Corrections and version notes

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1 Last updated 7 th May, 2014 Programming apps for the iphone Corrections and version notes Please feel free to Graeme (gbsummers@graemesummers.info) for additional help or clarification on any of the following. Specific Corrections For ALL programming examples refer to Xcode version notes that apply to the version you are using (starting on page 4 of these notes). Programming example 1 Page 26: There needs to be a 2 nd action connection (as shown on the Received Actions on page 27). From the Touch Up Inside event radio button of the Hide button, connect to hidegreeting. Programming example 3 Page 60: Point 6. If using Xcode 4.4 or later, there are ten keyboards. The additional two are Decimal Pad and Twitter. Page 61: Point 10 should read: Controls can be classified as active, static or passive. Page 62: If using Xcode 4.4 or later, the question should read What seven keyboards...? Programming example 4 Page 72: The 3 rd bullet point under Build and run on the ios simulator should read: Stop running Running Wolf then Quit the ios Simulator. Page 77: If using Xcode 5 or later: Question 10 suggests using the Touch Down event with the UISwitch. With the new UISwitch in ios 7 you should use the Value Changed event. Programming example 5 Page 80, 83: It should be noted that iphones 1 to 4 have a height of 480 but iphone 5 has a height of 568. So, if coding for iphone 5, the starting X attribute for each ImageView should be 466. Likewise, in the implementation file, if coding for iphone 5, the code in the resetcars method should read: xposred = ; xposblue = ; If coding for iphone 5, the code in the movecars method should read: xposred = ;... xposblue = ; Note that the height of any iphone or ipad can be coded: [[UIScreen mainscreen] bounds].size.height Page 84: If using Xcode 4.5 or later refer to the version notes concerning landscape orientation. Page 85: The 3 rd bullet point under Build and run on the ios simulator should read: Stop running Rally Cars then Quit the ios Simulator. 1

2 Programming example 6 Page 94: If using Xcode 5 or later, the tag attribute has the long data type, so the declarations and assignments for userchoice, iphonechoice and result must read: long userchoice = sender.tag; long iphonechoice = arc4random() % 3; // 0, 1 or 2 long result = iphonechoice - userchoice; So the assignments for the image names must contain placeholders for long values (%ld): NSString *userimagename = [NSString %ld.png",userchoice]; NSString *iphoneimagename = [NSString %ld.png",iphonechoice]; Page 95: If using Xcode 5 or later, remove [alert release]; No releases are required when using ARC (Automatic Reference Counting). Page 96: The 3 rd bullet point under Build and run on the ios simulator should read: Stop running Paper, Rock, Scissors then Quit the ios Simulator. Page 100: If using Xcode 5 or later: Question 6 involves the use of a segmented control. Refer to the version notes for Xcode 5 under More on images. Programming example 7 Page 109: The 3 rd bullet point under Build and run on the ios simulator should read: Stop running Word Count then Quit the ios Simulator. Programming example 8 Page 122: The 3 rd bullet point under Build and run on the ios simulator should read: Stop running Fibonacci then Quit the ios Simulator. Arrays Page 129: The array of NSString should be enclosed in square brackets: NSArray *trinums = nil]; The array of primitive C integers should have included the same numbers 1, 3, 6, 10, also enclosed in square brackets: NSArray *trinums = [NSArray arraywithobjects:[nsnumber numberwithint:1], [NSNumber numberwithint:3], [NSNumber numberwithint:6], [NSNumber numberwithint:10], nil]; For the above arrays take note of the alternatives for assigning literals made available in Xcode version 4.4 and later. Programming example 10 Page 149: If using Xcode 5 or later the variables firstindex and secondindex should be declared long. Page 152: If using Xcode 5 or later the variable correctmatch should be declared long. 2

3 Page 154: If using Xcode 5 or later: the method newgame is called in the last line of viewdidload. In ios 7 the view is loaded too soon for newgame to be executed. So the method viewdidappear must be used for this: -(void)viewdidappear:(bool)animated { [self newgame]; } Add this code to the implementation file. This same issue will apply to the Eight application (Quest. 10, p 159) Touches and Gestures If using Xcode 5 or later refer to the notes on BallDrag2 and Cup Cakes. Programming example 11 Page 182: If using Xcode 4.5 or later refer to the version notes concerning landscape orientation. Page 182: The 3 rd bullet point under Build and run on the ios simulator should read: Stop running Cup Cakes then Quit the ios Simulator. Page 183: When choosing a template for your new file (for Xcode 4.3 or later): Choose Objective-C class. The option UIViewController subclass has been bundled in with other Objective-C class templates. Then select UIViewController as subclass. You will also need to check with xib for user interface. Pages 187, 188: If using Xcode 4.6 or later refer to version notes concerning presenting and dismissing view controllers. If using Xcode 5 or later refer to version notes concerning Gesture Recognizers and Moving between scenes (segues). 3

