How does one implement an NSOutlineViewDataSource to allow dragging directories that do not exist in the file system at the time of dragging to the Finder? I have searched and searched and read a ton of the documentation, but have had great difficulty finding anything of value that works. I use a custom data source that manages a file system-like tree, and all the items are instances of a class that keeps track of its path. I would like to be able to drag files and directories out of the outline view into the Finder.
I have:
- (BOOL)outlineView:(NSOutlineView *)outlineView
writeItems:(NSArray *)items
toPasteboard:(NSPasteboard *)pasteboard
{
NSMutableArray *types = [NSMutableArray array];
for (JOItemInfo *itemInfo in items) {
NSString *extension = itemInfo.name.pathExtension;
if (extension.length > 0) [types addObject:extension];
}
[pasteboard declareTypes:#[(__bridge_transfer NSString *)kPasteboardTypeFileURLPromise]
owner:self];
[pasteboard setPropertyList:types
forType:(__bridge_transfer NSString *)kPasteboardTypeFileURLPromise];
DDLogInfo(#"Wrote types %# to pasteboard %# for key %#",
types,
pasteboard,
(__bridge_transfer NSString *)kPasteboardTypeFileURLPromise);
return YES;
}
and an implementation of -outlineView:namesOfPromisedFilesDroppedAtDestination:forDraggedItems: that writes the items inside of the given path. This works in that I can drag items out to the Finder, but when I let go nothing else happens, and the -...namesOfPromisedFilesDropped... method isn't even called. Also,
[self.outlineView setDraggingDestinationFeedbackStyle:NSTableViewDraggingDestinationFeedbackStyleRegular];
[self.outlineView setDraggingSourceOperationMask:NSDragOperationNone forLocal:YES];
[self.outlineView setDraggingSourceOperationMask:NSDragOperationCopy forLocal:NO];
is in my -awakeFromNib. The if (extension.length > 0) ... was based on an example I found somewhere, but it was dated, and the documentation says to return an extension, so I think that is appropriate. Personally, I find the documentation for this whole area very lacking, especially in regard to an NSOutlineView. Thanks!
I changed (__bridge_transfer NSString *)kPasteboardTypeFileURLPromise to NSFilesPromisePboardType, and I can now drag files (with an extension at least) and they can be dropped successfully in the Finder. (I had used the former b/c the documentation for the latter recommended that, but they do not have the same effect.)
Also, I tried removing the conditional and allowing it to add an empty string for an empty extension, which worked like a charm. I can now drag out of the outline view into the Finder.
Related
My application would like to add a promise to the pasteboard for a file that is stored remotely, and may never be pasted—similar to pasting a file copied from a session controlling a VM or other remote system. Ideally, a user can paste in a Finder folder (or the desktop) and the promise would trigger and away we go. I am willing to deal with the issues of fulfilling the promise once triggered, but I have been unable to get the promise to trigger.
All of the promise code I have found deals with drag and drop, which is not functionality what I need (though it is possible that something from DnD needs to be in place for promises to work?)
I have tried using NSFilePromiseProvider with a delegate, and adding that to the pasteboard. I can see the entries on the pasteboard using a clipboard viewer, but when I paste in Finder nothing happens and no delegate methods are called. I can trigger the delegate methods by having the clipboard viewer access the entries, so I know that much is hooked up.
#interface ClipboardMacPromise : NSFilePromiseProvider<NSFilePromiseProviderDelegate>
{
NSString* m_file;
}
#end
#implementation ClipboardMacPromise
- (id)initWithFileType:(NSString*)type andFile:(NSString*)file
{
m_file = file;
return [super initWithFileType:type delegate:self];
}
- (NSString *)filePromiseProvider:(NSFilePromiseProvider*)filePromiseProvider fileNameForType:(NSString *)fileType
{
return m_file;
}
- (void)filePromiseProvider:(NSFilePromiseProvider*)filePromiseProvider writePromiseToURL:(NSURL *)url completionHandler:(void (^)(NSError * _Nullable errorOrNil))completionHandler
{
// Finder can't paste, so we never get here...
