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Your Iphone, iPad & Android Application Factory

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We often have to update our application with the necessary high-resolution images needed for the new iPad (iPad 3 or iPad 4). Fortunately, the new iPad Mini has maintained the same resolution as the first iPad is 1024 × 768 pixels.
Since it is not always easy to find the documents ufficali Apple, in this article I have again gathered all the information we need to update the icons, the intro, and so on.

First of all let’s start with this handy table:

Device/Screen File Name (PNG) Icon Size (pixels)
iPhone and iPod
Application Icon for iPhone (retina display) Icon@2x.png 114 x 114
Application Icon icon for iPhone Icon.png 57 x 57
Settings/Spotlight icon for iPhone (retina display) Icon-Small@2x.png 58 x 58
Settings/Spotlight icon for iPhone Icon-Small.png 29 x 29
Launch image Portrait (retina display) Default@2x.png 640 x 960
Launch image Portrait Default.png 320 x 480
iPhone 5
Launch image for iPhone 5 Portrait (retina display) Default-568h@2x.png 640 x 1136
iPad
Application Icon for the new iPad (retina display) Icon-72@2x.png 144 x 144
Application Icon for the iPad Icon-72.png 72 x 72
Settings/Spotlight icon for iPad Icon-Small-50@2x.png 100 x 100
Settings/Spotlight icon for iPad Icon-Small-50.png 50 x 50
Launch image Portrait (retina display) Default-Portrait@2x.png 1536 x 2008
Launch image Portrait Default-Portrait.png 768 x 1004
Launch image Landscape (retina display) Default-Landscape@2x.png 2048 x 1496
Launch image Landscape Default-Landscape.png 1024 x 748
iTunes App Store
App icon for the App Store (retina display) iTunesArtwork@2x.png 1024 x 1024
App icon for the App Store iTunesArtwork.png 512 x 512

Remember that with the transition from iOS 5 to iOS 6 is where the new iPhone 5, along with the iPod touch 5th generation.
These new Apple devices have only one big change in terms of the development of the App: The resolution of the screen. These devices have a large 4 “screen, WDVGA (Wide VGA Double) 640 × 1136 pixels, 326 DPI Retina display. These devices have the same width but more iPhone 4/4S height of 176 pixels in portrait mode.

App Icon Template

Point out again, as I have done in another article, this useful tool downloaded from the site “appicontemplate.com

By downloading the file you will get a PSD of the ‘icon of the app that, through Smart Objects in Photoshop, allows you to automate the process of exporting various dimensions of the icon.png file that must be included in the bundle of all iOS App

Through this model Photoshop we can only change the icon size bigger and it will automatically render that allow you to have icons of smaller size through a fast workflow.
This model has been created and maintained by the Danish designer Michael Flarup.

How to use (How to) App Icon Template?
The model works with Photoshop CS2 or later. Just open the PSD file with your version of Photoshop and then “right click” on the LAYER  called “SMART EDIT THIS OBJECT” (EDIT THIS SUBJECT SMART) and click on ‘Edit Contents’.
This will open the file Icon.psb and you can create your artwork in this canvas (painting). After saving the Icon.psb should be automatically rendered for the various sizes of main PSD file. And is possible to use the Actions (automated actions) of Photoshop that are bundled with the resource to export icon file versions squared and rounded corners.

Good Design!

Il costo di un’ App per iPhone & iPad

This is the italian translation of the article Dear business people, an iOS app actually takes a lot of work!, written by Kent Nguyen. Thanks Kent for giving us permission to publish this translated article.

 

Il grande quesito: quanto costa un’app per iPhone?

Questa è una domanda estremamente comune che viene sempre chiesta da un sacco di persone che lavorano nel mondo degli affari oppure da clienti non molto esperti di tecnologia. Senza dubbio, ogni volta che ho fornito una stima iniziale prima ancora di formalizzare e analizzare in dettaglio le specifiche, ho potuto vedere sui loro volti l’espressione di shock a causa della inaspettatamente alta quotazione.

