iPhone and Android development with Titanium

Over the past few months I’ve worked on a couple of mobile applications for the iPhone and Android platforms. I’d looked at Phonegap some time before that, but determined that it wasn’t up to the job, but more recently I stumbled across Titanium from Appcelerator. The idea is that you code up your apps using HTML and Javascript. The Javascript calls the Titanium API to create things like lists, dialog boxes, and phone features such as geolocation.

Some of the advantages of using Titanium are:

– No need to learn Objective-C (iPhone) or Java (Android)
– Leverage existing HTML + Javascript skills
– Write one version of the code that can be deployed to both platforms
– Code is compiled up into native applications which are accepted in the App Store
– Potential to deploy to other platforms in the future (e.g. Blackberry, Symbian)

The level of support provided by the Appcelerator staff on the official forums is brilliant, and the tutorial videos are good for those who want to get an overview of creating apps without wading through documentation.

You’ll still need a Mac if you want to develop for the iPhone, because Titanium makes use of the iPhone SDK. But if you just want to do Android development then you can use Window or Linux as well.

Although you’ll be developing 1 set of code for both the iPhone and Android, you’ll probably want to customise the UI slightly differently for each platform. For example, Android apps often hide away items such as ‘Settings’ and ‘Help’ under the Menu button. It’s simple to code this kind of thing up:

	if (Titanium.Platform.name == 'android') {
		var menu = Titanium.UI.createMenu();
		menu.addItem("Help/About", function() {
			displayWindow('Help / About', 'window_about.html');
		}, Titanium.UI.Android.SystemIcon.HELP);
		Titanium.UI.setMenu(menu);
	} else {
		data.push({title:'Help / About',image:'tabicon_help.png', color:'#ffffff'});
	}

That code will create the Help/About option under a menu on Android, and add it to the home screen’s list on the iPhone. Simple.

Titanium is an awesome framework so if you’re considering developing for the iPhone and/or Android then I’d highly recommend you take a look.

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Power Meter Plus in PC Pro Magazine

pc-pro-logo Power Meter Plus has been getting a lot of coverage this month; it’s been mentioned on dozens of blogs and now in PC Pro magazine issue 172, in fact I think Lifehacker might have picked up on it from there & the blogs picked up on Lifehacker’s article.

pcpro-jan-2009

Power Meter Plus featured on Lifehacker

Lifehacker is one of my daily visits, so it was brilliant to see that it had Power Meter Plus as the Featured Windows Download :-D

Creating a Netvibes / iGoogle Gadget for Multi-Image Display

To help make it as easy as possible for family members to see new pictures from the Collinge household I decided to set them up with Netvibes homepages, each containing a widget to display the latest photos from Picasa Web Albums. Picasa Web Albums provide an RSS feed that you can subscribe to which is a good start.. but I couldn’t find a way to display them just as I wanted.

The spec is to display the latest images, over as many columns as the user specifies.. and have the images resize to fit the width of the widget. They pretty much get displayed in a grid style layout.

Step 1) Get the URL for Picasa Web Albums (or whatever service you’re using) and make sure it works. The first gotcha here was that Picasa Web Albums has a limitation which means that images > 800px will not be embedded. They’ll result in a 404 File Not Found. To get around this, append ?imgmax=800 to the RSS’s URL.

Step 2) The feed for Picasa Web Albums is sorted in ascending date order.. I wanted it in descending date order so that the latest photos show first. To do this I chose to re-format the feed using Yahoo Pipes.. it’s a way of tinkering with a feed an invaluable for times when you need to do something simple like this.

Picasa gives you an Atom-based feed which seems to be causing a few issues with my code.. it basically makes the images go into a different node from the one I expected.. and I’ve been unable to work out exactly where it’s putting them. The best way around this is to simply run the RSS feed through a simple Yahoo Pipe; I’ve published one which sorts the images in date descending order. Use that and copy the RSS feed it generates.

