I was able to duplicate your problem. This is what fixed it for me.

Add QuartzCore.framework to your project and this line to your .m file.

    #import &lt;QuartzCore/QuartzCore.h&gt;

This code almost does what I need it to..

    for line in all_lines:
        s = line.split(&#39;&gt;&#39;)

Except it removes all the &#39;&gt;&#39; delimiters.

So,

    &lt;html&gt;&lt;head&gt;

Turns into

    [&#39;&lt;html&#39;,&#39;&lt;head&#39;]

Is there a way to use the split() method but *keep* the delimiter, instead of removing it?

With these results..

    [&#39;&lt;html&gt;&#39;,&#39;&lt;head&gt;&#39;]



Python split() without removing the delimiter

I need to identify elements from which events are fired. 

Using `event.target` gets the respective element.

What properties can I use from there?


- href  
- id   
- nodeName


I cannot find a whole lot of info on it, even on the [jQuery][1] pages, so here is to hoping someone can complete the above list.


**EDIT:**

These may be helpful: [selfHTML node properties][2] and [selfHTML HTML properties][3] 


  [1]: http://api.jquery.com/event.target/
  [2]: http://de.selfhtml.org/javascript/objekte/node.htm
  [3]: http://de.selfhtml.org/javascript/objekte/htmlelemente.htm#universaleigenschaften

What properties can I use with event.target?

I&#39;m porting a block of code from an iOS4 project to iOS5 and I&#39;m having some troubles with ARC.  The code generates a PDF from a screen capture.

PDF Generation Code
&lt;pre&gt;&lt;code&gt;UIView *captureView;
...
NSMutableData *pdfData = [NSMutableData data];
UIGraphicsBeginPDFContextToData(pdfData, captureView.bounds, nil);
UIGraphicsBeginPDFPage();
CGContextRef pdfContext = UIGraphicsGetCurrentContext();
[captureView.layer renderInContext:pdfContext];
UIGraphicsEndPDFContext();&lt;/code&gt;&lt;/pre&gt;

The renderInContext line
&lt;pre&gt;&lt;code&gt;[captureView.layer renderInContext:pdfContext];&lt;/code&gt;&lt;/pre&gt;
generates the following error.
&lt;pre&gt;&lt;code&gt;Automatic Reference Counting issue
Receiver type &#39;CALayer&#39; for instance message is a forward declaration&lt;/code&gt;&lt;/pre&gt;

Any ideas what is going on here?

What does &quot;Receiver type &#39;CALayer&#39; for instance message is a forward declaration&quot; mean here?

I'm porting a block of code from an iOS4 project to iOS5 and I'm having some troubles with ARC. The code generates a PDF from a screen capture.
PDF Generation Code
<pre><code class="hljs language-ini">UIView *captureView;
...
NSMutableData *pdfData = [NSMutableData data];
UIGraphicsBeginPDFContextToData(pdfData, captureView.bounds, nil);
UIGraphicsBeginPDFPage();
CGContextRef pdfContext = UIGraphicsGetCurrentContext();
[captureView.layer renderInContext:pdfContext];
UIGraphicsEndPDFContext();</code></pre>
The renderInContext line
<pre><code class="hljs language-ini">[captureView.layer renderInContext:pdfContext];</code></pre>
generates the following error.
<pre><code class="hljs language-python">Automatic Reference Counting issue
Receiver type 'CALayer' for instance message is a forward declaration</code></pre>
Any ideas what is going on here?

I have been searching everywhere and nothing so far has worked for me.

Basically I want to have a .xib file called rootView.xib and inside it I want to have a UIView  (lets call it containerView) that takes up only half of the screen (so there would be the regular view and a new view). Then I want a different .xib file called firstView.xib and load it inside of containerView. So I can have a bunch of stuff on firstView.xib and a bunch of different stuff in rootView.xib and load my firstView.xib inside of containerView in rootView.xib but since it only takes up half of the screen you would still see the stuff on rootView.xib

How to load a xib file in a UIView

Really simple question but it doesn&#39;t seem to be clear in Apple&#39;s docs.

