Question

How do I make Apple’s Cocoa GUI controls not automatically ‘flip’ lines that contain right-to-left text (such as arabic)?

Behold my test case, wherein I plan to keep the asterisks (**) in the beginning of the lines when they are printed on screen:

#import <Foundation/Foundation.h>  int main(int argc, char *argv[]) {     NSAutoreleasePool *autoReleasePool = [[NSAutoreleasePool alloc] init];      NSString *str1 = @'** english first then arabic تجر\n';     NSString *str2 = @'** تجر arabic first then english\n';     [str1 writeToFile:@'/dev/stdout' atomically:NO encoding:NSUTF8StringEncoding error:NULL];     [str2 writeToFile:@'/dev/stdout' atomically:NO encoding:NSUTF8StringEncoding error:NULL];      [autoReleasePool release];     return 0; } 

When I run this in Terminal.app I get:

$ gcc -framework Foundation test.m $ ./a.out ** english first then arabic تجر arabic first then english تجر ** 

In iTerm, though, the lines don’t get ‘flipped’:

$ gcc -framework Foundation test.m $ ./a.out ** english first then arabic تجر ** تجر arabic first then english     

Based on some cursory examination of iTerm’s code, it looks like this is due to iTerm’s ‘manual’ character-by-character handling of output and Terminal.app’s (assumed) use of OS-native string layout APIs. Is there any way to prevent this ‘flippage’ from occurring when using, for example, NSTextView to display these kinds of strings? I couldn’t find any answers in Apple’s documentation.

I’m running an english Mac OS 10.5.6 with english as the #1 language in the list under System Preferences > International > Language.

Answer 1

Have you tried:

[nstextviewobj setBaseWritingDirection:NSWritingDirectionLeftToRight]; 

This method is in the NSText parent class.