Step 3) Create a new widget using UWA so that it works with Netvibes and iGoogle. This is relatively simple.. just requiring a bit of coding to make it happen. As usual I’ve tried to make the code as generic as possible & driven by user preferences. The user can specify which node in the JSON object (returned from the RSS feed) contains the image to display.. useful when dealing with non-standard image enclosures. It will default to the first enclosure at item.enclosures[0].url

The finished widget is published here.

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:widget="http://www.netvibes.com/ns/"  >
	<head>
		<title>Multi-Image Display</title>
		
		<meta name="author" content="Matt Collinge" />
		<meta name="email" content="do-not-email@mt2009.com" />
		<meta name="description" content="Display multiple images from an RSS feed. Useful for feeds like those from Picasa Web Albums" />
		<meta name="version" content="1.0" />
		<meta name="website" content="http://eco.netvibes.com/widgets/298784/multi-image-display" />

		<meta name="keywords" content="image, rss, picasa, web album, picture, multiple, display, grid" />
		<meta name="autoRefresh" content="15" />
		<meta name="apiVersion" content="1.2" />
		
		<link rel="stylesheet" type="text/css" href="http://www.netvibes.com/themes/uwa/style.css" />
		<script type="text/javascript" src="http://www.netvibes.com/js/UWA/load.js.php?env=Standalone"></script>
		
		<style type="text/css">
			.imageDisplay {
				margin:0;
				padding:0;
			}
		</style>
		
		<widget:preferences>
			<preference name="title" type="text" label="Title" defaultValue="Multi-Image Display" />

			<preference name="url" type="text" label="RSS Feed" defaultValue="" />
			<preference name="limit" type="range" label="Number of images to display" defaultValue="10" step="1" min="1" max="50" />
			<preference name="columns" type="range" label="Number of columns to use" defaultValue="2" step="1" min="1" max="8" />
			<preference name="imagenode" type="text" label="Node in RSS Feed Containing Image" defaultValue="item.enclosures&#91;0&#93;.url" />
		</widget:preferences>
	
		<script>
			var BasicRSSReader = {};
			 
			BasicRSSReader.feed = false;
			 
			widget.onLoad = function() {
				if (widget.getValue('url') === '' || widget.getValue('url') == undefined) {
					widget.setBody('Please edit the preferences and enter the URL of the RSS feed where you want to take images from.<br><br>. Use a feed re-formatter like Yahoo Pipes if you need to tinker with a 3rd party RSS feed.');
				} else {
					widget.body.addClassName('imageDisplay');
					widget.setTitle(widget.getValue('title'));
					UWA.Data.getFeed(widget.getValue('url'), BasicRSSReader.display);
				}
			}
			
			BasicRSSReader.display = function(feed) {
				var bodyHTML = '';
				if (feed) BasicRSSReader.feed = feed;
				
				var imageWidth = widget.body.getDimensions().width / widget.getValue('columns');
				var imageCount = 0;
				var columnCount = 0;
				
				bodyHTML += '<table border=0 cellpadding=0 cellspacing=0>';
				for(var i=0; i < BasicRSSReader.feed.items.length; i++) {
					var item = BasicRSSReader.feed.items&#91;i&#93;;
					
					if (imageCount >= widget.getValue('limit')) {
						bodyHTML += '</tr>';
						break;
					}
					
					if (columnCount == 0) {
						bodyHTML += '<tr>';
					}
					bodyHTML += '<td><a href="' + item.link + '"><img src="' + eval(widget.getValue('imagenode')) + '" width="' + imageWidth + '" /></a></td>';
					
					columnCount++;
					
					if (columnCount == widget.getValue('columns')) {
						columnCount = 0;
						bodyHTML += '</tr>';
					}
					
					imageCount++;
				}
				bodyHTML += '</table>';
				
				if (imageCount==0) bodyHTML = 'Unable to load feed.';
				widget.setBody(bodyHTML);
			}
		</script>			
	
	</head>
	<body>
		<p>Loading...</p>

	</body>
</html>

Netvibes UWA

Netvibes is a pretty awesome personal homepage web app. It’s very similar to iGoogle, but IMO it’s a lot more stable & a lot better looking. Netvibes offer a unified API that allows you to write using their API and deploy your gadget to multiple providers, such as iGoogle, Opera, iPhone, MacOSX and Vista.

