Fixed
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jg...@google.com
Hi, thanks for reporting. Should be an easy fix!
I'm guessing it should work find until ~ 2^23 items = ~ 8M items. How did you come across this bug? Do you have a ViewPager2 with that many items?
I'm guessing it should work find until ~ 2^23 items = ~ 8M items. How did you come across this bug? Do you have a ViewPager2 with that many items?
da...@gmail.com
Hi, good to hear that.
We have an implementation of RecyclerView.Adapter that supports "infinite looping". So when the infinite looping is enabled, the adapter's getItemCount() reports Int.MAX_VALUE items. We also call setCurrentItem to somewhere in the middle of item count on the ViewPager2, so that's how we got that far.
We have an implementation of RecyclerView.Adapter that supports "infinite looping". So when the infinite looping is enabled, the adapter's getItemCount() reports Int.MAX_VALUE items. We also call setCurrentItem to somewhere in the middle of item count on the ViewPager2, so that's how we got that far.
je...@google.com
For future reference: first item for which it fails is probably when mCurrentItem = (1 << 25) + 2
je...@google.com
jg...@google.com
je...@google.com
ap...@google.com
Project: platform/frameworks/support
Branch: androidx-master-dev
commit 2e9f35536432bed0677171c8ae59b4f67850915a
Author: Jelle Fresen <jellefresen@google.com>
Date: Fri Jul 12 14:26:10 2019
Use double instead of float for decimal positions
A position ranges from 0 to Integer.MAX_VALUE, but floats only have a 23
bit mantissa. Values over 2^23 are rounded to a nearby value.
Solve this by using double instead of float when we need to represent a
position with a fractional component. A double has a mantissa of 52 bit
and can therefore represent all 2^32 possible int values.
Bug: 134858960
Test: ./gradlew viewpager2:cC
Change-Id: I08b97df6fac600caa83366ccab8671541e2c1e7f
A viewpager2/src/androidTest/java/androidx/viewpager2/test/ui/SparseAdapter.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/FakeDragTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/OffscreenPageLimitTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/PageChangeCallbackTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/PageTransformerTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/SetItemWhileScrollInProgressTest.kt
M viewpager2/src/main/java/androidx/viewpager2/widget/ScrollEventAdapter.java
M viewpager2/src/main/java/androidx/viewpager2/widget/ViewPager2.java
https://android-review.googlesource.com/1014538
https://goto.google.com/android-sha1/2e9f35536432bed0677171c8ae59b4f67850915a
Branch: androidx-master-dev
commit 2e9f35536432bed0677171c8ae59b4f67850915a
Author: Jelle Fresen <jellefresen@google.com>
Date: Fri Jul 12 14:26:10 2019
Use double instead of float for decimal positions
A position ranges from 0 to Integer.MAX_VALUE, but floats only have a 23
bit mantissa. Values over 2^23 are rounded to a nearby value.
Solve this by using double instead of float when we need to represent a
position with a fractional component. A double has a mantissa of 52 bit
and can therefore represent all 2^32 possible int values.
Bug: 134858960
Test: ./gradlew viewpager2:cC
Change-Id: I08b97df6fac600caa83366ccab8671541e2c1e7f
A viewpager2/src/androidTest/java/androidx/viewpager2/test/ui/SparseAdapter.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/FakeDragTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/OffscreenPageLimitTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/PageChangeCallbackTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/PageTransformerTest.kt
M viewpager2/src/androidTest/java/androidx/viewpager2/widget/SetItemWhileScrollInProgressTest.kt
M viewpager2/src/main/java/androidx/viewpager2/widget/ScrollEventAdapter.java
M viewpager2/src/main/java/androidx/viewpager2/widget/ViewPager2.java
Description
Issue found when `mCurrentItem` value is 1073742144. The result of `Math.abs(item - previousItem)` is 128 instead of 1, when the item we scroll to is 1073742145. This makes the ViewPager "pre-jump to nearby item for long jumps".