Inoltre nessuna delle mie quotazioni si è lontanamente avvicinata ai valori discussi in, nel quale vengono discussi i costi di sviluppo dell’app Twitterific. Nonostante il fatto che la domanda originale fosse stata posta nel 2008 e la migliore risposta (da uno degli sviluppatori di Twitterific) fosse arrivata nel 2010, è ancora molto precisa all’inizio del 2012 ed è facile prevedere che lo sarà almeno fino alla fine dell’anno.

Cosí, con il crescere del numero di imprese che desiderano avere un’app per iOS, penso che sia una buona idea spiegare perché i costi siano effettivamente alti cercando di dividere i vari passi e spiegare le variabili coinvolte. Spero che questo articolo sia di beneficio per i non sviluppatori e gli uomini d’affari che devono prendere delle decisioni o semplicemente vogliono comprendere il processo. Le idee in questo articolo ovviamente non sono ristrette al solo mondo iOS ma possono essere estese ad altre piattaforme (Android, Windows Mobile, forse Blackberry).

Checklist: prepararsi ad un’app per iPhone

Il procedimento non è affatto semplice e cerco innanzitutto di informare il cliente a fare tutte le considerazioni guidandolo attraverso questi passi:

PRIMO: Una delle maggiori scoperte che ottengo parlando con i clienti è quanto siano inconsapevoli delle grande infrastruttura necessaria per un’app per iPhone. Dato che essi assumono che un’app sia semplicemente un’app, si aspettano che gli venga fornito il prezzo di fare qualunque cosa con l’app senza tener conto di problematiche quali: avere un server di supporto col quale l’iPhone comunichi, dove immagazzinare i dati dell’utente. La prima volta che incontrai un tale cliente ero furioso ma in seguito ho realizzato il fatto che il concetto di client-server non deve essere dato per scontato tra i non programmatori. Avevo sbagliato, i manager di solito non hanno il senso-tecnico comune che noi programmatori ci attendiamo.

Perciò, cari lettori non tecnici: è necessario che disponiate di un server nel quale memorizzare i dati per qualunque tipo di app che come minimo debba fare qualche autenticazione (login) o qualunque tipo di personalizzazione che volete cambiare in seugito o comunque qualunque operazione che richieda il recepimento di informazioni dall’utente (sto cercando di usare il linguaggio il più semplice possibile).

SECONDO: Dato che avete bisogno di un server, bisogna fare in modo che l’iPhone possa comunicare con tale server, inviando e ricevendo dati. Non esiste una maniera standard, non esiste nessun componente plug-and-play per fare questo, ogni cosa va customizzata. Questo è analogo a creare il vostro linguaggio personalizzato: non volete che gli altri comprendano ciò che state dicendo ma le due estremità, telefono e server, devono capirsi.

Questo processo consiste nella creazione di API (Application Programming Interface) per la vostra app. Queste API devono esistere prima che si proceda con lo sviluppo dell’app. Perché? perché prima di cominciare a comunicare occorre definire il linguaggio! Questo ci porta al prossimo passo, come creare queste API.

TERZO: Non prendere questo passo alla leggera, le API hanno un’importanza pari al 50% dell’intera soluzione. Fare un’API è come mettere in piedi un sito web. Prima devi definire i dati, quindi la logica di business, quali sono i parametri di ingresso a tale logica, come interagiscono fra loro i vari moduli quando accade un evento. Per semplificare, il risultato finale è un sito web completo dove però le pagine non mostrano risultati grafici ma solamente del testo che verrà compreso dalla nostra app: ad esempio una pagina di autenticazione conterrà, in caso di successo, la semplice parola YES.

L’iPhone quindi farà una serie di richieste a questi punti terminali predefiniti (pagina di login) usando il formato di ingresso predefinito dall’API (nome utente + password) e quindi interpreterà il risultato fornito da queste pagine in risposta alla sua richiesta (YES/NO). L’app senza questo non potrà mai registrarsi e fare il login magicamente da sola.

Ci sono *un sacco* di variabili che devono essere prese in considerazione in questa fase, come preparare un server, selezionare il linguaggio di programmazione con cui scrivere le API, dove immagazzinare i dati per minimizzare i tempi di comunicazione, ecc.

