Open a Finder window, and navigate to the /Developer/Applications folder. Drag the Project Builder and Interface Builder icons to your Dock.

Open a Finder window and navigate to the /Developer/Documentation/Cocoa folder. Drag the CocoaTopics.html file to your Dock.

One way to access the documentation:

Open the /Developer/Documentation/Cocoa/CocoaTopics.html file in your web browser of choice, click on the Foundation link in the Objective-C Framework Reference section, and then follow the NSObject and NSString links.

One way to find the documentation:

In the Foundation reference document that the NSObject and NSString links are on, go to the bottom of the page, and click on the Functions link. You’ll find the NSLog documentation on this page.

Tip

Use the Find functionality of your browser (Edit → Find, or

-F on most browsers) to search for the NSLog documentation on this rather large page.

One way to do it is to add the following line to the initWithName:artist: method of the Song class:

NSLog(@"isa: %@ self %@", isa, self);

This will print the name of the class as well as the description.

Here’s one way to do it:

Open the strings project we created, and place a breakpoint before the [artist release] statement. Debug the application, and enter in the following commands into the gdb console:

(gdb) print-object [artist lowercaseString]
(gdb) print-object [artist uppercaseString]

One possible solution is to create a project named “fileprinter” with the following main.m file:

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    if (argc > 1) {
                             NSString * filename = [NSString stringWithCString:argv[1]];
                             NSString * file = [NSString stringWithContentsOfFile:filename];
                             printf("%s
", [file UTF8String]);
                         }
    [pool release];
    return 0;
}

When executed from Project Builder, nothing will happen, but if you go to the terminal and issue the following commands, you will see the contents of the main.m file printed:

[titanium:~] duncan% cd ~/LearningCocoa/fileprinter
[titanium:~/LearningCocoa/fileprinter] duncan% build/fileprinter main.m

Try this with a few other files.

One way to look up this documentation:

Open the /Developer/Documentation/Cocoa/CocoaTopics.html file in your web browser of choice, click on the Foundation link in the Objective-C Framework Reference section, and then follow the NSArray, NSSet and NSDictionary links.

One solution is to add the following line of code to the main method:

                     [array writeToFile:@"foo.plist" atomically:YES];

When you run the arrays program with this additional line, a foo.plist file will be written into ~/LearningCocoa/arrays/build containing the elements of the array.

One possible solution is to create a project named “dictionarysaver” with the following main.m file:

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    NSMutableDictionary * dict = [NSMutableDictionary dictionary];
                         [dict setObject:@"The Meaning of Life" forKey:@"A String"];
                         [dict setObject:[NSNumber numberWithInt:42] forKey:@"An Integer"];
                         [dict writeToFile:@"dict.plist" atomically:YES];
    [pool release];
    return 0;
}

When you run this program, the dictionary will be written to the dict.plist file in the ~/LearningCocoa/dictionarysaver folder. This file will look as follows:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.
com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>A String</key>
        <string>The Meaning of Life</string>
        <key>An Integer</key>
        <integer>42</integer>
</dict>
</plist>

The dictionaries example application doesn’t release the dict object. The following line of code is needed after the printf statement:

                     [dict release];

One way to do this is to select the text labels, then change the font using the Font Panel (Format → Show Fonts, or

-T).

One way to do this is to select the totalField, then change the font color using the Font Panel. To access the color picker, use the Extras... pull-down menu on the Font Panel.

The documentation can be found in the /Developer/Documentation/Cocoa /CocoaTopics.html folder. Click on the Application Kit link in the Objective-C Framework Reference section, and then follow the NSWindow and NSView links.

The easiest way to do this is to select the window in Interface Builder and change the title using the Attributes inspector. You can bring the inspector up by hitting Shift-

-I.

One way to do this is to edit the Controller.h file directly to match the following code:

@interface Controller : NSObject
{
    IBOutlet id converter;
    IBOutlet NSTextField dollarField;
                         IBOutlet NSTextField rateField;
                         IBOutlet NSTextField totalField;
}
- (IBAction)convert:(id)sender;
@end

One way to do this is to edit the drawRect: method as follows:

- (void)drawRect:(NSRect)rect
{
    [[NSColor colorWithCalibratedRed:1.0 green:0.0 blue:0.0 alpha:1.0] set];
    NSRectFill([self bounds]);
}

The easiest way to do this is to add the drawing code from the String View application into the Line View drawRect: method as follows:

