iOS Beginners Lesson 4

LOGIC & INTERFACE
Building our App

OVERVIEW
• Lesson 1: Introductions
• Lesson 2: iOS specifics
• Lesson 3: Data Model
• Lesson 4: Logic (Controller) & Interface

LESSON 3: DATA MODEL
• Hour 1: Storyboard
• Hour 2: Creating & Editing
• Hour 3: Display & Deleting Notes

Storyboard
• Visual representation of iOS user interface (UI)
• Shows screens of content and connections
between screens. Screens referred to as
“Scene”
• 1 “Scene” represents 1 View Controller and
Views
• Many “views” can be placed on 1 “scene” (e.g.
buttons, table views, text views). Think of views

Storyboard
• Each scene has a dock (displays icons
representing the top-level objects of the
scene)

Storyboard
• The “dock” is where we make connections
between code in our View Controller and its
Views (“visual objects on the scene”)

View Controllers
• A storyboard displays View Controllers and
corresponding Views visually

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
UISplitViewController *splitViewController = (UISplitViewController *)self.window.rootViewController;
UINavigationController *navigationController = [splitViewController.viewControllers lastObject];
splitViewController.delegate = (id)navigationController.topViewController;
}
return YES;
}
View Controllers

View Controllers
UISplitViewController *splitViewController = (UISplitViewController *)self.window.rootViewController;

View Controllers
UINavigationController
• Sub-class of UIViewController
• a special View Controller that manages the navigation of
hierarchical content

View Controllers
UINavigationController
• It is a “container” that embeds content of other View
Controllers inside itself

View Controllers
AppDelegate.m
#import "AppDelegate.h"
#import "Data.h"
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[Data getAllNotes];
return YES;
}

View Controllers
MasterViewController.m
#import “Data.h"
- (void)insertNewObject:(id)sender
{
if (!_objects) {
_objects = [[NSMutableArray alloc] init];
}
//[_objects insertObject:[NSDate date] atIndex:0];
NSString *key = [[NSDate date] description];
[Data setNote:kDefaultText forKey:key];
[Data setCurrentKey:key];
[_objects insertObject:key atIndex:0];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
}

View Controllers
DetailViewController.m
#import “Data.h"
- (void)setDetailItem:(id)newDetailItem
{
if (_detailItem != newDetailItem) {
_detailItem = newDetailItem;
[Data setCurrentKey:_detailItem];
// Update the view.
[self configureView];
}
if (self.masterPopoverController != nil) {
[self.masterPopoverController dismissPopoverAnimated:YES];
}
}

View Controllers
- (void)configureView
{
NSString *currentNote = [[Data getAllNotes] objectForKey:[Data getCurrentKey]];
if (![currentNote isEqualToString:kDefaultText]) {
self.tView.text = currentNote;
} else {
self.tView.text = @"";
}
[self.tView becomeFirstResponder];
}

View Controllers
- (void)viewWillDisappear:(BOOL)animated
{
if (![self.tView.text isEqualToString:@""]) {
[Data setNoteForCurrentKey:self.tView.text];
} else {
[Data removeNoteForKey:[Data getCurrentKey]];
}
[Data saveNotes];
}

View Controllers
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath
*)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"
forIndexPath:indexPath];
NSDate *object = _objects[indexPath.row];
cell.textLabel.text = [[Data getAllNotes] objectForKey:[object description]];
return cell;
}

View Controllers
- (void)makeObjects
{
_objects = [NSMutableArray arrayWithArray:[[Data getAllNotes] allKeys]];
[_objects sortUsingComparator:^NSComparisonResult(id obj1, id obj2) {
return [(NSDate *)obj2 compare:(NSDate *)obj1];
}];
}

View Controllers
- (void)insertNewObject:(id)sender
{
[self makeObjects];
if (!_objects) {
_objects = [[NSMutableArray alloc] init];
}
//[_objects insertObject:[NSDate date] atIndex:0];
NSString *key = [[NSDate date] description];
[Data setNote:kDefaultText forKey:key];
[Data setCurrentKey:key];
[_objects insertObject:key atIndex:0];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:0 inSection:0];
[self.tableView insertRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
[self performSegueWithIdentifier:kDetailView sender:self];
}

View Controllers

View Controllers
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
self.detailViewController.detailItem = object;
}
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if ([[segue identifier] isEqualToString:@"showDetail"]) {
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
[[segue destinationViewController] setDetailItem:object];
}
}

View Controllers
- (void)viewWillAppear:(BOOL)animated
{
[super viewDidAppear:animated];
[self makeObjects];
[self.tableView reloadData];
}

View Controllers
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle
forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleDelete) {
[Data removeNoteForKey:[_objects objectAtIndex:indexPath.row]];
[Data saveNotes];
[_objects removeObjectAtIndex:indexPath.row];
[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
} else if (editingStyle == UITableViewCellEditingStyleInsert) {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table
view.
}
}

iOS Beginners Lesson 4

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iOS Beginners Lesson 4