iCloud8_Code Listings

代码清单Code Listings

本附录提供了STEAppDelegate、STEMasterViewController、STEDetailViewController、STESimpleTextDocument类的接口和实现的代码清单。代码清单没有显示从文件模板生成的方法的实现。This appendix provides listings for the interfaces and implementations of the STEAppDelegate, STEMasterViewController, STEDetailViewController, and STESimpleTextDocument classes. The listings do not show unchanged method implementations from the file templates.

 

STEAppDelegate.h

#import <UIKit/UIKit.h>

@interface STEAppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;

@end

 

STEAppDelegate.m

#import "STEAppDelegate.h"

@implementation STEAppDelegate

@synthesize window = _window;

- (void)initializeiCloudAccess {

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

        if ([[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil])

            NSLog(@"iCloud is available.\n");

        else

            NSLog(@"iCloud is not available.\n");

    });

}

- (BOOL)application:(UIApplication *)application

        didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    [self initializeiCloudAccess];

    // Override point for customization after application launch.

    return YES;

}

@end

 

STEMasterViewController.h

#import <UIKit/UIKit.h>

@interface STEMasterViewController : UITableViewController

@property (weak, nonatomic) IBOutlet UIBarButtonItem *addButton;

@end

 

STEMasterViewController.m

#import "STEMasterViewController.h"

#import "STESimpleTextDocument.h"

#import "STEDetailViewController.h"

NSString *STEDocFilenameExtension = @"stedoc";

NSString *DisplayDetailSegue = @"DisplayDetailSegue";

NSString *STEDocumentsDirectoryName = @"Documents";

NSString *DocumentEntryCell = @"DocumentEntryCell";

@interface STEMasterViewController()

- (NSString*)newUntitledDocumentName;

- (void)setupAndStartQuery;

@end

@implementation STEMasterViewController {

    NSMutableArray *documents;

    NSMetadataQuery *_query;

}

@synthesize addButton;

- (NSMetadataQuery*)textDocumentQuery {

    NSMetadataQuery* aQuery = [[NSMetadataQuery alloc] init];

    if (aQuery) {

        // Search the Documents subdirectory only.

        [aQuery setSearchScopes:[NSArray

                    arrayWithObject:NSMetadataQueryUbiquitousDocumentsScope]];

        // Add a predicate for finding the documents.

        NSString* filePattern = [NSString stringWithFormat:@"*.%@",

                    STEDocFilenameExtension];

        [aQuery setPredicate:[NSPredicate predicateWithFormat:@"%K LIKE %@",

                    NSMetadataItemFSNameKey, filePattern]];

    }

    return aQuery;

}

- (void)setupAndStartQuery {

    // Create the query object if it does not exist.

    if (!_query)

        _query = [self textDocumentQuery];

    // Register for the metadata query notifications.

    [[NSNotificationCenter defaultCenter] addObserver:self

                    selector:@selector(processFiles:)

                    name:NSMetadataQueryDidFinishGatheringNotification

                    object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self

                    selector:@selector(processFiles:)

                    name:NSMetadataQueryDidUpdateNotification

                    object:nil];

    [_query startQuery];

}

- (void)awakeFromNib

{

    [super awakeFromNib];

    if (!documents)

        documents = [[NSMutableArray alloc] init];

    self.navigationItem.leftBarButtonItem = self.editButtonItem;

    [self setupAndStartQuery];

}

- (void)didReceiveMemoryWarning

{

    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.

}

#pragma mark Document Management

- (NSString*)newUntitledDocumentName {

    NSInteger docCount = 1;   // Start with 1 and go from there.

    NSString *newDocName = nil;

    // At this point, the document list should be up to date.

    BOOL done = NO;

    while (!done) {

        newDocName = [NSString stringWithFormat:@"Note %d.%@",

                        docCount, STEDocFilenameExtension];

        // Look for an existing document with the same name. If one is

        // found, increment the docCount value and try again.

        BOOL nameExists = NO;

        for (NSURL* aURL in documents) {

            if ([[aURL lastPathComponent] isEqualToString:newDocName]) {

                docCount++;

                nameExists = YES;

                break;

            }

        }

        // If the name wasn't found, exit the loop.

        if (!nameExists)

            done = YES;

    }

    return newDocName;

}

- (IBAction)addDocument:(id)sender {

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

        // Create the new URL object on a background queue.

        NSFileManager *fm = [NSFileManager defaultManager];

        NSURL *newDocumentURL = [fm URLForUbiquityContainerIdentifier:nil];

        if (newDocumentURL) {

            newDocumentURL = [newDocumentURL

                URLByAppendingPathComponent:STEDocumentsDirectoryName

                isDirectory:YES];

            newDocumentURL = [newDocumentURL

                URLByAppendingPathComponent:[self newUntitledDocumentName]];

            // Perform the remaining tasks on the main queue.

            dispatch_async(dispatch_get_main_queue(), ^{

                // Update the data structures and table.

