Vince Yuan's blog

Scroll NSScrollView to Top

2011-12-27T23:29:00.001+08:00

AppKit is old and is not as convenient as UIKit. But we have to use it on Mac app development. "Scroll a scrollview to top" sounds easy, but actually it isn't. If you assign a documentView to a NSScrollView, you will see it scrolls to the bottom. (Very stupid!) The doc did not mention how to scroll to top. I found a way to control the vertical scroller. I can set the scroller to top, but the

Wrong info from proc_pidinfo

2011-12-09T20:03:00.001+08:00

proc_pidinfo is a very useful function to get a Mac OS X process's info such as the size of resident memory, consumed CPU time. However, sometimes, the returned info is not correct. For example, a little process's resident memory becomes 4GB. Apple does not provide any document about this function, and I did not see useful comments in the header files. I am lucky enough to see code snippet in the

Let Several Apps Use the same Facebook App ID

2011-10-18T22:25:00.000+08:00

If you want to let your user post something from your app onto Facebook, you need to register a Facebook app and call Facebook SDK to post messages. But if you have a free version and a paid version, you would like to share the same Facebook App ID. Just follow Facebook tutorial to register Facebook App and config your apps. https://developers.facebook.com/docs/mobile/ios/build/ The only one

Xcode 4 and Git

2011-10-09T17:35:00.001+08:00

I am new to Git. I used Perforce (P4) before, so I thought it is easy to use Git. Actually I was wrong. Git is not complex, but it has different concept. In P4, we just check out and check in files. In Git, checking in has a new name Commit. When I committed my first change, I was surprised to see it does not appear in the server. Actually, Git did not really submit my code to the server. It was

Fixing the Problem of Cocos2D Game Disappearing in iPhone Simulator

2011-10-04T23:23:00.001+08:00

I Created a new Cocos2D game. But it did not work well in iPhone simulator. It often disappeared in the simulator. I had to relaunch the simulator or relaunch Xcode. It was very boring. I didn't know why, because this project was still very simple. I noticed there is a warning that Info.plist is included in the target. I did the following things: 1. Renamed Info.plist to ProjectName-Info.plist 2.

Why Use Cocos2D Instead of UIKit to Develop Games

2011-09-29T15:26:00.001+08:00

I am leaning Cocos2D for iPhone. I am thinking why we should use cocos2D instead of UIKit to develop games. Here are the reasons: 1. Cocos2D is built on OpenGL. You may not know OpenGL. 2. Cocos2D supports tiled map. 3. Cocos2D helps you reduce memory cost by supporting atlas images and providing CCSpriteBatchNode. 4. Cocos2D supports parallax backgrounds. 5. Cocos2D has more animations and

Add Tool Tip to Controls with Xcode4

2011-08-19T22:50:00.001+08:00

Like many Apple developers, I was a developer on Windows platform before. It is very easy to add tool tip to a control (e.g. a button) in Visual Studio. But I don't know how to do it in Xcode. When I am working on iPhone apps, it is not a problem because iPhone apps need not tool tip. But it is a problem when I am working on Mac apps. Actually it is easy to add tool tip in Xcode 4. Looks like

Making Your Mac App Support Full Screen in 1 Minute

2011-07-18T19:40:00.001+08:00

Full screen mode is a cool feature on Mac OS X Lion. I'd like to let my app support full screen. I googled, but did not find any tutorial. I thought there would be an option like'Support full screen' when a new project is created with the new Xcode 4.1 on Lion. Surprisingly, there is no that option. Today I watched a video of WWDC2011 and made this article. I am sure you can follow the steps to

Decreasing the iPhone/iPad app size

2011-07-18T11:09:00.001+08:00

1. Delete unnecessary files. 2. Convert PNG images to JPG format. We like PNG because it supports transparency. But for those images without transparency, the size of png is twice of jpg file. I converted PNG files to JPG and reduced the app size from 17MB to 9MB. 3. For the universal app, iPad version could reuse retina @2x images.

The way to stop UIView animations

2011-07-18T11:03:00.001+08:00

#import <QuartzCore/QuartzCore.h> [self.view.layer removeAllAnimations];

Adding a framework in Xcode 4

2011-07-18T11:02:00.001+08:00

The steps of adding a framework in Xcode 4: 1. Click current project in Project navigator. 2. Click a target in Project editor. 3. Choose Build Phases tab. 4. Expand Link Binary With Libraries 5. Click + button, add a framework. 6. Go back to Project navigator. You will see the new framework added. You can drag it into Framework group. If you have more than one target, you need not repeat the

What's New in iOS 5 sdk

2011-07-18T10:56:00.001+08:00

The key developer-related features introduced in iOS 5.0 (Official doc): 1. iCloud 2. Storyboard Storyboard is not xib. "A storyboard file captures your entire user interface in one place and lets you define both the individual view controllers and the transitions between those view controllers." I think It sounds like Keynote or Powerpoint. You can design every page's content and the transition

Showing an animation when NSView loading

2011-07-18T10:52:00.001+08:00

An UIView of one of my iOS app shows a fade-in animation. I implemented this animation in viewDidLoad. When I was porting this app onto Mac OS X, I found there is no viewDidLoad. I tried adding the fade-in animation in awakeFromNib, but no animation appeared. My solution: Put the animation code in a method and call it after a short delay. [self performSelector:@selector(animationShowButton)