Will `writeToFile:atomically:` for `NSData`, `NSArray` etc. overwrite existing data on a file?

Will writeToFile:atomically: overwrite data?

I&#39;m trying to make a `UIButton` that has two lines of text in its titleLabel. This is the code I&#39;m using:
    
    UIButton *titleButton = [[UIButton alloc] initWithFrame:CGRectMake(15, 10, frame.size.width-100, 100)];
    titleButton.titleLabel.font = [UIFont boldSystemFontOfSize:24.0];
    [titleButton setTitle:@&quot;This text is very long and should get truncated at the end of the second line&quot; forState:UIControlStateNormal];
    titleButton.titleLabel.lineBreakMode = UILineBreakModeTailTruncation;
    titleButton.titleLabel.numberOfLines = 2;
    [self addSubview:titleButton];

When I try this, the text only appears on one line. It seems the only way to achieve more than one line of text in `UIButton.titleLabel` is to set `numberOfLines=0` and use `UILineBreakModeWordWrap`. But this doesn&#39;t guarantee the text to be exactly two lines.

Using a plain `UILabel`, however, does work:

    UILabel *titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(15, 10, frame.size.width-100, 100)];
    titleLabel.font = [UIFont boldSystemFontOfSize:24.0];
    titleLabel.text = @&quot;This text is very long and should get truncated at the end of the second line&quot;;
    titleLabel.numberOfLines = 2;
    titleLabel.lineBreakMode = UILineBreakModeTailTruncation;
    [self addSubview:titleLabel];

        

Does anyone know how to make the `UIButton` work with two lines? Is the only solution to create a separate `UILabel` to hold the text, and add it as a subview of the button?



UIButton with two lines of text in the title (numberOfLines=2)

It is my understanding that setting an ivar now retains the object being assigned to it, since setting variables defaults to the `strong` qualifier. Because ivars are in the scope of the object they are declared in and `strong` retains objects within the scope of the variable, this means the ivars value would never be released while the object containing the ivar is still alive.

Is this correct?

If so, am I right in thinking that there is, in terms of memory management, no difference between a retaining (strong) property and a simple ivar anymore?

Property vs. ivar in times of ARC

I want to check if the user is running the app on iOS less than 5.0 and display a label in the app.

How do I detect which iOS is running on user&#39;s device programmatically?

Thanks!

How can we programmatically detect which iOS version is device running on?

What is the ***iOS 5.0*** user agent string?

Here is the ***iOS 4.0*** user agent: https://stackoverflow.com/q/3105555/836407

What is the iOS 5.0 user agent string?

Both have most of the same attributes, both support different kind of animations, both represent different data.
What are the differences between a UIView and a CALayer?

What are the differences between a UIView and a CALayer?

I wish to create an animation. The best way I can explain this is if you can imagine drawing a circle. It starts at the top or 12 o clock and draws clockwise all the way around until it becomes a complete circle over the space of 10 or so seconds.

The closet I have come to this is to draw a point rotating around a center point using Core Animation (using the sample code [here][1]). But I am at a loss on how to draw the circle? Any suggestions are very welcome.

Many Thanks :)

  [1]: http://nachbaur.com/blog/core-animation-part-1

iPhone Core Animation - Drawing a Circle

I want to add a view under my tab bar analog in iOS and then show it with animation coming from behind it. But when I use my code, the view that must come from behind my tab bar  overlaps my tab bar for a while. 

