UnigramDev/Unigram/develop • 255025a • 2 files, +84/-31 Carry the gesture inside the page's scrollin

UnigramDev/Unigram/develop • 255025a • 2 files, +84/-31
Carry the gesture inside the page's scrolling host

On settings pages the chip only appeared in the title strip and nowhere in the
page itself. A vertical ScrollViewer takes the touchpad pan before any ancestor
sees it, and the source lives on DetailRoot, which is an ancestor of the page -
so the header, sitting outside the scroller, was the only place left.

The chat history was never evidence to the contrary: what works there is
MessageSelector's source, which is a descendant of the scroller and so wins the
contact. This does the same thing deliberately, putting a second source on the
scrolling host's content element and adding it to the same tracker. Rails and an
X-only source mode leave vertical panning to the ScrollViewer, as they already
do in the chat history.

Only ScrollViewer hosts. A ListViewBase one would need its ItemsPanelRoot, which
does not exist until the list realises, and the list that matters is the chat
history.

The old source is dropped on the way in rather than on the way out, because
OnNavigating is never subscribed.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

UnigramDev/Unigram/develop • b8b17c5 • 2 files, +68/-5
Reach the gesture to the foot of a short page, and slide back from the left

Moving the source inside the scrolling host fixed only the long pages. Privacy
and Security worked; Power Saving and Advanced did not, and those are the two
shortest settings pages in the app. A ScrollViewer arranges content shorter than
the viewport at its desired height, so the source reached the rows and stopped -
everything below the last one is bare scroller, which takes the pan.

The source has to sit inside the scrolled content, since that is the only thing
that beats the scroller to the contact. So the content is what has to cover the
viewport: its MinHeight now comes from the host's ViewportHeight, kept current on
SizeChanged. Nothing else moves, because the extent still matches the viewport
and a short page stays unscrollable. ViewportHeight is 0 at OnNavigated, so
SizeChanged is where the height first lands rather than only where it is kept.

Committing the gesture now navigates with a FromLeft slide, mirroring the
FromRight that TLNavigationService uses going forward - the default entrance
transition reads as unrelated to the finger that asked for it. Gated on the power
saving policy, which FrameFacade applies to Navigate but not to GoBack, so
nothing else would have stopped it animating.

Drops a comment that claimed this route lets an INavigablePage answer for
itself. It does not: NavigationService.GoBack goes straight to the frame and
never reaches OnBackRequested. That matches the visible back button, which takes
the same route.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

#unigram