Question

I need to resize an ImageView such that it fits to the screen, maintains the same aspect ratio. The following conditions hold:

• Images are a fixed width (size of the width of screen)
• Images are downloaded from the Internet, i.e. size can only be determined later
• Aspect ratio for each image will vary; some are tall, some are square, some are flat
• ImageView’s height needs to change, either bigger or smaller based on the aspect ratio of the
• Excess height is cropped, can’t have a lot of empty space like it is by default.

For example, a tiny 50×50 image on a 400 px width screen would scale the image up to 400×400 px. A 800×200 image would scale to 400×100.

I’ve looked at most of the other threads, and many proposed solutions like simply changing adjustViewBounds and scaleType will only scale down an image, and not scale it up.

Answer 1

ImageView mImageView; // This is the ImageView to change

// Use this in onWindowFocusChanged so that the ImageView is fully loaded, or the dimensions will end up 0.
public void onWindowFocusChanged(boolean hasFocus) 
{
    super.onWindowFocusChanged(hasFocus);

    // Abstracting out the process where you get the image from the internet
    Bitmap loadedImage = getImageFromInternet (url);

    // Gets the width you want it to be
    intendedWidth = mImageView.getWidth();

    // Gets the downloaded image dimensions
    int originalWidth = loadedImage.getWidth();
    int originalHeight = loadedImage.getHeight();

    // Calculates the new dimensions
    float scale = (float) intendedWidth / originalWidth;
    int newHeight = (int) Math.round(originalHeight * scale);

    // Resizes mImageView. Change "FrameLayout" to whatever layout mImageView is located in.
    mImageView.setLayoutParams(new FrameLayout.LayoutParams(
            FrameLayout.LayoutParams.WRAP_CONTENT,
            FrameLayout.LayoutParams.WRAP_CONTENT));
    mImageView.getLayoutParams().width = intendedWidth;
    mImageView.getLayoutParams().height = newHeight;
}