Stanford CS193p. Developing Applications for ios. Spring Stanford CS193p. Spring 2012

Transcription

1 Developing Applications for ios

2 Today Shutterbug Map Demo Final part: customizing the callout. Final Projects Requirements Some ideas from the Stanford community Persistence (time-permitting) More ways to make things stick around between launchings of your app

3 Demo continued... Shutterbug Map

4 Final Project Proposal due immediately! And must be received no later than next Wednesday. Send PDF of your proposal to your CA (the one who has graded your latest assignment). Proposal must say not only what you are doing, but also what parts of SDK will be featured. Project (including Keynote) due on Friday, June 8th. Use normal submission process. NO LATE DAYS (next week s assignment is the last opportunity to use free late days). Required presentation during final exam period Monday, June 11th at 12:15pm in this room (Hewlett 200). 2-minute Keynote (not PowerPoint) presentation (more on this in a moment). Alternate presentation available on Tuesday, June 5th (Keynotes due by Monday, June 4th). If you need/want the alternate presentation time, let us know immediately (via class staff ).

5 Final Project Scope is the same as three weeks of homework Luckily, you ll have three weeks to do it (counts as 35-40% of your overall grade). P/NC students must pass both homework and final project segments separately. Check out past itunesu presentations to get an idea of scope. One- or two-person teams If two, be sure to include the proposed team in your proposal. Division of work must be VERY CLEARLY explained (both in proposal and in final submission). Two-person team is equivalent of six weeks of homework total (obviously). Must work on hardware! Bring your hardware to final exam to demo to TA (if not used during your presentation). ipad or iphone or ipod Touch okay. Only ios SDK code counts Don t waste your time writing server-side code Okay to simulate a server-side interaction to make your code demonstrable.

6 Final Project You ll be graded on proper use of SDK Hackery will count against you. Use good object-oriented programming technique. Must have at least one feature which was NOT taught in lecture/demo/homework assignment. Breadth is VERY important. Don t get stuck down a rathole. Aesthetics of your user-interface matter (although we do not expect professional graphic designer quality graphics) Sloppy layouts will be graded down. Lots of places to get graphics from on the internet. Be careful not to get side-tracked on non-ios-code Some students in the past have spent 80% of their time working on stuff that didn t demonstrate their mastery of the class material. (e.g. preparing some large database or working on graphics too much, etc.) In the end, this is an ios PROGRAMMING course, so we want to see how well you can program on this platform.

7 Final Project Presentation Quality Matters A (tiny) portion of your grade will be related to the quality of your presentation. Not okay to just put up a recording of you or of your application and say nothing. Being able to make a live presentation is a valuable skill. Practice your presentation before you show up. You only get 2 minutes (strictly enforced), so make em count. Live demo? All projects will be loaded onto the demo ipad2, so you can try to demo it live if you want. Or you can use your own hardware (ipad2, new ipad and iphone4s are only supported platforms) Live demos are perilous, as you saw all quarter :). You must, at worst, show screen shots of your application. Keynote/Quicktime has some tools to animate screen shots (better than static). Video (screen capture) of your app in action can be good also.

8 Sample Proposal Section 1: What am I doing? I will be building a Shakespeare Director application. It will have the following features: A table for choosing a Shakespearean play from a list downloaded from Folio*. A custom view for laying out the blocking of a chosen Shakespearean play. A dialogue-learning mode. * Folio is an on-line database of all of Shakespeare s works. The custom view will be simple (only rectangles and circles with colors for stroke/fill, and text). Photos (from Camera or Library) can be put in rectangles in the blocking view. The blocking can change from line to line in the dialog (but no more often than that). Blocking can be stepped through, line by line, or played back in time lapse mode. The dialogue-learning mode will step through all the dialog line by line. Users can record the dialog for other parts (as prompts for them to learn their own part). ipad only.

