Native tick sound on button click with PhoneGap

PhoneGap is a good framework to build hybrid applications, but for a great usability the devil is in the detail. A difference with native buttons is that HTML5 rendered hyper-links don’t produce a click sound with PhoneGap. Such small difference gives directly a non standard user experience to your app. So I came up with a small PhoneGap plug-in to fix this small annoyance.

Java code:

public boolean execute(String action, JSONArray args, final CallbackContext callbackContext) throws JSONException {
	if("click".equals(action)) {
		try {
			cordova.getActivity().runOnUiThread(new Runnable(){
				public void run(){
					try {
						View view = cordova.getActivity().getWindow().getDecorView();
						view.playSoundEffect(SoundEffectConstants.CLICK);
					}
					catch(Exception ex) {
						callbackContext.error(ex.getMessage());
					}
				}
			});
		}
		catch(Exception ex) {
			callbackContext.error(ex.getMessage());
		}

		return true;
	}

	return false;
}

JavaScript code:

$(function() {
	$(document).on("click", ".sound-click", function() {
		cordova.exec(function () { },
					function () { },
					"SoundEffects",
        			"click",
        			[]);
	});
});

In order to have the click sound, it it sufficient to add the “sound-click” class to your HTML5 buttons (and jQuery referenced in your page).

Developing mobile applications with PhoneGap and JQuery Mobile

Introduction

For a very long time I have avoided learning HTML and ASP.Net and stayed away of applications using it. I didn’t wanted to end up with messy code and hacks to support multiple browsers (read: Internet Explorer 6.0). But as HTML5 and CSS3 are gaining more momentum, I have changed my mind and I have started learning HTML, CSS and JavaScript. Even if these technologies have their annoyances, they are THE way to develop cross platform software applications.

Recently there was a lot of buzz around PhoneGap. This a software framework that allows wrapping HTML5 applications into native applications for various mobile platforms (including iPhone, Android and Windows Phone). The idea of developing a mobile application for multiple platforms with a single code base is very tempting.

During the article I have still used the old name PhoneGap, but the framework has recently been open-sourced and renamed into Cordova (http://incubator.apache.org/projects/callback.html). Adobe will continue to offer a commercial version using the PhoneGap branding (http://phonegap.com/).

During the past days, I have developed a simple Todo Application using the following technologies:

• PhoneGap to wrap in into a native application.
• JQuery Mobile for the UI.
• HTML5 local storage to store the user data.

The applications consists of 6 screens and runs completely local; it does not require internet access to function. Theoretical it should be able to run on iPhone, Android and Windows Phone, but I was only able to test on a real Windows Phone device and on the desktop versions of Firefox, Safari and Chrome. So although it was not tested on multiple devices, I don’t expect a lot of issues when running it on IOS or Android.

 

PhoneGap & JQuery Mobile

I selected JQuery Mobile for the user interface because I like using JQuery for JavaScript development and thus it seemed the most natural choice for my screens. JQuery Mobile was pleasant and easy to use; in no time I was able to develop my screens using a simple HTML syntax combined with HTML5 data-* attributes.

I tested the application both on local browsers (Firefox, Chrome, etc.) and on the Windows Phone mobile browser. But the issues started when I started wrapping my HTML code into PhoneGap. Suddenly nothing still worked. After some trial and error, I discovered that it was required to add the PhoneGap JavaScript library to the web pages, even if you don’t need to use any special features of PhoneGap.

A second issue that I discovered was that JQuery Mobile and PhoneGap currently don’t work good together on Windows Phone 7. I was using a single HTML file per page, but the only thing that worked was either disabling the AJAX based loading of pages in JQuery Mobile or reverting to multi page HTML files. I choose for the multi page HTML files.

I hope that the page loading issue on Windows Phone will be fixed by either the PhoneGap or the JQuery Mobile developers as it is annoying.

Debugging

Debugging a HTML application wrapped in PhoneGap is not possible. The only option is to test and debug it with the developer tools of desktop browsers. If something goes wrong on the mobile device in PhoneGap, the only thing you can do is using old school console log statements to figure out what is happening.

I solved this issue this by creating two projects: a web application and the phone gap WP7 project. I develop and test with the web application project on a local browser and when I want to run it on a device, I execute a script to put the HTML  and JavaScript code into the WP7 project. Below you can find the synchronization script that I used:

@ECHO OFF

SET sourceDirectory=Html5TodoApp
SET destinationDirectory=Html5TodoApp.WindowsPhone\www

MKDIR %destinationDirectory%\images\

COPY "%sourceDirectory%\*.js" %destinationDirectory%\
COPY "%sourceDirectory%\*.html" %destinationDirectory%\
COPY "%sourceDirectory%\*.css" %destinationDirectory%\
COPY "%sourceDirectory%\images\*.gif" %destinationDirectory%\images\
COPY "%sourceDirectory%\images\*.png" %destinationDirectory%\images\

patch.exe "%destinationDirectory%\index.html" index.patch

The patch of my index.html file is required because for PhoneGap I have to add a reference to the cordova.js file. Something that is not possible in a regular browser. The “index.patch” is a regular patch file that saves me from having to update my index.html manually when I copy the source code to the PhoneGap project.

*** C:\Users\Pieter\Documents\Visual Studio 2010\Projects\Html5TodoApp\Html5TodoApp\index.html    Thu Mar 22 17:15:13 2012
--- C:\Users\Pieter\Documents\Visual Studio 2010\Projects\Html5TodoApp\Html5TodoApp.WindowsPhone\www\index.html    Thu Mar 22 17:20:51 2012
***************
*** 4,9 ****
--- 4,10 ----
<meta name="viewport" content="width=device-width, height=device-height, initial-scale=1.0, maximum-scale=1.0, user-scalable=no;" />
<title>Todo Demo Pieter</title>
<link rel="stylesheet" href="jquery.mobile-1.1.0-rc.1.css" />
+         <script src="cordova-1.5.0.js"></script>
<script src="jquery-1.7.1.js"></script>
<script src="jquery.mobile-1.1.0-rc.1.js"></script>
<script src="todo.logic.js"></script>

Conclusion

Would I recommend developing mobile applications using PhoneGap? It would depend on the application. It was a little bit more difficult to develop and test everything compared to using c# and Silverlight and the performance of the interface was also less “fluent” than a native application on my Nokia Lumia 800. But the big advantage is that my application can run on multiple platforms with almost the same code and this can be important for companies that want to deploy their business application on multiple platforms.