When using XCode and you open a "plist" file you get the contents in a nice outline view.
In my project CoreDataUtility I would like to do something very similar. In core data a developer can store NSDictionary and NSArray as a transformable object. I would like to be able to present those object in a nice tree view instead of just dumping the description to a NSTextView.
I'm sure I can start coding it and get it to work but first I wanted to check if anyone knows how to get NSTreeView to do this intrinsically or if anyone has sample code that already does something similar?
Thanks for any help you might be able to offer.
Sample below not uses bindings, but should help: https://developer.apple.com/library/mac/samplecode/SidebarDemo/Introduction/Intro.html
I think, above sample is easier to implement than using bindings (even if there is a lot of more code).
Related
I am learning Objective-C Cocoa programming for OS X, and object-based programming in general, so I am a big novice here, so my question is a bit general and my guess is the answer to this is simply "experience"; however, I am curious if there is some route of knowledge to understanding what methods in various classes are best or perhaps required for getting tasks done.
For example, in a programming guide I am instructed to create a document-based program, and the document class contains an array to store data, with the following method bound to a button to create a new entry in the array:
- (IBAction)insertItem:(id)sender {
if (!theItems) {
theItems = [NSMutableArray array];
}
[theItems addObject:#"Double-click to edit."];
[theTableView reloadData];
[self updateChangeCount:NSChangeDone];
}
The array is "theItems" and its data is being presented in a TableView object. I understand that the steps here add a new string to the array and then refresh the table to display it, followed by setting the document to be set to an unsaved state.
What I am not getting is how one would know these specific steps and methods are required. Intuitively it seems one would just add items to the array, and that would be all that's required to have the new values simply show up in the table view for which the array is the data source, so how would one know that the tableView would need to be refreshed with the "reloadData" call? I can see someone (myself) figuring it out by trial and error, but is there some quick resource or guide (ie, some quick flow-chart) either in XCode or elsewhere that indicates for a table view that this would have to be a required action to display the new entry?
If I look at Apple's NSTableView class reference, it claims in the overview that you "modify the values in the data source and allow the changes to be reflected in the table view" which suggest the view is updated automatically, so the requirement to call "reloadData" on the view seems a little obscure.
Look for the guides. In the online class reference for NSTableView, there's a section at the top called "Companion Guides". For NSTableView, it lists the Table View Programming Guide for Mac. (In the prerelease 10.10 docs, the guides are listed under Related Documentation in the left-hand sidebar.)
I could have sworn this same information was available in Xcode's Documentation window, albeit somewhat hidden behind a "More related items" pseudo-link, but when I check right now there's no link to the guide anywhere in the NSTableView class reference. Which is a terrible oversight.
You can also browse or search the Guides section of the developer library.
Familiarity, studying the documentation and possibly reading some good books is the answer. For example, in the docs you quoted (emphasis mine)
you should modify the values in the data source and allow the changes to be reflected in the table view
You should do both these things. If you want it to happen "automatically", look into bindings, which uses several other Cocoa features you won't understand at this point either to do the table data source stuff for you. I'd recommend understanding what is happening manually before handing over control to bindings, so you have some chance of understanding when things go wrong.
As well as looking at the table view documentation, you also need to study the cell, delegate and datasource references. All of those objects work together to give you the functioning table view.
I had my iPhone app working, developed with Storyboard. I decided to take all of the methods that belonged in a SQLite method and move them to a new SQLite class (.h and .m).
Now I have errors that I can't seem to get rid of. The basic problem is the textfields on the "scene" are now unreachable from the SQLite class (they are in another class, where they belong). The properties are defined in EDVController.m... I am trying to reach them from SQLite.m.
I have read the docs, but can't find anything that fits my problem.
How do I do this?
I give full credit to Jeremy Roman... I would up using NSMutableDictionary to pass the parameters, and it works like a champ! Thank you Jeremy and Jia Yow.
How I can create a code in XCode 4.2.1 what will create NSTableView and add just couple of items to it?
All what I wanted to do is:
1) Window where is NSTableView
2) I have an array of strings in NSArray which I like to show in that NSTableView
3) All of this should be done in code. So I don't want to learn how to add this action happen when you press button (I know already how to do actions when user click buttons etc), I just want that application launch -> draws the table where is those items from my array. That's it, nothing more.
And yeah I have understood that I do not add items to NSTableView directly. That is not the point in this question. I just mean that I want to show couple of items in that table but I have no and kind of clue WHERE I should add my data from my array.
I have tried to google for example pages for hours (just too many and have not find help) but I will always be stucked in the part when
a) I must do something in the Interface Builder and the images of the interface builder are from version 2.x or 3.x and I have 4.2.1 and it is totally different (new to XCode...). Surely I have drawn my TableView element to UI but I mean delegations etc. Are those necessary at all? Can those be made from source code?
b) Code just does not work anymore because language (Cocoa or Objective-C, I don't know) has changed and I don't know how and what I have to do to make it work on newest version of XCode.
c) There is too much different ways told: "use binding", "you must create new class what is NSTableViewDataSource" etc. I have no any kind of clue what is preferred way, is another way optional or it is "you should use this because another is going deprecated soon" or something.
