Android: Setting button height in XML based on it's width

Question

I am working on layout in android XML in which I would like to set a buttons height to match it's width when setup to fill parent. Obviously this number will change based on screen size, so I cannot use a set pixel size. Can someone help me with getting the button width based on screen size and then passing that to the height setting?

Thank You, Josh

Answer 1

I once had a similar problem and found no solution which works just from XML. You have to write your own Button-Class and overwrite the [onMeassure][1] method.

Example:

/**
 * @see android.view.View#measure(int, int)
 */
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 setMeasuredDimension(measureWidth(widthMeasureSpec), measureHeight(heightMeasureSpec));
}
private int width; // saves the meassured width
/**
 * Determines the width of this view
 * 
 * @param measureSpec
 * A measureSpec packed into an int
 * @return The width of the view, honoring constraints from measureSpec
 */
private int measureWidth(int measureSpec) {
 int result = 30;
 int specMode = MeasureSpec.getMode(measureSpec);
 int specSize = MeasureSpec.getSize(measureSpec);
 if (specMode == MeasureSpec.EXACTLY) {
 // We were told how big to be
 result = specSize;
 } else {
 result =1123; // meassure your with here somehow
 if (specMode == MeasureSpec.AT_MOST) {
 // Respect AT_MOST value if that was what is called for by measureSpec
 result = Math.min(result, specSize);
 }
 }
 width = result;
 return result;
}
/**
 * Determines the height of this view
 * 
 * @param measureSpec
 * A measureSpec packed into an int
 * @return The height of the view, honoring constraints from measureSpec
 */
private int measureHeight(int measureSpec) {
 int result = 0;
 int specMode = MeasureSpec.getMode(measureSpec);
 int specSize = MeasureSpec.getSize(measureSpec);
 if (specMode == MeasureSpec.EXACTLY) {
 // We were told how big to be
 result = specSize;
 } else {
 result = width;
 if (specMode == MeasureSpec.AT_MOST) {
 // Respect AT_MOST value if that was what is called for by measureSpec
 result = Math.min(result, specSize);
 }
 }
 return result;
}

[1]: http://developer.android.com/reference/android/view/View.html#onMeasure(int, int)

Answer 2

Instead of using Pixel size by PX, mention dip(i.e. device independent pixel), dip will take the size in pixel according to the device screen size independently.

for example: android:textSize="12dip"

You can either use dip or dp.

Enjoy!!