Cocoa - How to distinguish between a click and scroll(continuous press of UP/DOWN key) inside a NSTableView

Question

I want to fire a query when a particular record gets selected in an NSTableView, not when the user just scrolls down or scrolls up by continuously pressing UP/DOWN button to reach to a record.

My current implementation is

if ([notification object] == myTableView)
    {
        if ([myTableView selectedRow] >= 0) {
            myCont = [[MyController alloc] init];
            if([[detailsView subviews]count]>0)
                [detailsView removeAllSubviews];
            NSRect frameRect = [[scDetailsViewController view] frame];
            frameRect.size.height = [detailsView frame].size.height;
            frameRect.size.width = [detailsView frame].size.width;
            [[myCont view] setFrame:frameRect];
            [detailsView addSubview:[myCont view]];
//Firing the Query
            [myCont populateDetails :[[self myList] entityAt:[myTableView selectedRow]]];
        }
}

But in this way the query gets fired even if a long UP/DOWN press is done which is not intended.

Is there any way to distinguish between a click and scroll(continuous press of UP/DOWN key) inside an NSTableView just like the Mail application.

Answer 1

Just wrote the below piece of code in the tableViewSelectionDidChange method and that almost works perfectly.

- (void)tableViewSelectionDidChange:(NSNotification *)notification
{
    if ([notification object] == myTableView)
    {
        NSTimeInterval delayInterval = 0.0;
        NSEvent *event = [NSApp currentEvent];
        if(event != nil && [event type] == NSKeyDown && [event isARepeat])
        {
            NSLog(@"Long press of UP and DOWn arrow key.");
            delayInterval = [NSEvent keyRepeatInterval] + 0.01;
        }
        [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(myMethod) object:nil];
        [self performSelector:@selector(myMethod) withObject:nil afterDelay:delayInterval];
    }
    else
    {
        if ([[detailsView subviews] count]>0)
        {
            [detailsView removeAllSubviews];
        }
    }
}

Also written the code to fire the query in another method myMethod which is being called above in performSelector.

-(void) myMethod
{
    if ([scenarioTableView selectedRow] >= 0) {
        NSLog(@"Normal selection on table view row.");
        scDetailsViewController = [[ScenarioDetailsViewController alloc] init];
        if([[detailsView subviews]count]>0)
            [detailsView removeAllSubviews];
        NSRect frameRect = [[scDetailsViewController view] frame];
        frameRect.size.height = [detailsView frame].size.height;
        frameRect.size.width = [detailsView frame].size.width;
        [[scDetailsViewController view] setFrame:frameRect];
        [detailsView addSubview:[scDetailsViewController view]];
        [scDetailsViewController populateScenarioDetails :[[self scenarioDetailsList] entityAt:[scenarioTableView selectedRow]]];
    }
    else {
        if ([[detailsView subviews] count]>0)
        {
            [detailsView removeAllSubviews];
        }
    }
}