Crear Emoticons Animados con Flash

Create UILabel in runtime

UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 50, 70)];

label.numberOfLines = 2;

label.text = @"text";

label.backgroundColor = [UIColor clearColor];

label.textColor = [UIColor blackColor];

label.highlightedTextColor = [UIColor blackColor];

label.textAlignment = UITextAlignmentLeft;

label.font = [UIFont systemFontOfSize:12];

[self.view addSubview:label];

[label release];

Show splash screen during loading

//In AppDelegate.m

- (void)applicationDidFinishLaunching:(UIApplication *)application {

m_viewController = [[SplashViewController alloc] initWithNibName:nil bundle:nil];

[window addSubview:m_viewController.view];

[window makeKeyAndVisible];

//set delay before showing new screen

[NSTimer scheduledTimerWithTimeInterval:5.0f target:self selector:@selector(onSlashScreenExpired:) userInfo:nil repeats:NO];

}

 

- (void)onSlashScreenExpired:(id)userInfo{

[m_viewController.view removeFromSuperview];

[window addSubview:[navigationController view]];

[window makeKeyAndVisible];

}

Check if device connected to the Internet

#import <SystemConfiguration/SCNetworkReachability.h>

#include <netinet/in.h>

- (BOOL) connectedToNetwork

{

    // Create zero addy

    struct sockaddr_in zeroAddress;

    bzero(&zeroAddress, sizeof(zeroAddress));

    zeroAddress.sin_len = sizeof(zeroAddress);

    zeroAddress.sin_family = AF_INET;

    // Recover reachability flags

    SCNetworkReachabilityRef defaultRouteReachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *)&zeroAddress);

    SCNetworkReachabilityFlags flags;

    BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags);

    CFRelease(defaultRouteReachability);

    if (!didRetrieveFlags)

    {

        printf("Error. Could not recover network reachability flags\n");

        return 0;

    }

    BOOL isReachable = flags & kSCNetworkFlagsReachable;

    BOOL needsConnection = flags & kSCNetworkFlagsConnectionRequired;

BOOL nonWiFi = flags & kSCNetworkReachabilityFlagsTransientConnection;

    return ((isReachable && !needsConnection) || nonWiFi) ? 

(([[NSURLConnection alloc] initWithRequest:[NSURLRequest 

requestWithURL: [NSURL URLWithString:@"http://www.apple.com/"] 

cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:20.0] 

  delegate:self]) ? YES : NO) : NO;

}

Tag Archive for 'UISplitViewController' Your first iPad split view application

La división de opiniones es algo muy fresco en el nuevo iPhone OS 3.2. Nos permite visualizar una vista maestra-detalle de una manera muy simple. Combinada con la pantalla iPads 'grande de 1024 × 748 píxeles, será posible crear incluso mejor, más aplicaciones fáciles de usar y valioso.

Básicamente, la vista dividida se compone de dos vistas separadas. La vista principal se muestra en la parte 320 píxeles de ancho en su pantalla si su IPAD está en posición horizontal, de lo contrario la vista principal será accesible como una vista Popover. La vista de detalles deben mostrar su contenido principal y estará a tamaño completo si su IPAD está en orientación vertical. Principalmente el usuario se centrará en su punto de vista los detalles y este hecho debe tener en cuenta.

Creación de una vista dividida pragmática dentro de la aplicación es una tarea fácil. El código siguiente muestra esto:

//create the master view
MasterViewController *masterView = [[MasterViewController alloc]
                initWithNibName:@"Master"
                bundle:[NSBundle mainBundle]];
 
//create the details view
DetailsViewController *detailsView = [[DetailsViewController alloc]
                initWithNibName:@"Details"
                bundle:[NSBundle mainBundle]];
 
//create the split view
UISplitViewController *splitController =
                [[UISplitViewController alloc] init];
 
//set the view controllers array
splitController.viewControllers = [NSArray
                arrayWithObjects:masterView, detailsView, nil];
 
//show split view as the main view
[window addSubview:splitController.view];
[window makeKeyAndVisible];
 
//release view
[masterView release];
[detailsView release];

Ahora vamos a acceder a la vista principal a través de un punto de vista Popover, cuando el IPAD está en modo retrato. El shouldAutorotateToInterfaceOrientation: el método de su maestro y el controlador debe ser compatible con detalle todas las orientaciones, de lo contrario no será posible girar una vista dividida. Una vez que implementan el protocolo UISplitViewControllerDelegate en cualquier clase y establecer el delegado del controlador de vista dividida. Los métodos dentro de este protocolo se llama cada vez que la vista principal se oculta o se muestra de nuevo.

