Respond to mouse events in text field in view-based table view

You really want to override validateProposedFirstResponder and allow a particular first responder to be made (or not) depending on your logic. The implementation in NSTableView is (sort of) like this (I'm re-writing it to be pseudo code):

- (BOOL)validateProposedFirstResponder:(NSResponder *)responder forEvent:(NSEvent *)event {

// We want to not do anything for the following conditions:
// 1. We aren't view based (sometimes people have subviews in tables when they aren't view based)
// 2. The responder to valididate is ourselves (we send this up the chain, in case we are in another tableview)
// 3. We don't have a selection highlight style; in that case, we just let things go through, since the user can't appear to select anything anyways.
if (!isViewBased || responder == self || [self selectionHighlightStyle] == NSTableViewSelectionHighlightStyleNone) {
    return [super validateProposedFirstResponder:responder forEvent:event];
}

if (![responder isKindOfClass:[NSControl class]]) {
    // Let any non-control become first responder whenever it wants
    result = YES;
    // Exclude NSTableCellView. 
    if ([responder isKindOfClass:[NSTableCellView class]]) {
        result = NO;
    }

} else if ([responder isKindOfClass:[NSButton class]]) {
    // Let all buttons go through; this would be caught later on in our hit testing, but we also do it here to make it cleaner and easier to read what we want. We want buttons to track at anytime without any restrictions. They are always valid to become the first responder. Text editing isn't.
    result = YES;
} else if (event == nil) {
    // If we don't have any event, then we will consider it valid only if it is already the first responder
    NSResponder *currentResponder = self.window.firstResponder;
    if (currentResponder != nil && [currentResponder isKindOfClass:[NSView class]] && [(NSView *)currentResponder isDescendantOf:(NSView *)responder]) {
        result = YES;
    }
} else {
    if ([event type] == NSEventTypeLeftMouseDown || [event type] == NSEventTypeRightMouseDown) {
        // If it was a double click, and we have a double action, then send that to the table
        if ([self doubleAction] != NULL && [event clickCount] > 1) {
           [cancel the first responder delay];
        }
   ...
          The code here checks to see if the text field 
        cell had text hit. If it did, it attempts to edit it on a delay. 
        Editing is simply making that NSTextField the first responder.
        ...

     }

Had the same problem. After much struggle, it magically worked when I selected None as against the default Regular (other option is Source List) for the Highlight option of the table view in IB!

Another option is the solution at https://stackoverflow.com/a/13579469/804616, which appears to be more specific but a little hacky compared to this.

I'll try to return the favor... Subclass NSOutlineView and override -mouseDown: like so:

- (void)mouseDown:(NSEvent *)theEvent {
    [super mouseDown:theEvent];

    // Only take effect for double clicks; remove to allow for single clicks
    if (theEvent.clickCount < 2) {
        return;
    }

    // Get the row on which the user clicked
    NSPoint localPoint = [self convertPoint:theEvent.locationInWindow
                                   fromView:nil];
    NSInteger row = [self rowAtPoint:localPoint];

    // If the user didn't click on a row, we're done
    if (row < 0) {
        return;
    }

    // Get the view clicked on
    NSTableCellView *view = [self viewAtColumn:0 row:row makeIfNecessary:NO];

    // If the field can be edited, pop the editor into edit mode
    if (view.textField.isEditable) {
        [[view window] makeFirstResponder:view.textField];
    }
}