A fantastic resource for Cocoa, Objective-C and programming in general

The script called PropertyFromInstanceVariable had already been added to by a couple of other people, Yung-Luen Lan & Mike Schrag and Pierre Bernard and I have now shaped it for my own specific needs, and possibly yours too.

The tedium I was trying to eliminate was the process of creating Objective-C properties from instance variables and doing basic memory management on them. This is a repetitive process that seems more appropriate to hand off to the machine.

Matt’s script allows you to take an instance variable defined in your interface file and automatically create a property for it, synthesize the property in the implementation, add a release statement and set the property to NULL in the dealloc method.

For example, running the script on this:

NSString *myString;

would automatically create this in the interface:

@property (nonatomic, retain) NSString *myString;

this at the top of the implementation:

@synthesize myString;

and adds these two lines to the dealloc method:

[myString release];
myString = NULL;

Because this script was written before the viewDidUnload method had been added to the UIViewController class it didn’t make use of the viewDidUnload method. I wanted to update it to set the retaining references to subviews in the view hierarchy to nil. These reference properties may have been set through IBOutlets when loading a nib or programmatically in the loadView method.

I have now modified the script to reflect my own coding habits. It still creates the property, synthesizes it and adds a release to the dealloc method, but if the class is a subclass of UIViewController then this is placed in viewDidUnload like so:

self.myString = nil;

This script can be run on multiple instance variables at once and greatly cuts down on the time it takes to set up a new class. Instructions on installing the script can be found here.

You can get my fork of the script on github.

NOTE: I have updated to script and edited this post to reflect those changes. All links are to the most recent version.

//
//  helloworld.m
//  helloworld
//
//  Created by John Smith on 24/10/09.
//  Copyright __MyCompanyName__ 2009. All rights reserved.
//

then it is time to open up your Terminal app.

OSX Terminal app

You will find it at ~/Applications/Utilities/Terminal.app.

Enter the following in the open terminal (replacing the company name with yours):

defaults write com.apple.Xcode PBXCustomTemplateMacroDefinitions '{"ORGANIZATIONNAME" = "Smith Incorporated";}'

Now when you create new source files in XCode you will see this:

//
//  helloworld.m
//  helloworld
//
//  Created by John Smith on 24/10/09.
//  Copyright Smith Incorporated 2009. All rights reserved.
//

Much better.

iPhone running TouchOSC

Today, in addition to working hard on my upcoming app release (which I am very excited about) I have been playing with the TouchOSC app from hexler.net. TouchOSC, available from the Apple App Store, provides several touchable interfaces including virtual faders, cross-faders, knobs, pads, keys, buttons, grids and x-y pads; all of which send OSC data over Wi-Fi using UDP. It is kind of  like a mini JazzMutant Lemur in your pocket.

The OSC data from TouchOSC can be used in software capable of receiving OSC messages, such as MaxMSP or Processing, or you can parse the OSC data to MIDI and then on to any MIDI controllable software such as Ableton Live. To translate the OSC to MIDI on a Mac I highly recommend you check out OSCulator. If you own Max you could build yourself a maxpat to do the same thing but OSCulator is prebuilt and there are some excellent presets available on the hexler.net website. Mac users will find instructions on using TouchOSC with Osculator and Ableton Live here. Windows users will find instructions to do something similar using a combination of Pure Data and MIDI Yoke here.

Setting up TouchOSC on your home wi-fi network is a piece of cake. All you have to do is open the TouchOSC Network settings and set the host and the  outgoing and incoming ports. The ports can be whatever you want to use; I use 8000 for outgoing and 9000 for the incoming port. The host should just be YOURCOMPUTENAME.local. This worked flawlessly for me the first time I tried it.

If however you are not at home, or are somewhere without wi-fi, and you want to use TouchOSC with your MacBook or MacBookPro, you need to create an ad-hoc wireless network. All an ad-hoc network is is a wireless network where the communciation between devices is direct, rather than through an access point or a router. Here are the steps to create an ad-hoc network and set up TouchOSC to communicate with your Mac:

1. Open up System Preferences->Network.

2. Click on the Network Name drop down and select  Create Network.

3. Give your network a name. A password is optional though probably a good idea.

4. Click on Advanced.

5. Click on the TCP/IP tab.

6. Click the Configure IPv4 drop down and select Manual.

7. Enter an IP and NetMask for your computer. I use 192.168.2.1 and 255.255.255.0.

8. Click OK and then Apply and close System Preferences.

9. On your iPhone open Settings->Wi-Fi and select the network you just created.

10. Click the arrow to the right of the network name.

11. Select Static for your IP type and enter your IP and NetMask for the iPhone. I use 192.168.2.2 for the IP. The NetMask must be the same as for the network which is 255.255.255.0.

