NavigationDrawerSliderView.java

/**
 * 
 */
import android.content.Context;
import android.os.Handler;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.widget.HorizontalScrollView;

/**
 * @author hemant
 *
 */
public class NavigationDrawerSliderView extends HorizontalScrollView {

	public NavigationDrawerSliderView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context);
    }

    public NavigationDrawerSliderView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    public NavigationDrawerSliderView(Context context) {
        super(context);
        init(context);
    }
	
	
	void init(Context context) {
        setHorizontalFadingEdgeEnabled(false);
        setVerticalFadingEdgeEnabled(false);
    }
	
	
	public void initViews(View[] children, int scrollToViewIdx, SizeCallback sizeCallback) {
        ViewGroup parent = (ViewGroup) getChildAt(0);
        parent.removeAllViews();

        for (int i = 0; i < children.length; i++) {
            children[i].setVisibility(View.INVISIBLE);
            parent.addView(children[i]);
        }

        OnGlobalLayoutListener listener = new MyOnGlobalLayoutListener(parent, children, scrollToViewIdx, sizeCallback);
        getViewTreeObserver().addOnGlobalLayoutListener(listener);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        // Do not allow touch events.
        return false;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        // Do not allow touch events.
        return false;
    }
    
    class MyOnGlobalLayoutListener implements OnGlobalLayoutListener {
        ViewGroup parent;
        View[] children;
        int scrollToViewIdx;
        int scrollToViewPos = 0;
        SizeCallback sizeCallback;
        
        public MyOnGlobalLayoutListener(ViewGroup parent, View[] children, int scrollToViewIdx, SizeCallback sizeCallback) {
            this.parent = parent;
            this.children = children;
            this.scrollToViewIdx = scrollToViewIdx;
            this.sizeCallback = sizeCallback;
        }

        @Override
        public void onGlobalLayout() {
        	
            final HorizontalScrollView me = NavigationDrawerSliderView.this;

            me.getViewTreeObserver().removeGlobalOnLayoutListener(this);

            sizeCallback.onGlobalLayout();

            parent.removeViewsInLayout(0, children.length);

            final int w = me.getMeasuredWidth();
            final int h = me.getMeasuredHeight();

            int[] dims = new int[2];
            scrollToViewPos = 0;
            for (int i = 0; i < children.length; i++) {
                sizeCallback.getViewSize(i, w, h, dims);
                children[i].setVisibility(View.VISIBLE);
                if(i == 0){
                	parent.addView(children[i], 0, dims[1]);//Making width of the menu 0 to prevent it from showing momentarily. 
                } else{
                	parent.addView(children[i], dims[0], dims[1]);
                }
                if (i < scrollToViewIdx) {
                    scrollToViewPos += dims[0];
                }
            }

            new Handler().post(new Runnable() {
                @Override
                public void run() {
                    me.scrollBy(scrollToViewPos, 0);
                }
            });
        }
    }

    /**
     * Callback interface to interact with the HSV.
     */
    public interface SizeCallback {
    	
        public void onGlobalLayout();

        public void getViewSize(int idx, int w, int h, int[] dims);
    }

}