4 Version notes for Xcode 4.3 or later What was referred to as a View-Based Application is now a Single View Application. When choosing options for your new project note the example shown below: o Enter the Class Prefix the same as the Product Name. o Leave all three check boxes unchecked (Use Storyboards, Use Automatic Reference Counting, Include Unit Tests). Labels (UILabel) no longer have the Adjust to Fit attribute in the Attributes Inspector. When checked this resulted in text shrinking to fit the available frame size. The Autoshrink attribute (in Xcode 4.3 or later) will serve the same purpose (as well as being able to set a minimum font size). dealloc does not appear in the implementation template. But as we are not using ARC (Automatic Reference Counting) then go ahead and include the dealloc method as shown in the is included in the implementation template (to implement private methods and class extensions). This will not be used in any projects in this book. When choosing a template for a New File the option UIViewController subclass has been bundled in with other Objective-C class templates. So select Objective-C class first and then select UIViewController as subclass (see Programming example 11 corrections). 4

5 Version notes for Xcode 4.4 or later String literals, first seen on page 27, show text data between double quotes and preceded by A simpler alternative method to express other literals has been introduced in version 4.4 of Xcode. NSArray literals can now be populated using a simpler syntax: NSArray The objects in the array are between square brackets that are preceded by character. Compare with the example given on page 129. Note that it is no longer necessary to include a terminating nil. A simpler alternative to express NSNumber literals greatly simplifies arrays with NSNumber objects. Previously an NSNumber being assigned a primitive C type required methods like numberwithint. For example NSNumber *howmany; howmany = [NSNumber numberwithint:345]; Now there is the alternative of expressing the literal in a simpler way: NSNumber *howmany; howmany Note also the simpler alternative for other primitive C types being assigned at literals to NSNumbers. Examples for float and BOOL are given below: NSNumber *whatever; whatever NSNumber *response; Response This simplifies arrays with primitive C types. It was stated on page 129 that there is no easy way to add primitive C types to an NSArray. There wasn t until version 4.4: NSArray @synthesize is auto-generated. However it is recommended that this be included in the implementation file as shown in all examples. 5

6 Version notes for Xcode 4.5 or later The method shouldautorotatetointerfaceorientation in the implementation file is no longer supported in Xcode 4.5 or later and is not included in the template. This method was used in Examples 5 and 11 where landscape orientation was required (also in exercises on pages 88, 101, 102, 114, 126, 142, 143, 191). Instead use the following method: - (NSUInteger)supportedInterfaceOrientations { return UIInterfaceOrientationMaskLandscape; } Note that in the Help view of Cup Cakes the orientation is portrait. So this method must return UIInterfaceOrientationMaskPortrait. The view can be set to the taller iphone 5 size (4 inches) or the size of the previous models (3.5 inches). Attribute settings for the view in the xib and settings in the ios simulator have to be consistent. For the 3.5 inch height (used for all examples in this book): Set the Size attribute of the view to None ios simulator > Hardware > Device > iphone ios simulator > Window > Scale > 100% For the 4 inch height: Set the Size attribute of the view to Retina 4 (Full Screen) ios simulator > Hardware > Device > iphone (Retina 4-inch) ios simulator > Window > Scale > 50% The viewdidunload method does not appear as part of the Xcode 4.5 (or later) template in implementation files. So if required it has to be added manually. For all the projects in this book we do not use ARC (Automatic Reference Counting); instead we use MRR (Memory Retain-Release) so I recommend using the dealloc and viewdidunload methods as shown in each example, however you may now choose to omit. 6

7 Version notes for Xcode 4.6 or later Xcode 4.6 adds support for ios 6.1 In support of iphone retina screens the file Default.png, copied to the Supporting Files folder in each project, should be named: If the file is not present Xcode will suggest adding one for you. The viewdidunload method was called when the controller s view was released from memory. It has been deprecated ion ios 6, so this method is no longer required in any of the projects. For projects with multiple views, the first example being Cup Cakes Example 11, the methods for presenting and dismissing view controllers has changed a little. The following methods should be used if the Deployment Target is ios 6.1 or later. Page 188: Previously [self presentmodalviewcontroller:helpview animated:yes]; Now [self presentviewcontroller:helpview animated:yes completion:nil]; Page 187: Previously [self dismissmodalviewcontrolleranimated:yes]; Now [self dismissviewcontrolleranimated:yes completion:nil]; If you open a project that was created with an earlier version of Xcode you will have the opportunity to migrate. Xcode 4.6 has a new version compiler and debugger (LLVM and LLDB). While Xcode 4.6 does still support the previous compiler and debugger it might be wise to bring all your work up to date. The first thing you will notice when you open an old project is a yellow triangular warning as the project loads: The example above indicates one issue. You might have a second issue with the Default png (2 nd bullet point above). Click on the yellow triangle and the issue(s) will be displayed: 7

