oldest version of Android that you are willing to support. It is expressed in terms of an API level. You can see common API levels in the Android dashboards, and the documentation will point out in many places where things need such-and-so an API level to work.
Is there a downside to using an older one?
Less stuff in Android will be supported. In your case, since you are following a tutorial, choosing a lower minSdkVersion may cause some more complaints from your IDE, saying that such-and-so is not available on your chosen minSdkVersion.
And if I follow a tutorial is it essential that I use the same one so I can follow along?
IMHO, that depends on your overall programming experience. If you are a veteran developer, and you want to play around with a lower minSdkVersion, go ahead, bearing in mind that the tutorial code might not run on that API level. If you are fairly new to programming overall, stick with what the tutorial tells you to do. If your concern is that your test device is not new enough for the tutorial, find a different tutorial, find a different device, or use the emulator instead of a device for testing this tutorial.
android:minSdkVersion
An integer designating the minimum API Level required for the application to run. The Android system will prevent the user from installing the application if the system's API Level is lower than the value specified in this attribute. You should always declare this attribute.
You can use your own min SDK but be careful about features you use. infact, minSDK with great number have more features.
I want to build an application where the front camera of the device is used to project the current image to a SurfaceView. All the tutorials I found so far implement this by using a Camera object from the android.hardware package.
This method, however, seems to be deprecated. When trying the 'new' preferred way to implement this feature following the Android documentation, I get the warning it can only be used with API level 21, which is pretty useless.
So I would like to know the currently preferred way to implement camera functionality in an application. Or is there maybe some support library for API levels lower than 21?
Thanks in advance.
Deprecated interface does not mean you should not use it. It means you should know that it will be phasing out in the future.
As a general rule, it is better to use a newer interface if possible, in order to avoid the need to update the software later.
The fact that API level 21 does not yet have a large enough market share means that you are probably better off using the old interface for now, and keep in mind that in a year or two, you may need to update the implementation.
I think you can implement the camera function in both sets of API and check the device`s build version first then decided to call which one implementation.
eg:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){
openCameraNewAPI();
}else{
openCameraOldAPI();
}
I am new to Android development and I am following the training at http://developer.android.com to get into it. I am confused whether I do use the support library or not.
To make it clear: I do not need to support APIs older than 11.
Situation: Adding Items to the ActionBar I had to use my own Namespace to make it work (app:showAsAction="ifRoom" instead of android:showAsAction="ifRoom"), which is a normal behaviour using the support-lib, am I right?
First Question: Why am I using it? I did never activate it on purpose!
Second Question:
Is it normal that I can use both getActionBar().setDisplayHomeAsUpEnabled(true); and getSupportActionBar().setDisplayHomeAsUpEnabled(true); to make the "up"-functionality work? I thought the first one wouldn't work if I used the support-lib?
I'd be glad if one of you could help me. I don't want to mess around with these basics so I'd like to know what I understood or configured wrong.
EDIT: My "uses-sdk" in the AndroidManifest actually looks like this:
<uses-sdk android:minSdkVersion="11" android:targetSdkVersion="19" />
To answer your first question, depending on how you created your project in the first place, it was probably enabled for you automatically. There are lots of other things in the support library besides ActionBar, so even if your minSdkVersion=11, it's probably still a good idea to use it.
To answer your second question, yes, it's normal that both methods work. Framework methods are not disabled or removed when you enable the support library. They will still work as long as they are supported by the Android OS you're eventually running on. For example, if your minSdkVersion was 10 instead of 11 and you tried to run the app on a device running Gingerbread, it would crash on the getActionBar() call.
In your case, you should use the framework method (getActionBar()). The documentation for ActionBar says:
This class is included in the support library for compatibility with
API level 7 and higher. If you're developing your app for API level 11
and higher only, you should instead use the framework ActionBar
class.
The best way to know whether you need to use the support library for a given method or class is to refer to the documentation for that class and pay attention to the "Added in API Level ?" notation. Here is the documentation non-support-library version of ActionBar, where you can see that some methods were added after API 11. If you need any of those methods, you should use the support library.
Also, as I said before, there other things besides ActionBar to consider in your app. GridLayout is an example. It was added in API 14, but it also exists in the support library for backwards compatibility. If you want to use GridLayout, you should use the support library version of it.
I'm looking for a way to use an equalizer within my app which does not rely on the
android.media.audiofx package especially android.media.audiofx. Equalizer class because these are only available for api level > 9.
Does anybody know about native libraries which work well under android? I've found mpg123 but it seems that this library is very slow. Or is there even another way to implement an equalizer without native librarys?
I did quite a bit of research on this and found that you would have to likely rewrite the entire AudioTrack library in order to accomplish this.
It would require heavy DSP which would be best accomplished using the NDK, if you really want to do it.
Otherwise, I would just write a wrapper that tells the application which API level you're in, and disable those features.
Here is the abstract I wrote on this problem:
http://isthisonthetest.com/?q=node/12
Hope this helps!
EDIT:
This link has been getting a few hits (and the link was broken), so I redirected it to a blog post I just made with the original text. The URL above should work now.
I'm developing an Android app which will target 2.1/2.2 devices, so I have my project set up to use the 2.2 SDK (API level 8), but allow for installation on devices with at least API level 7.
The problem is that during my daily development, I'm not always paying close attention to which API level of the methods/classes/constants that I'm using, which makes it very easy to break code on older devices. I have got dynamic classloading working, and as much as I dislike having a ton of extra factory classes and interfaces in my project, I'm willing to deal with that solution. Currently, the only way I have to check an older API level is to set my project's settings to the given level, rebuild, see what breaks, and then refactor. It's quite a pain.
What I would really like is the ability to scan my code and check compatibility for a given API level without changing my global project build settings. Is there some easy way to do this?
Android API Analysis Plug-In for Eclipse:
http://adt-addons.googlecode.com/svn/trunk/apianalysis/
Ok, so based on my research and the comment by #CommonsWare, there's no static analysis tool or some other easy way to do this. Shucks.