9 Sample Proposal Section 2: What parts of ios will it use? TableView for choosing plays and stepping through dialog Custom UITableViewCell prototypes (for dialog, including speaker, blocking instructions) Custom UIView with drawrect: for blocking Camera/Photo Library for putting images in blocking rectangles UITextField in a popover for text labels in the blocking view Popover for choosing stroke and fill color and shape in blocking mode Scroll view to zoom in/pan around in blocking view AVFoundation for record/playback of dialog NSTimer for time lapse playback of entire play with dialog/blocking linked Core Data to store the blocking and dialog Play entity Scene entity BlockingElement entity LineOfDialog entity Printing of blocking to AirPrint printers (this is the NOT COVERED IN LECTURE feature)

10 Sample Proposal What to notice about this sample proposal? Clear description of what the application will do (section 1). Clear list of the ios features that will be used (section 2). Lots of breadth (not necessarily that much depth in any one area). Clearly delineates the NOT COVERED IN LECTURE feature. Specifies platform (ipad only). It s creative (it s not just Places or Calculator recycled).

11 Ideas Kristen Pilner Blair, School of Education Sam Saenz, Office of Alcohol Policy/Education School of Medicine

12 Persistence Property Lists Use writetourl:atomically: and initwithcontentsofurl: in NSArray or NSDictionary Or NSUserDefaults if appropriate. Also NSPropertyListSerialization converts Property Lists to/from NSData. Archiving Objects SQLite Core Data Next week

13 Archiving There is a mechanism for making ANY object graph persistent Not just graphs with NSArray, NSDictionary, etc. in them. For example, the view hierarchies you build in Interface Builder Those are obviously graphs of very complicated objects. Requires all objects in the graph to implement NSCoding protocol - (void)encodewithcoder:(nscoder *)coder; - initwithcoder:(nscoder *)coder; It is extremely unlikely you will use this in this course Certainly not in the homework assignments. But almost certainly not in your Final Project either. There are other, simpler, (or more appropriate), persistence mechanisms (more on this later).

14 Archiving Object graph is saved by sending all objects encodewithcoder: - (void)encodewithcoder:(nscoder *)coder { } [super encodewithcoder:coder]; [coder encodefloat:scale forkey:@ scale ]; [coder encodecgpoint:origin forkey:@ origin ]; [coder encodeobject:expression forkey:@ expression ]; Absolutely, positively must call super s version or your superclass s data won t get written out! Object graph is read back in with alloc/initwithcoder: - initwithcoder:(nscoder *)coder { } self = [super initwithcoder:coder]; scale = [coder decodefloatforkey:@ scale ]; expression = [coder decodeobjectforkey:@ expression ]; origin = [coder decodecgpointforkey:@ origin ]; // note that order does not matter

15 Archiving NSKeyed[Un]Archiver classes used to store/retrieve graph Storage and retrieval is done to NSData objects. NSKeyedArchiver stores an object graph to an NSData... + (NSData *)archiveddatawithrootobject:(id <NSCoder>)rootObject; NSKeyedUnarchiver retrieves an object graph from an NSData... + (id <NSCoder>)unarchiveObjectWithData:(NSData *)data; What do you think this code does? id <NSCoder> object =...; NSData *data = [NSKeyedArchiver archiveddatawithrootobject:object]; id <NSCoder> dup = [NSKeyedArchiver unarchiveobjectwithdata:data]; It makes a deep copy of object. But beware, you may get more (or less) than you bargained for. Object graphs like view hierarchies can be very complicated. For example, does a view s superview get archived?

16 SQLite SQL in a single file Fast, low memory, reliable. Open Source, comes bundled in ios. Not good for everything (e.g. not video or even serious sounds/images). Not a server-based technology (not great at concurrency, but usually not a big deal on a phone). API int sqlite3_open(const char *filename, sqlite3 **db); // get a database into db int sqlite3_exec(sqlite3 *db, // execute SQL statements const char *sql, int (*callback)(void *, int, char **, char **), void *context, char **error); int mycallback(void *context, int count, char **values, char **cols); // data returned int sqlite3_close(sqlite3 *db); // close the database

17 Coming Up Next Week Core Data (object-oriented database)