Access UITableView cell and swipe between them from DetailView using XCode 4 - iphone

Question

I'm making my first app and I’m using XCode 4 with a Storyboard. Thanks to this place, lots of tutorials, Apple’s archives databases and a bit of me, I’m slowly getting the basics together. It’s an app populated from a plist. The plist is an array with dictionaries, the dictionarires containing stings with info about different red wines in Norway. First, the plist populates a TableView. I’m using NSSortDescritor to sort the TableView and added a button to the navigation bar for resorting if I want it displayed by another value. It looks like this:
RootTableViewController.h:
#import <UIKit/UIKit.h>
#interface RootTableViewController : UITableViewController <UIActionSheetDelegate> {
NSMutableArray *sortedObjects;
}
-(IBAction)sortButtonPressed:(id)sender;
#end
RootTableViewController.m:
#import "RootTableViewController.h"
#import "ObjectCell.h"
#import "DetailViewController.h"
#interface RootTableViewController ()
#end
#implementation RootTableViewController
- (IBAction)sortButtonPressed:(id)sender;
{
UIActionSheet *sort = [[UIActionSheet alloc]
//InitWithStyle etc for sheet
}
-(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
NSSortDescriptor *sortDesc;
if (buttonIndex == 0) {
sortDesc = [[NSSortDescriptor alloc] initWithKey:#"Name" ascending:YES];
[sortedWines sortUsingDescriptors:[NSArray arrayWithObject:sortDesc]];
}
if (buttonIndex == 1) {
sortDesc = [[NSSortDescriptor alloc] initWithKey:#"Country" ascending:YES];
[sortedWines sortUsingDescriptors:[NSArray arrayWithObject:sortDesc]];
}
[self.tableView reloadData];
}
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *myfile = [[NSBundle mainBundle]
pathForResource:#"Objects" ofType:#"plist"];
sortedObjects = [[NSMutableArray alloc]initWithContentsOfFile:myfile];
NSSortDescriptor * sortDesc = [[NSSortDescriptor alloc] initWithKey:#"Popularity" ascending:YES];
[sortedObjects sortUsingDescriptors:[NSArray arrayWithObject:sortDesc]];
[super viewDidLoad];
}
- (void)viewDidUnload
{
[super viewDidUnload];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
#pragma mark - Table view data source
- (void)viewWillAppear:(BOOL)animated {
[self.tableView deselectRowAtIndexPath:[self.tableView indexPathForSelectedRow] animated:YES];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [sortedObjects count];
}
//(I’m using a Custom Cell for the TableView)
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"objectCell";
ObjectCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[ObjectCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
cell.nameLabel.text = [[sortedObjects objectAtIndex:indexPath.row] valueForKey:#"Name"];
cell.countryLabel.text = [[sortedObjects objectAtIndex:indexPath.row] valueForKey:#"Country"];
return cell;
}
#pragma mark - Table view delegate
//Then the selected object is sent to the DetailViewController in this segue:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([[segue identifier] isEqualToString:#"DetailSegue"]) {
NSIndexPath *selectedRowIndex = [self.tableView indexPathForSelectedRow];
DetailViewController *detailViewController = [segue destinationViewController];
detailViewController.selectedObject = [sortedObjects objectAtIndex:selectedRowIndex.row];
}
}
#end
Then the DetailViewController recieves the selected object to populate the Labels and ImageViews with the data from it.
DetailViewController.h:
#import <UIKit/UIKit.h>
#interface DetailViewController : UIViewController
#property (nonatomic, strong) IBOutlet UILabel *districtLabel;
#property (nonatomic, strong) IBOutlet UILabel *countryLabel;
#property (nonatomic, strong) IBOutlet UIImageView *bottleImageView;
#property (nonatomic, strong) NSString *selectedObject;
#end
DetailViewController.m:
#import "WinesDetailViewController.h"
#interface WinesDetailViewController ()
#end
#implementation WinesDetailViewController
#synthesize districtLabel,countryLabel,bottleImageView;
#synthesize selectedObject;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidAppear:(BOOL)animated
{
self.title = [selectedObject valueForKey:#"Name"];
[super viewDidAppear:animated];
}
- (void)viewDidLoad
{
[super viewDidLoad];
districtLabel.text = [selectedObject valueForKey:#"District"];
countryLabel.text = [selectedObject valueForKey:#"Country"];
bottleImageView.image = [UIImage imageNamed:[selectedObject valueForKey:#"Image"]];
self.navigationController.navigationBar.translucent = YES;
self.wantsFullScreenLayout = YES;
//Then I’ve added recognizers for left and right swiping:
UISwipeGestureRecognizer *leftGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipeDetectedLeft:)];
leftGesture.direction = UISwipeGestureRecognizerDirectionLeft;
[self.view addGestureRecognizer:leftGesture];
UISwipeGestureRecognizer *rightGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipeDetectedRight:)];
rightGesture.direction = UISwipeGestureRecognizerDirectionRight;
[self.view addGestureRecognizer:rightGesture];
}
//And the voids to handle the swipes:
- (void)swipeDetectedRight:(UISwipeGestureRecognizer *)sender
{
//Access previous cell in TableView
}
- (void)swipeDetectedLeft:(UISwipeGestureRecognizer *)sender
{
//Access next cell in TableView
}
//Some more besic code for the view..
#end
As you can see, I’ve added UISwipeGestureRecognizers in the DetailViewController, because I want to reload it with data from the previous cell to when swiped to the right, and next cell when swiped to the left. Now I have no idea how to handle the voids for swipe detected, how can I reach selectedRowIndex from DetailView and swipe through cells? I’m new to programming, have been trying to figure this out for a long time now, so code examples would be great so the answer don't lead to 100 new questions if you know what I mean. Thank you so much if you can help me.

