Develop Reference

How does Android Studio know about backwards compatibility issues?

I am trying to understand how Android Studio determines if a code is available in a certain API. When using MediaStore.setRequireOriginal, Android Studio warns me that "this call requires API level 29". Does Android Studio check that this code is available in previous Android version sources?
photoContentUri = MediaStore.setRequireOriginal(photoContentUri)
I am trying to understand how it knows this.

The linter just knows all the APIs in all the versions. You don't need to download all the previous Android version sources (I was wondering how Android Studio's Linter knew about older versions when I only had API level 29 and 30 sources downloaded on my machine).
As you can see, lint now has a database of the full Android API such that it knows precisely which version each API call was introduced in.
Lint API Check page

The Short Answer:
It's set by the developer, And Android Studio just compares your minSdkVersion set in build.gradle file with the required api level.
The Longer Answer:
When you get this warning on a method, just CTRL+click on it to go to the source class, and there you will find it annotated #RequiresApi or/and #TargetApi, for example :
class MediaStore{
#RequiresApi(api = 29)
#TargetApi(29)
void setRequiredOriginal(...){}
}
Your build.gradle file:
defaultConfig {
minSdkVersion 23
...
}
Android Studio compares minSdkVersion to #RequiresApi or/and #TargetApi at the time you call the method MediaStore.setRequiredOriginal(...); and warn you if minSdkVersion is less that the recommended api.
Please note that there are differences between #RequiresApi and #TargetApi, sometimes you find them used along with each other but sometimes just one of them.
For more about difference between the two see: https://stackoverflow.com/a/50578783/10005752

There is something in build.gradle of application module like:
defaultConfig {
minSdkVersion 23
targetSdkVersion 30
}
So you can change the "minSdkVersion" to 29, and the warning message disappear ...
And if not:
With android OS version >= 29: your code works normally
With android OS version <29: might be an exception occurs

Androidx min sdk

What is androidx min sdk? I just migrated to androidx and i need to support minsdk 14. But my build fails indicating that androidx.browser:browser:1.0.0 has minsdk 15.
I can't find it in release notes or anywhere else

androidx.browser:browser:1.0.0 requires the minSdk = 15 (see) in order to function properly, so generally theres no way to support minSdk = 14 while still using androidx.browser:browser:1.0.0.
So basically you have these options:
a. Set minSdkVersion to 15 in app level build.gradle file(and stop supporting minSdkVersion 14)
However if u 'must' have to support minSdkVersion 14 :
b. You can add this line in AndroidManifest.xml file just before application tag:
<uses-sdk tools:overrideLibrary="androidx.browser"/>
this will ensure the project will run properly in most cases but it might lead to run time crashes in few occasions.If you are not really using some feature of the class that absolutely requires sdkVersion 15 then u might just get lucky.
c. Look for alternative classes that can do similar behaviour with minSdkVersion 14 (this might be extremely unlikely)
d. You can consider reverting back to android support libraries instead of androidx. Since, android support libraries will continue to stay around in the google's maven repo for a while.

As stated here:
Starting with Support Library release 26.0.0 (July 2017), the minimum supported API level across most support libraries has increased to Android 4.0 (API level 14) for most library packages.
AndroidX has started with the support library for API Level 28, so minSdk 14 will be the requirement.
For your artifact, the current stable version requires minSdk 15 and the current latest alpha release (1.2.0-alpha09) requires minSdk 16.
AndroidX browser is afaik a replacement / androidX version of Chrome Custom Tabs which had required minSdk 16, maybe this explains the sdk requirement.
By the way you can find the release notes here.

Can't update the project to Nougat (api 25)

I have an Android Studio project. The target- and compileSdkVersion for it - is 21. I want to change it to 25.
When I do this, some of the classes of the Android standard library become unavailable. For example org.apache.http.client.HttpClient.
here are some screenshots
Android classes before the rise of SDK version. You can see how many classes in org.apache.http.*
And Android classes after the rise of SDK version:
I also looked into the android reference, and saw that there is as little classes for 25 api, and (I was confused) for 21 api also. And I noticed that they are the same as I have after upgrade
Why in the case of 21 api, I have more classes? And how to fix it? Waiting for help. Thanks.

