IT Bytes

I wanted to see how tricky it would be to use Sketchflow to prototype a iPhone application. I think it’s worthy of a proper tutorial but for now I’ll give a quick pass since 1/2 the battle is just knowing it’s possible.

The first thing I needed was a template for an iPhone, I found one I liked at http://anoriginalidea.wordpress.com/category/sketchflow/. I made this into a User Control and then into a Screen Component (all via single right-clicks). With a couple of grids you can create the basic table view controller layout. Running with the seemingly accepted mono touch community theme of football RSS feeds I created the layout you see below. What you can see is the iPhone control as the background, a simple textbox for the view title, a databound list box pretending to be a table view controller and a stack panel of buttons playing the role of tab controller.

One of the important aspects of using SketchFlow is to create the navigation and state changes to allow your customers to see what is likely to happen. In my example (forgive the names) I’ve created Screen 1 (the table navigation view) which links to Screen 2 (the detail view). Looking at the screenshots does usually help but with the additional SketchFlow map you can see that there are blue navigation flows between the two. You can also see that I’m reusing two assets on both screens, namely the iPhone and tab components.

So I’ve created a design in SketchFlow, now what? How do I get feedback on this, how do I pass this onto to designers and developers? One way is to use the Export to Word option that creates a nice document for people to get their red pens out and dual over.

But this is all very stale, the real advantage is to create an interactive player that you can send out to your customers (WPF) or host on a web site (Silverlight). This allows for annotations & graphical feedback together with a simple way to navigate between the screens and states.

However, with the use of a few behaviours you can get the buttons and UI to execute the transitions by pressing them, far more intuitive and with little effort. I can’t really show that here, trust me the buttons highlight and and click through…

If there is enough interest I’ll write a tutorial and publish the source, but hopefully there is enough here to pique someone’s interest in using SketchFlow with MonoTouch. Now if MonoTouch represented the UI as XAML…

Creating a very simple MonoTouch application without the Interface Builder

I admit that I’m not a big fan of the Interface Builder (IB). I find that it either hides what I need to know or fails to help me implement what I what via a GUI. So I’ve decided to take a leaf from Craig Dunn (http://conceptdev.blogspot.com/search/label/monotouch) and avoid some of the hidden magic from IB and manually build some of the controls. However, there isn’t an empty iPhone project so I thought I’d write a quick blog to help me remember what I need to do.

Create a new project

First off create a new project, this will generate the usual set of files, so the next step is to get rid of those of IB files

Clean the project

Delete MainWindow.xib

Add AppDelegate.cs

I like Craig’s clean solution, so do as the man says and add a new class (File->New) AppDelegate

and add the following code snippet;
using System;
using MonoTouch.Foundation;
using MonoTouch.UIKit;

namespace UIWithoutIB
{

    [Register ("AppDelegate")]
    public class AppDelegate : UIApplicationDelegate
    {
        UIWindow window;
     public override bool FinishedLaunching (UIApplication app, NSDictionary options)
        {
            // Create the main window and add the navigation controller as a subview
            window = new UIWindow (UIScreen.MainScreen.Bounds);
            window.MakeKeyAndVisible ();
            return true;
        }
        // This method is allegedly required in iPhoneOS 3.0
        public override void OnActivated (UIApplication application)
        {
        }
    }
}

Change Main to use only AppDelegate.cs

Remove the partial class used to implement the Application Delegate from Main.cs. Main should look like;
using System;
using MonoTouch.Foundation;
using MonoTouch.UIKit;

namespace UIWithoutIB
{
    public class Application
    {
        static void Main (string[] args)
        {
            // UIApplication.Main (args); See blog comments from Philippe Laybaert….

            UIApplication.Main (args,null,"AppDelegate");

        }
    }
}

Prevent, Failed to load NSMainNibFile MainWindow

Ok so we’re in the land of Cocoa and we should play nice and say what our Main Window is. But hey I don’t want to, so if you build now you’ll get a strange message, ‘Failed to load NSMainNibFile MainWindow’. The template did a good job and created a MainWindow and filled in some extra “project” details. Since we no longer have MainWindow we should correct this. So make sure you have set your display options to Show all files, and navigate down the bin folders to the info.plist file. Open that and delete the ‘Main nib file base name’ setting.

