Editable transparent NSTextField text appears with white highlight - objective-c

Question

I am trying to create editable transparent NSTextField in a semi transparent window:
What I have noticed is that whenever the field is editable there is a white "selection like" background drawn even though the element is not actually selected.
Additional observable symptoms:
This highlight is not present when the field is set as non-editable.
If there are multiple fields only the first one has the highlight.
The highlight is not present if the text is not set programmatically
Following code was used to generate the field:
f = [[NSTextField alloc] initWithFrame:b2];
f.backgroundColor = [NSColor clearColor];
f.drawsBackground = YES;
f.bordered = NO;
f.bezeled = NO;
f.focusRingType = NSFocusRingTypeNone;
f.textColor = [NSColor whiteColor];
f.editable = YES;
f.selectable = YES;
f.backgroundColor = [NSColor clearColor];
f.allowsEditingTextAttributes = YES;
f.stringValue = #"Foo";
[self.contentView addSubview:f];
Additional observations (potentially a separate problem):
When field is not the first field on the screen and the initial text is set programmatically and removed by editing the field there is a shadow of the text:
I can't seem to find any documentation on this I wonder if any of you have had this happen and potentially have a solution or a pointer to docs I might have not stumbled upon.

Answer 1

part 1: removing highlight
there are two options here depending on the behavior you are looking for
option 1 - nil first responder
TextField is not first responder
No highlighted text
No Cursor at the end of text
Assuming you are using an NSWindow, set the first responder to nil after calling makeKeyAndOrderFront
[self.window makeKeyAndOrderFront:self];
[self.window makeFirstResponder:nil];
It appears as though makeKeyAndOrderToFront: looks for the first NSResponder in the window willing to accept first responder. Then becomeFirstResponder is called on that responder; leading to option 2
option 2 - override becomeFirstResponder
TextField is first responder
No highlighted text
Cursor appears at the trailing edge of text
Subclass NSTextfield and override it's becomeFirstResponder method
#implementation BPTextField
- (BOOL)becomeFirstResponder {
BOOL isResponder = [super becomeFirstResponder];
//Get Field editor, set selected range
NSText* fieldEditor = [[self window] fieldEditor:YES forObject:self];
[fieldEditor setSelectedRange:NSMakeRange(fieldEditor.string.length ,0)];
return isResponder;
}
#end
I prefer this option from a usability perspective
part 2: removing shadow
option 1 - add a solid background color
I'm not clear ; ) on why this is the case, but if you add a solid background color, the text will update.
option 2 - override textDidChange
override textDidChange:notification in your textfield
#implementation BPTextField
- (void)textDidChange:(NSNotification *)notification {
[super textDidChange:notification];
[self setNeedsDisplay:YES];
}
#end
Final notes
You'll notice that the text looks bad, or rigid. Adding a background color to the textfield, or to the superview's layer will fix this.

Answer 2

This is an answer to part 2 of the question.
The shadow artifact is from rendering window's shadow which is not updated when the text in the NSTextField changes.
If the window's hasShadow method returns "NO" the text's shadow will not create shadow for the text either.