Problems adding custom activity to UIActivityController

Question

I am trying to implement a custom activity to the standard activities (Print, Mail, FaceBook, etc.) but for now only want the standard Print (for AirPrint) and my own custom printing by a direct method. I am obviously missing something fundamental as none of the methods in my custom class ever get called. For now I only have some NSLog statement to figure out the calling sequence, and to get the framework to function.

The following is my test code for the custom activity class:

//  PrintActivity.h

#import <UIKit/UIKit.h>

@interface PrintActivity : UIActivity

@end

And the .m

#import "PrintActivity.h"

@interface PrintActivity ()
@property (nonatomic, strong) UIWebView *dummyWebView;
@end

@implementation PrintActivity

- (NSString *)activityType {
    NSLog(@"activityType");
    return @"MetriScan Print";
}

- (NSString *)activityTitle {
    NSLog(@"activityTitle");
    return @"MetriScan\nPrint";
}

- (UIImage *)activityImage {
    NSLog(@"activityImage");
    UIImage *icon = [UIImage imageNamed:@"metriscan_57_c2a_3.png"];
    return icon;
}

- (BOOL)canPerformWithActivityItems:(NSArray *)activityItems {
    NSLog(@"canPerformWithActivityItems");
    return YES;
}

- (void)prepareWithActivityItems:(NSArray *)activityItems {
    NSLog(@"prepareWithActivityItems");
}

- (void)performActivity {
    NSLog(@"Do the actual printing here");
// My custom code here

}

And this is the invocation in the main routine:

- (IBAction)printReport:(UIBarButtonItem *)sender {
    NSLog(@"Print Report");

    PrintActivity *metriscanPrint = [[PrintActivity alloc] init];

    UIViewPrintFormatter *printFormatter = [self.webView viewPrintFormatter];

    NSArray *activityItems = [NSArray arrayWithObjects:printFormatter, nil];
    NSArray *appActivities = [NSArray arrayWithObjects:metriscanPrint, nil];
    UIActivityViewController *activityController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:appActivities];
    //activityController.excludedActivityTypes = [NSArray arrayWithObjects:UIActivityTypePostToFacebook, UIActivityTypePostToTwitter, UIActivityTypePostToWeibo, UIActivityTypeMail, UIActivityTypeMessage, nil];
    activityController.completionHandler = ^(NSString *activityType, BOOL completed) {
        sender.enabled = YES;
    };

    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
        [self presentViewController:activityController animated:YES completion:nil];
    } else {
        sender.enabled = NO;
        self.printPop = [[UIPopoverController alloc] initWithContentViewController:activityController];
        [self.printPop presentPopoverFromBarButtonItem:sender permittedArrowDirections:UIPopoverArrowDirectionDown animated:YES];
    }

As I said, none of the methods in the custom class gets called, but the system Mail, Message, and Copy icons show in the activity sheet and not the Print icon. I expected just the system Print icon (and my own).

If I uncomment the top block of statements (and comment out the NSArray *activityItems ...........) further down, the systme Mail, Message, Print, and Copy icons. In this experiment I think I am mixing different methods by creating my own formatter, but that seemed to be the suggestion at WWDC 2012 ?

If I then uncomment the line with 'excludeActivityTypes' I only get the system Print icon.

I would welcome any input to help me figuring this out.

And if anybody know of any example code to do what I want, that would be terrific.

Edit: Updated code to my working code.

Answer 1

I was pulling my hair out over UIActivity as well this past tweek, it really needs to be explained better by Apple and have more features added; Try this:

PrintActivity.h

#import <UIKit/UIKit.h>
@interface PrintActivity : UIActivity
@end

PrintActivity.m

#import "PrintActivity.h"

@implementation PrintActivity

- (NSString *)activityType
{
   return @"MetriScan.Print";
}

- (NSString *)activityTitle
{
    return @"Print MtriScan";
}

- (UIImage *)activityImage
{   
    //***** Note: I recommend using two sizes, as the iPad's UIActivity image size differs from 
    //***** the iPhone's. Also, create @2x sizes for Retina compatible devices. So you will     
    //***** have a total of 4 images.
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
{
    return [UIImage imageNamed:@"test_72.png"];
}

    return [UIImage imageNamed:@"test_57.png"];
}

- (BOOL)canPerformWithActivityItems:(NSArray *)activityItems
{
    NSLog(@"%s", __FUNCTION__);
    return YES;
}

- (void)prepareWithActivityItems:(NSArray *)activityItems
{
    NSLog(@"%s",__FUNCTION__);
}

- (UIViewController *)activityViewController
{
    NSLog(@"%s",__FUNCTION__);
    return nil;
}

- (void)performActivity
{
    // This is where your custom print code should go

}

@end

Don't forget to make these two files as well:

PrintProvider.h

#import <UIKit/UIKit.h>

@interface PrintProvider : UIActivityItemProvider <UIActivityItemSource>

@end

PrintProvider.m

#import "PrintProvider.h"

@implementation PrintProvider

#pragma mark - UIActivityItemSource

- (id)activityViewController:(UIActivityViewController *)activityViewController itemForActivityType:(NSString *)activityType
{
    NSLog(@"%s",__FUNCTION__);
    NSLog(@"%@", activityType);
    return [super activityViewController:activityViewController itemForActivityType:activityType];
}

@end  

Now we can finally call it:

- (IBAction)printReport:(UIBarButtonItem *)sender {


CustomProvider *customProvider =
                [[CustomProvider alloc]init];
                NSArray *items = [NSArray arrayWithObjects:customProvider,nil];

                CustomActivity *ca = [[CustomActivity alloc]init];

                UIActivityViewController *activityVC =
                [[UIActivityViewController alloc] initWithActivityItems:items
                                                  applicationActivities:[NSArray arrayWithObject:ca]];

                activityVC.excludedActivityTypes = @[UIActivityTypePostToWeibo,
                UIActivityTypeAssignToContact,UIActivityTypeCopyToPasteboard,
                UIActivityTypeSaveToCameraRoll,UIActivityTypeMail,UIActivityTypePostToTwitter,
                UIActivityTypePostToFacebook,UIActivityTypeMessage];

                activityVC.completionHandler = ^(NSString *activityType, BOOL completed)
                {
                    NSLog(@" activityType: %@", activityType);
                    NSLog(@" completed: %i", completed);
                };

                    self.popoverController = [[UIPopoverController alloc] initWithContentViewController:activityVC];

                    CGRect rect = [[UIScreen mainScreen] bounds];

                    [self.popoverController
                     presentPopoverFromRect:rect inView:self.view
                     permittedArrowDirections:0
                     animated:YES];
}