SLNumberPickerView is a control that presents a 3-digit number picker. It's very customisable, highly themable, and very easy to use. We made SLNumberPickerView after a designer, the marvellous @padschneider, crafted this look for a number picker:

Our first reaction: "argh, UIPickerView can't be made to look like that, no matter how many UIView hierarchy hacks you throw at it!"

Our second reaction: "hey, UIPickerView sucks anyway, let's make a better version for this problem!"

So, here's SLNumberPickerView. The image above it isn't from our PSDs, it's a screenshot from the working thing in the simulator.

It does one thing: present a suitcase-combination-lock-style interface to the user, which lets the user choose three digits. You can then query the view to get the integer value of the number the user's chosen. SLNumberPickerView also provides a delegate protocol that you can implement to be notified of any changes.

SLNumberPickerView keeps its own view hierarchy in a separate nib, which makes it very easy to theme - you can change the background colours, overlay images, and do all kinds of things with it.

SLNumberPickerView allows you to control the colour and font of the numerals, and also allows you to specify a tiled background image that is placed beneath the numerals. We added this in order to add the tick-marks that you see at the right of each column in the above screenshot.

How to use it

Download SLNumberPickerView from GitHub, and add the files to your project. SLNumberPickerView requires ARC.

Next, add an empty UIView to your interface. Size it to something like 145 wide by 100 high, and set its class to SLNumberPickerView. At runtime, the number picker view will be placed inside it.

You can query the number picker view for its value via the read-only value property:

Alternatively, you can conform to the SLNumberPickerViewDelegate protocol, which defines the following method:

Set yourself to be the delegate, and you'll receive messages every time the number selected by the user changes.

Caveats

SLNumberPickerView currently doesn't support setting a value programmatically.

It's available on GitHub now.

SLTutorialController is a class that manages the user’s progression through a linear tutorial. We built it while adding a tutorial to a game we made for a client. In this post, you’ll learn what it can be used for, and how to use it!

Tutorial Tutorial!

Say you have three stages in a tutorial: build a building, select a unit, and defeat an enemy.

First, you’d list the stages in SLTutorialController.h:

Next, whenever your player builds a building (at any stage), you add this line:

Likewise, whenever your player selects a unit, you do this:

Likewise for SLTutorialDefeatAnEnemy.

Calls to -tutorialStagePerformed: will ONLY move to the next tutorial stage if the tutorial is actually at that stage. This means your game logic code doesn’t have to do a bunch of state checks on the tutorial, you just stick a -tutorialStagePerformed: at the right spots.

You can ask SLTutorialController for the tutorial’s current state via the tutorialStage property:

SLTutorialController posts the SLTutorialStageUpdated notification whenever the tutorial state changes. This means that you can easily be notified when the state changes.

SLTutorialController stores its data in NSUserDefaults, so it’s remembered for you.

It's available on our GitHub now.

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