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 
         

@interface STEAppDelegate : UIResponder 
         

@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 
         

@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 
         

#import "STESimpleTextDocument.h"

@interface STEDetailViewController : UIViewController 
         

@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 
         

@protocol STESimpleTextDocumentDelegate;

@interface STESimpleTextDocument : UIDocument

@property (copy, nonatomic) NSString* documentText;

@property (weak, nonatomic) id
         
           delegate;
         

@end

@protocol STESimpleTextDocumentDelegate 
         

@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