Post on 09-Feb-2017
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Android UX Tricks: Nested Scrolling without Nested Scrolling
11 JAN 2017 PRESENTED BY BRENDAN WEINSTEIN ( VSCO )
BRENDANW@VSCO.CO
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Camera Preview
Header that hides when you scroll fast down or up
RecyclerView w/ GridLayoutManager
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AppBarLayout & CoordinatorLayout
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NestedScrollingParent
NestedScrollingChild
→ boolean onStartNestedScroll(child, target, axes) → void onNestedScrollAccepted(child, target, axes) → void onStopNestedScroll(target) → void onNestedScroll(target, dxConsumed, dyConsumed, dxConsumed, dyUnconsumed) → void onNestedPreScroll(target, dx, dy, consumed) → boolean onNestedFling(target, velocityX, velocityY, consumed) → boolean onNestedPreFling(target, velocityX, velocityY)
→ void setNestedScrollingEnabled(enabled) → boolean isNestedScrollingEnabled() → startNestedScroll(axes) → stopNestedScroll() → hasNestedScrollingParent() → dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed,
dyUnconsumed, offsetInWindow) → dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow) → dispatchNestedFling(velocityX, velocityY, consumed) → dispatchBestedPreFling(velocityX, velocityY)
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ParentScrollView RedView ChildScrollView
BlueView WhiteView BlueView WhiteView
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How to pass a fling from one view to another?
→Need to find velocity of the fling at the point at which there is no more of the child to be scrolled, record that as the initial velocity for the a VelocityTracker in the parent and initiate a new fling.
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Did I really search hard enough for alternative solutions? What about open source?
→me.henrytao.smoothappbarlayoutdemo →ksoichiro/Android-ObservableScrollView
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Tracking the scrollY of a RecyclerView is error-prone
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How do these libraries actually work under the hood?
Why are there not two Scrollable elements?
Incredibly relevant quote from the great Nolan Brothers Film The Prestige:
“Now you're looking for the secret. But you won't find it because of course, you're not really looking. You don't really want to work it out. You
want to be fooled.”
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11 JAN 2016 BRENDAN WEINSTEIN (VSCO)
BRENDANW@VSCO.CO