                [documents addObject:newDocumentURL];

                // Update the table.

                NSIndexPath* newCellIndexPath =

                [NSIndexPath indexPathForRow:([documents count] - 1) inSection:0];

                [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newCellIndexPath]

                                 withRowAnimation:UITableViewRowAnimationAutomatic];

                [self.tableView selectRowAtIndexPath:newCellIndexPath

                                animated:YES

                                scrollPosition:UITableViewScrollPositionMiddle];

                // Segue to the detail view controller to begin editing.

                UITableViewCell* selectedCell = [self.tableView

                               cellForRowAtIndexPath:newCellIndexPath];

                [self performSegueWithIdentifier:DisplayDetailSegue sender:selectedCell];

            });

        }

    });

}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    if (![segue.identifier isEqualToString:DisplayDetailSegue])

        return;

    // Get the detail view controller.

    STEDetailViewController* destVC =

           (STEDetailViewController*)segue.destinationViewController;

    // Find the correct dictionary from the documents array.

    NSIndexPath *cellPath = [self.tableView indexPathForSelectedRow];

    UITableViewCell *theCell = [self.tableView cellForRowAtIndexPath:cellPath];

    NSURL *theURL = [documents objectAtIndex:[cellPath row]];

    // Assign the URL to the detail view controller and

    // set the title of the view controller to the doc name.

    destVC.detailItem = theURL;

    destVC.navigationItem.title = theCell.textLabel.text;

}

#pragma mark Table View methods

- (NSInteger)tableView:(UITableView *)tableView

             numberOfRowsInSection:(NSInteger)section {

    return [documents count];

}

- (UITableViewCell*)tableView:(UITableView *)tableView

                    cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    UITableViewCell *newCell = [tableView dequeueReusableCellWithIdentifier:DocumentEntryCell];

    if (!newCell)

        newCell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault

                                           reuseIdentifier:DocumentEntryCell];

    if (!newCell)

        return nil;

    // Get the doc at the specified row.

    NSURL *fileURL = [documents objectAtIndex:[indexPath row]];

    // Configure the cell.

    newCell.textLabel.text = [[fileURL lastPathComponent] stringByDeletingPathExtension];

    return newCell;

}

 - (void)tableView:(UITableView *)tableView

         commitEditingStyle:(UITableViewCellEditingStyle)editingStyle

         forRowAtIndexPath:(NSIndexPath *)indexPath {

     if (editingStyle == UITableViewCellEditingStyleDelete) {

         NSURL *fileURL = [documents objectAtIndex:[indexPath row]];

         // Don't use file coordinators on the app's main queue.

         dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

             NSFileCoordinator *fc = [[NSFileCoordinator alloc]

                                      initWithFilePresenter:nil];

             [fc coordinateWritingItemAtURL:fileURL

                 options:NSFileCoordinatorWritingForDeleting

                 error:nil

                 byAccessor:^(NSURL *newURL) {

                     NSFileManager *fm = [[NSFileManager alloc] init];

                     [fm removeItemAtURL:newURL error:nil];

             }];

         });

         // Remove the URL from the documents array.

         [documents removeObjectAtIndex:[indexPath row]];

         // Update the table UI. This must happen after

         // updating the documents array.

         [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath]

                    withRowAnimation:UITableViewRowAnimationAutomatic];

     }

 }

#pragma mark Query Method

- (void)processFiles:(NSNotification*)aNotification {

    NSMutableArray *discoveredFiles = [NSMutableArray array];

    // Always disable updates while processing results.

    [_query disableUpdates];

    // The query reports all files found, every time.

    NSArray *queryResults = [_query results];

    for (NSMetadataItem *result in queryResults) {

        NSURL *fileURL = [result valueForAttribute:NSMetadataItemURLKey];

        NSNumber *aBool = nil;

        // Don't include hidden files.

        [fileURL getResourceValue:&aBool forKey:NSURLIsHiddenKey error:nil];

        if (aBool && ![aBool boolValue])

            [discoveredFiles addObject:fileURL];

    }

    // Update the list of documents.

    [documents removeAllObjects];

    [documents addObjectsFromArray:discoveredFiles];

    [self.tableView reloadData];

    // Reenable query updates.

