Xcode desktop directory and writeToFile: always with different name COCOA APPLICATION

Question

I am creating a application that screenshot the mac desktop...

But I am having 2 problems:

what is the "global" directory of desktop?

In my computer is /Users/miguelcosta/Desktop/ but i want a directory that works for all macs..

My second problem is:

When you screenshot he creates a image on your desktop with the name Result.jpg. However when you take another screenshot he replace the previous screenshot... So I was thinking how can I save this images always with a different name...

Here is my code:

NSString *targetPath =@"/Users/miguelcosta/Desktop/Result.jpg";

NSData *imageData = [newImage  TIFFRepresentation];
NSBitmapImageRep *imageRep = [NSBitmapImageRep imageRepWithData:imageData];
NSDictionary *imageProps = [NSDictionary dictionaryWithObject:[NSNumber numberWithFloat:0.9] forKey:NSImageCompressionFactor];
imageData = [imageRep representationUsingType:NSJPEGFileType properties:imageProps];
[imageData writeToFile:targetPath atomically:NO];

Thanks for your help!

Answer 1

Here is a code snippet... Refer also to this topic: Getting desktop path for current user on OS X

#import "ViewController.h"

@interface ViewController()
{
    NSInteger _count;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    _count = 1;

    NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDesktopDirectory, NSUserDomainMask, YES );
    NSString* desktopPath = [paths objectAtIndex:0];

    NSString *fileName = @"Result.jpg";
    NSString *filePath = [NSString stringWithFormat:@"%@/%@", desktopPath, fileName];

    filePath = [self filePathWithPath:filePath];

    // write to file now using filePath ...

}

// generate new name ...
- (NSString*)filePathWithPath:(NSString*)filePath
{
    if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
        NSArray *parts = [[filePath lastPathComponent] componentsSeparatedByString:@"."];
        NSString *name = parts[0];
        NSString *ext = parts[1];
        filePath = [self filePathWithPath:[NSString stringWithFormat:@"%@/%@%ld.%@", filePath, name, _count++, ext]];
    }

    return filePath;
}


@end