QUARTO: Queste API o sono già pronte e ben documentate dal vostro team interno per essere fornite allo sviluppatore iPhone oppure preparatevi a pagare di più che solo per la pura app. In funzione delle conoscenze dello sviluppatore che avrete contattato per farvi l’app, egli/ella potrebbe avere o meno le capacità per fare ciò di cui avete bisogno. Se lo sviluppatore è in grado di fare questo lavoro, allora vi consiglio fortemente di affidargli anche questa parte del progetto dato che egli sa esattamente quali API servono per far funzionare l’app al meglio.

Nel caso abbiate già le API dovrete dare allo sviluppatore la possibilità di parlare apertamente e liberamente con il vostro team di back-end e non limitarvi a dargli la documentazione; questo perché il più delle volte egli richiederà che venga fatto del lavoro in più (più API) per supportare l’applicazione mobile in maniera appropriata.

Adesso, la parte iPhone

Caspita, tutto questo per essere appena pronti a sviluppare l’app e non siamo ancora partiti! In generale, qualunque cosa riguardo iOS è molto restrittiva. Dovete quasi sempre aver definito circa il 100% dello scopo e del design prima che lo sviluppatore possa partire con la programmazione; diversamente dallo sviluppo di siti web, lo sviluppo di un’app per iOS sotto contratto ha pochissimi margini di cambiamento:

Disegnare l’interfaccia: La scelta se si devono utilizzare i componenti grafici standard o personalizzati deve essere presa già dall’inizio, dato che l’architettura dell’intera app dipende da come si vuole l’interfaccia e da come la utilizzeranno gli utenti.Un esempio è la Tab Bar in basso: se si vogliono i bottoncini colorati invece di quelli monocromatici standard, la modifica al codice è sostanziale!

Il codice è fortemente integrato: Con i siti web voi potete aggiungere semplicemente una pagina in più, quindi create un link a quella pagina ove richiesto. Non potete fare questo con un’app per iOS, dato che ogni cosa va decisa all’inizio e ogni cambiamento può risultare in cambiamenti significativi in altre parti dell’app. Il modo in cui il codice iOS è strutturato è come quello di una breadboard (le basette sperimentali per circuiti elettrici), dove ogni cosa è collegata con fili: voi potete sempre cambiare delle cose qui e là ma se tocchi il filo sbagliato allora l’intero circuito smetterà di funzionare. Anche se viene usato del codice estremamente ben strutturato la flessibilità non aumenterà molto. L’aggiunta di un bottone email addizionale nella schermata “About” potrebbe richiedere un ridotto numero di linee di codice addizionali, ma l’aggiunto di un bottone “Facebook Like” sulla stessa pagina è una cosa completamente differente e non ci può attendere che venga fatto in poche ore.

Convertire un’app per iPhone in un’app iPhone/iPad universale: Questa è la peggiore ‘funzionalità aggiuntiva’ presente nei contratti di sviluppo di app per iPhone. Questo perché un’app per iPad non è una banale funzionalità aggiuntiva. Le app per iPad sono di solito molto più complesse delle app per iPhone e il più delle volte sono richiesti un’interfaccia e un meccanismo di interazione completamente differenti. Non solo quello, dato che anche le API potrebbero essere diverse: l’app Denso, che ho sviluppato (e quindi conosco), ha alcune funzionalità esclusive dell’app per iPad che richiedono dati addizionali dal server. Inoltre l’iPhone e l’iPad richiedono esperienze utente differenti.

Dunque siete pronti a partire?

Spero che dopo aver letto questo abbiate un’idea più chiara di quel che è necessario alla vostra ditta per sviluppare un’app per il mondo mobile. A meno che non facciate un’app completamente offline (come una Calcolatrice!) che non raccoglie dati dagli utenti, non potrete pretendere che questa vi venga sviluppata a un prezzo basso. Dopo aver considerato le variabili elencate sopra, se non potrete giustificare lo sviluppo a contratto allora l’altra opzione è assumere a tempo determinato dei progettisti a tempo pieno che lavorino a tempo pieno per l’intera durata del progetto.