I’ve been writing a gadget for my company but decided I also wanted one to take the first image out of an RSS feed and present so that it takes up all the space in the gadget. Useful for things like LOLcats. It was surprisingly simple to create.. so with some UWA coding, and a simple pipe at Yahoo Pipes, I’m now able to bring in the first image from a specified RSS feed.. assuming the image’s URL has been put into the item.content tag.

Here’s the finished gadget.. and the source code is below…

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:widget="http://www.netvibes.com/ns/"  >
	<head>
		<title>Single Image Display</title>
		
		<meta name="author" content="Matt Collinge" />
		<meta name="author_email" content="gadget@mattcollinge.co.uk" />
		<meta name="description" content="Display an image from the content section of the first item in an RSS feed. Useful for feeds like those from LOLCats. Use Yahoo Pipes to get the image URL (only) into the item.content tag." />
		<meta name="version" content="1.1" />
		<meta name="website" content="http://www.mattcollinge.co.uk/" />
		<meta name="keywords" content="image, rss, lolcats, single, full width" />
		<meta name="autoRefresh" content="15" />
		
		<link rel="stylesheet" type="text/css" href="http://www.netvibes.com/themes/uwa/style.css" />
		<script type="text/javascript" src="http://www.netvibes.com/js/UWA/load.js.php?env=Standalone"></script>
		
		<style type="text/css">
			.imageDisplay {
				margin:0;
				padding:0;
			}
		</style>
		
		<widget:preferences>
			<preference name="title" type="text" label="Title" defaultValue="Single Image Display" />
			<preference name="url" type="text" label="URL" defaultValue="" />
		</widget:preferences>
	
		<script>
			var BasicRSSReader = {};
			 
			BasicRSSReader.feed = false;
			 
			widget.onLoad = function() {
				if (widget.getValue('url') === '' || widget.getValue('url') == undefined) {
					widget.setBody('Please edit the preferences and enter the URL of the RSS feed where you want to take the image from.<br><br>The image URL must be in the item.content tag otherwise this will not work. Use feed a reformatter like Yahoo Pipes if you need to tinker with a 3rd party RSS feed such as LOLcats.');
				} else {
					widget.body.addClassName('imageDisplay');
					widget.setTitle(widget.getValue('title'));
					UWA.Data.getFeed(widget.getValue('url'), BasicRSSReader.display);
				}
			}
			
			BasicRSSReader.display = function(feed) {
				var feedList = 'Unable to load feed.';
				if (feed) BasicRSSReader.feed = feed;
				var item = BasicRSSReader.feed.items[0];
				feedList = '<img src="' + item.content + '" width="' + widget.body.getDimensions().width + '" />';
				widget.setBody(feedList);
			}
		</script>			
	
	</head>
	<body>
		<p>Loading...</p>
	</body>
</html>

Using JSLint with Notepad++

I’m doing a fair amount of development using the ExtJS framework. IE is a bit picky about getting JavaScript properly formatted (otherwise it refuses to render the page). That’s why I’ve found JSLint really useful for locating stray commas or semi-colons.

To make it a bit quicker to put the file contents in the JSLint box I decided to hook it up to the Run menu in Notepad++. However, the JSLint web page doesn’t allow us to pass in data to it. To get around this you can copy the HTML + JS files from the authors website an copy them locally. Once you’ve got them locally you can modify the source to allow the passing of data.. here’s the change I made to do it on my system:

jslint.php changes.. add this right near the end

<script src="javascript.js"></script>

You’ll then need a way to take the file contents and fire it off to the page. At first I tried passing the file contents via the GET request, but it’s limited in length. Also, Notepad++ won’t let you send the file contents via the Run command. In the end I chose to use a piece of VBScript to bring up the webpage in the default browser, and some JavaScript to read in the file & place it into the page.

