A project I’m currently working on requires image masking. I had already developed the site with plans to deploy to Heroku using Paperclip for image attachments using Amazon S3 for storage (you can read how I set that up here). I scoured the web for existing tutorials and documentation but found little that was relevant to my situation. My first inclination was to write a post-process method – grab the image, mask it and write it back to S3 which proved to be a dead-end (you can see the problem I ran into here – granted it’s possible you could still go that route). After a bit of Googling I ended up using a processor. Here’s what I did (I must confess the “boilerplate” code for the processor was some I found, unfortunately I did not keep the link – if you recognize it please let me know!):

In my model:

  has_attached_file :image,
  :styles =>{
    :main_feature => {:geometry => "1020x470", :processors => [:masker] },
    :large => "1020x470",
    :event_page => "460x212", 
    :top_feature => "345x159",
    :smallest => "229x131"#,
  },
  :storage => :s3,
  :s3_credentials => "#{Rails.root}/config/s3.yml",
  :path => ":attachment/:id/:style.:extension",
  :url => "/:id/:style/:basename.:extension",
  :bucket => "yo-bucket-name"

Note line 3, where I’ve added a processor called “masker”. I created a folder called ‘paperclip_processors’ inside my lib directory and created masker.rb. In that same folder I included the png of my mask (mine is simply called mask.png). I’m using an alpha mask. In masker.rb I placed the following code:

module Paperclip
  class Masker < Processor
    def initialize file, options = {}, attachment = nil
      super
      @format = File.extname(@file.path)
      @basename = File.basename(@file.path, @format)
    end

     def make  
          
      src = @file
      dst = Tempfile.new([@basename, @format])
      dst.binmode

      begin
        parameters = []
        
        parameters << ':source'
        parameters << ':mask'
        parameters << '-alpha'
        parameters << 'on'
        parameters << '-compose'
        parameters << 'CopyOpacity'
        parameters << '-composite'
        parameters << ':dest'

        parameters = parameters.flatten.compact.join(" ").strip.squeeze(" ")

        mask_path = File.expand_path('lib/paperclip_processors/mask.png')
        success = Paperclip.run("convert", parameters, :source => "#{File.expand_path(src.path)}[0]", :mask => "#{mask_path}[0]", :dest => File.expand_path(dst.path))
      


       rescue PaperclipCommandLineError => e
         raise PaperclipError, "There was an error during the mask for #{@basename}" if @whiny
       end

       dst
     end

  end
end

Lines 18-25 show the arguments we’ll be using to interface with ImageMagick (the documentation for this is found here). Basically we’re inputting the source and mask, turning the alpha flag on, using the compose method with CopyOpacity to copy the opacity of the mask to the final composite (masked) image and finally the destination. Now when an image is added to my model, a new image is sized and created – best of all, it works on Heroku!

viewDidLoad:

self.refreshControl = [[UIRefreshControl alloc] init];    
[self.refreshControl addTarget:self action:@selector(refreshView:) forControlEvents:UIControlEventValueChanged];

Refresh:

- (void)refreshView:(UIRefreshControl *)sender {
    //Refresh...
    NSLog(@"Refresh");
    
    [sender endRefreshing];
}

Source: stackoverflow.com/questions/12607015/uirefreshcontrol-ios-6-xcode

Often I’ll see an app incorporate a new UI implementation that really impresses me. Still being a learner, I always wonder how these elements are coded or put together — is it an image trick? Maybe a CGGradientLayer? How are they able to achieve so much speed? It’s times like these that it helps to get a small peek under the hood. Like Mac apps, iOS apps are bundled together basically as a zip file — you can actually change the IPA extension to ZIP and unarchive the app very easily. The limitation here is Xcode compresses (or ‘crushes’) the png’s used in an app to keep the file size down. Luckily, since iOS 3.2, the command line tool that compressed these images included the added functionality of decompressing them. Peter Boctor (of iDevRecipes) wrote a Ruby script called App Crush that would uncrush the png files (with instructions here) but it hasn’t been updated in about a year. Since then, Apple has changed how Xcode is deployed (through the App Store these days) and the location in which they put it. It’s very easy to update the Ruby script to find the new Xcode and several have. I wanted to make it just a tad easier and created an Applescript Droplet that allows you to drag the IPA onto it and uncrushes the png files. You can download it here. I’ve also made this version’s source available here. This is my first attempt at an AppleScript Droplet (which seems like a dying tech) so if you see something that could be done better, let me know!

