- (void)tableView:(UITableView *)tv accessoryTappedForRowAtIndexPath:(NSIndexPath *)ip;

- (UITableViewCell *)tableView:(UITableView *)sender cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
   // get a cell to use (instance of UITableViewCell)
   UITableViewCell *cell;
   cell = [self.tableView dequeueReusableCellWithIdentifier:@“My Table View Cell”];
   if (!cell) { 
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
                                      reuseIdentifier:@“My Table View Cell”];
   }
   cell.textLabel.text = [self getMyDataForRow:indexPath.row inSection:indexPath.section];
   return cell;
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)sender; 
- (NSInteger)tableView:(UITableView *)sender numberOfRowsInSection:(NSInteger)section;

- (void)tableView:(UITableView *)sender didSelectRowAtIndexPath:(NSIndexPath *)path {
     // go do something based on information 
     // about my data structure corresponding to indexPath.row in indexPath.section
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
     NSIndexPath *indexPath = [self.tableView indexPathForCell:sender]; 
     // prepare segue.destinationController to display based on information 
     // about my data structure corresponding to indexPath.row in indexPath.section
}

#import "CalculatorGraphViewController.h"
#import "CalculatorBrain.h"
#import "CalculatorProgramsTableViewController.h"

@interface CalculatorGraphViewController() <CalculatorProgramsTableViewControllerDelegate>
@property (nonatomic, strong) UIPopoverController *popoverController; // added after lecture to prevent multiple popovers
@end

@implementation CalculatorGraphViewController

@synthesize popoverController;

#define FAVORITES_KEY @"CalculatorGraphViewController.Favorites"

- (IBAction)addToFavorites:(id)sender
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSMutableArray *favorites = [[defaults objectForKey:FAVORITES_KEY] mutableCopy];
    if (!favorites) favorites = [NSMutableArray array];
    [favorites addObject:self.calculatorProgram];
    [defaults setObject:favorites forKey:FAVORITES_KEY];
    [defaults synchronize];
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"Show Favorite Graphs"]) {
        // this if statement added after lecture to prevent multiple popovers
        // appearing if the user keeps touching the Favorites button over and over
        // simply remove the last one we put up each time we segue to a new one
        if ([segue isKindOfClass:[UIStoryboardPopoverSegue class]]) {
            UIStoryboardPopoverSegue *popoverSegue = (UIStoryboardPopoverSegue *)segue;
            [self.popoverController dismissPopoverAnimated:YES];
            self.popoverController = popoverSegue.popoverController; // might want to be popover\'s delegate and self.popoverController = nil on dismiss?
        }
        NSArray *programs = [[NSUserDefaults standardUserDefaults] objectForKey:FAVORITES_KEY];
        [segue.destinationViewController setPrograms:programs];
        [segue.destinationViewController setDelegate:self];
    }
}

- (void)calculatorProgramsTableViewController:(CalculatorProgramsTableViewController *)sender
                                 choseProgram:(id)program
{
    self.calculatorProgram = program;
    // if you wanted to close the popover when a graph was selected
    // you could uncomment the following line
    // you\'d probably want to set self.popoverController = nil after doing so
    // [self.popoverController dismissPopoverAnimated:YES];
    [self.navigationController popViewControllerAnimated:YES]; // added after lecture to support iPhone
}

// added after lecture to support deletion from the table
// deletes the given program from NSUserDefaults (including duplicates)
// then resets the Model of the sender

- (void)calculatorProgramsTableViewController:(CalculatorProgramsTableViewController *)sender
                               deletedProgram:(id)program
{
    NSString *deletedProgramDescription = [CalculatorBrain descriptionOfProgram:program];
    NSMutableArray *favorites = [NSMutableArray array];
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    for (id program in [defaults objectForKey:FAVORITES_KEY]) {
        if (![[CalculatorBrain descriptionOfProgram:program] isEqualToString:deletedProgramDescription]) {
            [favorites addObject:program];
        }
    }
    [defaults setObject:favorites forKey:FAVORITES_KEY];
    [defaults synchronize];
    sender.programs = favorites;
}

@end

#import <UIKit/UIKit.h>

@class CalculatorProgramsTableViewController;

@protocol CalculatorProgramsTableViewControllerDelegate <NSObject> // added <NSObject> after lecture so we can do respondsToSelector: on the delegate
@optional
- (void)calculatorProgramsTableViewController:(CalculatorProgramsTableViewController *)sender
                                 choseProgram:(id)program;
- (void)calculatorProgramsTableViewController:(CalculatorProgramsTableViewController *)sender
                                 deletedProgram:(id)program; // added after lecture to support deleting from table
@end

@interface CalculatorProgramsTableViewController : UITableViewController
@property (nonatomic, strong) NSArray *programs; // of CalculatorBrain programs
@property (nonatomic, weak) id <CalculatorProgramsTableViewControllerDelegate> delegate;
@end

#import "CalculatorProgramsTableViewController.h"
#import "CalculatorBrain.h"

@implementation CalculatorProgramsTableViewController

@synthesize programs = _programs;
@synthesize delegate = _delegate;

// added after lecture to be sure table gets reloaded if Model changes
// you should always do this (i.e. reload table when Model changes)
// the Model getting out of synch with the contents of the table is bad

- (void)setPrograms:(NSArray *)programs
{
    _programs = programs;
    [self.tableView reloadData];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return YES;
}

#pragma mark - UITableViewDataSource

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self.programs count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Calculator Program Description";
    
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }
    
    // Configure the cell...
    id program = [self.programs objectAtIndex:indexPath.row];
    cell.textLabel.text = [@"y = " stringByAppendingString:[CalculatorBrain descriptionOfProgram:program]];
    
    return cell;
}

// this method added after lecture to support deletion
// simply delegates deletion

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        id program = [self.programs objectAtIndex:indexPath.row];
        [self.delegate calculatorProgramsTableViewController:self deletedProgram:program];
    }
}

// added after lecture
// don\'t allow deletion if the delegate does not support it too!

- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
    return [self.delegate respondsToSelector:@selector(calculatorProgramsTableViewController:deletedProgram:)];
}

#pragma mark - UITableViewDelegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    id program = [self.programs objectAtIndex:indexPath.row];
    [self.delegate calculatorProgramsTableViewController:self choseProgram:program];
}

@end