Google Health Viewer

I am preparing to take on the task of writing a Google Health Viewer for Android phones. I have done a bit of background reading, but still not enough to launch into the project. What I'm wondering, by publishing this post, is whether there are like-minded collaborators out there, also interested in such a product.

Firstly, I should state that it's my wish to make this an open-source project, and, like the Google Health service itself, be a free app.

I know a lot of folk have concerns about Digital Medical Records, but surely the usefulness, and potentially life-saving benefits to come from it outweigh whatever overly sensitive, and largely unfounded anxieties we have about privacy?

So, if anyone's interested just bung a comment to this post. Would be interested in knowing if things like useful wrapper classes on the Google Data API's are available? Or even ready-made classes for Google Health data entities themselves?

Xml Handling in Android

In recent years I have mostly coded in C#, so on entering the wonderful world of Android and polishing up my Java skills, I find I sorely miss some of the niftier C# language elements like indexers and properties and their proliferation throughout various .NET frameworks classes.

When it came to querying/modifying XML in Android, I found it handy to write a handful of helper methods which achieve the equivalents of the below in C#:

   XmlElement XmlNode[string name];  (get)
   string XmlNode.InnerText;  (get)
   string XmlNode.InnerText;  (set)
   string XmlNode.OuterText;  (get)

Also, note a solution to the very annoying org.w3c.dom.Node.setNodeValue(String) problem/workaround in setInnertext().

Enjoy:

import java.io.IOException;

import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xmlpull.v1.XmlSerializer;

/**
 * A class containing a collection of helper methods for common Xml node navigation/query
 * 
 * @author Scott Powell
 */
public class XmlUtils
{
    public static Element getChildByName(Element e, String name)
    {
        NodeList l = e.getChildNodes();
        if (l == null || l.getLength() == 0)
            return null;    // not found
        
        for (int i = 0; i < l.getLength(); i++)
        {
            Node n = l.item(i);
            if ((n instanceof Element) && n.getNodeName().equals(name))
                return (Element)n;
        }
        return null;   // not found
    }
    
    public static String getInnerText(Element e)
    {
        NodeList l = e.getChildNodes();
        if (l == null || l.getLength() == 0)
            return "";    /// empty
        
        int idx = 0;
        while (idx < l.getLength())
        {
            if (l.item(idx).getNodeType() == Node.TEXT_NODE)
                return l.item(idx).getNodeValue();
            idx++;
        }
        return "";    // no #text node found, so return empty string
    }
    
    public static void setInnerText(Element e, String val)
    {
        NodeList l = e.getChildNodes();
        if (l != null && l.getLength() > 0)
        {
            int idx = 0;
            while (idx < l.getLength())
            {
                Node n = l.item(idx); 
                if (n.getNodeType() == Node.TEXT_NODE)
                {
                    //n.setNodeValue(val);  //  this isn't changing value!!
                    Node text = e.getOwnerDocument().createTextNode(val);
                    e.replaceChild(text, n);
                    return;
                }
                idx++;
            }
        }
        // no #text Node, so create one
        Node text = e.getOwnerDocument().createTextNode(val);
        e.appendChild(text);
    }
    
    public static void writeElementTo(Element e, XmlSerializer s) throws IOException
    {
        s.startTag("", e.getNodeName());
        if (e.hasAttributes())
        {
            NamedNodeMap m = e.getAttributes();
            for (int i = 0; i < m.getLength(); i++)
            {
                Node n = m.item(i);
                s.attribute("", n.getNodeName(), n.getNodeValue());
            }
        }
        if (e.hasChildNodes())
        {
            NodeList kids = e.getChildNodes();
            for (int i = 0; i < kids.getLength(); i++)
            {
                Node n = kids.item(i);
                if (n.getNodeType() == Node.ELEMENT_NODE)
                    writeElementTo((Element)n, s);  // recursively write child element
                else if (n.getNodeType() == Node.TEXT_NODE)
                {
                    s.text(n.getNodeValue());
                }
            }
        }

        s.endTag("", e.getNodeName());
    }
}

Auto-repeat Buttons in Android

To my surprise there doesn't seem to be an attribute with the standard android.View.Button class to make it auto-repeat while the Button is pressed. I've seen this behaviour in the DatePicker dialog, so assumed the behaviour is standard. Well, unless I'm going blind and just missed it, I went and wrote my own AutoRepearButton class.

For the Android fans out there, here is the source:

package com.spleenware;

import java.util.TimerTask;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.Button;

/**
 * Surprisingly, an AutoRepeatButton doesn't seem to be in the standard Android View frameworks.
 * So, simple implementation here. When Button is held down its onClickListener is called on a timer.
 *  
 * @author Scott Powell
 */
public class AutoRepeatButton extends Button
{
    public AutoRepeatButton(Context c)
    {
        super(c);
    }
    
    /**
     * Constructor used when inflating from layout XML 
     */
    public AutoRepeatButton(Context c, AttributeSet attrs)
    {
        super(c, attrs);
    }

    /**
     * TODO: These could be made variable, and/or set from the XML (ie. AttributeSet) 
     */
    private static final int INITIAL_DELAY = 900;
    private static final int REPEAT_INTERVAL = 100;
    
    private TimerTask mTask = new TimerTask()
    {
        @Override
        public void run()
        {
            if (isPressed())
            {
                performClick();  // simulate a 'click'
                postDelayed(this, REPEAT_INTERVAL);   // rinse and repeat...
            }
        }
    };
    
    @Override
    public boolean onTouchEvent(MotionEvent event)
    {
        if (event.getAction() == MotionEvent.ACTION_DOWN)
            postDelayed(mTask, INITIAL_DELAY);
        else if (event.getAction() == MotionEvent.ACTION_UP)
            removeCallbacks(mTask);  // don't want the pending TimerTask to run now that Button is released!

        return super.onTouchEvent(event);
    }
    
}