launchJSLint.vbs

Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile(wscript.Arguments(0), 1)

Dim strCharacters

Do Until objFile.AtEndOfStream
    strCharacters = strCharacters + objFile.Read(1)
Loop

strCharacters = Escape(strCharacters)

Set objFileSystem = CreateObject("Scripting.fileSystemObject")
Set objOutputFile = objFileSystem.CreateTextFile("c:\progra~1\notepad++\jslint\javascript.js", TRUE)
objOutputFile.WriteLine("document.getElementById(""input"").value = unescape(""" & strCharacters & """);")

Dim wShell
Set wShell = CreateObject("WScript.Shell")
wShell.Run "c:\progra~1\notepad++\jslint\jslint.html", 9

Finally, this is the Run command you can use in Notepad++ to launch the script…

wscript "C:\Program Files\Notepad++\launchJSLint.vbs" "$(FULL_CURRENT_PATH)"

Switching FoxyProxy Profiles using Script

FoxyProxy is a useful extension to Firefox, but I’m always having to switch profiles back and forth as I take my laptop from work to home, and vice versa. I experimented with proxy PAC files without any success (mainly because laptops have multiple network adapters and the PAC scripts only detect your first IP address). Plus, as far as I can tell, PAC files are checked for every single HTTP request which must be a hit on browser performance.

Anyway, what I decided to do was directly modify the FoxyProxy config file before Firefox was run, and this would then select which FoxyProxy profile was used. The script below detects the host of something on my local network (which doesn’t exist at work) and switches accordingly. You could get it to switch on anything you like, but this works for me.

runfirefox.vbs

Set WshShell = WScript.CreateObject("WScript.Shell")

' Code to determine where you are and switch profiles accordingly
if (Ping("somehost") = "201.69.34.132") then
	ModifyFoxyProxy("3402440320")
else 
	ModifyFoxyProxy("patterns")
end if

' Run Firefox - this uses a specific profile.. your command line can simply exclude it
ReturnCode  = WshShell.Run("""C:\Program Files\Mozilla Firefox\firefox.exe"" -profile ""z:/firefox/profiles/qtxjee58.default""", 6, False)



sub ModifyFoxyProxy(sProfile) 
	' Path to your foxyproxy.xml file
	xmlfile="Z:\Firefox\Profiles\qtxjee58.default\foxyproxy.xml"
	outfile="Z:\Firefox\Profiles\qtxjee58.default\foxyproxy.xml"
	set oparser=createobject("msxml2.domdocument")
	with oparser
	    .async=false
	    .validateOnParse=false
	    .resolveExternals=false
	    .load xmlfile
	end with
	    
	if oparser.parseerror.errorcode<>0 then
	    wscript.echo "xml file " & xmlfile & " is not well-formed." & vbcrlf & "Operation aborted."
	    wscript.quit 999
	end if
	
	set oroot=oparser.documentElement
	oroot.setAttribute "mode", sProfile
	oparser.save outfile
	    
	set oparser=nothing 

end sub


function Ping(strHost)

    dim objPing, objRetStatus

    set objPing = GetObject("winmgmts:{impersonationLevel=impersonate}").ExecQuery ("select * from Win32_PingStatus where address = '" & strHost & "'")

    for each objRetStatus in objPing
        if IsNull(objRetStatus.StatusCode) or objRetStatus.StatusCode<>0 then
    		Ping = ""
            'WScript.Echo "Status code is " & objRetStatus.StatusCode
        else
            'Ping = True
            'Wscript.Echo "Bytes = " & vbTab & objRetStatus.BufferSize
            'Wscript.Echo "Time (ms) = " & vbTab & objRetStatus.ResponseTime
            'Wscript.Echo "TTL (s) = " & vbTab & objRetStatus.ResponseTimeToLive
            Ping = objRetStatus.ProtocolAddress 
        end if
    next
    
end function