Answer 1

One way to go about this is to pass the "sorted" datasource array to the DetailViewController and the indexpath through the "prepareForSegue" method.
RootTableViewController.h:
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([[segue identifier] isEqualToString:#"DetailSegue"]) {
NSIndexPath *selectedRowIndex = [self.tableView indexPathForSelectedRow];
DetailViewController *detailViewController = [segue destinationViewController];
detailViewController.selectedObject = [sortedObjects objectAtIndex:selectedRowIndex.row];
//added code
detailViewController.detailsDataSource = [[NSArray alloc]initWithArray:sortedObjects];
detailViewController.detailIndex = selectedRowIndex.row;
}
}
Then you could reload the UI elements of the DetailViewController.
Here is the declaration of the new properties.
DetailViewController.h:
#import <UIKit/UIKit.h>
#interface DetailViewController : UIViewController
#property (nonatomic, strong) IBOutlet UILabel *districtLabel;
#property (nonatomic, strong) IBOutlet UILabel *countryLabel;
#property (nonatomic, strong) IBOutlet UIImageView *bottleImageView;
#property (nonatomic, strong) NSString *selectedObject;
// added code
#property (strong, nonatomic) NSArray *detailsDataSource;
#property int detailIndex;
#end
Don't forget to synthesize the new properties
#synthesize detailsDataSource,detailIndex;
//And the voids to handle the swipes:
- (void)swipeDetectedRight:(UISwipeGestureRecognizer *)sender
{
//Access previous cell in TableView
if (detailIndex != 0) // This way it will not go negative
detailIndex--;
districtLabel.text = [[detailsDataSource objectAtIndex: detailIndex] valueForKey:#"District"]];
countryLabel.text = [[detailsDataSource objectAtIndex: detailIndex] valueForKey:#"Country"];
bottleImageView.image = [UIImage imageNamed:[[detailsDataSource objectAtIndex: detailIndex] valueForKey:#"Image"]];
}
- (void)swipeDetectedLeft:(UISwipeGestureRecognizer *)sender
{
//Access next cell in TableView
if (detailIndex != [detailsDataSource count]) // make sure that it does not go over the number of objects in the array.
detailIndex++; // you'll need to check bounds
districtLabel.text = [[detailsDataSource objectAtIndex: detailIndex] valueForKey:#"District"]];
countryLabel.text = [[detailsDataSource objectAtIndex: detailIndex] valueForKey:#"Country"];
bottleImageView.image = [UIImage imageNamed:[[detailsDataSource objectAtIndex: detailIndex] valueForKey:#"Image"]];
}
//Some more besic code for the view..
#end
Give this a try it might work for you. Otherwise, I think you might want to take a look at Scrollview and "paging." iPhone/iPad users are used to this UI design, and you might be able to modify it to fit what you are doing.