How to create table with highlighted-on-mouseover cells on macOS cocoa?

Question

I'm trying to create a tray popover app with table very similar to the one Dropbox has in it's popover view. There is a table of files and when you hover mouse over a table cell, cell will highlight and show additional controls. I'm not sure if NSTableView is suitable for this at all? Does anyone have any advice?

Answer 1

This would be an ideal use of NSTableView. Using a view-based NSTableView, you'll be easily able to create the look of those cells (views). The highlight on mouse-over should be accomplishable if you add an NSTrackingArea to the table view (scroll view might be better) with -[NSView addTrackingArea:], which gives you callbacks for -mouseMoved: events. From that method you can use the locationInWindow property on the NSEvent, and then use NSTableView's -rowAtPoint: call to query which row you should change to display the hover event.

Answer 2

As a possible amendment here, I had to do the following to make this work:

highlightedRow: MyCustomRow?

func viewWillAppear(){
    configureTableHighlight()
}

func configureTableHighlight() {
    let trackingArea = NSTrackingArea(rect: scrollView.frame, options: [.mouseMoved, .activeInKeyWindow, .inVisibleRect], owner: self, userInfo: nil)
    scrollView.addTrackingArea(trackingArea)
}

override func mouseMoved(with event: NSEvent) {
    let pointInTableView = tableView.convert(event.locationInWindow, to: nil)
    let row = tableView.row(at: pointInTableView)
    
    if row == -1 {
        highlightedRow?.highlight = false
        highlightedRow = nil
        return
    }
    
    guard let view = tableView.view(atColumn: 0, row: row, makeIfNecessary: false) as? MyCustomRow else {
        return
    }
    
    if(highlightedRow == view){
        return
    }
    
    view.highlight = true;
    highlightedRow?.highlight = false
    highlightedRow = view;
}

This might depend on where you add the trackingView however.

Additional reference:

mouseover detection in NSTableView's NSCell?