8 Before dealing with the compiler-debugger issue click on the project icon to set the ios deployment target to 6.1 as shown below: Then click on Validate Project Settings. You will see the following window: Click on the Perform Changes button. Xcode versions 4.6.1, and are responses to various developer issues, none that require responses beyond what was listed above for Xcode

9 Version notes for Xcode 5.1 or later Xcode 5 adds support for ios 7. The most noticeable changes are in the early stages of creating a project. Despite the fact that Xcode 5 has introduced notable changes to its environment, the steps taken to create an application remain the same: Create the project Add images Create the interface Write the header code Make the outlet and action connections Write the implementation code Create the project For all the examples in the book we start with a Single View Application when choosing a template. We will use the Paper Rock Scissors example in these notes. 9

10 You will notice you have no choice when it comes to using storyboards or ARC (Automatic Reference Counting), both are used in Xcode 5. You will see, in the notes to follow, that ARC reduces the amount of code. The code that was used with MRR (Memory Retain-Release) is no longer required. When you enter the Xcode workspace the Deployment Info is displayed. Set the Deployment Target at 7.1. The Device Orientation(s) required should be checked. For Paper Rock Scissors only Portrait is selected. Add images In previous versions of Xcode required images were placed in the Supporting Files folder. They are now organized in Images.xcassets. 10

11 The application icon in ios 7 has to be a png pixels and named icon@2x.png. Drag it from its source to the dotted frame titled iphone App ios7, as shown below. The launch images have to suit the model iphone and be named for use in ios 7. For iphone 4 Retina using ios 7 the image must be a png pixels and named Default_iOS7@2x.png. For iphone 5 Retina using ios 7 the image must be a png pixels and named Default_iOS7-568h@2x.png. Drag them from their sources to the 2x and R4 (Retina 4 inch) dotted frames respectively. 11

12 All other images required for the application should be dragged on below the LaunchImage folder. The last 3 characters in the name should For example PRS 0@2x.png. Create the interface Now the interface can be created. This is done in the same way as with an xib, by selecting the storyboard (Main.storyboard). Show the File Inspector, as shown above. Deselect the Use Auto Layout checkbox. There is a lot of detail associated with Auto Layout and it is not covered in this edition of the book. 12

13 Drag on the controls from the Object Library and set the attributes as described in the book. Write the code to make header declarations There are minor variations to the code in Paper_Rock_ScissorsViewController.h. Before Xcode 5 the code looked like this: #import Paper_Rock_ScissorsViewController : UIViewController { UIButton *btnpaper, *btnrock, *btnscissors; UIImageView *imvuser, *imviphone; UILabel *lblwins, *lbldraws, *lbllosses; } int wins, draws, nonatomic) IBOutlet UIButton *btnpaper, *btnrock, nonatomic) IBOutlet UIImageView *imvuser, nonatomic) IBOutlet UILabel *lblwins, *lbldraws, *lbllosses; - (IBAction)buttonPress:(UIButton 13

14 With Xcode 5 the code looks like this: #import Paper_Rock_ScissorsViewController : UIViewController { UIButton *btnpaper, *btnrock, *btnscissors; UIImageView *imvuser, *imviphone; UILabel *lblwins, *lbldraws, *lbllosses; } int wins, draws, nonatomic) IBOutlet UIButton nonatomic) IBOutlet UIButton nonatomic) IBOutlet UIButton nonatomic) IBOutlet UIImageView nonatomic) IBOutlet UIImageView nonatomic) IBOutlet UILabel nonatomic) IBOutlet UILabel nonatomic) IBOutlet UILabel *lbllosses; - (IBAction)buttonPress:(UIButton Notice the property declarations are made one object at a time. You will see how this makes the Outlet connections very easy to perform. The keyword retain has been replaced with strong. If you were to use retain it would still work fine. More will be said about this when discussing ARC. Make connections to the outlets and actions Create an extra pane by clicking Show the Assistant editor button. 14

15 The buttons allow you to scroll through the storyboard and code files. Scroll so that you have the storyboard in one pane and the header code in the other. Make connections to the outlets by dragging from the radio button beside each property declaration to its corresponding control on the storyboard. Do this for each declared button, imageview and label, as shown above. To make connections to the actions right-click the buttons one at a time to reveal all the possible actions. Then drag from the radio button beside the action to the centre of the IBAction declaration in the header. Note: you are dragging in the opposite direction to the outlet connections. Do this for each of the buttons that will use this method. 15

