NSSavePanel Changing File Name Extensions With AccessoryView - objective-c

Question

I have NSSavePanel with accessoryView to let the user select a graphic format so that they can save an image (NSImage) as a file. So far, I have the following. (I'm skipping some lines to make it short.)
- (void)exportFile {
NSString *filename;
if (formatIndex1 == 0) { // Default selection by user in Preferences
filename = #"Untitled.bmp";
}
else if (formatIndex1 == 1) {
filename = #"Untitled.gif";
}
...
[panel setAllowedFileTypes:[[NSArray alloc] initWithObjects:#"bmp",#"gif",#"jpg",#"jp2",#"png",nil]];
[panel setAllowsOtherFileTypes:NO];
[panel setExtensionHidden:NO];
[panel setCanCreateDirectories:YES];
[panel setNameFieldStringValue:filename];
[panel setAccessoryView:accessoryView1];
[formatMenu1 setAction:#selector(dropMenuChange:)]; // formatMenu1 is NSPopUpButton
[formatMenu1 setTarget:self];
[panel beginSheetModalForWindow:window completionHandler:^(NSInteger result) {
if (result == NSFileHandlingPanelOKButton) {
// getting panel url
}
}];
}
-(void)dropMenuChange:(NSPopUpButton *)sender {
NSSavePanel *savePanel = (NSSavePanel *)[sender window];
[savePanel setNameFieldStringValue:#"..."];
}
I'm not 100% sure that I'm doing it right. What I want to achieve is that I want to append the right extension to the current file name whenever the user selects a file format on accessoryView's NSPopUpButton. Is there a magical way of doing that? Or do I have to set the current file name with the right extension to setNameFieldStringValue programmatically for myself?
Thank you for your help.

Answer 1

What I want to achieve is that I want to append the right extension to the current file name whenever the user selects a file format on accessoryView's NSPopUpButton. Is there a magical way of doing that?
Yes, there is. You need not do it yourself with setNameFieldStringValue: , let the savePanel do it. Let us assume fileName is a full path like /Users/hg/Pictures/2013/08/Airplanes/pic123.png and it exists an accessoryView for the savePanel with a matrix of radio buttons. Each button has a title like #"jpg" or #"png" or... The action of the matrix is -selectFileType:
- (IBAction) selectFileType:(id)sender
{
[savePanel setAllowedFileTypes:#[ [[sender selectedCell] title] ] ];
// this will set the right extension
}
For using the savePanel I tried the following code:
- (void) saveImage:(NSImage *) theImg
{
savePanel = [NSSavePanel savePanel];
NSString *imageName = [fileName lastPathComponent];
NSString *suffix = [imageName pathExtension];
NSString *baseName = [imageName stringByDeletingPathExtension];
// prepare the savePanel
[savePanel setAccessoryView:accessoryView];
[savePanel setAllowedFileTypes:#[ suffix ] ];
[savePanel setDirectoryURL:[NSURL fileURLWithPath:fileName]]; // convert to URL
[savePanel setNameFieldStringValue:baseName ]; // without extension !
// savePanel does append the suffix
// and now start the savePanel and choose the wanted fileType
int rtn = [savePanel runModal]; // preferred method since 10.6
if( rtn==NSFileHandlingPanelCancelButton) return; // do nothing
// finally create and save the file
if( [[[savePanel allowedFileTypes] objectAtIndex:0] isEqualToString:#"jpg" ){
// save as jpg-file
}
// check for other fileTypes
. . .
}

Answer 2

You have to set current file name with the right extension using setNameFieldStringValue
-(void)dropMenuChange:(NSPopUpButton *)sender {
NSSavePanel *savePanel = (NSSavePanel *)[sender window];
NSString *nameFieldString = [savePanel nameFieldStringValue];
NSString *nameFieldStringWithExt = [NSString stringWithFormat:#"%#.%#",[savePanel nameFieldStringValue], popupvalue];
[savePanel setNameFieldStringValue:nameFieldStringWithExt];
}