12. Exit your iPhone settings and open TouchOSC.

13. Touch the field under the heading Network.

14. Enter the IP address you created for your Mac. In my case this is 192.168.2.1.

15. Make sure your ports are as you want them. Remember, the ports can be whatever you want to use, just make sure that they agree with whatever you are communicating with, ie OSCulator, MaxMSP, Processing etc. I use 8000 for the outgoing port and 9000 for the incoming port.

16. Touch the done button and then once you are at the mainscreen of TouchOSC, select your Layout and touch done again.

It sometimes takes a few seconds to connect to the network and open the TouchOSC Layout but once it opens you should be able to communicate with your Mac over the ad-hoc wireless network. To test out the ad-hoc network try using OSCulator or one of the Max patches provided on hexler.net. This is what worked for me; hopefully you will find that these instructions get you up and running TouchOSC over an ad-hoc network too. If you have any problems please leave a comment and I will do my best to help you.

Though Apple’s documentation is great, I find that getting several different takes on the same topic helps me to learn quickly. I also find that books with examples are useful learning tools. This led me to purchase two introductory offerings on iPhone development: iPhone in Action published by Manning and written by Christopher Allen and Shannon Appelcline and Beginning iPhone Development published by APress and written by Dave Mark and Jeff LaMarche.

iPhone in Action

The great thing about iPhone in Action is that it covers both native and web programming for the iPhone (about a third of the book). It does not assume pre-knowledge of Objective-C and even has a very brief overview of the C programming language that may be useful for someone coming from a non-C background. This is certainly not the book for someone who has no programming experience In fact, neither of these two books are aimed at people completely new to programming, but it does provide an adequate intro for Objective-C is you already know C.

iPhone in Action contains many helpful examples and covers topics not found in the APress book such as customizing web pages to be viewed on the iPhone and how to POST to a web server. On the downside I sometimes found the explanations for creating the examples in the book to be unclear. For some example apps the authors’ have included lists of steps to accomplish a task but they are inconsistant about flushing those steps out. In some places I needed to sift through the text to find the one tidbit that I was missing; something that could easily have been included in the step-by-step lists. Overall though it is a useful book to have in your library and will probably serve as a good reference for your iPhone projects for some time to come.

Beginning iPhone Development

Beginning iPhone Development provides a great introduction to native iPhone development. Though this book does not cover web programming for the iPhone, and though it assumes knowledge of Objective-C programming, it does cover native development in greater depth than the Manning title. The explanations of the example apps that you build in this book are very clearly written. My personal preference in an introductory programming book is for a fun read that holds your hand a bit through the examples. Beginning iPhone Development definitely does this better than iPhone in Action, and does so without being patronizing.

At the end of the day either book will give you a good start developing apps for the iPhone. Whereas iPhone in Action gives a little broader treatment by including web programming and an introduction to Objective-C, Beginning iPhone Development covers more of the iPhone SDK and in greater depth. I personally think that these two books work great as companions, both filling in the missing bits in the other.

Finally I will reccomend the forums at iPhone Dev SDK as a great place to have your questions answered as you start developing your first apps. Happy coding!

Setting the Page-Up key-binding in Terminal

Open Terminal then go to Terminal -> Preferences -> Settings -> Keyboard. Scroll down to find the key that you want to change and highlight it. Click the edit button at the bottom of the window. A new window will open like the one pictured above. Set everything as shown and replace the string to send to the shell with the appropriate one from the following list:

Key        Escape Sequence
End        \033[4~
Home       \033[1~
Page-Down  \033[6~
Page-Up    \033[5~

Enjoy.

Open Terminal and type:

defaults write com.apple.itunes show-genre-when-browsing -bool FALSE

Then close and reopen iTunes and voila, genre is gone form the list view.

To put genres back, type:

defaults write com.apple.itunes show-genre-when-browsing -bool TRUE

Your iTunes browser will now look like this:

iTunes with browse by genre removed

This driver is a virtual midi device that you can use to route MIDI to, through and from. My Max patch parses the serial data from the Arduino to the IAC Driver. By choosing the IAC Driver as a MIDI input in Live (or any other MIDI capable app) you can then use the serial MIDI CC data sent from the Arduino to control your software.