16 Remove the Assistant editor. You can check that all the outlet and action connections have been done correctly by using the Connections Inspector. Below the storyboard is a bar with three icons. The left icon is the Files Owner. Select this icon the click the Show the Connections inspector button as shown below. You will see all the connections displayed. 16

17 Write the code for the implementation There are very few changes to the implementation code, mainly omissions. With ARC the following methods do not exist: - (void)dealloc - (void)viewdidunload In some examples an object is explicitly released. In Paper Rock Scissors : [alert release]; With ARC this is not to be used as objects are automatically released. MRR could be used prior to Xcode 5. The RR stands for Retain-Release. The keyword retain has been replaced with strong in the property declarations. This is a way of distancing from MMR (no retain, no release). More on images Segmented control There is an issue with the use of images in the ios 7 segmented control. Images loaded into the segments will not display correctly unless there is an adjustment of the rendering mode. As an example, question 6 on page 100 suggests the use of a UISegmentedControl. When the images are first added they look like they are completely blue with no definition. Each image has to be re-rendered and added back to the control (!!!). The following code added to the ViewDidLoad method will do the trick: for(int i=0; i<5; i++) { UIImage *imgold = [scgpick imageforsegmentatindex:i]; UIImage *imgnew = [imgold imagewithrenderingmode:uiimagerenderingmodealwaysoriginal]; [self.scgpick setimage:imgnew forsegmentatindex:i]; } Launch images in landscape orientation Launch images in ios 7 for the iphone can only be in portrait orientation. So when the orientation for the opening view is landscape the launch image will not be displayed. A way around this is to have the opening view in portrait orientation then immediately switch it to landscape when the view first appears. To do this the following import command needs to be added to the implementation file: #import <objc/message.h> as well as the following method: -(void)viewdidappear:(bool)animated { objc_msgsend([uidevice } 17

18 Gesture recognizers Creating recognizers without code This is best demonstrated using the DragBall2 example. In the Object Library there is an object for each of the gestures. Instead of creating a recognizer with code in the ViewDidLoad method (though it can still be done this way), the appropriate object can be dragged onto the control that that requires a gesture. For DragBall2 a Pan Gesture Recognizer is dragged onto the image view containing the basketball: Then the recognizer must be connected to a declared action in the header file. Right click on the recognizer in the bar below the scene, drag from the Sent Actions button to the Action. 18

19 Note that there is no need to declare a variable for the ImageView, or a property declaration in the header file The code in the implementation is a little simpler too. No synthesize required for the ImageView, just the code for the method handling the pan. - (IBAction)handlePan:(UIPanGestureRecognizer *)recognizer { // store translation in a CGPoint CGPoint translation = [recognizer translationinview:self.view]; // relocate centre of ball with translation recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x, recognizer.view.center.y + translation.y); // must set translation back to (0, 0) [recognizer settranslation:cgpointzero inview:self.view]; } Make sure the ImageView has User Interaction enabled. Gesture recognizers in Cup Cakes With nine controls to pan the code in both the header and implementation files is greatly reduced when creating gesture recognizers from the Object Library. Like DragBall2 there is no need for variables for each of the ImageViews, or property declarations in the header file. The implementation file doesn t require a synthesize statement or any of the code in ViewDidLoad. Add a Pan Gesture Recognizer to each of the nine controls. 19

20 With so many recognizers on the one scene creating connections to the Action is easier done using Document Outline. There is a button at the bottom of the centre pane that will show/hide the Document Outline. 20

21 Each of the nine recognizers can be connected to the Action after a Right Click and a drag. The same method used in DragBall2 can be used in Cup Cakes implementation. - (IBAction)handlePan:(UIPanGestureRecognizer *)recognizer { // store translation in a CGPoint CGPoint translation = [recognizer translationinview:self.view]; // relocate centre of ball with translation recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x, recognizer.view.center.y + translation.y); // must set translation back to (0, 0) [recognizer settranslation:cgpointzero inview:self.view]; } 21

22 Moving between scenes (segues) Adding an additional scene in Cup Cakes A New File can be added to the project as before, however choose NOT to Also create an XIB file ; we will be adding a new view from the Object Library. Drag on another View Controller from the Object Library. Select the new view and show the Identity Inspector in the right pane. Choose the newly created HelpViewController for its class. 22

23 Select the View Controller icon in the bar below the view, set its Orientation to Landscape. Add all the required controls. Adding a segue Right Click the Help button. Drag from the Triggered Segues action button to the Help view. Choose Modal. 23

24 A segue is created. A segue to go from Help back to the starting scene is created in the same way. Attributes of the segue can be set by selecting the segue button and then displaying the Attributes Inspector. You might want to change the type of Transition.. 24