}
#end
NSPasteboard* pboard = [NSPasteboard generalPasteboard];
[pboard clearContents];
NSMutableArray* items = [[NSMutableArray alloc] init];
ClipboardMacPromise* promise = [[ClipboardMacPromise alloc] initWithFileType:(NSString*)kUTTypeFileURL andFile:#"dummy.txt"];
[items addObject:promise];
[pboard writeObjects:items];
I have also tried NSPasteboardItem with NSPasteboardItemDataProvider where I setup a promise for content on kUTITypeFileURL. It provided very similar entries on the pasteboard, but still no action when I paste in finder. Clipboard viewer will again trigger the provider fine when accessing the individual pasteboard entries. (NSPasteboard's declareTypes:owner: has the same behavior)
#interface ClipboardMacPromise : NSPasteboardItem<NSPasteboardItemDataProvider>
{
NSString* m_file;
}
#end
#implementation ClipboardMacPromise
- (id)initWithFile:(NSString*)file
{
m_file = file;
id _self = [super init];
if (_self) {
[_self setDataProvider:_self forTypes:#[(NSString*)kPasteboardTypeFileURLPromise]];
[_self setString:(NSString*)kUTTypeFileURL forType:(NSString*)kPasteboardTypeFilePromiseContent];
}
return _self;
}
- (void)pasteboard:(NSPasteboard *)pasteboard item:(NSPasteboardItem *)item provideDataForType:(NSPasteboardType)type
{
// we don't get here when we paste in Finder because
// Finder doesn't think there's anything to paste
// but using a clipboard viewer, we can force the promise to
// resolve and we do get here
}
#end
NSPasteboard* pboard = [NSPasteboard generalPasteboard];
[pboard clearContents];
NSMutableArray* items = [[NSMutableArray alloc] init];
ClipboardMacPromise* promise = [[ClipboardMacPromise alloc] initWithFile:#"file:///tmp/dummy.txt"];
[items addObject:promise];
[pboard writeObjects:items];
And for completeness, here is my Carbon attempt since Pasteboard.h seems to detail how this should work in a copy/paste scenario... but it still does not provide Finder what it is looking for. The generated clipboard entries look very similar between the three implementations.
OSStatus PasteboardPromiseKeeperProc(PasteboardRef pasteboard, PasteboardItemID item, CFStringRef flavorType, void * _Nullable context)
{
// 6) The sender's promise callback for kPasteboardTypeFileURLPromise is called.
string s = "dummy.txt";
CFDataRef inData = CFDataCreate(kCFAllocatorDefault, (UInt8*)s.c_str(), s.size());
PasteboardPutItemFlavor(pasteboard, item, flavorType, inData, 0);
return noErr;
}
PasteboardRef p = NULL;
PasteboardCreate(kPasteboardClipboard, &p);
PasteboardClear(p);
PasteboardSetPromiseKeeper(p, &PasteboardPromiseKeeperProc, this);
// 1) The sender promises kPasteboardTypeFileURLPromise for a file yet to be created.
PasteboardPutItemFlavor(p, (PasteboardItemID)1, kPasteboardTypeFileURLPromise, kPasteboardPromisedData, 0);
// 2) The sender adds kPasteboardTypeFilePromiseContent containing the UTI describing the file's content.
PasteboardPutItemFlavor(p, (PasteboardItemID)2, kPasteboardTypeFilePromiseContent,CFStringCreateExternalRepresentation(NULL, kUTTypeFileURL, kCFStringEncodingUTF8, 0), 0);
It really seems that there is a certain UTI that Finder is looking for on the pasteboard, and I don't have it. If I put a kUTTypeFileURL directly on the clipboard, it appears that finder actually checks for the existence of the file (ie. triggers Catalina's Desktop access prompt) before offering it to paste.
Does anyone know if or how file promises can be provided to Finder through Copy/Paste instead of Drag-and-Drop?
It appears that the key piece here is that Finder requires that the file actually be present on disk for the paste action to be enabled for a file URL. This one detail rules out the possibility of promises working for copy/paste -- at least with Finder.
The correct solution therefore requires a virtualized file system (like FUSE) so that the promises can be made and fulfilled at the filesystem level. Thus a collection of temporary zero-length files can be written to disk, and actual file URLs be added to the pasteboard. This fulfills the requirements that Finder has to enable paste. Then when a paste action is made, the file data is read from the virtualized file system which can in turn retrieve the actual data from the remote system. Finder is none the wiser. The copy will even have a built in progress bar!