D’altro canto, se decidete di andare avanti e affidare in outsourcing il lavoro, c’e’ un’altra cosa da aggiungere: le lungaggini burocratiche. Se lavorate in una grande azienda o in un ambiente molto regolamentato, il vostro lavoro sarà essenzialmente di aiutare lo sviluppatore ad evitare le lungaggini burocratiche che potrebbe incontrare lungo la strada e talvolta avrete necessità di aggirare un pochino le regole. Ho parlato con molti clienti e ho potuto notare il loro scetticismo quando ho cercato di saperne di più sulle loro API, dato che essi o non desideravano esporsi maggiormente per non violare le loro regole di segretezza, e non potevo biasimarli, oppure non possono portare certi dati al di fuori del perimetro aziendale, oppure semplicemente (e questa è la cosa peggiore) le regole di branding aziendale richiedono che ogni singola pagina dell’app presenti il logo dell’azienda (!!!). Alla fine ho preferito non lavorare con questi clienti dato che non potevo immaginare quando a lungo avrei penato per ottenere anche un minimo supporto sulle API di cui avrei avuto bisogno.

P.S. Avrete bisogno di tempo, un sacco, per cui siate pazienti.

 

HTML(5) Approach
The final technique is something that is emerging now, especially thanks to the great improvements in term of stability and speed introduced by the latest version of iOS for the in-app web views. A couple of good examples of this approach are the Ars Technica app (link) and the Bloomberg Businessweek+ magazine (link).

The concept is quite simple: html and css are common and powerful techniques to layout a page on screen: why not leverage the skills developed by many web designers to make a magazine that perfectly fits with the iPad?
The core block at the base of this approach is the UIWebView Cocoa Touch object: with this view we can load any kind of html document, loaded locally or remotely, and layout it in the page at an adequate speed (but not the fastest) and without surprises. Besides we can get rid of the overlay
technique, as the web view is capable of displaying images, playing movies and of course execute javascript based widgets. Also this component provides a two way interaction between the javascript world and the objective-c runtime (and in fact this justifies the existence of extension languages
such as Objective-J, provided with the Cappuccino framework: http://cappuccino.org/). Finally the web view is highly respondent to user interactions, and some features like text selection and dictionary lookup come for free.
The open-source world is highly active in this area: projects like Baker (www.bakerframework.com), Siteless (www.siteless.org), Laker (www.lakercompendium.com) and pugpig (pugpig.com) make publicly available this kind of solution.

Sincerely we don’t know if this will be the final solution for everybody. Of course a publisher that already invested in setting up a web site (but not in Flash!), and this is quite common between newspapers, will be able to port most of the layout and contents to the iPad, and sometimes this can
be achieved with an adaption of the CMS output views to provide files that can be easily fed to the app.

Careful must be given to don’t push this behavior at its extremes: don’t forget in fact that web page rendering requires an inner engine and at the end any intermediate layer will require resources and extra time. Sometimes, and this is particularly evident with the first generation of the iPad, content
updates following user interaction are not very reactive. So it is not recommended to transform every single aspect of the magazine app into web based content: clearly in this way you’re helping all javascript developers not skilled with objective-c, but
a performance penalty will be visible.

As an example, the toolbar typical of all magazine apps used to access extra features (sharing, table of contents, home page, etc.) should always be done using the native Cocoa Touch component and not an html+css solution.

However if the publisher accepts to convert his design flow to a web based one and you, as developer, prefer to base your work on consolidated and easy to manipulate methodologies, this one should be your first choice to be taken in consideration.

Conclusions
We hope this article gives a good overview of the major techniques used to render pages in a magazine, newspaper or e-book. It could be we have not mentioned some technique we’re not aware of, in such case dear reader any feedback from you is welcome!

About the author: Carlo Vigiani
He is an electronics engineer and software developer, located in Italy. He is CTO and co-founder of new startup i3Factory.com, active in the development of iOS, Android and Win Mobile apps, with special focus on publishing, tourist and music apps.

