Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[Android][Flatlist] Fix last item removal scroll position #28977

Closed
wants to merge 1 commit into from
+50 −1
Closed

[Android][Flatlist] Fix last item removal scroll position #28977

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
51 changes: 50 additions & 1 deletion ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.HorizontalScrollView;
import android.widget.OverScroller;
import androidx.annotation.Nullable;
Expand All @@ -48,7 +49,8 @@

/** Similar to {@link ReactScrollView} but only supports horizontal scrolling. */
public class ReactHorizontalScrollView extends HorizontalScrollView
implements ReactClippingViewGroup {
implements ReactClippingViewGroup, ViewGroup.OnHierarchyChangeListener,
View.OnLayoutChangeListener {

private static @Nullable Field sScrollerField;
private static boolean sTriedToGetScrollerField = false;
Expand Down Expand Up @@ -81,6 +83,7 @@ public class ReactHorizontalScrollView extends HorizontalScrollView
private @Nullable List<Integer> mSnapOffsets;
private boolean mSnapToStart = true;
private boolean mSnapToEnd = true;
private View mContentView;
private ReactViewBackgroundManager mReactBackgroundManager;
private boolean mPagedArrowScrolling = false;
private int pendingContentOffsetX = UNSET_CONTENT_OFFSET;
Expand All @@ -106,6 +109,7 @@ public ReactHorizontalScrollView(Context context, @Nullable FpsListener fpsListe
mFpsListener = fpsListener;

mScroller = getOverScrollerFromParent();
setOnHierarchyChangeListener(this);
}

@Nullable
Expand Down Expand Up @@ -568,6 +572,51 @@ protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolea
super.onOverScrolled(scrollX, scrollY, clampedX, clampedY);
}

private int getMaxScrollX() {
int contentWidth = mContentView.getWidth();
int viewportWidth = getWidth() - getPaddingLeft() - getPaddingRight();
return Math.max(0, contentWidth - viewportWidth);
}

@Override
public void onChildViewAdded(View parent, View child) {
mContentView = child;
mContentView.addOnLayoutChangeListener(this);
}

@Override
public void onChildViewRemoved(View parent, View child) {
mContentView.removeOnLayoutChangeListener(this);
mContentView = null;
}

/**
* Called when a mContentView's layout has changed. Fixes the scroll position if it's too large
* after the content resizes. Without this, the user would see a blank ScrollView when the scroll
* position is larger than the ScrollView's max scroll position after the content shrinks.
*/
@Override
public void onLayoutChange(
View v,
int left,
int top,
int right,
int bottom,
int oldLeft,
int oldTop,
int oldRight,
int oldBottom) {
if (mContentView == null) {
return;
}

int currentScrollX = getScrollX();
int maxScrollX = getMaxScrollX();
if (currentScrollX > maxScrollX) {
scrollTo(maxScrollX, getScrollY());
}
}

private void enableFpsListener() {
if (isScrollPerfLoggingEnabled()) {
Assertions.assertNotNull(mFpsListener);
Expand Down