Implementing Fade-In Fade-Out animation in NSView on Mac OS X

2011-07-18T10:46:00.001+08:00

It is easy to implement Fade-In animation in UIView on iOS. We just need to change alpha value in the animation. theView.alpha = 0.0f; [UIView beginAnimations:@"fadeIn" context:nil]; [UIView setAnimationDuration:1.0]; theView.alpha = 1.0f; [UIView commitAnimations]; But the following code does not work in NSView on Mac Snow leopard. [theView setAlphaValue:0.0f]; [[theView animator] setAlphaValue:

Change the parameter order in Objective-C formatting string

2011-07-18T10:37:00.001+08:00

(I got this idea from cocoa programming for mac os x 3rd) When we do localizations, the problem is the words order of a language differs to other languages. For example, this sentence "Ted wants a scooter." may be something like "A Scooter is what Ted wants" in another language. You can localize strings this way: NSString * theFormat = NSLocalizedString(@"WANTS", @"%@ wants a %@"); x = [NSString

WWDC2011 Session 323 Introducing Automatic Reference Counting

2011-06-30T22:50:00.001+08:00

Summary: Automatic Reference Counting (ARC) dramatically simplifies memory management in Objective-C. This session introduces what ARC is, how it is implemented and how to migrate to ARC. Apple asks every developer to move Objective-C code to ARC. Problems of memory management: Many (new) developers do not understand reference counting. They don’t know when to retain/release/autorelease. Memory

WWDC2011 Learning Notes and Index

2011-06-30T10:54:00.001+08:00

WWDC2011videos come out before I finish WWDC2010 videos. It's time to learn WWDC2011 videos. :-) Index WWDC2011 Session 323 Introducing Automatic Reference Counting

Programming with Core Animation on Mac

2011-04-21T13:19:00.001+08:00

Learning notes of Core Animation for Mac OS X and the iPhone 1. The Simplest animation (CABasicAnimation) Without animation: [theView setFrame:newFrame]; With animation: [[theView animator] setFrame:newFrame]; [theView animator] is the Animator Proxy which is simply finding an animation and then invoking it. The default animation is CABasicAnimation. 2. CAKeyframeAnimation With

Add an existing framework in Xcode 4

2011-04-11T23:29:00.001+08:00

Steps to add an existing framework in Xcode 4: 1. Click the project in the project navigator. 2. In the project editor, click a target. 3. Select 'Build Phases' tab 4. Expand 'Link Binary With Libraries' 5. Click '+' button to add a framework. 6. Go back to the project navigator, you will see the new framework. You can drag it to 'Frameworks' group.

WWDC2010 Session211 Simplifying iPhone App Development with GCD

2011-04-08T12:49:00.001+08:00

GCD Overview 1. GCD is part of libSystem.dylib 2. Available to all Apps. - #include <dispatch/dispatch.h> 3. GCD API has block-based and function-based variants - Focus today on block-based API Introduction to GCD recap 1. Blocks - dispatch_async() 2. Queues - Lightweight list of blocks - Enqueue/dequeue is FIFO 3. dispatch_get_main_queue() - Main thread/main runloop 4. dispatch_queue_create() -

WWDC2010 Session206 Introducing Blocks and Grand Central Dispatch (2)

2011-04-07T15:31:00.000+08:00

Grand Central Dispatch With GCD, you can make your app responsive. Threading is hard. Using GCD makes it simple and fun. You need not do explicit thread management. Cool! Keeping your app responsive： 1. Do not block the main thread 2. Move work to another thread 3. Update UI back on main threaad Code without GCD: - (void)addTweetWithMsg:(NSString*)msg url:(NSURL*)url { // Controller UI callback

WWDC2010 Session206 Introducing Blocks and Grand Central Dispatch (1)

2011-04-06T16:04:00.000+08:00

Blocks and Grand Central Dispatch are available on iOS4, and have been available on Snow Leopard. Technology Stack Blocks Blacks are available in C++ and Objective-C++. Basic Blocks We will use ^ for blocks because this character is unique and could not be used as operator in C++. Block Literal Syntax ^ [Return type][Arguments] { Body } Just looks like a function without function name starting

WWDC2010 Session313 LLVM Technologies in Depth

2011-04-06T10:14:00.001+08:00

This session covers: Clang in Xcode 4 (Code completion, Fix-it, Indexing and Edit-all-in-scope), Clients of LLVM(LLDB, Integrated assembler). Using Clang Inside Xcode 4 Many contents have been covered in Session 312. Just more examples. Benefits of LLDB Design Higher fidelity expression parsing and evaluation Support all language constructs Inline function, template instantiation

WWDC2010 Session312 What's New in the LLVM Compiler

2011-04-05T20:31:00.000+08:00

LLVM stands for Low Level Virtual Machine which is a compiler infrastructure, written in C++. The LLVM project started in 2000 at the University of Illinois at Urbana-Champaign, under the direction of Vikram Adve and Chris Lattner. In late 2000, Lattner joined the University of Illinois at Urbana-Champaign as a research assistant and M.Sc. student. Lattner was hired by Apple in 2005. Compiler

WWDC2010 Session315 Using Interface Builder in Xcode 4

2011-04-05T15:49:00.000+08:00

Interface Builder is integrated into Xcode 4. All the window or views in a xib file will show in the design canvas not in a separate window any more. There is a media library in the interface builder. You can preview and add a picture to your UI directly. Select a control, press Option key, and move your mouse, you will see some useful annotations. In Identity Inspector, there is a small arrow