Source: www.icodermag.com

01/2012

Pages Pre-Rendered by images
This technique is heavily used inside the highly interactive magazines published using the Adobe Digital Solutions environment: well known examples are the Condé Nast magazines (Wired is one of the most famous examples).
The way these magazines are implemented starts with the well known suite of Adobe Digital Publishing tools, In Design in primis. These tools are used by many publishers around the world and the latest versions offer the pos sibility to export the project, other than in the ubiquitous pdf format, in a package suited for distribution through iPad. The output of these files can be tested using the free app Adobe Content Viewer downloadable from the App Store, but of course the final branded app, together with the server infrastructure required to serve the contents, requires a higher tier license.

What characterizes this kind of magazines is that at the moment of project creation all pages are pre-rendered as jpeg or png images and then special effects are overlaid.
This means that the core section of the magazine reader is essentially an image viewer. Sure these images will span an area slightly larger than the iPad screen, so they will be embedded inside a scroll view, but they are still images. All in all technically the choice is not bad: the iPad is quite better in rendering images than PDF files, as the required calculations needed to transform the pdf data in bitmaps is completely skipped here, while the CPU will just need to decompress the image and send it to the graphics hardware. Exactly as we did in the PDF case, we can apply the overlay technique to over impose somecontent that requires user interaction on top of the bottom rendering layer.

While this technique is highly efficient from the point of view of rendering time, and is simple to implement as all the page layout complexities have been taken into account and solved by the desktop publishing tools, it offers a few limitations that need to be considered:

•     every single page takes quite more space on disk and download time of this kind of magazines is increased correspondingly; in comparison with a pdf page, the space taken is much more as every pixel of text must be provided in the file and we cannot force high compression ratios if we don’t want to introduce blurring in the text. The pdf page, especially those pages made of text only, is much lighter as the text is not pre-
rendered.

•     zooming or font resizing is not feasible: both pdf and core text redraw the text using vectorial algorithms or per-size font representations, this is not possible to achieve on a static image. This means that the magazine needs to be drawn with specific fonts types and sizes, fonts which are well suited for jpeg compression (no blur) and the screen resolution (132 dpi, not so high; things will be better with the next retina display iPad!)

•     text search, highlight and selection is impossible, unless the digital publishing tool exports together with the pre-rendered pages a full map of text coordinates, something I haven’t seen yet!

Adobe is not alone in publishing this kind of magazines:
there are several custom apps in the market that follow exactly the same approach. It’s not bad but is not leveraging the great publishing frameworks that Apple is offering to its developers. And it has too many limitations if compared with other techniques. For sure a publisher that is mastering the digital publishing tools I mentioned before can take advantage of this approach, as the final quality is undoubtable and the time to market is the shorter, and at the same time allows to provide a content suited for the iPad, and not just a pdf fit on screen.

But I would recommend to all developers that are making custom products and are not using specialized page composition tools to stay away from such methodology.

Source: www.icodermag.com

01/2012

 

CORE TEXT RENDERING
Core Text (short: CT) is another of those technologies developed for the Mac and later ported to iOS.
The Core Text framework is dedicated to text layout and font handling. Just to summarize the capabilities of this framework, consider that is at the base of the desktop publishing revolution that made the Mac famous in this professional sector.
As CG, even CT has a C-based API, even if there are several third-party open source wrappers that pack together the most common functionalities in a high-level Objective-C interface.

CT should not be used to replace web based rendering based on html and css, this is a too complex field that is better to leave to dedicated system components such as then UIWebView instead it can be used to efficiently render some rich text.

CT talks with CG, in fact text rendering is done at the same time of view Quartz based rendering. The two APIs have similar conventions and memory management rules, so the developer already accustomed with Core Foundation programming model will not find an hurdles in understanding the CT API. This gives the possibility to the developer to eventually mix the text rendering and image drawing at the same rendering stage (CT is limited to text only, it has no image drawing capabilities).

The main reason to use Core Text is because it does direct rendering of text on page without any intermediaries. It differs from PDF which consider each page as a whole, it differs from web based techniques as there is no intermediate language (html) or layout interpretation (css) in between, you can write directly on the page. The basic components behind CT are layout objects such as “runs”, which are direct translation of characters
into drawable glyphs, “lines” of characters and “frames”, which correspond to paragraphs. The translation of characters to glyphs is done by “typesetters” and the text to be plotted is provided using attributed strings, which are common strings enriched with attribute informations (font size, color, ornaments).