En mi ejemplo he creado otra clase que obtiene una referencia al controlador de ver los detalles y tiene la barra de herramientas objetos vamos a utilizar para presentar el botón Popover. El siguiente código es bastante simple y contiene los tres métodos del protocolo UISplitViewControllerDelegate. El primer método se llama cada vez que la vista principal se ocultará. Así que en este caso vamos a añadir una barra de herramientas con el botón Popover dado a nuestro punto de vista los detalles. Usted es libre de la etiqueta del botón que desee. El segundo método se llama cada vez que la vista principal se muestra de nuevo. Ahora simplemente ocultar la barra de herramientas. Por lo tanto, eso es bastante todo. La lógica de la visualización de la vista principal dentro de una visión Popover se hace automáticamente, pero todavía se puede modificar en el último método (que está vacío en mi caso).

//the master view controller will be hidden
- (void)splitViewController:(UISplitViewController*)svc
    willHideViewController:(UIViewController *)aViewController
    withBarButtonItem:(UIBarButtonItem*)barButtonItem
    forPopoverController:(UIPopoverController*)pc {
 
  if(toolBar == nil) {
    //set title of master button
    barButtonItem.title = @"Show Master";
 
    //create a toolbar
    toolBar = [[UIToolbar alloc]
                    initWithFrame:CGRectMake(0, 0, 1024, 44)];
    [toolBar setItems:[NSArray arrayWithObject:barButtonItem]
                    animated:YES];
  }
 
  //add the toolbar to the details view
  [detailController.view addSubview:toolBar];
}
 
//the master view will be shown again
- (void)splitViewController:(UISplitViewController*)svc
    willShowViewController:(UIViewController *)aViewController
    invalidatingBarButtonItem:(UIBarButtonItem *)button {
 
  //remove the toolbar
  [toolBar removeFromSuperview];
}
 
// the master view controller will be displayed in a popover
- (void)splitViewController:(UISplitViewController*)svc
    popoverController:(UIPopoverController*)pc
    willPresentViewController:(UIViewController *)aViewController {
 
  //empty for now
 
}

Bueno, que hay que hacer algo más que esto si desea crear aplicaciones realmente útiles para dividir la vista. A menudo será conveniente usar una vista de tabla como su maestro. Algunas cosas me di cuenta, mientras que jugando con la vista División son los siguientes:

     * No son capaces de presentar una vista dividida como un punto de vista modal
     * Si la vista maestra o de detalle no permite que todas las orientaciones de la interfaz, la vista dividida no funcionará correctamente. Así que si usted no ve la vista Patrón revisar su método de shouldAutorotateToInterfaceOrientation dentro de su regulador de la visión.

Va a encontrar el código fuente de este ejemplo en mi github repositorio. El proyecto se llama MasterDetail.

Saludos,

Andreas
Actualización:

Algunas personas me preguntan si es posible mantener la vista Patrón visible incluso en el modo de retrato. He intentado todo y las observadas tras la solución de trabajo:

Crear una subclase de UISplitViewController y sólo willAnimateRotationToInterfaceOrientation sobrescribir el método: duración:. Este método será llamado cada vez que la orientación de un punto de vista va a ser cambiado. Todo lo que tienes que hacer es comprobar si la interfaz se convertirá en un método de retrato y si eso es verdad, ajustar el marco a vista de su maestro y las vistas de detalle. A continuación encontrará el código que utiliza para conseguir este trabajo:

/**
 * Sent to the view controller just before
 * the user interface begins rotating.
 */
- (void)willAnimateRotationToInterfaceOrientation:
            (UIInterfaceOrientation)interfaceOrientation
            duration:(NSTimeInterval)duration {
 
      //get master and detail view controller
      UIViewController* master = [self.viewControllers objectAtIndex:0];
      UIViewController* detail = [self.viewControllers objectAtIndex:1];
 
