Bug #456
closedThe scroll position indicator can move below the bottom of the screen when app bar scrolling is enabled.
Added by Moderator ✓ almost 5 years ago. Updated almost 5 years ago.
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Files
| recording_20190601_061121.mp4 (5.76 MB) recording_20190601_061121.mp4 | Moderator ✓, 05/31/2019 09:28 PM | ||
| recording_20190601_094416.mp4 (5.73 MB) recording_20190601_094416.mp4 | The touch is virtually not moving. | Moderator ✓, 06/01/2019 12:45 AM |
Updated by Moderator ✓ almost 5 years ago
Updated by Soren Stoutner almost 5 years ago
I watched the attached video several times, but I couldn't tell what was the unexpected behavior. Can you be more specific about what is not functioning correctly?
Updated by Moderator ✓ almost 5 years ago
Look closely at the scrollbar - whenscrolling up, it's first covered below the screen rather than going up. This is espevially frustrating with webpages that adapt to your screen size, because the canvas can't be shown all at once.
I'd suggest to move both the window list and address bar into the left sidebar. For me personally, it feels rather like it's getting in my way than actually help, especially since I rarely browse more than one page anyway.
Updated by Moderator ✓ almost 5 years ago
Or websites that are smaller than your screen and you just want a static view that doesn't move up or down.
Updated by Moderator ✓ almost 5 years ago
Updated by Soren Stoutner almost 5 years ago
This is expected behavior related to how nested scrolling works between the WebView and the app bar (the WebView must maintain a section equal to the height of the app bar that is scrolled off when the app bar is displayed). For those who don't want it, app bar scrolling can be disabled in the settings.
As a side note, the wisdom in using this methodology for scrolling the app bar is that it isn't susceptible to bugs like the following one in Chrome, which are caused because they let the WebView intercept the scrolling before the app bar, where Privacy Browser does it the other way around.
Also, you might enjoy reading the following blog post for a general discussion of the design principles used in Privacy Browser.
Updated by Moderator ✓ almost 5 years ago
Oh yes thanks it is much better now. Howewer, I still think that the issue should be kept open, because the behavior persists if the top app bar is completely hidden in fullscreen (Which is probably why I haven't thought about the right setting)
Updated by Soren Stoutner almost 5 years ago
- Subject changed from Part of the webside "hides" below bottom screen edge when scrolling up. to The scroll position indicator can move below the bottom of the screen when app bar scrolling is enabled.
Just to clarify, the problem is not that any part of the website is hidden or inaccessible. Rather, if app bar scrolling is enabled, the scroll position indicator (scroll bar) will temporarily move below the screen when scrolling up from the bottom of the page if the height of the scroll bar is less than the height of the app bar.
If app bar scrolling is disabled, this does not happen in either normal or full-screen browsing mode (with or without hiding the app bar in full-screen browsing mode enabled). So users do not need to experience this behavior if it bothers them.
Because no actual information from the website is missing, I don't consider this a significant bug. If there were something easy I could do to fix this without breaking important parts of the interface I would do it. But, because there is nothing I can do, I don't see any reason in leaving the bug report open.
As a side note, you might find https://redmine.stoutner.com/issues/398 interesting, which was a related but much more significant bug that cut off the bottom portion of the WebView.
Updated by Moderator ✓ almost 5 years ago
I think that probably the easiest way to fix this would be to keep the WebView of constant size, let the app bar overlay it, and only move it down when the top of the website is reached.
Thanks for the links BTW.
Updated by Soren Stoutner almost 5 years ago
Actually, the root of the problem is that the WebView is kept a constant size and offset from the screen when the app bar is displayed (the bottom of the WebView pokes off the bottom of the screen). So, a possible solution that could be implemented would be to dynamically resize the WebView. But not only would that introduce a whole lot of rendering issues, it would also break nested scrolling. https://developer.android.com/reference/android/support/v4/view/NestedScrollingChild
The real fix is for Android to correct their buggy scroll bar implementation. The scroll bar should be calculated and drawn only on the visible part of the WebView. You are welcome to submit a bug report to the Android Open Source Project, but my experience is that they often don't even read their bug reports, and even when they do they rarely fix them.