The MIDI data that the Max patch expects at the serial input is in the standard MIDI format for a CC message; a status byte, a control number and a value. This simple patch just listens for a status byte of 176 which is a control change on channel 1. The baud rate I chose for this patch was 57600. Note that you do not have to use the standard MIDI data rate of 31250 baud.

MIDI Devices

To enable the IAC Driver go to Applications->Utilities->Audio MIDI Setup, click on the MIDI Devices tab and then double click the IAC Driver icon make sure that the Device is online check box is checked.

To use this patch you need the MaxMSP Runtime. Once you have that installed open it up and then open the patch with it. Double click on the midiout object and select the IAC Driver. Then click the button at the top of the chain to start reading the serial port and parsing the data. You should now be able to use  midi learn to map your controllers and start tweaking stuff in realtime with your potentiometers.

Here is what the patch looks like:

Serial to MIDI Max patch

If you own Max just copy the following code and then paste it in a blank patcher.

----------begin_max5_patcher----------
488.3ocuVsrahCCEccxWwUdclQ9QdTlcUpa5h9ETUMxPLTOJwFkXTof5+9X6
.COFjvIjhDgHesu1m64dNIYabDZpdsnEA+BdEhh1FGE4C4BDsabDpludVEu0
uLjR7gd5ePIcSYDqM9vapf4xJinAHE46mUspVppDFelzCA0qLmGctVYT7Zge
ydrQxq1uIK4lYuKUK9ciXloCozT7OwI.kl4tkOwOvFBdaWNcGf4ykhtDPnD6
0+l1cXsxM9IITa1cgkk9S2Vd+ffbg9JN18WxsQMKajJC7xyO87E4ExE4E7P3
ER1I7B6+3kqW3ECovM5EKpD8n5HWs2xv6A+0ZsVx8Pm8nJgMhsvZgoQCY8PW
StAccgu8kQtdsOkqVzGYMcD4jVgqZ.NjUjiwvC.Av8PBbKFeRmtfPxCSdzSy
OaLc+0xRoETe2VeZpWtvRSc2RmL.qOCOxk8bcSM+xUdwnaZnO3cMDbeejQ.t
lIiIw3p.2KIAkx9a.OzbPNl77fYmd8dxrioFehnJo57OovCLW7S4qV8plY6O
1caWBb.ZkhViTwMRs53EcxZdWVVJTG6arRukZaKdGFf2tXyKXHE.hrBDKod2
fDKDLcFU9ciIZ.Phce6brP5b2WRZRHrD99puCwxUbCPxN3q3+JxEVKJ
-----------end_max5_patcher-----------

If you don’t own Max then you can download the patch here.

I will try and put together a more complete patch with user selectable options sometime soon.

Don't fear the command line!

To use it you first need to open Terminal via Applications->Utilities->Terminal. Then you need to get a list of the serial ports available. These devices are listed in the /dev folder and all start with the prefix tty. To see a list of all the serial ports on your computer, type:

ls /dev/tty.*

The ls is the Unix list command and the * after tty. is a wild card so that you are returned a list of everything in the /dev folder that starts with tty., namely all your serial ports. To connect to one of those serial ports you need to use screen. The format for calling screen is:

screen portname datarate

For example, to connect to a serial port called /dev/tty.usbserial-A3000Xg3 at 9600 bits per second, type:

screen /dev/tty.usbserial-A3000Xg3 9600

Now anything you type will be sent out the serial port (though there is no local echo of your typing) and anything the serial port receives will be displayed on the screen. The command to close the serial port is Control-A followed by Control-\.

For more info on screen check the man pages by typing:

man screen

Aggregate Device Editor

To accomplish this, open Audio MIDI Setup under Applications->Utilities. In the Audio MIDI Setup menu bar, select Audio->Open Aggregate Device Editor. Click the + button to create a new aggregate device and then in the Structure window select which devices you want to include. As an example, I selected the Duet and the Built-In Output and made sure that the Duet was in charge of timing by clicking the radio button next to it. Now in a program such as Ableton Live you can use both the Duet and the Built-In Output at the same time allowing you to cue loops and tracks before you bring them into the main mix.

You could also create other aggregate devices to allow recording on both your Built-In Input and your external device inputs but be warned that the recording quality may vary between the two devices.