Usage instructions:

1. If you don’t know the location of the IPA (app) you’d like to uncrush, open iTunes and click the apps tab, right click on the app you’d like and click “Reveal in Finder”
2. Drag IPA onto the App Uncrusher
3. It’ll take up to a few minutes to finish and you’ll have a folder called “APPNAME images” on your desktop that should be full of pngs.

Be ethical with this. Don’t steal another app’s images and call them your own.

I’m always thinking about how to make my apps run and load faster. It’s incredibly important, especially to your users. Earlier today I ran across a Twitter conversation (twitter.com/flyosity/status/239044820394471424) between a few guys I consider to be top notch: Sam Soffes, Jake Marsh and Mike Rundle. They were discussing best practices for getting your app loading speed down.

There’s a great article by Brent Simmons in which he discusses his methods for making Glassboard 2.2 load faster, it’s available here:
inessential.com/2012/08/23/an_iphone_app_startup_performance_techni

Mike also pointed out Sam’s code from Cheddar:
https://github.com/nothingmagical/cheddar-ios/blob/master/Classes/CDIAppDelegate.m#L68

In his didFinishLaunching method, he performs only the most essential tasks and puts everything else in an async queue to run in the background without blocking the main thread. This frees the app up to get the UI and other elements rolling.

On top of this optimization you can do a few things to make your app APPEAR to load faster, namely, a proper Default.png. It’s easy to fall into the temptation to create a cool splash screen but it’s my belief a good Default.png will help “lead” your user into the app and reduces the amount of perceived load time. Apple recommends (developer.apple.com/library/ios/#DOCUMENTATION/iPhone/Conceptual/iPhoneOSProgrammingGuide/App-RelatedResources/App-RelatedResources.html) you use a screenshot of your initial view with the text and buttons removed. Here are a few examples of good Default.pngs:

WordPress

Colloquy

Cheddar

In reality, Default.png will only show for a second or so but when properly done, in conjunction with a few of the techniques mentioned by the other guys, can help make your app load feel snappier.

This is a quick walk-through on using a font other than those supplied by Apple on an iOS device.

For reference purposes, you can find out what fonts are available to you “out of the box” by checking out this comprehensive list:
iosfonts.com/

I’m going to be using Bebas for my example, a great font created by Dharma Type. You can pick it up here: www.dafont.com/bebas.font or use a font of your own choice. It’s important to note you should check a font’s license before you use it in an app you intend to distribute in the app store.

If your font’s not installed on your Mac, go ahead and install it. Before we get too deep into coding and while you’re in or around Font Book let’s go ahead and get the PostScript name of your font. You can do this by selecting your font from the list inside of Font Book and pressing Command + I to toggle the font information. The right side of the window will look like this:

The PostScript name is listed on the top, with Bebas, the PostScript name is simple… it’s Bebas but most are more complicated. Take the PTSans family for example: PTSans-Regular to PTSans-CaptionBold. Keep this PostScript name handy as we’ll reference it later.

Moving on let’s get the ttf file into an Xcode project.

I started with a Single View Application template, go ahead and get that going as normal. Inside my Supporting Files folder I’m going to create a group named “Fonts”. I’m going to drag BEBAS___.TTF into that directory and make sure “Copy items into destination group’s folder (if needed)” is checked. Click finish.

Next, open your app’s plist. Right click and add a row, we’re going to add the key “Fonts provided by application” which is an array of the ttf font files. Toggle that down and for Item 0 add BEBAS___.TTF.