![tab bar and a view that shows when tab bar button pressed][1]


  [1]: http://i.stack.imgur.com/72HWj.png

This is my code: 

    - (void)handlePressedButton {
    if (pressedButton.selected) {
        [UIView beginAnimations:nil context:nil];
        [UIView setAnimationDuration:0.5];
        CGAffineTransform transform1 = CGAffineTransformMakeTranslation(-196.0, 0.0);
        CGAffineTransform transform2 = CGAffineTransformMakeTranslation(0.0, 0.0);
        [leftPanelView setTransform:transform1];
        [movedView setTransform:transform2];
        [UIView commitAnimations];
        pressedButton.selected = NO;
    }
    else {
        pressedButton.selected = YES;
        if (leftPanelView) {
            [leftPanelView removeFromSuperview];
            leftPanelView = nil;
        }
        CGRect viewFrame = CGRectMake(-196, 0, 236, 748);
        leftPanelView = [[UIView alloc] initWithFrame:viewFrame];
        leftPanelView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@&quot;left-nav-content.png&quot;]];
        
        // Code to populate leftPanelView according to what button is pressed.
        [self populateLeftPanelView];
        
        [UIView beginAnimations:nil context:nil];
        [UIView setAnimationDuration:0.5];
        [self.view addSubview:leftPanelView];
        CGAffineTransform transform1 = CGAffineTransformMakeTranslation(236.0, 0.0);
        CGAffineTransform transform2 = CGAffineTransformMakeTranslation(112.0, 0.0);
        [leftPanelView setTransform:transform1];
        [movedView setTransform:transform2];
        [UIView commitAnimations];
    }
}

Here the leftPanelView is the view that must come under a tab bar. Moved view is another view, that is at the right of left panel (don&#39;t mind it)

How to add a view behind other view in iOS

I&#39;m trying to rotate a `UIImageView` 360 degrees, and have looked at several tutorials online. I could get none of them working, without the `UIView` either stopping, or jumping to a new position.

* How can I achieve this?

The latest thing I&#39;ve tried is:

    [UIView animateWithDuration:1.0
						  delay:0.0
						options:0
					 animations:^{
						 imageToMove.transform = CGAffineTransformMakeRotation(M_PI);
					 } 
					 completion:^(BOOL finished){
						 NSLog(@&quot;Done!&quot;);
					 }];

But if I use 2*pi, it doesn&#39;t move at all (since it&#39;s the same position). If I try to do just pi (180 degrees), it works, but if I call the method again, it rotates backwards.

**EDIT**:

    [UIView animateWithDuration:1.0
						  delay:0.0
						options:0
					 animations:^{
						 [UIView setAnimationRepeatCount:HUGE_VALF];
						 [UIView setAnimationBeginsFromCurrentState:YES];
						 imageToMove.transform = CGAffineTransformMakeRotation(M_PI);
					 } 
					 completion:^(BOOL finished){
						 NSLog(@&quot;Done!&quot;);
					 }];

doesn&#39;t work either. It goes to `180` degrees, pauses for a split second, then resets back to `0` degrees before it starts again.


UIView Infinite 360 degree rotation animation?

I am using `CABasicAnimation` to move and resize an image view. I want the image view to be added to the superview, animate, and then be removed from the superview.

In order to achieve that I am listening for delegate call of my `CAAnimationGroup`, and as soon as it gets called I remove the image view from the superview.

The problem is that sometimes the image blinks in the initial location before being removed from the superview. What&#39;s the best way to avoid this behavior?

    CAAnimationGroup *animGroup = [CAAnimationGroup animation];
    	animGroup.animations = [NSArray arrayWithObjects:moveAnim, scaleAnim, opacityAnim, nil];
    	animGroup.duration = .5;
    	animGroup.delegate = self;
    	[imageView.layer addAnimation:animGroup forKey:nil];


Objective-C - CABasicAnimation applying changes after animation?

I have a `CABasicAnimation` and want to start it after a delay. In UIKit I can specify delays. The `CAMediaTiming` protocol has a `timeOffset` property but I can&#39;t see an effect. My next try is to use GCD to delay it but it feels like overkill.

How to delay a CABasicAnimation?

I have a `UIView` which contains an `AVPlayer` to show a video.  When changing orientation, I need to change the size and location of the video.

I&#39;m not very experienced with resizing layers, so I&#39;m having problems making the video resize.