      //only handle the interface orientation
      //of portrait mode
      if(interfaceOrientation == UIInterfaceOrientationPortrait ||
            interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
            //adjust master view
            CGRect f = master.view.frame;
            f.size.width = 320;
            f.size.height = 1024;
            f.origin.x = 0;
            f.origin.y = 0;
 
            [master.view setFrame:f];
 
            //adjust detail view
            f = detail.view.frame;
            f.size.width = 830;
            f.size.height = 1024;
            f.origin.x = 320;
            f.origin.y = 0;
 
            [detail.view setFrame:f];
      }
      else {
            //call super method
            [super willAnimateRotationToInterfaceOrientation:interfaceOrientation
                        duration:duration];
      }
}

Ahora, sólo tiene que utilizar su propia subclase UISplitViewController dentro de su código y la vista principal debe estar visible incluso en el modo de retrato. Espero que este código puede responder a sus preguntas y será útil para usted.

Iconos en IPAD

Custom Icon and Image Creation Guidelines

Every application needs an application icon and a launch image. It’s recommended that applications also provide an icon for iOS to display in Spotlight search results (and, if necessary, in Settings). In addition, some applications need custom icons to represent custom document types or application-specific functions and modes in navigation bars, toolbars, and tab bars.
Unlike other custom artwork in your app, these icons and images must meet specific criteria so that iOS can display them properly. Table 9-1 contains a summary of information about these icons and images and provides links to specific guidelines for creating them. To learn what to name these files, and how to specify them in your code, see “Application Icons” in iOS Application Programming Guide and “Application Launch Images” in iOS Application Programming Guide.

Note: To support resolution independence, you should provide high-resolution versions of your icons and images in addition to the resources you already supply. For guidelines on how to make the most of your high-resolution artwork, see “Tips for Creating Great Artwork for the Retina Display.”

Table 9-1  Custom icons and images

Description	Size for iPhone and iPod touch (in pixels)	Size for iPad (in pixels)	Guidelines
Application icon (required)	57 x 57 114 x 114 (high resolution)	72 x 72	“Application Icons”
App Store icon (required)	512 x 512	512 x 512	“Application Icons”
Small icon for Spotlight search results and Settings (recommended)	29 x 29 58 x 58 (high resolution)	50 x 50 for Spotlight search results 29 x 29 for Settings	“Small Icons”
Document icon (recommended for custom document types)	22 x 29 44 x 58 (high resolution)	64 x 64 320 x 320	“Document Icons”
Web Clip icon (recommended for web applications and websites)	57 x 57 114 x 114 (high resolution)	72 x 72	“Web Clip Icons”
Toolbar and navigation bar icon (optional)	Approximately 20 x 20 Approximately 40 x 40 (high resolution)	Approximately 20 x 20	“Icons for Navigation Bars, Toolbars, and Tab Bars”
Tab bar icon (optional)	Approximately 30 x 30 Approximately 60 x 60 (high resolution)	Approximately 30 x 30	“Icons for Navigation Bars, Toolbars, and Tab Bars”
Launch image (required)	320 x 480 640 x 960 (high resolution)	For portrait: 768 x 1004 For landscape: 1024 x 748	“Launch Images”

Note: For all images and icons, the PNG format is recommended.
The standard bit depth for icons and images is 24 bits (8 bits each for red, green, and blue), plus an 8-bit alpha channel.
You do not need to constrain your palette to web-safe colors. Although you can use alpha transparency in the icons you create for navigation bars, toolbars, and tab bars, do not use it in application icons.

Application Icons

An application icon is an icon users put on their Home screens and tap to start an application. This is a place where branding and strong visual design should come together into a compact, instantly recognizable, attractive package. Every application needs an application icon.

Note: Your app icon is also used in Game Center.

Try to balance eye appeal and clarity of meaning in your icon so that it’s rich and beautiful, and clearly conveys the essence of your application’s purpose. Also, it’s a good idea to investigate how your choice of image and color might be interpreted by people from different cultures.
Create different sizes of your application icon for different devices. If you’re creating a universal application, you need to supply application icons in all three sizes.
For iPhone and iPod touch both sizes are required:

• 57 x 57 pixels
• 114 x 114 pixels (high resolution)

For iPad:

• 72 x 72 pixels

When iOS displays your application icon on the Home screen of a device, it automatically adds the following visual effects:

• Rounded corners
• Drop shadow
• Reflective shine (unless you prevent the shine effect)

For example, a simple 57 x 57 pixel iPhone application icon might look like this:

When it’s displayed on an iPhone Home screen, the same application icon would look like this:

Note: You can prevent iOS from adding the shine to your application icon. To do this, you need to add the UIPrerenderedIcon key to your application’s Info.plist file (to learn about this file, see “The Information Property List” in iOS Application Programming Guide).
The presence (or absence) of the added shine does not change the dimensions of your application icon.

