Use LayoutManager.onLayoutCompleted as a signal that content has changed
onChildAttachedToWindow is called before the layout manager is finished
processing the layout, so incorrect measurements / intermediate
animation states can be present.
onLayoutCompleted occurs after each full layout calculation, including
measuring multiple views or animating, and is a better signal to use.
Fix: 190391539
Test: verified locally with search use case and other expand collapse
cases
Change-Id: If01caf33c6c3371636895e1361d80de536363239
diff --git a/src/com/android/launcher3/widget/picker/WidgetsListLayoutManager.java b/src/com/android/launcher3/widget/picker/WidgetsListLayoutManager.java
new file mode 100644
index 0000000..2b7f544
--- /dev/null
+++ b/src/com/android/launcher3/widget/picker/WidgetsListLayoutManager.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.launcher3.widget.picker;
+
+import android.content.Context;
+
+import androidx.annotation.Nullable;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.android.launcher3.widget.picker.SearchAndRecommendationsScrollController.OnContentChangeListener;
+
+/**
+ * A layout manager for the {@link WidgetsRecyclerView}.
+ *
+ * {@link #setOnContentChangeListener(OnContentChangeListener)} can be used to register a callback
+ * for when the content of the layout manager has changed, following measurement and animation.
+ */
+public final class WidgetsListLayoutManager extends LinearLayoutManager {
+ @Nullable
+ private OnContentChangeListener mOnContentChangeListener;
+
+ public WidgetsListLayoutManager(Context context) {
+ super(context);
+ }
+
+ @Override
+ public void onLayoutCompleted(RecyclerView.State state) {
+ super.onLayoutCompleted(state);
+ if (mOnContentChangeListener != null) {
+ mOnContentChangeListener.onContentChanged();
+ }
+ }
+
+ public void setOnContentChangeListener(@Nullable OnContentChangeListener listener) {
+ mOnContentChangeListener = listener;
+ }
+}
diff --git a/src/com/android/launcher3/widget/picker/WidgetsRecyclerView.java b/src/com/android/launcher3/widget/picker/WidgetsRecyclerView.java
index 090362b..6e10bf6 100644
--- a/src/com/android/launcher3/widget/picker/WidgetsRecyclerView.java
+++ b/src/com/android/launcher3/widget/picker/WidgetsRecyclerView.java
@@ -23,7 +23,6 @@
import android.view.View;
import android.widget.TableLayout;
-import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
@@ -78,7 +77,9 @@
super.onFinishInflate();
// create a layout manager with Launcher's context so that scroll position
// can be preserved during screen rotation.
- setLayoutManager(new LinearLayoutManager(getContext()));
+ WidgetsListLayoutManager layoutManager = new WidgetsListLayoutManager(getContext());
+ layoutManager.setOnContentChangeListener(mOnContentChangeListener);
+ setLayoutManager(layoutManager);
}
@Override
@@ -87,22 +88,6 @@
mAdapter = (WidgetsListAdapter) adapter;
}
- @Override
- public void onChildAttachedToWindow(@NonNull View child) {
- super.onChildAttachedToWindow(child);
- if (mOnContentChangeListener != null) {
- mOnContentChangeListener.onContentChanged();
- }
- }
-
- @Override
- public void onChildDetachedFromWindow(@NonNull View child) {
- super.onChildDetachedFromWindow(child);
- if (mOnContentChangeListener != null) {
- mOnContentChangeListener.onContentChanged();
- }
- }
-
/**
* Maps the touch (from 0..1) to the adapter position that should be visible.
*/
@@ -266,6 +251,10 @@
public void setOnContentChangeListener(@Nullable OnContentChangeListener listener) {
mOnContentChangeListener = listener;
+ WidgetsListLayoutManager layoutManager = (WidgetsListLayoutManager) getLayoutManager();
+ if (layoutManager != null) {
+ layoutManager.setOnContentChangeListener(listener);
+ }
}
/**