You will decide to use Core Text for a magazine whose layout will be mostly based on text with standard layout, so it fits well for newspapers also. Probably it’s not the best choice for glamour magazines where graphics layout is changing on every page and could be quite complicated.
A clear advantage of the Core Text based solution is that you don’t need to apply the overlay technique we mentioned in the paragraph dedicated to pdf. With CT you will directly divide your page in frames and each of these frames will contain text (rendered by CT) or multimedia. Essentially you can define the page layout by selecting a size (it can fit the iPad screen or it can be vertical or horizontal scrolling page), then you will decide the size and position of media content in this page and finally you will define the frames (several rectangular frames) that will contain the text. The text frames organization can be of any kind, from compact single column structures, two multicolumn layout or varying size frames. Inside the frames you will render the text and Core Text will help you to manage line breaks for these paragraphs. Then you can easily provide the user the possibility to change font type and size and the same rendering code can be reused to quickly rearrange the text inside the frames.

The page layout representation can be provided in any form decided by the developer together with the publisher, the best choice will be XML (all in all it’s the base of any markup format!) and it will be shipped to the app together with the texts (still XMLs) and the assets in a zip file package.
One limitation of Core Text is that it is a text drawing technology and is not optimized for editing (but we don’t need it at this stage) and user interaction. This means that if we want to provide text highlight or select and copy features we’ll need to implement them by our own; the framework provides us some APIs to facilitate this task but in any case the code to implement these functionalities must be written by the developer to manage every single detail. In any case all these tasks will be greatly simplified in comparison with PDF: here you have full control of the text and its position of screen, while pdf is still an opaque entity hidden behind a complex data structure that you cannot control in its entirety.

Our recommendation is that if you must implement a digital magazine, without extreme layout requirements, some multimedia content and a fast and powerful control of text, using Core Text is the first technology choice to be considered.

An excellent tutorial on the subject is available at this link on Ray Wenderlich blog: http://www.raywenderlich.com/4147/how-to-create-a-simple-magazine-app-with-core-text

Source: www.icodermag.com

01/2012

 

The Magazine is a PDF File
You may like it or not, but should your software house be committed to develop a magazine iPad app, the magazine will be with high probability given to you as a PDF file. As there is no way to “escape” from it, at the end you will need to develop your own pdf reader or integrate some free or  commercial external library.
The reason why pdf is still the dominant format in the e-publishing world is clear: most of the publishers are porting their existing printed  publications on the iPad, and for obvious budget reasons they want to reuse all the investment done in the creation of their issues. You will not be able to escape from the pdf format dictatorship with the exception of two cases: the publication is brand new and only digital, so there are no previous investments to drive the final choice, or the publisher has large budgets and/or is a strong user experience (UX) believer and accepts to allocate the extra budget to recreate a different format for its publications. Both cases are not so uncommon with those publishers that already did the effort to bring their products to the web (with the notable exception of those that did it in Flash!), but the large part of the small and medium publishers will
still be locked to the pdf format.

Unfortunately the pdf is not the best way to port a magazine in the iPad. And this for several reasons:

•     printed magazines page size is usually larger than the iPad screen: this means that when the page fits to the screen, all characters appear smaller and then something readable in the printed paper could become unreadable without zoom; but zoom is not always efficient and in particular it’s not loved by readers that may lose their “orientation” inside the page.

•     printed magazines pages have not the same aspect ratio of the iPad screen: this means that a page that fits in the screen will be bordered by top/bottom or left/right empty stripes.

•     often printed page layouts are optimized for facing pages, e.g. a panorama picture which is spread between two pages; when the device is kept in portrait orientation, these graphical details will be lost, instead if the device is kept in landscape you will be able to appreciate the two-pages layout but characters will be too small to be read comfortably.

•     as these files are not optimized for digital, normally the outlines (table of contents) and annotations (links to pages or external resources) are not exported; this means that even if your pdf reader code is aware of this information, in the majority of cases it is not available and then you will need to define a different way to provide it.