It appears that Microsoft's Mac RDP client mostly works this way, although I was only ever able to get it to copy zero length files so this may be harder to get right than it sounds.
I've been working on adding icloud to my project (which is quite a pain in the buns) and I'm able to save and remove files, but I can't get a list of the files stored in iCloud. I've tried solutions from about 10 different websites (including the Apple documentation). Whenever I call [self.query startQuery]; everything seems to be working: The correct methods get called, the methods execute exactly as they should. Then when I ask for an nsarray of the files in my app's iCloud Documents directory I get two parenthesis with nothing between them (when I view in NSLog): File List: ( ). I know for a fact that there are many different documents of all shapes, extensions, sizes, and names in my app's iCloud Documents directory because I've been using the iCloud Developer site to check if things are working. My first method to setup the query is as follows:
- (void)syncWithCloud {
self.query = [[NSMetadataQuery alloc] init];
NSURL *mobileDocumentsDirectoryURL = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil];
[query setSearchScopes:[NSArray arrayWithObjects:NSMetadataQueryUbiquitousDocumentsScope, nil]];
//[query setPredicate:[NSPredicate predicateWithFormat:#"%K LIKE '*'", NSMetadataItemFSNameKey]];
[query setPredicate:[NSPredicate predicateWithFormat:[NSString stringWithFormat:#"%%K like \"%#*\"", [mobileDocumentsDirectoryURL path]], NSMetadataItemPathKey]];
//Pull a list of all the Documents in The Cloud
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(processFiles:)
name:NSMetadataQueryDidFinishGatheringNotification object:self.query];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(processFiles:)
name:NSMetadataQueryDidUpdateNotification object:self.query];
[self.query startQuery];
}
The process files method provided by Apple is next:
- (void)processFiles:(NSNotification*)aNotification {
NSMutableArray *discoveredFiles = [NSMutableArray array];
//Always disable updates while processing results.
[query disableUpdates];
//The query reports all files found, every time.
NSArray *queryResults = [query results];
for (NSMetadataItem *result in queryResults) {
NSURL *fileURL = [result valueForAttribute:NSMetadataItemURLKey];
NSNumber *aBool = nil;
// Don't include hidden files.
[fileURL getResourceValue:&aBool forKey:NSURLIsHiddenKey error:nil];
if (aBool && ![aBool boolValue])
[discoveredFiles addObject:fileURL];
}
//Update the list of documents.
[FileList removeAllObjects];
[FileList addObjectsFromArray:discoveredFiles];
//[self.tableView reloadData];
//Reenable query updates.
[query enableUpdates];
NSLog(#"File List: %#", FileList);
}
Why doesn't this give me a list of files or at least some kind of data? Am I defining the NSMetadata query wrong, maybe my predicate isn't formatted right? I know I'm doing something wrong because there's no way iCloud could be this complicated (or could it?).
Thanks for the help in advance!
Edit #1: I am continuing to try different approaches to this problem. Using one of the answers below I have changed the predicate filter as follows:
[query setPredicate:[NSPredicate predicateWithFormat:#"NSMetadataItemFSNameKey LIKE '*'"]];
I have also added the following lines before the [query enableUpdates] call:
for (NSMetadataItem *item in query.results) {
[FileList addObject:[item valueForAttribute:NSMetadataItemFSNameKey]];
}
In the processFiles method, I've tried placing all of the code on the background thread, but this makes no difference - as a matter of fact, when the code is not executed on the background thread FileList gives me this (null) instead of this ( ).
Could my problem have to do with thread management or memory allocation? Please note that I am using ARC.
Edit #2: The FileList variable is an NSMutableArray defined in my #interface and initialized in the -(id)init method before calling the processFiles method.
Edit #3: When testing my code with breakpoints I found that the following for-loop never gets run through - not even once. This leads me to believe that:
A. The proper directory isn't being connected with
B. iCloud can't see the files in the directory
C. My NSMetadataQuery isn't being setup properly
D. Something completely different
Here's the code that starts the for-loop which never gets run:
NSArray *queryResults = [query results];
for (NSMetadataItem *result in queryResults) {
Since you already set the search scope correct, there's no need to use special filters in the predicate.