Ensure your icon is eligible for the visual enhancements iOS provides. You should produce an image that:

• Has 90° corners
• Does not have any shine or gloss (unless you’ve chosen to prevent the addition of the reflective shine)
• Does not use alpha transparency

Give your application icon a discernible background. Icons with visible backgrounds look best on the Home screen primarily because of the rounded corners iOS adds. This is because uniformly rounded corners ensure that all the icons on a user's Home screen have a consistent appearance that invites tapping. If you create an icon with a background that disappears when it's viewed on the Home screen, users don't see the rounded corners. Such icons often don't look tappable and tend to interfere with the orderly symmetry of the Home screen that users appreciate.
Be sure your image completely fills the required area. If your image boundaries are smaller than the recommended sizes, or you use transparency to create “see-through” areas within them, your icon can appear to float on a black background with rounded corners.
For example, an application might supply an icon on a transparent background, like the blue star on the far left. When iOS displays this icon on a Home screen, it looks like the image in the middle (if no shine is added) or it looks like the image on the right (if shine is added).

An icon that appears to float on a visible black background looks especially unattractive on a Home screen that displays a custom picture.
Create a 512 x 512 pixel version of your application icon for display in the App Store. Although it’s important that this version be instantly recognizable as your application icon, it can be subtly richer and more detailed. There are no visual effects added to this version of your application icon.
If you’re developing an application for ad-hoc distribution (that is, to be distributed in-house only, not through the App Store), you must also provide a 512 x 512 pixel version of your application icon. This icon identifies your application in iTunes.
iOS might also use this large image in other ways. In an iPad application, for example, iOS uses the 512 x 512 pixel image to generate the large document icon, if a custom document icon is not supplied.

Small Icons

Every application should supply a small icon that iOS can display when the application name matches a term in a Spotlight search. Applications that supply settings should also supply this icon to identify them in the built-in Settings application.
This icon should clearly identify your app so that people can recognize it in a list of search results or in Settings.
For iPhone and iPod touch, iOS uses the same icon for both Spotlight search results and Settings. If you do not provide this icon, iOS might shrink your application icon for display in search results and in Settings. For your iPhone app, create small icons that measure:

• 29 x 29 pixels
• 58 x 58 pixels (high resolution)

For iPad, you supply separate icons for Settings and Spotlight search results. Create icons that measure:

• 50 x 50 pixels (for Spotlight search results)
  Note that the final visual size of this icon is 48 x 48 pixels. iOS trims 1 pixel from each side of your artwork and adds a drop shadow. Be sure to take this into account as you design your icon.
• 29 x 29 pixels (for Settings)

Document Icons

If your iOS application creates documents of a custom type, you might want to create a custom icon that identifies this type to users. If you don’t provide a custom document icon, iOS creates one for you by default, using your application icon (including the added visual effects).
For example, a default document icon that uses the 57 x 57 pixel white star iPhone app icon would look like this:

A high-resolution default document icon that uses the 114 x 114 pixel white star iPhone app icon would look like this:

For iPad, a default document icon that uses the 72 x 72 pixel white star app icon would look like this:

Optionally, you can provide custom artwork for iOS to use instead of your application icon. Because people will see your document icon in different places, it’s best to design an image that's memorable and clearly associated with your application. Your custom artwork should be attractive, expressive, and detailed.
Depending on whether your app runs on iPhone or iPad, you use different specifications to create this icon.

