滑动关闭带RecyclerView的BottomSheet后ImageView位置偏移，疑因Snackbar

Hey GGK, let's break down this tricky position shift issue with your BottomSheet's ImageView and work through possible fixes:

You've got a BottomSheet with a peekHeight of 35px, containing a RecyclerView and a small ImageView. After triggering a close action on the RecyclerView, the ImageView jumps from 42px to 80px. The issue disappears when using a fullscreen theme, which points to a theme/layout insets-related bug. Manual attempts to reset the ImageView's position via layout params haven't worked, and you suspect Snackbar might be the culprit.

1. Fix Window Insets Interference #

Since the problem vanishes in fullscreen mode, non-fullscreen theme window insets (status/navigation bars) are likely messing with the BottomSheet's layout calculations when it closes. Try these adjustments:

• Add android:fitsSystemWindows="false" to your BottomSheet's root layout XML.
• Or handle insets manually in code to prevent them from altering the layout:

ViewCompat.setOnApplyWindowInsetsListener(bottomSheet, (view, insets) -> {
    // Ignore system insets to avoid unexpected layout shifts
    return insets.consumeSystemWindowInsets();
});

2. Adjust ImageView Position After BottomSheet Fully Closes #

Your current position reset code might be running before the BottomSheet's close animation completes, so system layout calculations overwrite your changes. Use the BottomSheet callback to trigger adjustments only after it's fully hidden:

BottomSheetBehavior<View> bottomSheetBehavior = BottomSheetBehavior.from(bottomSheet);
bottomSheetBehavior.addBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
    @Override
    public void onStateChanged(@NonNull View sheet, int newState) {
        if (newState == BottomSheetBehavior.STATE_HIDDEN) {
            // Post the adjustment to ensure it runs after layout is finalized
            sheet.post(() -> {
                ConstraintLayout.LayoutParams imageParams = (ConstraintLayout.LayoutParams) yourImageView.getLayoutParams();
                imageParams.topMargin = 42; // Set your desired fixed position
                yourImageView.setLayoutParams(imageParams);
                yourImageView.requestLayout();
            });
        }
    }

    @Override
    public void onSlide(@NonNull View sheet, float slideOffset) {}
});

3. Isolate Snackbar's Impact #

Snackbar can alter layout parameters or window settings indirectly, even when attached to different views. Try these steps:

• Dismiss the Snackbar explicitly before closing the BottomSheet:

if (snackbar != null && snackbar.isShown()) {
    snackbar.dismiss();
}
// Now trigger BottomSheet close
bottomSheetBehavior.setState(BottomSheetBehavior.STATE_HIDDEN);

• Attach the Snackbar to the root content view instead of RecyclerView/BottomSheet to minimize interference:

View rootView = findViewById(android.R.id.content);
Snackbar snackbar = Snackbar.make(rootView, "remove", Snackbar.LENGTH_SHORT);

4. Lock ImageView's Layout Constraints #

Ensure your ImageView uses fixed constraints instead of dynamic ones that might be affected by RecyclerView's state change. For example:

<ImageView
    android:id="@+id/your_image"
    ...
    app:layout_constraintTop_toTopOf="parent"
    android:layout_marginTop="42dp" />

Also, test disabling the BottomSheet's animation to rule out animation-induced layout glitches:

bottomSheetBehavior.setDisableAnimation(true);

内容的提问来源于stack exchange，提问作者GGK stands for Ukraine