From 9bf3c128509de5bd66222943a00acfcd1000cd62 Mon Sep 17 00:00:00 2001
From: Adam Powell <adamp@google.com>
Date: Fri, 26 Feb 2010 11:32:07 -0800
Subject: [PATCH] ListView now tries to keep the position containing focused
 child views on-screen.

---
 core/java/android/widget/AbsListView.java |  5 ++++
 core/java/android/widget/ListView.java    | 36 +++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/core/java/android/widget/AbsListView.java b/core/java/android/widget/AbsListView.java
index 23e5806ee5eda..2ea6abcad0da8 100644
--- a/core/java/android/widget/AbsListView.java
+++ b/core/java/android/widget/AbsListView.java
@@ -4017,6 +4017,10 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
          * View type for this view, as returned by
          * {@link android.widget.Adapter#getItemViewType(int) }
          */
+        @ViewDebug.ExportedProperty(mapping = {
+            @ViewDebug.IntToString(from = ITEM_VIEW_TYPE_IGNORE, to = "ITEM_VIEW_TYPE_IGNORE"),
+            @ViewDebug.IntToString(from = ITEM_VIEW_TYPE_HEADER_OR_FOOTER, to = "ITEM_VIEW_TYPE_HEADER_OR_FOOTER")
+        })
         int viewType;
 
         /**
@@ -4025,6 +4029,7 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
          * been added to the list view and whether they should be treated as
          * recycled views or not.
          */
+        @ViewDebug.ExportedProperty
         boolean recycledHeaderFooter;
 
         public LayoutParams(Context c, AttributeSet attrs) {
diff --git a/core/java/android/widget/ListView.java b/core/java/android/widget/ListView.java
index 912dd5e0ab84f..7f77fa9b75009 100644
--- a/core/java/android/widget/ListView.java
+++ b/core/java/android/widget/ListView.java
@@ -140,6 +140,9 @@ public class ListView extends AbsListView {
     // allocating these thingies too often.
     private final ArrowScrollFocusResult mArrowScrollFocusResult = new ArrowScrollFocusResult();
 
+    // Keeps focused children visible through resizes
+    private FocusSelector mFocusSelector;
+    
     public ListView(Context context) {
         this(context, null);
     }
@@ -1017,6 +1020,39 @@ public class ListView extends AbsListView {
         return sel;
     }
 
+    private class FocusSelector implements Runnable {
+        private int mPosition;
+        private int mPositionTop;
+        
+        public FocusSelector setup(int position, int top) {
+            mPosition = position;
+            mPositionTop = top;
+            return this;
+        }
+        
+        public void run() {
+            setSelectionFromTop(mPosition, mPositionTop);
+        }
+    }
+    
+    @Override
+    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+        if (getChildCount() > 0) {
+            View focusedChild = getFocusedChild();
+            if (focusedChild != null) {
+                final int childPosition = mFirstPosition + indexOfChild(focusedChild);
+                final int childBottom = focusedChild.getBottom();
+                final int offset = Math.max(0, childBottom - (h - mPaddingTop));
+                final int top = focusedChild.getTop() - offset;
+                if (mFocusSelector == null) {
+                    mFocusSelector = new FocusSelector();
+                }
+                post(mFocusSelector.setup(childPosition, top));
+            }
+        }
+        super.onSizeChanged(w, h, oldw, oldh);
+    }
+
     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         // Sets up mListPadding