    [_query enableUpdates];

}

 

STEDetailViewController.h

#import <UIKit/UIKit.h>

#import "STESimpleTextDocument.h"

@interface STEDetailViewController : UIViewController <STESimpleTextDocumentDelegate>

@property (strong, nonatomic) NSURL *detailItem;

@property (strong, nonatomic) IBOutlet UILabel *detailDescriptionLabel;

@property (weak, nonatomic) IBOutlet UITextView *textView;

@end

 

STEDetailViewController.m

#import "STEDetailViewController.h"

@interface STEDetailViewController ()

- (void)configureView;

@end

@implementation STEDetailViewController {

    STESimpleTextDocument *_document;

}

@synthesize detailItem = _detailItem;

@synthesize detailDescriptionLabel = _detailDescriptionLabel;

@synthesize textView = _textView;

#pragma mark View Management

- (void)viewWillAppear:(BOOL)animated {

    [super viewWillAppear:animated];

    // Clear out the text view contents.

    self.textView.text = @"";

    // Create the document and assign the delegate.

    _document = [[STESimpleTextDocument alloc] initWithFileURL:self.detailItem];

    _document.delegate = self;

    // If the file exists, open it; otherwise, create it.

    NSFileManager *fm = [NSFileManager defaultManager];

    if ([fm fileExistsAtPath:[self.detailItem path]])

        [_document openWithCompletionHandler:nil];

    else

        // Save the new document to disk.

        [_document saveToURL:self.detailItem

                   forSaveOperation:UIDocumentSaveForCreating

                   completionHandler:nil];

    // Register for the keyboard notifications

    [[NSNotificationCenter defaultCenter] addObserver:self

                        selector:@selector(keyboardWillShow:)

                        name:UIKeyboardWillShowNotification

                        object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self

                        selector:@selector(keyboardWillHide:)

                        name:UIKeyboardWillHideNotification

                        object:nil];

}

- (void)viewWillDisappear:(BOOL)animated {

    [super viewWillDisappear:animated];

    NSString *newText = self.textView.text;

    _document.documentText = newText;

    // Close the document.

    [_document closeWithCompletionHandler:nil];

    [[NSNotificationCenter defaultCenter] removeObserver:self

                        name:UIKeyboardWillShowNotification

                        object:nil];

    [[NSNotificationCenter defaultCenter] removeObserver:self

                        name:UIKeyboardWillHideNotification

                        object:nil];

}

#pragma mark Keyboard Handlers

- (void)keyboardWillShow:(NSNotification*)aNotification {

    NSDictionary *info = [aNotification userInfo];

    CGRect kbSize = [[info objectForKey:UIKeyboardFrameEndUserInfoKey]

                            CGRectValue];

    double duration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey]

                            doubleValue];

    UIEdgeInsets insets = self.textView.contentInset;

    insets.bottom += kbSize.size.height;

    [UIView animateWithDuration:duration animations:^{

        self.textView.contentInset = insets;

    }];

}

- (void)keyboardWillHide:(NSNotification*)aNotification {

    NSDictionary *info = [aNotification userInfo];

    double duration = [[info objectForKey:UIKeyboardAnimationDurationUserInfoKey]

                            doubleValue];

    // Reset the text view's bottom content inset.

    UIEdgeInsets insets = self.textView.contentInset;

    insets.bottom = 0;

    [UIView animateWithDuration:duration animations:^{

        self.textView.contentInset = insets;

    }];

}

 

STESimpleTextDocument.h

#import <UIKit/UIKit.h>

@protocol STESimpleTextDocumentDelegate;

@interface STESimpleTextDocument : UIDocument

@property (copy, nonatomic) NSString* documentText;

@property (weak, nonatomic) id<STESimpleTextDocumentDelegate> delegate;

@end

@protocol STESimpleTextDocumentDelegate <NSObject>

@optional

- (void)documentContentsDidChange:(STESimpleTextDocument*)document;

@end

 

STESimpleTextDocument.m

#import "STESimpleTextDocument.h"

@implementation STESimpleTextDocument

@synthesize documentText = _documentText;

@synthesize delegate = _delegate;

- (void)setDocumentText:(NSString *)newText {

    NSString* oldText = _documentText;

    _documentText = [newText copy];

    // Register the undo operation.

    [self.undoManager setActionName:@"Text Change"];

    [self.undoManager registerUndoWithTarget:self

            selector:@selector(setDocumentText:)

            object:oldText];

}

- (id)contentsForType:(NSString *)typeName

      error:(NSError *__autoreleasing *)outError {

    if (!self.documentText)

        self.documentText = @"";

    NSData *docData = [self.documentText dataUsingEncoding:NSUTF8StringEncoding];

    return docData;

}

- (BOOL)loadFromContents:(id)contents

        ofType:(NSString *)typeName

        error:(NSError *__autoreleasing *)outError {

    if ([contents length] > 0)

        self.documentText = [[NSString alloc]

                initWithData:contents

                encoding:NSUTF8StringEncoding];

    else

        self.documentText = @"";

    // Tell the delegate that the document contents changed.

    if (self.delegate && [self.delegate respondsToSelector:

                           @selector(documentContentsDidChange:)])

        [self.delegate documentContentsDidChange:self];

    return YES;

}

@end