Load our views

Change the App Delegate to add our views (and controller), or in this case a label control. Change the FinishedLaunching override to;
public override bool FinishedLaunching (UIApplication app, NSDictionary options)
        {   
            // Create the main window and add the navigation controller as a subview
            window = new UIWindow (UIScreen.MainScreen.Bounds);
         UILabel purpleLabel = new UILabel();
         purpleLabel.BackgroundColor = UIColor.Purple;
         purpleLabel.Text = "Hello none IB World";
         purpleLabel.Frame = window.Frame;
         window.AddSubview(purpleLabel);
            window.MakeKeyAndVisible ();
            return true;
        }

Run the app

So from here we can add other view-controllers without having to use IB. Having said that, I still use IB to create the odd view, and you can still use those controllers with this method.
A quick note about troubleshooting, I’ve found that if you’ve built with a IB file (xib) you later delete it’s worth asking for a Build->Clean, Build->Rebuild.

I’ve just started down the rocky road of iPhone development via MonoTouch. I suspect like many .net developers I’ve found the iPhone thang can be downright weird. One of the bloggers I’ve found helpful is Simon Says. One such post explains how to create a PageControl, http://simon.nureality.ca/?p=135. You know, that series of dots at the bottom of an iPhone view that allows you to move between pages of information. Although the post is great one thing still puzzled me, how do I shows pages of different views, i.e. if this was WinForms how would I can create different forms (Views) and show them as different pages? So first off, follow Simon’s post and get to the point where you should now have 10 pages each showing a label then;

NB. I’m no expert at this, if you know a better way to do something (or just spot a mistake) please let me know.

1. How do I get the PageControl to move between the pages?

Simon’s post allows you to ‘flick’ your way through the views and the PageControl reflects the changes, however if the user flicks the PageControl nothing happens.

In CreatePanel add the following event handler;

pageControl.TouchUpInside += HandlePageControlTouchUpInside;

…

void HandlePageControlTouchUpInside (object sender, EventArgs e)
        {
            // big assumption: the user moves the page control and after the control has set the current page this event is fired
            RectangleF toRect = new RectangleF(scrollView.Frame.Width * pageControl.CurrentPage, scrollView.Frame.Y, scrollView.Frame.Width, scrollView.Frame.Height);
            scrollView.ScrollRectToVisible(toRect, true);       
        }

2. Having 10 repeated Labels as Views is nice, but how do I use a mixture of my views I’ve created in the Interface Builder?

I recommend that for every different Form/View you want to display create a ViewController via File->New File->View with Definition Controller. In my example I created a controller called BertController.

Open the xib file in the Interface Builder (IB). You can drop whatever UI widgets onto the View, but for now let’s start by dropping a UILabel. In the weird world of iPhone development you need to create field to represent the UI element by creating an outlet, so in the Library viewer make sure the class representing the controller is selected (in my case BertController) and select the outlet tab. Create a new outlet to represent the label called, myLabel (or a much better name). Make sure the File Owner is selected and view the connection inspector’s outlet tab. Drag the name of you outlet to the label control. I know, it’s weird but you get used to it (so they tell me). Save and quit IB. Now we have something much more like our familiar forms class. So let’s expose the label control to the outside world (yes it’s bad practice but hey it wouldn’t be a tutorial without it). Open your controllers cs file (BertController.xib.cs) and add a property to it;

public UILabel MyLabel {
            get
            {
                return this.myLabel;   
            }
        }

See just like a normal form 😉

Now we have a view controller like our beloved form class we need to add it to the pages. Revisit CreatePanels in main and comment out all the for-loop and add the following function;

void AddView (string label)
        {
            RectangleF lastFrame = scrollView.Frame;
            PointF lastLocation = new PointF();
            lastLocation.X = lastFrame.Width * scrollView.Subviews.Count();
            lastFrame.Location = lastLocation;
            BertController controller = new BertController();
            controller.View.Frame = lastFrame;
            controller.MyLabel.Text = label;
            scrollView.AddSubview(controller.View);
        }

Pages on the iPhone are a series of frame-sized ‘views’. So to create them you need to know where in the virtual frame-set to add them. I think I’ve got the maths right, so if you use the function it should append a new BertController to the set. So add the following to CreatePanels;

AddView ("Well hello there 1");
AddView ("Well hello there 2");

There you have it, two of our views/forms all handled by the PageControl. So if you wanted to add different Forms create a new View Controller and add the controllers view. Hope it helps.