Just use:
query.predicate = [NSPredicate predicateWithFormat:#"NSMetadataItemFSNameKey == '*'"];
And to get the array use:
NSMutableArray *array = [NSMutableArray array];
for (NSMetadataItem *item in query.results) {
[array addObject:[item valueForAttribute:NSMetadataItemFSNameKey]];
}
I've solved my problem. Getting the list of files in iCloud was just a matter of correctly defining, allocating, and initializing properties. SAE's answer and this SO posting helped me solve my problem and create this GitHub Repo called iCloud Document Sync. The iCloud Document Sync class simplifies the whole iCloud Document storage process down to a few lines of code. The commit linked here fixes the issues from my question.
I processed drag operation from browser view to custom view.It work well in snow lepoard,but not in Mountain Lion with sandbox.
in browser view:
NSMutableArray* urls = [[[NSMutableArray alloc] init] autorelease];
..............put some NSUrl to urls array....................
[pasteboard writeObjects:[NSArray arrayWithArray:urls]];
in my receive custom view:
NSArray* pasteboardItems = [pasteboard readObjectsForClasses:[NSArray arrayWithObject:[NSString class]] options:nil];
NSArray* pasteboardItems2 = [pasteboard readObjectsForClasses:[NSArray arrayWithObject:[NSURL class]] options:nil];
NSArray* pasteboardItems3 = [pasteboard readObjectsForClasses:[NSArray arrayWithObject:[NSImage class]] options:nil];
NSLog(#"%#",pasteboardItems);
NSLog(#"%#",pasteboardItems2);
NSLog(#"%#",pasteboardItems3);
my log is:
2012-08-09 18:33:43.886 iCollage[6885:303] __CFPasteboardIssueSandboxExtensionForPath: error for [/Users/xxxx/Library/Containers/xxxxxxxxxxxx/Data/Downloads/1343902069.jpg]
2012-08-09 18:33:44.546 iCollage[6885:303] ( "file://localhost/Users/xxx/Library/Containers/xxxxxxxx/Data/Downloads/1343902069.jpg")
2012-08-09 18:33:44.547 iCollage[6885:303] ( "file://localhost/Users/xxxxx/Library/Containers/xxxxxx/Data/Downloads/1343902069.jpg")
2012-08-09 18:33:44.547 iCollage[6885:303] ()
my question is:
1.how to fix this error __CFPasteboardIssueSandboxExtensionForPath;I refer the docs and found nothing about that.I am ensuer that i have the permission to access the file!google says, may be "startAccessingSecurityScopedResource" will help me, then i try and failed
2.why pasteboardItems2 have value?i write to pasteboard only url but not string.It disgusted me that I can get the url both from NSString type and NSUrl type! (I try drag a file from iFinder, the url will only exist in pasteboardItems but not pasteboardItems2).Anybody know why? I think the first problem will auto fixed when some one help me fix this problem.
I believe Apple answer question 1:
Important: Although you can support dragging file paths, in general,
you should avoid doing so unless you are certain that the destination
app will never be run in an app sandbox. If you use an NSString, OS X
has no way to know whether that string should be interpreted as a
path; thus, OS X does not expand the destination app’s sandbox to
allow access to the file or directory at that location. Instead, use
an NSURL, a bookmark, or a filename pasteboard type.
WRT to question 2, it looks like you have pasted URLs so reading NSURL objects would seem to be correct. However I think you should implement the dragging using the following code (also from the link above):
- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender
{
NSPasteboard *pboard = [sender draggingPasteboard];
if ( [[pboard types] containsObject:NSFilenamesPboardType] ) {
NSArray *files = [pboard propertyListForType:NSFilenamesPboardType];
int numberOfFiles = [files count];
// Perform operation using the list of files
}
return YES;
}
You need to generate security-scoped URL bookmark data on the sender side, and turn that data back into a URL on the receiver side. There's some other stuff you have to do after that when you want to actually access the URL; the documentation elaborates.
The receiving application, when running in a sandbox, will not be able to handle bare paths. This is a core part of being sandboxed; you are not allowed to use bare paths or their corresponding URLs to access files that aren't in your sandbox container and haven't been explicitly handed to you by the user.