Document Icon Specifications for iPhone

For your iPhone app, create a document icon in two sizes:

• 22 x 29 pixels
• 44 x 58 pixels (high resolution)

Place your custom artwork within each rectangular space as desired. The artwork can be centered, offset, or it can fill the entire space.
For example, if you supply a 22 x 29 pixel icon that looks like the image on the left, iOS creates a document icon that looks like the image on the right:

Similarly, if you supply a 44 x 58 pixel icon that looks like the image on the left, iOS creates a document icon that looks like the image on the right:

Document Icon Specifications for iPad

iOS uses two sizes of document icons for iPad applications: 64 x 64 pixels and 320 x 320 pixels. It’s a good idea to create both sizes so that your document icons look good in different contexts.
For both sizes, the overall dimensions include specific amounts of padding, leaving a smaller “safe zone” for your artwork. It’s essential to make sure your artwork fits well in these safe zones, or it may get cropped or scaled up.
Although your artwork can fill an entire safe zone, the upper right corner will always be partially obscured by the page curl effect that iOS adds. In addition, iOS adds a gradient that transitions from black (near the top, just below the page curl) to transparent (at the bottom edge).

Important: Be sure to follow the guidelines in this section as you create a custom document icon for your iPad app. If your icon is too large, too small, or improperly padded, the resulting document icon will not look good.

To create a 64 x 64 pixel document icon:

1. Create a 64 x 64 pixel image in PNG format.
2. Add the following margins to create the safe zone:
   
   • 1 pixel on top
   • 4 pixels on bottom
   • 10 pixels on each side
   Your safe zone should look similar to the colored area shown below:
   
   
3. Place your custom artwork within the 44 x 59 pixel safe zone. The artwork can be centered, offset, or it can fill the entire safe zone. (Remember that iOS adds the page curl to the upper right corner and a gradient that runs from the page curl to the bottom edge.)

For example, if you supply an icon that looks like the image on the left, iOS creates a document icon that looks like the image on the right.

To create a 320 x 320 pixel document icon:

1. Create a 320 x 320 pixel image in PNG format.
2. Add the following margins to create the safe zone:
   
   • 5 pixels on top
   • 20 pixels on bottom
   • 50 pixels on each side
   Your safe zone should look similar to the colored area shown below:
   
   
3. Place your custom artwork within the 220 x 295 pixel safe zone. The artwork can be centered, offset, or it can fill the entire safe zone. (Remember that the page curl will obscure some of the artwork in the upper right corner of the safe zone.)

For example, if you supply an icon that looks like the image on the left, iOS creates a document icon that looks like the image on the right.

Web Clip Icons

If you have a web application or a website, you can provide a custom icon that users can display on their Home screens using the Web Clip feature. Users tap the icon to reach your web content in one easy step. You can create an icon that represents your website as a whole or an icon that represents a single webpage.
If your web content is distinguished by a familiar image or recognizable color scheme, it makes sense to incorporate it in your icon. However, to ensure that your icon looks great on the device, you should also follow the guidelines in this section. (To learn how to add code to your web content to provide a custom icon, see Safari Web Content Guide.)
For iPhone and iPod touch create icons that measure:

• 57 x 57 pixels
• 114 x 114 pixels (high resolution)

For iPad create an icon that measures:

• 72 x 72 pixels

As it does with application icons, iOS automatically adds some visual effects to your icon so that it coordinates with the built-in icons on the Home screen. Specifically, iOS adds:

• Rounded corners
• Drop shadow
• Reflective shine

For example, a simple 57 x 57 pixel webpage icon might look like this:

When it’s displayed on an iPhone Home screen, the same icon would look like this:

Note: You can prevent the addition of all effects by naming your icon apple-touch-icon-precomposed.png (this is available in iOS 2 and later).

Ensure your icon is eligible for the visual enhancements iOS adds (if you want them). You should produce an image in PNG format that:

• Has 90° corners
• Does not have any shine or gloss

Icons for Navigation Bars, Toolbars, and Tab Bars

As much as possible, you should use the system-provided buttons and icons to represent standard tasks in your application. For a complete list of standard buttons and icons, and guidelines on how to use them, see “System-Provided Buttons and Icons.”
Of course, not every task your application performs is a standard one. If your app supports custom tasks users need to perform frequently, you need to create custom icons that represent these tasks in your toolbar or navigation bar. Similarly, if your app displays a tab bar that allows users to switch among custom application modes or custom subsets of data, you need to design tab bar icons that represent these modes or subsets.
Before you create the art for your icon, you need to spend some time thinking about what it should convey. As you consider designs, aim for an icon that is:

• Simple and streamlined. Too many details can make an icon appear sloppy or indecipherable.
• Not easily mistaken for one of the system-provided icons. Users should be able to distinguish your custom icon from the standard icons at a glance.
• Readily understood and widely acceptable. Strive to create a symbol that most users will interpret correctly and that no users will find offensive.

