Cocoa dragging methods/design question

Question

hello,
i hope someone can help educate me on the right way to handle a situation like this:
in my example i have a custom view that accepts file drags. after receiving the drag i want to make a search using NSTask and the "find" command. for testing purposes i have placed my search code inside the concludeDragOperation method and it works ok, but the problem is the CPU usage goes way up at this time. i'm sure using NSTask and "find" makes the CPU usage go up depending on how much of the disk i search, but i guessing my main problem is that all this is happening before the concludeDragOperation is finished. so my question is what is the right way to finish the concludeDragOperation method and then to somehow trigger the search?
thank you for your help,
rick

Answer 1

To format your code, put it between two lines of:
like so:
rick722 wrote:
NSArray *filenames;
- (void)concludeDragOperation:(id <NSDraggingInfo>)sender
NSPasteboard *pboard = [sender draggingPasteboard];
if ([[pboard types] containsObject:NSFilenamesPboardType])
NSTask *task = [[NSTask alloc] init];
[task setLaunchPath:@"/usr/bin/find"];
NSArray *args = [NSArray arrayWithObjects:pathToSearch, @"-name", nameToSearch, nil];
[task setArguments:args];
NSPipe *outPipe = [[NSPipe alloc] init];
[task setStandardOutput:outPipe];
[outPipe release];
[task launch];
NSData *data = [[outPipe fileHandleForReading] readDataToEndOfFile];
[task waitUntilExit]; // i tried removing this...
[task release];
NSString *aString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
[filenames release];
filenames = [[aString componentsSeparatedByString:@"
"] retain];
[aString release];
[tableView reloadData];
I've never used "concludeDragOperation". I've never needed to. The documentation says "Invoked when the dragging operation is complete, signaling the receiver to perform any necessary clean-up."
You are doing far more than just cleaning up here. In fact, in a GUI application, you must do this in a separate thread. Not only are you launching a task, you are communicating with it. I would probably put the code somewhere else, but concludeDragOperation should work too. You just have to create a new thread to run the task. Detach a thread to do this and just forget about it. You can return the file names you read back to your main thread via a custom notification.