There is a lag (almost a second) from the time a folder is clicked to the time the folder is entered. Why? Windows Explorer is instantaneous. Can Opus be that "snappy"? It really feels sluggish after having used Explorer. Do I have some option enabled that is causing the sluggish folder navigation performance? (I'm using listview, but the issue occurs in the other styles too).
If you're using single click mode, the delay is based on your system double-click speed setting.
I set the mouse double-click speed to one notch below the maximum. The lag is still noticeable enough to leave one wanting (even at "Fast" double-click speed), especially since Explorer's performance in that regard is excellent. I find it an odd implementation, to tie navigation performance to double-click speed! The lag reduces the enjoyment of my otherwise fast PC. I consider this a design flaw and suggest that the sluggish performance in folder navigation be corrected.
Opus is waiting to see if you did a single click or a double-click, which is unknown after the first click until either a second click or the double-click time has expired.
Explorer intentionally worked this way as well, at least in the past. Long time since I've tested how it behaves in this mode, though:
If Explorer is in one-click mode, it waits to see if there is a second click, and if so, it ignores it. Otherwise, when people double-click, they launch two copies of the program. Furthermore, if you suppress the second click but don't wait a tick, then the program they launched gets stuck behind the Explorer window, since the user clicked on Explorer after launching the program.
But you should try turning off single-click mode and checking how fast things are when you double-click normally. If it is still slow then, then that's a different situation and we can suggest directions to look in. If it is only slow in single-click mode then that's just how single-click mode works, at least right now.
Most mice let you bind a button to do an instant double-click, which you might find works better if you have trouble double-clicking manually, as long as you have a mouse with an extra button you don't mind assigning to that purpose. That can be useful outside of Opus as well as inside it, and removes the need for using single-click mode if you find it slow. It would also mean not losing some of the features that single-click mode inherently conflicts with.
Well, from the top-down analysis: Explorer is superfast, while Opus is sluggish. If one could not create a similar program to Explorer without a performance hit, that would be class action material against MS, so I doubt that is the case. Folder navigation on the order of X tenths of a second? C'mon now, that's outrageously slow, especially for a program where folder navigation is the primary user interface. Apparently Explorer abandoned the idea of waiting for a potential second click (as the 14-yr-old article states it does) probably because the performance is abysmal when doing that. I would say that if a program gets stuck behind the file manager because a user double-clicked when the program was in single-click mode, that is a good training lesson. Indeed, that is what happens in Explorer (I just tested it).
New information: When in single-click mode, but double-clicking the folders for navigation, Opus seems as fast as Explorer--no matter what the mouse button double-click speed adjustment is set to, so it's not a rendering problem. Seems like it's the ill-chosen strategy of waiting for a click (though it seems to wait much longer than the double-click speed).
We recommend turning off the ill-chosen single click mode for maximum performance.
Folder navigation is the scenario in which the issue resides. I abandoned use of double-click mode in Windows years ago and with no regrets (and I suggest others try it for a week or month if they are still double-clicking on everything). I hope the Opus team will get the performance of Opus on par with Explorer by abandoning the "wait for potential click" strategy.
You're right about "folder navigation" not indicating the scope of the problem. The problem is apt to be program-wide (everything clicked-on in Opus).
What else in Opus is affected by single-click mode other than opening files/folders in the file display? I am not sure what you are talking about here, unless it was pure hyperbole.
Single-click mode is an accessibility feature, there for people who have physical difficulties double-clicking the mouse button due to muscular problems. If you don't have that difficulty, a double-click is as quick and easy as a single click, and how most of Windows works. I would not recommend anyone uses single-click mode who doesn't need to because it (inherently) breaks the ability to easily select files, which is a pretty major part of a file manager. (Of course, for people who need to use it, that's a valid compromise, as selecting files using the mouse can also be difficult with related muscular problems.)
Since single-click mode (inherently) breaks basic file selection, it will never be our primary focus. But we keep it there as an accessibility feature, for people who could not use the program and their computer otherwise. (Although I would still recommend those people who need it look into getting a mouse that can have a dedicated double-click button, as that is much more versatile and works with everything that uses double-clicks.)
Not an exageration, but an extrapolation: anywhere single-clicking is present is apt to be governed by the same mechanism employed. If that's the only place single-clicking vs. double-clicking is a choice, so be it.
Single-click mode is great! (IMO). It is not categorized along with the accessibility features in Windows. Though, as it is often seen for new computer users, double-clicking is a weird and difficult concept. Single-clicking is also more like the way the web works. If you prefer double-clicking, perhaps you'd want to double-click on web links also(?). Heck, more is better right? Let's introduce TRIPLE-clicking!. Selecting files via hover-and-move-mouse-cursor is the only negative, but I (and others) find it well-worth the convenience of not having to perform thousands of needless clicks a day. It's not a need-to to thing primarily, but a want-to thing which make a lot of sense to some of those that actually think about it. Most people don't know about single-click mode and therefore just do what they first encounter and taught, which, unfortunately, is double-clicking.
Anyway, I just wanted to bring your attention on the performance issue of single-click mode, and hope that it will be fixed in a soon-to-be updated Opus.