So please, can somebody give help in step-by-step what I exactly have to do? Should I create some bindings? If so, how and where? Do I have to create DataSource component myself? Are those ways valid any more? If I have to, how I can create it? Create a new class and implement it as a NSTableViewDataSource and then use it? Is that way valid any more and if it is, can sombody show code what is as simple as possible?
I have also checked Apple Documentation page many many times, checked those example codes but there is just too much totally unrelated stuff that I just don't understand at this point so they are totally useless (I mean, I don't know what is required for this task, what are not etc.
I would be very happy if somebody can help short tutorial step-by-step what to do. I mean "step-by-step" like:
1) Create new project
2) Draw NSTableView in project
3) Create new class with this name
4) Write this code: blah blah blah
5) Create another class with this name
6) Write this code
7) Run and see those items from array in NSTableView using (bindings/datasource/whatever is preferred).
Thanks :)
Your tableview needs a datasource. Your datasource is a custom class, it implements the "NSTableViewDataSource" protocol. This protocol contains a few methods that you can use to tell the tableview what data you got.
this includes the objectValue ( the value of the NSCell that is displaying your data on the specified row, and a method that returns the amount of rows the tableview has ( the amount of items in your array ).
Here a tutorial I found by googling:
CocoaDev.com NSTableView tutorial
You can also implement the NSTableViewDelegate protocol which allows some greater control. Like what rows you can select, or some extra configuring of a custom tableview cell.
I must say that back in the day when I started developing desktop applications ( only had experience with web technologies ) that this design pattern confused me as well. Hope you will get your mind round it soon.
I want to create a new object so as to instantiate and use it several times;
For example, if I want to create an object that has a label and a button inside, how do I? I created a new NSObject but inside it has nothing, then how do I make everything from scratch since there was a viewDidLoad for example (obviously, since it has a view)?
thanks!
Your questions lead me to think that you're really just starting out. There's nothing wrong with that, but rather than trying to summarize several megabytes of documentation in a few paragraphs, I'm just going to point you to the iOS Starting Point. I think that you're just trying to create a container that can hold other UI components? If so, use a UIView for that. However, don't jump in and try to get something specific done without first reading through some of the Getting Started documents -- you'll just end up back here, and we'll just point you back to the docs. You might like the Your First iOS Application guide, as that lets you get your feet wet but explains things along the way.
Currently I'm writing an app for OSX which will eventually need to be ported to iOS.
The data that needs to be printed is being drawn via CoreGraphics into a PDF context - that is working perfectly.
I've been reading the Apple dev documentation on printing in both iOS and OSX, and, ironically, it actually seems printing from iOS will be easier.
On iOS, UIPrintInteractionController's printingItem property can take an NSData object containing PDF data and print that. Looks like it should be fairly straight-forward.
OSX on the other hand, (looks like it) requires using the NSPrintOperation class - but it seems the only way to get data into an instance is via an NSView. (+printOperationWithView: or +printOperationWithView:printInfo:).
Seeing as the content is formatted and paginated already it seems rather pointless to have to re-draw the PDF data to something like an NSView.
Could there possibly be another way of achieving this that I've missed?
This code is by no means complete, but for anyone who comes across this later, this is basically how you can print directly from an NSData stream:
#define kMimeType #"application/pdf"
#define kPaperType #"A4"
- (void)printData:(NSData *)incomingPrintData {
CFArrayRef printerList; //will soon be an array of PMPrinter objects
PMServerCreatePrinterList(kPMServerLocal, &printerList);
PMPrinter myPrinter;
//iterate over printerList and determine which one you want, assign to myPrinter
PMPrintSession printSession;
PMPrintSettings printSettings;
PMCreateSession(&printSession);
PMCreatePrintSettings(&printSettings);
PMSessionDefaultPrintSettings(printSession, printSettings);
CFArrayRef paperList;
PMPrinterGetPaperList(myPrinter, &paperList);
PMPaper usingPaper;
//iterate over paperList and to set usingPaper to the paper desired
PMPageFormat pageFormat;
PMCreatePageFormatWithPMPaper(&pageFormat, usingPaper);
CGDataProviderRef dataProvider = CGDataProviderCreateWithCFData((CFDataRef)incomingPrintData);
PMPrinterPrintWithProvider(myPrinter, printSettings, pageFormat, (CFStringRef)kMimeType, dataProvider);
}
(via Core Printing Reference)
Beware this code lacks memory management so you will need to use the PMRetain() and PMRelease() functions as well as the CoreFoundation memory-management functions as well.
If anyone can tell me how I can get data from the OSX print dialogue into data I can use in this method I'll accept their answer instead of this. That is, without using Carbon functions.