Fixed aspect ratio View

Question

How would I go implementing a fixed aspect ratio View? I\'d like to have items with 1:1 aspect ratio in a GridView. I think it\'s better to subclas

Answer 1

I recently made a helper class for this very problem and wrote a blog post about it.

The meat of the code is as follows:

/**
 * Measure with a specific aspect ratio

 * 

 * @param widthMeasureSpec The width MeasureSpec passed in your View.onMeasure() method
 * @param heightMeasureSpec The height MeasureSpec passed in your View.onMeasure() method
 * @param aspectRatio The aspect ratio to calculate measurements in respect to 
 */
public void measure(int widthMeasureSpec, int heightMeasureSpec, double aspectRatio) {
    int widthMode = MeasureSpec.getMode( widthMeasureSpec );
    int widthSize = widthMode == MeasureSpec.UNSPECIFIED ? Integer.MAX_VALUE : MeasureSpec.getSize( widthMeasureSpec );
    int heightMode = MeasureSpec.getMode( heightMeasureSpec );
    int heightSize = heightMode == MeasureSpec.UNSPECIFIED ? Integer.MAX_VALUE : MeasureSpec.getSize( heightMeasureSpec );

    if ( heightMode == MeasureSpec.EXACTLY && widthMode == MeasureSpec.EXACTLY ) {
        /* 
         * Possibility 1: Both width and height fixed
         */
        measuredWidth = widthSize;
        measuredHeight = heightSize;

    } else if ( heightMode == MeasureSpec.EXACTLY ) {
        /*
         * Possibility 2: Width dynamic, height fixed
         */
        measuredWidth = (int) Math.min( widthSize, heightSize * aspectRatio );
        measuredHeight = (int) (measuredWidth / aspectRatio);

    } else if ( widthMode == MeasureSpec.EXACTLY ) {
        /*
         * Possibility 3: Width fixed, height dynamic
         */
        measuredHeight = (int) Math.min( heightSize, widthSize / aspectRatio );
        measuredWidth = (int) (measuredHeight * aspectRatio);

    } else {
        /* 
         * Possibility 4: Both width and height dynamic
         */
        if ( widthSize > heightSize * aspectRatio ) {
            measuredHeight = heightSize;
            measuredWidth = (int)( measuredHeight * aspectRatio );
        } else {
            measuredWidth = widthSize;
            measuredHeight = (int) (measuredWidth / aspectRatio);
        }

    }
}