- (void)drawRect:(NSRect)rect
{
    NSRect bounds = [self bounds];
    NSPoint bottom = NSMakePoint((bounds.size.width/2.0), 0);
    NSPoint top = NSMakePoint((bounds.size.width/2.0), bounds.size.height);
    NSPoint left = NSMakePoint(0, (bounds.size.height/2.0));
    NSPoint right = NSMakePoint(bounds.size.width, (bounds.size.height/2.0));

    [[NSColor whiteColor] set];
    [NSBezierPath fillRect:bounds];

    [[NSColor blackColor] set];
    [NSBezierPath strokeRect:bounds];

    [NSBezierPath strokeLineFromPoint:top toPoint:bottom];
    [NSBezierPath strokeLineFromPoint:right toPoint:left];

    [[NSBezierPath bezierPathWithOvalInRect:bounds] stroke];
    NSString * hello = @"Hello World!";
                         NSMutableDictionary * attribs = [NSMutableDictionary dictionary];
                         [attribs setObject:[NSFont fontWithName:@"Times" size:24]
                                     forKey:NSFontAttributeName];
                         [attribs setObject:[NSColor redColor]               
                                     forKey:NSForegroundColorAttributeName];
                         [hello drawAtPoint:NSMakePoint((bounds.size.width/2.0),
                                                        (bounds.size.height/2.0))
                             withAttributes:attribs];
  
}
@end

One way to do this is to insert the following line of code before drawing any of the lines in Line View:

                     [NSBezierPath setDefaultLineWidth:3.0];

This will cause all paths to be drawn with 3-point-wide strokes. Try some other values.

One way of finding the NSBezierPath documentation is to click the Find tab in Project Builder (or use the menu Find → Show Batch Find). Enter NSBezierPath into the Find box, and hit Return. After a few moments, Project Builder will show you all the occurrences of the NSBezierPath string, both in your project and in the frameworks against which it’s linked. To limit the search to just your project, adjust the “This Project” pull-down to “This Project, no frameworks.”

The easiest way to accomplish this is to rename the mouseDown: method to mouseDragged:.

One way to do this is to modify the initWithFrame: method as follows:

- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithFrame:frame];
    center.x = frame.size.width / 2.0;
                         center.y = frame.size.height / 2.0;
    radius = 20.0;
    color = [[NSColor redColor] retain];
    return self;
}

One way of changing the setRadius: method is as follows:

                     - (IBAction)setRadius:(id)sender
                     {
                         float newRadius = [sender floatValue];
                         if (newRadius != radius) {
                             radius = newRadius;
                             [self setNeedsDisplay:YES];
                         }
                     }

This will ensure that a redraw of the interface only occurs when it is needed.

One way to do this is to make the MyDelegate object instance a delegate of NSApplication and implement the applicationShouldTerminate: method. To do this, Control-drag a connection from File’s Owner to MyDelegate in Interface Builder, then add the following method to the MyDelegate class:

- (NSTerminationReply)applicationShouldTerminate:(NSApplication *)sender
{
    int answer = NSRunAlertPanel(@"Quit", @"Are you sure?",
                                @"Quit", @"Cancel", nil);
    if (answer == NSAlertDefaultReturn) {
        return NSTerminateNow;
    } else {
        return NSTerminateCancel;
    }
}

We suggest changing it to blue by modifying the initWithFrame: method as follows:

- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithFrame:frame];
    center.x = frame.size.width / 2;
    center.y = frame.size.height / 2;
    radius = 20.0;
    color = [[NSColor blueColor] retain];
    return self;
}

Of course you can change it to whatever color you please.

To do this requires setting the springs appropriately in Interface Builder.

Go into Interface Builder, and either edit the column header, either directly or using the inspector.

One way to do it is to make the MyDataSource object instance a delegate of NSApplication and implement the applicationShouldTerminate: method. To do this, Control-drag a connection from File’s Owner to MyDataSource in Interface Builder, then add the following method to the MyDataSource class:

- (NSTerminationReply)applicationShouldTerminate:(NSApplication *)sender
{
    int answer = NSRunAlertPanel(@"Quit", @"Are you sure?",
                                @"Quit", @"Cancel", nil);
    if (answer == NSAlertDefaultReturn) {
        return NSTerminateNow;
    } else {
        return NSTerminateCancel;
    }
}

The FoodItem class needs a dealloc method to release the name and price variables.

Once again, the documentation can be found in the /Developer/Documentation /Cocoa/CocoaTopics.htmlfile.

In the active target panel of Project Builder (Project → Edit Active Target), add a document type with the following settings:

Build and run (

-R) the application. You should be able to read and write plist files now.

