#55 Cursor keys ignore page flipping steps

[Ark]

If you view an image that is so wide you need to scroll horizontally but not vertically, the cursor left/right/up/down keys ignore the "Number of 'steps' to take before flipping the page" but flip to the next/previous image immediately. This also happens in fullscreen mode.

That is, if you cannot scroll vertically but horizontally, all cursor keys behave like "Number of 'steps' to take before flipping the page" is set to 1.

[Oddegamra]

Hello,

I have some reasons to believe that this is intentional behavior. When an image doesn't need to be scrolled vertically, the scroll protection feature is disabled. At least that was how the code originally behaved when I took over this project, so I kept it in place after reworking some of it. I'd assume that it would be a bit irritating to have to scroll an image that already completely fits into the view port.

[Ark]

I'd assume that it would be a bit irritating to have to scroll an image that already completely fits into the view port.

I know what you mean, but this does not refer to the problem I described. Currently, the protection for all directions is enabled if and only if you can scroll vertically.

Thus, if you need to scroll vertically but not horizontally, the protection is enabled. However, if you need to scroll horizontally but not vertically, the protection is disabled.

I think there are two reasonable policies:

• If you need to scroll in a direction, then protection is enabled for the very same direction. (That is, if you can scroll horizontally, then protection is enabled for left and right, otherwise not. And, if you can scroll vertically, then protection is enabled for up and down, otherwise not.)
• If you need to scroll in any direction, then protection is enabled for all directions. (That is, if you can scroll horizontally or vertically, then protection is enabled for left and right and up and down, otherwise not. Equivalently, protection is disabled if and only if the entire image is completely visible.)

I prefer the latter since it reliably tells me that I may have missed a part of the current image. What do you think?

[Oddegamra]

I'm still not sure I understand. Scrolling horizontally cannot flip a page, as far as I am aware (thus, there would be no need for a protection function, as the page wouldn't turn no matter how many times the user scrolls). For clarification, are you referring to mouse wheel/space key scrolling, or normal arrow key scrolling? The code base for these are a bit different.

[Ark]

I refer to scrolling (and page flipping) using the arrow keys.

I'm still not sure I understand. Scrolling horizontally cannot flip a page, as far as I am aware (thus, there would be no need for a protection function, as the page wouldn't turn no matter how many times the user scrolls).

Actually, this scares me somehow. I just tried it again: You can flip a page using arrow left/right. It depends on whether you use manga mode or not to make it flip to the next page or the previous page, respectively (depending on the direction). But it is definitely possible.

[Oddegamra]

I feel somewhat confused. This changes things - you're probably right, if a page is scrollable in any direction, the scroll protection should be activated, seeing that scrolling in any direction can actually change the page, that is.

[Ark]

Thank you for r888. But it looks like it is fixed only for the "next page" direction. If you go the "previous page" direction, you still go to the previous page immediately. (Note that I didn't use the terms "left" or "right" since it depends on using manga mode or not.)

[Oddegamra]

Thanks - missed that that other function that should have been fixed.

[Ark]

Thanks again. It seems to be fixed now.