iPad on the other hand has 9.7″ (diagonal) with 1024×768 resolution, which gives 132ppi. John Siracusa said that next iPad will most likely have the same improvement in display rez, meaning it will have 2048×1536 – so the iOS4′ @2x API stuff work the same.
Granted, such resolution sounds ginormous – not even Apple’s latest 27″ monitor is big enough to design interfaces that big. But if that really happen…

…how big the iPad would physically needs to be?

iPad has 1.33x aspect ratio and 9.7″ diagonal display now. 2048x1536 and with 326ppi equals to about 9650in in one very long line, or divide again to get about 29.6in2. From there, the math is easy: 1.33x * x = 29.6, means that x is 4.71in and that physical screen size of the Retina Display iPad would be 4.71 x 6.28, or about 7.85″ diagonal.

Sounds quite possible, does it not?

Color swirl

What I need from there is the actual RGB representation of the pixel color. To get that, there’s quite a bit of code involved. A large part of it is taken from Apple’s technical note QA1509.

Pixel color fetching is done in this if block from that article:

if (data != NULL)


{


    // **** You have a pointer to the image data ****


    // **** Do stuff with the data here ****


} 

I picked up the code to get the pixel color from some web page I lost track of. This is the code:

int offset = ((w*round(point.y))+round(point.x)) * 4;


int alpha =  data[offset];


int red = data[offset+1];


int green = data[offset+2];


int blue = data[offset+3];


color = [UIColor colorWithRed:(red/255.0f) green:(green/255.0f) blue:(blue/255.0f) alpha:(alpha/255.0f)]; 

w is the width of one row of data, and point {x,y} is where the screen was touched. The * 4 in the first line means 4 bytes of raw data per pixel. Well, 4 bytes when your screen res is up to 160ish ppi. On iPhone 4’s Retina Display, with its 326ppi resolution, this should be 8. Which means correct code now is:

int offset = ((w*round(point.y))+round(point.x)) * 4 * [[UIScreen mainScreen] scale]; 

Welcome to wonderful world of resolution independent programming.

Recently, David Frampton posted great idea how Apple should have done this (the idea got picked by Daring Fireball, TUAW and many others). While idea is great, it’s more than doubtful that Apple would do this.

What Apple would likely prefer is that you, as developer, make an iPad version of your iPhone app and use the full capability of the device. In the process, you’ll create proper iPad icons and no ugliness then. In the Apple’s DevForums, there’s a thread with guidelines on how to populate App–info.plist file and what icon files are needed.

In there, it says that for iPhone-only apps you need to populate CFBundleIconFile key with 57px icon. However, if you move down a bit, you’ll find section on setting up universal app. Do that, even if your app is not universal and voila — iPad will use the proper icon for your iPhone-only app.

Setting up icon meta data, so it displays proper icons on iPhone/iPad

The settings above are from my Quickie to do app — here’s before and after:

Quickie icon on the iPad, before and after

Much better looking.

Quickie uses Core Data for storage and in one particular place I was comparing the NSString variable to a NSString–typed property of my CoreData class, QuickieList. Like this:

if (QuickieList.listName != theListName) 

listName is defined as NSString and theListName is obviously that as well. In this particular instance, both of those had the value of “test”.
In the iPhone Simulator (running on 10.6.2) this comparison returned false, but on the iPhone running 3.1.2 it returned true. When changed into:

if (![QuickieList.listName isEqualToString:theListName]) 

result was the same.

Never – I repeat — never assume that simulator testing will be fine, even for seemingly small things. It can bite you when you least expect it.

if (![addNewCellTextField.text isEqualToString:@""]) {


…


} 

However, this will fail if the field is never touched. That is, until your user taps the field and it gets focus, UITextField.text is nil. Which means that condition above yields true, which is not what you want.
Once it is touched though, this becomes an instance of NSString with value of @””. Thus, always use:

if (addNewCellTextField.text != nil && ![addNewCellTextField.text isEqualToString:@""]) {


…


} 

Watch out for this little trap hole.

What does this solve?

If you have any of these issue, this article will most likely help you.

1. You use Windows 2003 and iTunesSetup.exe refuses to run on it (it’s touting only XP or Vista/Windows 7 as supported OSes).
2. At the end of the iTunes install, when dialog says “Starting services” it failes to start iPodService.exe with the following message: “Service ‘iPodService’ (iPodService) failed to start. Verify that you have sufficient privileges to start system service.”
3. You have trouble starting iTunes.exe after install.
4. You see dialog boxes telling iTunesHelper.exe failed to start.

My wife uses Windows 2003 as development machine and I had all of these happening.

iTunes refuses to install due to OS mismatch

Apple is — like many other companies do in the last year or two — touting iTunes 9 as compatible only with Windows XP and Vista or Windows 7. This is safe net for them. If you run Windows 2003, this is just about the same thing as XP, regarding ordinary software.

