Question

I would like to enter text in a NSTextView so that when I hit return the NSTextView clears with the cursor going back to the original position. Then the entered text displays on the screen using the drawRect of an NSView.

This what I have currently which doesn’t work. Basically self.outputString is always the current value of [textview string] even though I draw and then clear. The current code below doesn’t draw any string to the screen. If I remove [textview setString:@""] then the current text always shows what I’m writing.

- (void)drawRect:(NSRect)dirtyRect
{
    [[NSColor whiteColor] setFill];

    NSRectFill(dirtyRect);

    // Drawing code here.

    NSPoint point = NSMakePoint(50.0f, 700.0f);
    NSMutableDictionary *font_attributes = [[NSMutableDictionary alloc] init];
    NSFont *font = [NSFont fontWithName:@"Futura-MediumItalic" size:35.0f];
    [font_attributes setObject:font forKey:NSFontAttributeName];
    [self.outputString drawAtPoint:point withAttributes:font_attributes];
    [font_attributes release];
}


- (BOOL)textView:(NSTextView *)textView doCommandBySelector:(SEL)commandSelector {

    [self enterPressed:[textView string]];
    [textView setString:@""];


    NSRange range = { 0, 0 };
    [self.textView setSelectedRange: range];

    return YES;
}

- (void) enterPressed:(NSString*)stringEntered
{
    NSLog(@"enter pressed with string:  %@", stringEntered);

    self.outputString = stringEntered;
    [self setNeedsDisplay:YES];
}

Answer 1

First off, set a delegate on the NSText object so you can take advantage of some of the delegate methods declared by the NSTextDelegate protocol.

The method you probably want to catch first is the textDidChange: notification, looking for when a enter is pressed.

Also, does your drawRect method ever get called? If you don’t know, set a breakpoint and find out. What object is that drawRect associated with? Why do drawRect anyways? You could just have a nice centered NSTextField as an IBOutlet and set the font on that.