I start by creating the `AVPlayer` and adding its player to my videoHolderView&#39;s layer:

    NSURL *videoURL = [NSURL fileURLWithPath:videoPath];
    self.avPlayer = [AVPlayer playerWithURL:videoURL];
    
    AVPlayerLayer* playerLayer = [AVPlayerLayer playerLayerWithPlayer:self.avPlayer];
    playerLayer.frame = videoHolderView.bounds;
    playerLayer.videoGravity = AVLayerVideoGravityResizeAspect;
    playerLayer.needsDisplayOnBoundsChange = YES;
    
    [videoHolderView.layer addSublayer:playerLayer];
    videoHolderView.layer.needsDisplayOnBoundsChange = YES;

Then, at a later point, I change the size and location of the videoHolderView&#39;s frame:

    [videoHolderView setFrame:CGRectMake(0, 0, 768, 502)];

At this point, I need the avPlayer to resize to these same dimension.  This doesn&#39;t happen automatically - the avPlayer stays at it&#39;s small size within the videoHolderView.

If anyone can help, I&#39;d really appreciate any advice.

Thanks guys.

AVPlayer layer inside a view does not resize when UIView frame changes

In an animation I added a lot of **sublayers** to a **view**, with:

    [self.view.layer addSublayer:layer1];
    [self.view.layer addSublayer:layer2];

....

I would like to remove all sublayers with an action.
I already tried with this suggestion of a similar question:

    rootLayer.sublayers = nil;

but it doesn&#39;t work...

Could you help me?
Than you!


remove all subLayers from a view

**Note**: Things have moved on since this question was asked; see [here](http://revealapp.com/blog/constraints-and-transforms.html) for a good recent overview.

---

Before auto layout, you could change the anchor point of a view&#39;s layer without moving the view by storing the frame, setting the anchor point, and restoring the frame. 

In an auto layout world, we don&#39;t set frames any more, but constraints don&#39;t seem up to the task of adjusting the position of a view back to where we want it to. You can hack the constraints to reposition your view, but on rotation or other resizing events, these become invalid again. 

The following bright idea doesn&#39;t work as it creates an &quot;Invalid pairing of layout attributes (left and width)&quot;:

    layerView.layer.anchorPoint = CGPointMake(1.0, 0.5);
    // Some other size-related constraints here which all work fine...
    [self.view addConstraint:
        [NSLayoutConstraint constraintWithItem:layerView
                                     attribute:NSLayoutAttributeLeft
                                     relatedBy:NSLayoutRelationEqual 
                                        toItem:layerView 
                                     attribute:NSLayoutAttributeWidth 
                                    multiplier:0.5 
                                      constant:20.0]];

My intention here was to set the left edge of `layerView`, the view with the adjusted anchor point, to half of its width plus 20 (the distance I want inset from the left edge of the superview). 

Is it possible to change the anchor point, without changing the location of a view, in a view that is laid out with auto layout? Do I need to use hardcoded values and edit the constraint on every rotation? I do hope not. 

I need to change the anchor point so that when I apply a transform to the view, I get the correct visual effect. 

How do I adjust the anchor point of a CALayer, when Auto Layout is being used?

I must add a UIImageView as subview of MapView. To do this I created a layer above the MapView. In this layer I want to put my image, but I get a white rectangle and nothing else. My image is not visible.

This is the code:

    - (void)viewDidLoad
    {
        //......

        CALayer *layer = [CALayer layer];
        layer.backgroundColor = [[UIColor whiteColor] CGColor];
   
        if(UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
        {
            layer.bounds = CGRectMake(self.mapView.bounds.origin.x,
                                      self.mapView.bounds.origin.y, 80, 300);
        }
        else
        {
            layer.bounds = CGRectMake(self.mapView.frame.origin.x,
                                      self.mapView.frame.origin.y, 150, 700);
        }
    
        layer.contents = (id)[UIImage imageNamed:@&quot;myImage.png&quot;];
        //the name is correct but  in the output the image is not visible
    
        [[self.mapView layer] addSublayer:layer];
        [layer setNeedsDisplay];
    }


add UIImage in CALayer

Today, I have update my xCode to 4.2 version,  And I want to disable the ARC,  I also search with the google.  but can&#39;t fix my problem. According the search results, In the target setting,  I can&#39;t find the &#39;Objective-C Automatic reference counting&#39; item,  So have no chance to set it to NO.  I find the item one by one,  and also use the search field.