•     the official pdf format supports multimedia content; unfortunately the iOS is not able to manage it, so all interactive content must be provided  outside the pdf file.

The page rendering is achieved in iOS (and OSX too) through the Quartz 2D API, provided within the Core Graphics framework (shorted with CG). Quartz 2D is the two-dimensional drawing engine on which are based many (but not all) of the drawing capabilities of iOS. The
PDF API is a subset of the huge CG API. This API is “old fashioned” and is not based on Objective-C but on pure
old C; besides all memory management rules will follow the Core Foundation (CF) rules which are different from Obj-C one: this means that special attention must be provided to avoid memory leaks, as each PDF page manipulation can take several megabytes and leaks will easily trigger the memory watchdog, thus force quitting your app.

be immediate to render a PDF page, by following these basic steps:

1. get the CG reference to the pdf page to be drawn;
2. get the current graphics context for the view that will contain the page;
3. instruct Quartz to draw the pdf page to the context.

As you can see, apart the required steps needed by the drawing model of Quartz, the full rendering is accomplished by the system and you don’t need to have any knowledge of the data format of a pdf file. So for you the pdf rendering processor is just a black box, and this is clear when you
see that all CG data structures are in fact opaque and their inner contents can be accessed only via API.
But a valid pdf magazine reader cannot limit itself to rendering, so you will be required to support zoom. Now as your maximum zoom level can be theoretically very high (don’t forget that characters in the pdf file are like fonts in the computer, they will never lose in precision even for
extreme zoom-ins), it is impossible to render the full zoomed page in a canvas much higher than the device screen:
here we have pixels, not vectors, and it would be immediate to crash the app because all the memory has gone away for one page only. So you will be forced to introduce tiling techniques that will limit the effective rendering to the visible part of the page, not always an easy task.

More difficult is document parsing: this is required if you want to extract outlines, annotations, do some text search and highlight. In such case apart a few meta data extraction functions, what the API gives you is a set of functions that will allow you to explore the data structures inside the document. You will not be able to get any information from the file if you don’t explore the data tree correctly and if you don’t follow the specs of the PDF document.
This is worsened by the many versions the PDF specs got in the years and by the fact that many publishers still use old software that exports the  content in the old formats.
I have developed a general purpose PDF explorer, this was part of a commitment of a client that asked me to develop a general purpose PDF reader; but as it is really hard to apply all the specs of the PDF official reference, my suggestion is to concentrate on the most used features and test them with many documents. As I said before, CG navigates the data tree but it doesn’t interpret it for us!

The last section of this part, long explanation but required given the importance of the topic, is how to provide multimedia content on top of a PDF file: all in all the iPad is a so versatile device that we cannot limit ourselves to simple page rendering. By adding extra content to the printed page you can leverage the device characteristics and still taking benefit on the investment done in the magazine creation.

There are many reasons to justify this choice: e.g. a printed advertisement can offer a video instead of a static picture, or a printed link to a web page can be replaced by an active link to a web view, or finally we can show the current weather using an html5 widget. As I previously said it is not recommended to introduce all this content inside the pdf file: it will not be rendered by Quartz and you will still be forced to traverse the data tree to extract the CG object reference for further manipulation. Finally not all publishers are aware of these functionalities or their digital publishing software is too old to fully support them.

So the best solution is based on the “overlay technique”.
This methodology consists in representing the pages in two layers:

•     the bottom layer (“rendering layer”) will contain the PDF rendering, so it will contain the bitmap image of the page;
•     the top layer (“overlay layer”) will draw all overlays and is sensible to user touches.

