cs193p – Lecture #10 – iPad and Blocks

Please note, this blog entry is from a previous course. You might want to check out the current one.

Lecture #10 introduces tool bars, pop overs and split views (which are demonstrated adjusting Shutterbug for the iPad) and finishes with blocks and multi threading including the new (iOS6) refresh-control feature.

The code of the demo is available at Stanford and on github.

Slides are available on iTunes …..

The lecture is available at iTunes and is named “10. iPad and Blocks (February 7, 2013)”.

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cs193p – Assignment #4 Extra Task #1

Please note, this blog entry is from a previous course. You might want to check out the current one.

Show your lists sorted alphabetically. There are two methods that might be helpful in this: sortedArrayUsingSelector: and sortedArrayUsingDescriptors:. The former is good when you have an array of NSString objects. The latter is good when you have an array of NSDictionary objects (and you want to sort by one of the values in the dictionaries).

… actually use both! The first one to sort the tags:

- (NSString *)tagForRow:(NSUInteger)row
{
    return [[self.photosByTag allKeys] sortedArrayUsingSelector:@selector(compare:)][row];
}

The second one to sort the photos by name:

- (void)setPhotos:(NSArray *)photos
{
    _photos = [photos sortedArrayUsingDescriptors:@[[[NSSortDescriptor alloc] initWithKey:FLICKR_PHOTO_TITLE ascending:YES]]];
    [self.tableView reloadData];
}

The complete code is available on github.

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cs193p – Assignment #4 Task #9 & #10

Please note, this blog entry is from a previous course. You might want to check out the current one.

Since all the lists you display allow further navigation, they should display a disclosure indicator in every cell (Xcode will automatically add this for you when you create a segue from a table view cell).

… if you would like to adjust it yourself you could do so in storyboard using the inspector to set the accessory to disclosure indicator, or set it in code:

cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

This application must work properly in both portrait and landscape modes on the iPhone 4 and iPhone 5. It is extra credit to also do the iPad, but the iPhone version is required.

… it does 😉

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cs193p – Assignment #4 Task #8

Please note, this blog entry is from a previous course. You might want to check out the current one.

The recents tab must show a list of the most recently view photos in order, with the most recent at the top and no duplicates in the list. The list of recents must also persist across application termination and relaunch. When a recent photo in the list is chosen, it should navigate to a view of the photo in the same way as other table views in the application do. Limit the size of the list to a reasonable number.

Create a new class derived from NSObject to handle saving and storing the recent photos. Create a public interface to get all photos and to set a new photo:

+ (NSArray *)allPhotos;
+ (void) addPhoto:(NSDictionary *)photo;

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cs193p – Assignment #4 Task #6

Please note, this blog entry is from a previous course. You might want to check out the current one.

When a photo first appears, and as the bounds of the UIScrollView showing a photo change (due to, for example, autorotation), you must adjust the zooming to show as much of the photo as possible with no extra, unused space. Once the user starts pinching to zoom on a given photo, you can stop doing this automatic zooming while that photo continues to be visible.

Like described in lecture #9 viewDidLayoutSubviews is for such occasions the proper place. First calculate which scale would be needed to either show the complete width, or the complete height of the photo. Then pick the higher one because the smaller one would show unused space:

- (void)viewDidLayoutSubviews
{
    [super viewDidLayoutSubviews];
    double wScale = self.scrollView.bounds.size.width / self.imageView.image.size.width;
    double hScale = self.scrollView.bounds.size.height / self.imageView.image.size.height;
    if (wScale > hScale) self.scrollView.zoomScale = wScale;
    else self.scrollView.zoomScale = hScale;
}

The complete code is available on github.

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cs193p – Assignment #4 Task #5

Please note, this blog entry is from a previous course. You might want to check out the current one.

When the user then chooses a particular photo from the list, display it inside a UIScrollView that allows the user to pan and zoom.

Like in the previous task, you can safe some time be reusing code from Shutterbug.

In storyboard drag out a new view controller. Create a new subclass for it and link them. Add a scroll view and provide an outlet for it in the new class:

@property (weak, nonatomic) IBOutlet UIScrollView *scrollView;

Create a push segue from the cell of the second table to the new view controller and set its identifier to “Show Image”:
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cs193p – Assignment #4 Task #4

Please note, this blog entry is from a previous course. You might want to check out the current one.

When the user chooses one of the tags in the list, navigate to a new list of the titles of all the photos (in the data you queried originally with stanfordPhotos) that have that tag. The subtitles in this list should be the photo’s description (if it has one).

This task is similar to the previous one (and you could safe some time by reusing the code from shutterbug).

Create a new table-view-controller sub class. As model use an array to hold the photos – note, this time it has to be public, as the other view controller needs to set it.

@property (nonatomic, strong) NSArray *photos; // of NSDictionary

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