Important: Be sure to avoid using images that replicate Apple products in your designs. These symbols are copyrighted and product designs can change frequently.

After you’ve decided on the appearance of your icon, follow these guidelines as you create it:

• Use pure white with appropriate alpha.
• Do not include a drop shadow.
• Use anti-aliasing.
• If you decide to add a bevel, be sure that it is 90° (to help you do this, imagine a light source positioned at the top of the icon).

For toolbar and navigation bar icons, create an icon in the following sizes:

• For iPhone and iPod touch:
  
  • About 20 x 20 pixels
  • About 40 x 40 pixels (high resolution)
• For iPad:
  
  • About 20 x 20 pixels

For tab bar icons, create an icon in the following sizes:

• For iPhone and iPod touch:
  
  • About 30 x 30 pixels
  • About 60 x 60 pixels (high resolution)
• For iPad:
  
  • About 30 x 30 pixels

Note: The icon you provide for toolbars, navigation bars, and tab bars is used as a mask to create the icon you see in your application. It is not necessary to create a full-color icon.

Don’t include a pressed or selected appearance with your icons. iOS automatically provides these appearances for items in navigation bars, toolbars, and tab bars, so you do not need to provide them. Because these visual effects are automatic, you cannot change their appearance.
Give all icons in a bar a similar visual weight. Aim to balance the overall size, level of detail, and use of solid regions across all icons that can appear in a specific bar. In general, it does not look good to combine in the same bar icons that are large, blocky, and completely filled with icons that are small, detailed, and unfilled.

Launch Images

To enhance the user’s experience at application launch, you must provide at least one launch image. A launch image looks very similar to the first screen your application displays. iOS displays this image instantly when the user starts your application. As soon as it’s ready for use, your app displays its first screen, replacing the launch placeholder image.
Supply a launch image to improve user experience; avoid using it as an opportunity to provide:

• An “application entry experience,” such as a splash screen
• An About window
• Branding elements, unless they are a static part of your application’s first screen

Because users are likely to switch among applications frequently, you should make every effort to cut launch time to a minimum, and you should design a launch image that downplays the experience rather than drawing attention to it.
Design a launch image that is identical to the first screen of the application, except for:

• Text. The launch image is static, so any text you display in it will not be localized.
• UI elements that might change. Avoid including elements that might look different when the application finishes launching, so that users don’t experience a flash between the launch image and the first application screen.

For iPhone and iPod touch create launch images that include the status bar region in the following sizes:

• 320 x 480 pixels
• 640 x 940 pixels (high resolution)

For iPad create launch images that do not include the status bar region in the following sizes:

• 768 x 1004 pixels (portrait)
• 1024 x 748 pixels (landscape)

Note that most iPad applications should supply a launch image for each orientation.
If you think that following these guidelines will result in a plain, boring launch image, you’re right. Remember, the launch image is not meant to provide an opportunity for artistic expression; it is solely intended to enhance the user’s perception of your app as quick to launch and immediately ready for use. The following examples show you how plain a launch image can be.
The iPhone Settings launch image displays only the background of the application, because no other content in the application is guaranteed to be static.

In the launch image for iPhone Stocks, only static images are included because these are always visible in the front view of the Stocks app.

Tips for Creating Great Artwork for the Retina Display

The Retina display allows you to display high-resolution versions of your art and icons. If you merely scale up your existing artwork, you miss out on the opportunity to provide the beautiful, captivating images users expect. Instead, you should rework your existing resources to create large, higher quality versions that are:

• Richer in texture. For example, in the high-resolution versions of the Settings and Contacts icons, the metal and paper textures are clearly visible.
  
• More detailed. For example, in the high-resolution versions of the Safari and Notes icons, you can see details such as the accurate contours of the continents behind the compass and the torn paper left by the previous note.
  
• More realistic. For example, the high-resolution versions of the Compass and Photos icons combine rich texture and fine details to create realistic portrayals of a compass and a photograph.
  

http://developer.apple.com/library/ios/#documentation/UserExperience/Conceptual/MobileHIG/IconsImages/IconsImages.html