Since Api 23 (Marshmallow - Android 6.0), the Apache HTTP Client has been removed.
To continue using the Apache HTTP APIs, you must first declare the
following compile-time dependency in your build.gradle file:
android {
useLibrary 'org.apache.http.legacy'
}

Find higher api 23 calls than minSdk 21

Hello there are some answer on this topic, but none which worked for me so far.
My build.gradle looks like this
compileSdkVersion 23
buildToolsVersion "23.0.3"
minSdkVersion 21
targetSdkVersion 23
Somewhere in my Fragments I called the method getContext() and that crashed the app on a Lollipop 5.0 device. It works fine on Marshmallow 6.0.
The Fragment is imported from the non support library package.
import android.app.Fragment;
and since I have compileSDK on 23 I can call the method getContext() withing the Fragment to get the Context.
This will lead to a crash on Lollipop 5.0 and 5.1 since that method was added with API 23 and not API 21,22.
My Question is, how can I find such high level calls in Android Studio when the min SDK is below that?

how can I find such high level calls in Android Studio when the min
SDK is below that?
AFAIK Android studio normally warn the developer whenever they are using any methods which is not completely backward compatible till minSDKVersion defined by the application. So, At that point of time, you can check out current version of device and call relevant other method accordingly.
However, for some reason its not showing any lint warning while calling getContext() method. So, It seems we have to deal with it now.

Go to
-> Analyze -> Inspect Code -> run code inspection
Then in the result view there is
"Project Name"
- Android > Lint > Correctness
- calling new methods in older versions
Under (calling new methods in older versions) all unavailable calls should be listed

Now that we're in 2022, I found a more appropriate solution.
Run the gradlew lint command in Terminal and waiting for it to finish will generate a report file.
Wrote HTML report to file:///C:/Users/Administrator/path/to/project/module/build/reports/lint-results-$flavorName$buildType.html
open this file in browser, find InlinedApi and NewApi and you will find all of it.

Android studio check for compatibility with API < 19

I have an application project with this settings:
android {
compileSdkVersion 21
buildToolsVersion '19.1.0'
defaultConfig {
minSdkVersion 10
targetSdkVersion 19
}
buildTypes {
release {
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_7
targetCompatibility JavaVersion.VERSION_1_7
}
}
And I have a block with try-with resources which not use checking if Build.SDK is less than API 19.
I don't get any errors from IDE about it.
I ran a program on emulator with target SDK Android 4.1.2 and everything is fine, also checked on the device with Android 4.2.2. The program is invoke this code, checked with the debugger.
Is everything ok? I expect that there is might be compatibility errors from IDE but there's not.
If I try to create a new project in IDE with same minVersionSdk 10, I've got a error from IDE about the compatibility.
But in my working project I don't get it.
I don't know, is there any other settings for compatibility, not in build.gradle and AndroidManifest.xml? Why is it working on API < 19 ?
UPDATE:
you need to check Lint settings in Android Studio.
Editor - Inspections
Android Lint, Calling new methods on older versions

Why is it working on API < 19 ?
According to this: https://code.google.com/p/android/issues/detail?id=73483 It "mostly works" from API 15, and you tested on an API 16 emulator (4.1.2).
Issue raiser states:
Since it was unhidden in API level 19, try-with-resources is backwards compatible down to API level 15.
Google member replies (edited down):
AutoCloseable was in ics. and it's just an interface; it's javac that emits code to actually do the closing. iirc there are fewer classes that are AutoCloseable in ics than we actually unhid
so "backwards compatible" is a bit misleading. "mostly works" is closer to the truth.
Because it's not fully compatible, the warning is from API 19.
As to why you are not seeing the warning, I think that is down to your very old buildToolsVersion which dates back to December 2013. https://developer.android.com/tools/revisions/build-tools.html
You should always keep your Build Tools component updated by downloading the latest version using the Android SDK Manager

If you only use methods which were created before API 10 (You can check here) everything is ok.
If you are not sure, you can run lint (by right clicking on your root folder) and then you can check if lint warn you about deprecated method usage.
If you want more explanation don't hesitate to comment