The overlay layer is typically made of UIKit components, so we’ll add a UIWebView for html widgets, we’ll introduce a UIScrollView to display a gallery of sliding images, or we’ll add a Media Player view for video execution. Typically the overlay descriptions are provided on a separate file, e.g. an xml, json or plist, and they will be packed together with the pdf file and all assets (movies, images, html files, music
files) in a zip file.
The app will download the zip file, will unpack it and then for each page it will use the pdf page to fill the rendering layer, and the overlay information associated to that page to build the overlay layer.
Note that this technique can be applied also in the other rendering techniques we’ll talk about in the next paragraphs, in such case it allows to overcome many of the pdf format limitations. The major requirement for the deve loper is to define a suitable format, follow all page zoom
and rotations with a corresponding overlay transformation and finally provide the publisher with the instruments and
guidelines required to easily create such overlays.

source: www.icodermag.com

01/2012

 

This article was written to our CTO, Carlo Vigiani, for iCoder magazine

One of the great improvements in all iPad owners lifestyle is the possibility to bring everywhere any sort of magazine or book, thanks to the screen size and the device light weight which both facilitate reading and carrying. In particular reports demonstrated that in a printed publications decreasing market there is a huge increase in the number of subscriptions to the digital versions of the same product (the interested reader can read this report from MPA: http://www.magazine.org/association/press/mpa_press_releases/mag-mobile-reader-study.aspx)

Apple is following this trend with great interest, and this is quite clear if we take a look at the evolution of the iOS features that have been introduced since the release of the version dedicated to iPad, that is 3.2.
In the particular the milestones that have been reached are three, shared between three major releas es of the operating system:

•     iOS 3.2 was enriched by the CoreText framework, a technology dedicated to rendering text on display available since long time on Mac OSX and  never ported in the earlier versions of the iPhone OS.

•     iOS 4.x introduced the concept of auto-renewable subscriptions, as an addition to standard non consumable In App Purchases; this feature has been introduced after long discussions between Apple, that applies the 30% commission on every In App sale and forbids any other external cheaper store access within its devices, and the publishers looking for customer fidelity techniques.

•     finally iOS 5.0 added the Newsstand feature, which provides a central place to collect all magazine and newspaper apps and at the same time provide night-time content push to all subscribers, letting them to immediately read the latest issues of their publications and saving them for the extra time (sometimes long) required for the download.

What Apple didn’t provide instead is a common and unique developer platform dedicated to the creation of apps dedicated to the magazine consumption. This lead to a lot of initiatives dedicated to help publishers to enter in the iPad market with their own magazines. These initiatives were taken by major and well known companies, such Adobe with its Digital Publishing business, and a lot of many start-
ups, everyone with its own solution.

As I said, Apple doesn’t provide a unique solution, but developers have the availability of a set of frameworks and techniques, with different levels of complexity, that provide different way of representing the page on the screen.
There is not an optimal choice, as the final decision needs to take care of aspects that go beyond pure technical considerations.
In this article we will try to depict these solutions mainly from the app developer point of view, but will never forget to enumerate the pro and cons that can affect the publisher decision on which technology to adopt.

Page rendering overview
We assume that you, the developer, are in a certain point of your app development where the magazine has been purchased, downloaded and it’s ready to be read. Your document data at this point is safely stored in the device file system and it can be represented by a single pdf file, or a collection of html and css files or a directory containing assets of different formats, such as images, videos, html5 widgets, text files. You’re now facing the problem of taking one page (which can extend beyond the screen boundaries) and presenting it in the empty space of your UIView dedicated to the
page rendering.

In the next post I will present the following methodologies to achieve this result:

•     pdf document rendering
•     pre-rendered image display
•     free format CoreText rendering
•     web based approach

01/2012 – source: www.icodermag.com

 

TestFlight, iOS beta testing on the fly

We are testing a service (free for now) that looks interesting for testing and distribution to customers of our app.
The procedure is the following:
– You register at the website: http://testflightapp.com/
– Open Safari from any device and from that login and proceed with the authorization of the device itself.

TestFlight install a certificate and a profile on the Apple device, which authorizes him to install the build that the developers to create i3Factory from time to time.
The service members will be notified automatically of any distribution and made for some beta-testers will test our trusted app, apart from the customers themselves.
Here is a time-lapse video of Jeff Broderick, the lead designer Daniel R. Hate in Silicon Valley, where it creates an icon for the application testflight

The sketch was provided by people TestFlight, and Jeff turned him into an icon.

Test Flight App Icon Time Lapse from Jeff Broderick on Vimeo.

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