And one know the newest Xcode4.2 ,how to disable the ARC for the project, not for the specific file.

Thanks very much.

How to disable Xcode4.2 Automatic Reference Counting

I have a working app and I&#39;m working on converting it to ARC in Xcode 4.2. One of the pre-check warnings involves capturing `self` strongly in a block leading to a retain cycle. I&#39;ve made a simple code sample to illustrate the issue. I believe I understand what this means but I&#39;m not sure the &quot;correct&quot; or recommended way to implement this type of scenario.

 - self is an instance of class MyAPI
 - the code below is simplified to show only the interactions with the objects and blocks relevant to my question
 - assume that MyAPI gets data from a remote source and MyDataProcessor works on that data and produces an output
 - the processor is configured with blocks to communicate progress &amp; state

code sample:

    // code sample
    self.delegate = aDelegate;
    
    self.dataProcessor = [[MyDataProcessor alloc] init];
    
    self.dataProcessor.progress = ^(CGFloat percentComplete) {
        [self.delegate myAPI:self isProcessingWithProgress:percentComplete];
    };
    
    self.dataProcessor.completion = ^{
        [self.delegate myAPIDidFinish:self];
        self.dataProcessor = nil;
    };
    
    // start the processor - processing happens asynchronously and the processor is released in the completion block
    [self.dataProcessor startProcessing];

Question: what am I doing &quot;wrong&quot; and/or how should this be modified to conform to ARC conventions?

How do I avoid capturing self in blocks when implementing an API?

With the new automatic reference counting (ARC) introduced in Xcode 4.2, we no longer need to manually manage retain / release in Objective-C.

This seems similar to garbage collection, as done in Objective-C on the Mac, and in other languages.  How does ARC differ from garbage collection?

What is the difference between Objective-C automatic reference counting and garbage collection?

I am trying to learn Automatic Reference Counting in iOS 5. Now the first part of this question should be easy:

 1. Is it correct that I do **NOT** need to write explicit
    release-property statements in my dealloc when using ARC? In other
    words, is it true that the following does **NOT** need a explicit
    dealloc?

        @interface MyClass : NSObject
        @property (strong, nonatomic) NSObject* myProperty;
        @end
    
        @implementation MyClass
        @synthesize myProperty;
        @end

 2.   My next and more important question comes from a line in the [Transitioning to ARC Release Notes][1] document:

    &gt; You do not have to (indeed cannot) release instance variables, but you may need to invoke [self setDelegate:nil] on system classes and other code that isn’t compiled using ARC.

 This begs the question: how do I know which system classes are not compiled with ARC? When should I be creating my own dealloc and explicitly setting strongly retaining properties to nil? Should I assume all NS and UI framework classes used in properties require explicit deallocs?

There is a wealth of information on SO and elsewhere on the practices of releasing a property&#39;s backing ivar when using manual reference tracking, but relatively little about this when using ARC.


  [1]: http://developer.apple.com/library/mac/#releasenotes/ObjectiveC/RN-TransitioningToARC/_index.html

Content Type	Original Author	Original Content on Stackoverflow
Question	Jason George	View Question on Stackoverflow
Solution 1 - Objective C	NJones	View Answer on Stackoverflow

What does "Receiver type 'CALayer' for instance message is a forward declaration" mean here?

Objective C Problem Overview

Objective C Solutions

Solution 1 - Objective C

What properties can I use with event.target?

Python split() without removing the delimiter

Attributions