How to present an Open Panel and let users open files of specific types (files with specific extensions).I would recommend to take a look at the Apple’s Human Interface Guidelines about dialogs, alerts and sheets. The common thing with the modal presentation is that the new window stays there until we dismiss it, and it doesn’t allow interaction with any other content underneath. Instead, the new window is sliding in from the top of the current window and looks like it’s a part of it. When presenting a window as a sheet, then there’s no separate window and no dragging can happen. There is a title bar and window can be dragged around in the screen. When presenting as a modal dialog, the new window sits on top of the current window and interaction is allowed with that only. Presenting any of the above can happen in two different ways: Either as a modal dialog, or as a sheet. You can start with the first tutorial if you’re new to macOS app development. Editor’s note: This is the third article of our macOS Programming tutorial series.
