Android Studio ImageView Change Only Width and Maintain Aspect Ratio

Question

I've got an imageview, like this:

    <ImageView
        android:id="@+id/add_image_signup"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/other_text"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        app:srcCompat="@drawable/add_button" />

which I'm trying to scale programmatically (based on device size) with Layout Params. Something like this works great:

        val displayMetrics = DisplayMetrics()
        windowManager.defaultDisplay.getMetrics(displayMetrics)
        val height = displayMetrics.heightPixels
        val width = displayMetrics.widthPixels

        val addImage = findViewById<ImageView>(R.id.add_image_signup)
        val layoutParams = addImage.getLayoutParams()
        layoutParams.width = width * 0.3
        layoutParams.height = height * 0.1

        addImage.setLayoutParams(layoutParams)

and scales the image. However, I'd like to scale only the width, and have the height scale accordingly so that the image maintains its aspect ratio.

I tried only scaling the width, like this:

        val addImage = findViewById<ImageView>(R.id.add_image_signup)
        val layoutParams = addImage.getLayoutParams()
        layoutParams.width = width * 0.3
        addImage.setLayoutParams(layoutParams)

but that seems to have no effect.

Is there a way to only specify the width value, and have the height scale accordingly so that the image maintains its aspect ratio?

Thanks

Answer 1

Take the set width and divide it by the aspect ratio to get the height then set it like the code below

Display display = requireActivity().getWindowManager().getDefaultDisplay();
        DisplayMetrics outMetrics = new DisplayMetrics();
        display.getMetrics(outMetrics);

        Resources r = getResources();

        float density = getResources().getDisplayMetrics().density;
        //float dpHeight = outMetrics.heightPixels / density;
        float dpWidth = outMetrics.widthPixels / density;

        int widthPX = Math.round(TypedValue.applyDimension(
                TypedValue.COMPLEX_UNIT_DIP, yourImageFixedWidthValue, r.getDisplayMetrics()));

        float imageAspectRatio = (float) 335 / 217;
        float imageWidth = widthPX;
        float imageHeight = imageWidth / imageAspectRatio;

        imageView.getLayoutParams().height = Math.round(TypedValue.applyDimension(
                TypedValue.COMPLEX_UNIT_DIP, imageHeight, r.getDisplayMetrics()));
        imageView.setAdjustViewBounds(true);
        imageView.setScaleType(ImageView.ScaleType.FIT_XY);