Your pasteboardItems read object of NSString type, but you dragged a file(with jpg extension), you should register for NSString type in your init method:
[self registerForDraggedTypes:[NSArray arrayWithObject:NSPasteboardTypeString]];
You need to have Document Types defined in your application so that the sandboxing mechanism knows your application should be opening files with those extensions. You can do this by clicking the project on the left in Xcode, and in the Info tab, under Document Types add a new document type for each extension.
You just need to fill in the name and extensions field.
Also if you want to persist your permission to access the files dragged onto your application, you can use this class to wrap up all that logic. https://github.com/leighmcculloch/AppSandboxFileAccess
I have created a document based Mac OSX application, and when I'm editing in Interface Builder, the title is correct (I filled out that portion of the inspector) but once the program runs, the application title is 'Untitled'. How can I change it? In my IB Doc Window, I have instances of Files Owner, First Responder, NSApplication, and NSWindow. There is no view controller, is that the issue? I'm new to Cocoa..
One solution is to override -displayName in your NSDocument subclass:
- (NSString *)displayName {
if (![self fileURL])
return #"Some custom untitled string";
return [super displayName];
}
You can also check out NSWindowController's -windowTitleForDocumentDisplayName: if you're using custom window controllers.
you have created a document based Cocoa application. For new documents, Cocoa sets the proposed name of the document to 'Untitled'.
That's because you checked Create Document-Based Application when you created this project:
You can remove it from info.plist by clicking the - button next to Document types:
Type in your own title in Storyboard and check the window to "is Inital Controller". After you run your project again, it will be OK.
Do you mean the application menu title? That is changed to match the name of the application at runtime. The simplest way to change it would be to change the Product Name build setting on your target in Xcode.
- (NSString *)displayName
{
NSMutableString *displayName = [NSMutableString stringWithString:[super displayName]];
if ([self fileURL] == nil) {
NSString *firstCharacter = [[displayName substringToIndex:1] lowercaseString];
[displayName deleteCharactersInRange:NSMakeRange(0, 1)];
[displayName insertString:firstCharacter atIndex:0];
}
return [NSString stringWithString:displayName];
}
I want to drag a file from a NSTableView row to copy it to another application (i.e. Finder). I implemented the first two steps ('Configuring Your Table View', 'Beginning a Drag Operation') of this guide and thought that would do the trick:
http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/TableView/Tasks/UsingDragAndDrop.html
However, when I attempt to drag a row, the row text follows my mouse but the file does not copy when released. Here's what I'm sending to my UITableView upon initialization:
#define librarySongDataType #"NSFileContentsPboardType"
- (void)awakeFromNib
{
[self setDraggingSourceOperationMask:NSUIntegerMax forLocal:YES]; // allow interapplication drags
[self registerForDraggedTypes:[NSArray arrayWithObject:librarySongDataType] ]; // NSFileContentsPboardType
}
Here's how I'm handling the drag in my NSTableView's data source (an NSArrayController):
- (BOOL)tableView:(NSTableView *)aTableView writeRowsWithIndexes:(NSIndexSet *)rowIndexes toPasteboard:(NSPasteboard *)pboard
{
NSLog(#"writeRowsWithIndexes");
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:rowIndexes];
[pboard setData:data forType:librarySongDataType];
return YES;
}
To be clear, I'm not trying to drag files into my table view, I'm just trying to drag file(s) out of it.
Firstly, which document did you refer to when you wrote this line ?
[self setDraggingSourceOperationMask:NSUIntegerMax forLocal:YES];
This doesn't make sense. Don't use NSUIntegerMax. Use operation masks as defined here. It's written there that NSUIntegerMax stands for everything, but you shouldn't use it; Apple may re-define the bit in the future. You should use NSDragOperationCopy or something specific. If you copied that line from a webpage or a book, you should stop trusting that book/webpage.
Secondly, forLocal: should be NO to pass the data to another application; local here means application local.
Third, instead of just setting the archived data in
[pboard setData:data forType:librarySongDataType];
Consider making an NSFileWrapper and set it using writeFileWrapper:, see here. That way you can specify the file name to be created in Finder. Otherwise, the system doesn't have any idea what the data represent.