any one find out screen width solution? – Mayur R. Amipara Jun 5 '15 at 10:27
override your custom view's onMeasure, set it's width to screen width. and in onLayout, relayout your child views.
it works for me.
import android.content.Context;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.View;
import android.widget.RelativeLayout;
import com.android.gallery3d.R;
public class SelectActionModeCustomView extends RelativeLayout {
    private View mLeftButton;
    private View mRightButton;
    private int mScreenWidth;
    private static final String TAG = "SelectActionView";
    public SelectActionModeCustomView(Context context, AttributeSet attrs) {
        super(context, attrs);
        DisplayMetrics metrics = context.getResources().getDisplayMetrics();
        mScreenWidth = metrics.widthPixels;
    }
    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        mLeftButton = findViewById(R.id.cancel);
        mRightButton = findViewById(R.id.select_action);
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        this.setMeasuredDimension(mScreenWidth, this.getMeasuredHeight());
    }
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);
        int childLeft = 0;
        int childTop = 0;
        childLeft = 0;
        childTop = ((b - t) - mLeftButton.getMeasuredHeight()) / 2;
        mLeftButton.layout(childLeft, childTop, 
                childLeft + mLeftButton.getMeasuredWidth(), 
                childTop + mLeftButton.getMeasuredHeight());
        childLeft = (r - l) - mRightButton.getMeasuredWidth();
        childTop = ((b - t) - mRightButton.getMeasuredHeight()) / 2;
        mRightButton.layout(childLeft, childTop, 
                childLeft + mRightButton.getMeasuredWidth(), 
                childTop + mRightButton.getMeasuredHeight());
    }
}