Thus, solution here is to kill the OS-based launch conditions, which good people at WebKeyDesign have already explained how to do. The solution goes like this:

1. Unpack iTunesSetup.exe so you have all the various .msi files inside it copied to some folder. Use Winzip, Total Commander or any other de-archiver to open iTunesSetup.exe and extract the files
2. Download free tool called InstED and start it
3. Drag all .msi files into InstED
4. For each of them, find the LaunchCondition key in the left panel and then in the right-panel look for ((VersionNT=501 And ServicePackLevel>=2) OR VersionNT>501) and delete it. Then save the file.

InstEd — removing launch conditions

QuickTime has two conditions, remove both

Once you’re done with all of them, install them, one by one. Start with AppleApplicationSupport, then AppleMobileDeviceSupport and then continue until iTunes as the last. Ignore SetupAdmin.exe

iPodService.exe failed to start

At the end of iTunes installation, it will try to start iPodService.exe. This fails and manifests in a variety of ways. There’s an amazing number of “solutions” on the net, but remarkably none has pinpointed the actual cause.

It’s Data Execution Prevention feature of the Windows — it will kill the process as soon as it tries to run. DEP is made to prevent malicious software using private or undocumented API or doing any sort of suspected malicious activity. iPodService.exe falls into this trap according to DEP, so we need to tell DEP to let it go as exception to the rule.
Here’s how:

1. Right-click My computer, choose Properties
2. Go to Advanced tab, click on Settings under Performance, then onto the DEP tab
3. Click Add, go to Program Files\iPod\bin and choose iPodService.exe
4. Retry/continue the iTunes installation and it will finish it up very quickly.

Data Execution Prevention is what kills iPodService.exe

iTunes.exe or iTunesHelper.exe don’t start

You click, they appear to start but then fail. The reason is the same as above: DEP. Add both .exe files (they are in Program Files\iTunes folder) to the DEP exception window and they will start just fine afterwards.

To expand this a bit — every time you have a known, valid software failing to start, always add them to DEP and see if they work. Most likely they would.

Hmm…say again?

This is in Windows Explorer, copying/moving files across networked disks.

Given my experience so far in big software projects, this kind of bad UI is direct consequence of the background API being done before front-end people had any say. At the moment when front-end work came to play, there was probably no info to determine is the current operation a copy or move, so they did what they could. Or it could be sloppy FE work, but I somehow believe it’s the former.

However, not all of the crashes appear there, or are slow to appear. Thus, if you have a desperate problem with someone’s application, it’s a good idea to pick these up and send them to a developer.

Here’s how, in three major operations systems: Mac OS X, Windows Vista / Windows 7 and for Windows XP.

iTunes sync

Application crash logs are transfered to your computer each time you do a sync with the device, in the iTunes. Thus, first step is to sync with iTunes:

Sync the iPhone or iPod Touch through iTunes

Mac OS X

On the Mac, crash logs are kept at:

~/Library/Logs/CrashReporter/MobileDevice/<DEVICE_NAME>

where ~ is your Home folder. Here’s an example:

Crash logs on the Mac OS X. Device name is “iPhone AV” here

There’s the .crash file and .plist file — archive them both and send to a developer. Actually, pick all the files you find there that have the name of the problematic application.

Windows Vista / Windows 7

Files are located here:

C:\Users\<USERNAME>\AppData\Roaming\Apple computer\Logs\CrashReporter/MobileDevice/<DEVICE_NAME>

AppData folder is hidden by default, so here’s how to access it. Get into your personal folder:

User folder, with Vista folder path

Now click on the folder (address) bar which will change the display into Windows folder path and add \AppData to it, then click Enter.

When clicked, the address bar changes into regular Windows folder path

This will then show the folder contents. From here, you can follow the path above until you get to the crash logs.

For Windows 7, follow the same procedure.

Windows XP

Location is here:

C:\Documents and Settings\<USERNAME>\Application Data\Apple computer\Logs\CrashReporter/<DEVICE_NAME>

<USERNAME> is your login username. Application Data folder is usually hidden by default, so you need to reveal it in the same way as in Vista — by typing in and pressing Enter.

And that’s it. Easy :) — rest is for developer to sweat it.

Here’s a proposal: remove the DVD drive entirely. I don’t know about you, but I have used that thing less than 10 times in last 2 years of owning Macbook Pro. It mostly collected dust and stopped working reliably rather quickly due to that same dust; last few times when I wanted to do anything with it, it spent ages trying to recognize the disk. Or even failed to read it — even Leopard original install disk, which is in pristine condition. Or last night, when it failed to write an empty DVD, which I then burned with no issues on my wife’s Sony VAIO drive.
It’s by far the worst part of the otherwise great notebook.

It’s useless outdated thing, ripe for replacement. It would free up huge space in the notebook for many, much more useful things like:

• integrated SIM card slot
• ExpressCard/34 or even /54 slot
• one or two eSATA connectors
• at least one more USB port

For anyone that needs the drive, they already sell external SuperDrive for Macbook Air and there’s plenty of 3rd party external packages.

What’s not to like? Eh, Apple, how about that?