The revert functionality doesn’t work because the windowControllerDidLoadNib method isn’t called, and that is where we turn the contents of a file into a string to use. To fix this, edit the loadDataRepresentation:ofType: method as follows:

- (BOOL)loadDataRepresentation:(NSData *)data ofType:(NSString *)type
{
    if (textView){
                             NSString * text = [[NSString alloc]initWithData:dataFromFile
                                                                    encoding:NSUTF8StringEncoding];
                             [textView setString:text];
                             [text release];
                         } else {
                             dataFromFile = [data retain];
                         }
                         return YES;
}

To turn on the ability for the TextView to handle graphics from within Interface Builder, simply click on the TextView, and bring up the Attributes inspector, as shown in Figure A-4. Simply click on the radio buttons, and then remove the corresponding lines of code from MyDocument.m.

Figure A-4. TextView attribute inspector

Add the following line to the awakeFromNib: method:

                     [textView setRulerVisible:YES];

One solution:

Add a menu item named “Speak” to the File menu of the MainMenu.nib file. Connect the menu item to FirstResponder.startSpeaking by Control-dragging a connection from the menu item to the First Responder icon. This makes our speakText method obsolete, so it can be removed.

One way to do this is to modify the analyzeText: method, as shown here:

- (IBAction)analyzeText:(id)sender
{
    int count = 0;                                                       
    int fontChanges = -1;                                                
    id lastAttribute = nil;                                              
    NSTextStorage * storage = [textView textStorage];                    
    
    while (count < [storage length]) {                                   
        id attributeValue = [storage attribute:NSFontAttributeName
                                    atIndex:count
                             effectiveRange:nil];
        if (attributeValue != lastAttribute) {                           
            fontChanges++;
        }
        lastAttribute = attributeValue;                                  
        count++;                                                         
    }
     
    NSBeginAlertSheet(@"Analysis",         // title                       // i                              
                      @"OK",               // default button label
                      nil,                 // cancel button label
                      nil,                 // other button label
                      [textView window],   // document window
                      nil,                 // modal delegate
                      NULL,                // selector to method
                      NULL,                // dismiss selector
                      nil,                 // context info
                      @"Font Changes %i
Character Count %i",
                                           fontChanges, [storage length]);
}

The easiest way to do this is to add the Font menu to the MainMenu.nib file. Then, in your application, use the Font menu to bring up the Font Panel (or hit

-T).

This is almost a trick question.

By default, the File → Print command works and will print out the Dot View window. To print just the Dot View, disconnect the File → Print menu item from FirstResponder.print, then connect it (by Control-dragging) to the DotView area and the print: action.

Simply drag the image view to encompass the entire window. You may even want to turn the border off so that only the image contained by the view will print. Try setting the image view to some of the images in the /Library/Desktop Pictures folder for printing.

One way to do this:

Add the following method to Controller.m, and connect it to a “Previous Image” button:

                     - (IBAction)prevousImage:(id)sender
                     {
                         if (currentImage == 0) {
                             currentImage = [images count] - 1;
                         } else {
                             currentImage--;
                         }
                         [imageView setImage objectAtIndex:currentImage];
                     }

One way to do this is in Interface Builder. In the inspector, set the key equivalent of the next button to “n” and of the previous button to “p”.

The best way to do this is to follow the procedure that we detailed in the chapter:

Find the ~/Library/Preferences/com.oreilly.Favorites file, and double-click it to open it in the Property List Editor (/Developer/Applications).

Create a button on the interface for the Favorites application, and have it call the following action method:

                     - (IBAction)reset:(id)sender
                     {
                         [prefs removeObjectForKey:@"FavBook"];
                         [prefs removeObjectForKey:@"FavCity"];
                         [prefs removeObjectForKey:@"FavColor"];
                         [prefs removeObjectForKey:@"FavFood"];
                     }

One way to do this:

One way to do this:

Create a new action method in the Controller.h file as follows:

                     - (IBAction)rateUpdated:(id)sender
                     {
                         [[NSUserDefaults standardUserDefaults] setFloatValue:[sender floatValue]
                                                                      forKey:@"rate"];
                     }

Hook the rateField text field to the rateUpdated: action method so that it is called whenever the contents of the field are changed. Next, add an awakeFromNib method to the Controller.h file as follows:

                     - (void)awakeFromNib
                     {
                         [rateField setFloatValue:[[NSUserDefaults standardUserDefaults]
                             floatForKey:@"rate"];
                     }

One way to do this:

Follow the same process as listed earlier with a new paraCountField, and separate the string based on the character.

Use the following process to guide you: