Android adjust view when keyboard appears

Question

I want to create a dynamic login screen that includes a decorative branding image when the screen is sufficiently tall but excludes the image on short screens. When the keyboard appears, it's likely the image will need to be removed. When the keyboard is hidden, the image can come back.

With a web page, I'd just use CSS media queries for the device height, show or hide the image appropriately, and it would all work nicely. I don't think anything that simple and clean is possible for an Android view, is it? So I figure I need to know the height of the window when the activity is created and create the view appropriately.

In the manifest, I've set my main activity to adjustResize when the keyboard appears. When the keyboard appears, my view does resize but my activity is surprisingly not recreated. When the screen is rotated, the activity is recreated.

The documentation says the view will be recreated when the keyboard availability changes. The first paragraph from https://developer.android.com/guide/topics/resources/runtime-changes

Some device configurations can change during runtime (such as screen orientation, keyboard availability, and when the user enables multi-window mode). When such a change occurs, Android restarts the running Activity ( onDestroy() is called, followed by onCreate()). The restart behavior is designed to help your application adapt to new configurations by automatically reloading your application with alternative resources that match the new device configuration.

My questions are

What's the best way to handle my design goal?

Why is my activity not recreated when the keyboard appears?

Below are the relevant parts of my test app. There is no image in this as I didn't even get that far before running into what seems like behavior contradicting the documentation.

AndroidManifest.xml

<activity
    android:name=".MainActivity"
    android:windowSoftInputMode="adjustResize">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

MainActivity.kt

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        Log.d("MainActivity", "onCreate")
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/intro"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textAlignment="center"
        android:text="Top"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:background="@color/colorAccent" />

    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@id/intro"
        android:singleLine="true" />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textAlignment="center"
        android:text="Bottom"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:background="@color/colorAccent" />

</android.support.constraint.ConstraintLayout>

Answer 1

The activity isn't recreated when the keyboard appears because that isn't how Android works. Its not supposed to be. (Although if you have an old fashioned device with a slide out physical keyboard it will be recreated when you slide it out, because its treated as a hardware configuration change). Keyboards being shown/hidden is done without recreation. Which is a good thing, that many recreate events would be expensive given how many people just shove a ton of logic into onCreate.

How to do what you want- you can't. There is no API to detect when the keyboard is opened. There are commonly used hacks that attempt to discover it, but they're all flawed (they can have problems with split screen mode, picture in picture mode, multiple screens, and keyboards which are too small, because they all work based on guessing based on height changes).

Answer 2

The method OnFocusChangeListener() will detect whenever a View gains or loses focus. EditText makes the keyboard show up whenever it gains focus. Therefore, you should attach a OnFocusChangeListener() to those EditText that you want:

EditText myET = (EditText)findViewById(R.id.myET);

myET.setOnFocusChangeListener(new OnFocusChangeListener() {
    @Override          
    public void onFocusChange(View v, boolean hasFocus) {
        if(hasFocus) {
            //Hide image
        } else {
            //Reveal image
        }
    }
});

Moreover, to hide and reveal the image you should use the property called visibility. The methods are:

myImageView.setVisibility(View.VISIBLE); //This will show the Image
myImageView.setVisibility(View.INVISIBLE); //This will make the Image invisible
myImageView.setVisibility(View.GONE); //This will make the Image invisible, and also it will collapse the layout, occupying no space at all.

Don't try using INVISIBLE and GONE simultaneously, since that could cause some trouble. In your case, from what I understand you might want to use GONE and VISIBLE.

The only problem with this approach is that if you have multiple EditText, you would have to set up many times the same code. To solve that, please refer to the following link: EditText setOnFocusChangeListener on all EditTexts

Answer 3

I've been searching for an answer and I came across this:

https://developer.android.com/training/keyboard-input/visibility#java

It says android DOES do what you want.

I just tried it, add 1 line, ONE LINE!, to your manifest and it works.

Oh wait... you want the brand to disappear... hmmm well with this it wouldn't have to?

DOH! You already knew about that.....

Answer 4

"What you want to do you can't"... I don't know how to do it, but I disagree that it can't be done. I have the PayPal app and when the keyboard appears the login button and the rest of the login screen resize so that the login button isn't covered by the keyboard. How they're doing it, I don't know, but obviously somehow the app knows the keyboard appears and adjusts accordingly.

I've been searching for an answer and I came across this:

https://developer.android.com/training/keyboard-input/visibility#java

It says android DOES resize the screen when then soft keyboard appears/disappears.

I just tried it, add 1 line, ONE LINE!, to your manifest and it works.