Now you need to head over to your project’s build phases tab. Click to the “Copy Bundle Resources” and click the + icon to add a new item and choose BEBAS___.TTF.

Now, when your window looks like this, you’re ready to use the font in the application:

I put some simple code to create a UILabel in my viewDidLoad method like this:

    UILabel *bebasFlavoredLabel = [[UILabel alloc] initWithFrame: CGRectMake(0, 0, 320, 44)];
    bebasFlavoredLabel.text = @"Bebas on iPhone";
    [bebasFlavoredLabel setFont: [UIFont fontWithName:@"Bebas" size:15]];

    [self.view addSubview: bebasFlavoredLabel];

On line 3 you see where we use [UIFont fontWithName:@"Bebas" size:15]. The name you use there is the PostScript name you found at the beginning. Go ahead and run:

Viola! Your font is ready to be used as you wish!

Tweeting on iOS hasn’t been easier since iOS 5.

To get started, add the Twitter.framework to your project:

Next, import Twitter.h into your ViewController:

#import <Twitter/Twitter.h>

You’ll probably want to create a new action on a UIButton, so we’ll call that tweetButtonPress:

- (void) tweetButtonPress:sender {
    
}

Inside that method we’ll create a TWTweetComposeViewController, this is what is referred to as the “TweetSheet” and looks something like this:

if([TWTweetComposeViewController canSendTweet]){
//Create the tweetsheet
    TWTweetComposeViewController *tweetSheet = [[TWTweetComposeViewController alloc] init];

//Set initial text of the tweet
[tweetSheet setInitialText: @"Hello Twitter World"];

//Add a completion handler for the tweetsheet
    tweetSheet.completionHandler = ^(TWTweetComposeViewControllerResult result){
        [self dismissModalViewControllerAnimated:YES];
    };

//Show the tweetsheet
[self presentModalViewController:tweetSheet animated:YES];
}

else{
 NSLog(@"Handle inability to send Tweet");
}

Most of this is pretty straightforward but on line 6 we set the initial text of the Tweet. This will be user editable but you can certainly have a “recommended tweet”. On line 1 we check to see that the user can even send a Tweet. There are a few reasons they might not be able to: they may not have a Twitter account setup on their device or they may not currently have an internet connection — you can handle these issues however you please in the else starting on line 17. On lines 9-11 we setup a completion handler that will dismiss the TweetSheet when the user is done. Finally, on line 14 we bring the TweetSheet into the view.

Now, there are a few additional methods you can call to attach images and links to the user’s tweets.

To add a URL to the Tweet:

[tweetSheet addURL:[NSURL URLWithString:@"jaysonlane.net"]];

Twitter will automatically shorten this to a t.co link.

To add an image to the Tweet:

[tweetSheet addImage:[UIImage imageNamed:@"image.png"]];

And Twitter will handle the uploading for you. These types of attachments will be displayed on the right side of the TweetSheet held on by the paperclip to let the user know they’ve been added.

Note: Example project is available here

One of the great additions iOS 5 brought us is the ability to display meta data about currently playing tracks on the lock screen. This is a great convenience to users and a must if your app has background audio playing. I know I use this to great extent, especially when driving. Best of all, it’s actually quite simple to get going.

For the sake of this tutorial, we’re going to be focusing mainly on the MPNowPlayingInfoCenter and not much on how to play streaming audio. If you have questions, as always, please feel free to leave a comment. I, as I’ve stated in the past, am still fairly new to the iOS/Objective-C world so if you see something that makes you say ‘UR DOING IT WRONG!’, please let me know. If you’d like to review the details of MPNowPlayingInfoCenter, you can read the Apple documentation.

To get started, create a new project. I created one using the single view template but feel free to do whatever you’d like. Once you’ve created the project there are a few things we need to do to get the project setup. By default, simply playing audio won’t persist if the application leaves the foreground. We need to tell iOS we’d