Fix bug 3413800 - Revise AutoCompleteTextView dropdown behavior

Be more conservative with when we let an AutoCompleteTextView's
dropdown box of completion suggestions cover the IME.

Disable the expand-when-touched behavior of the dropdown list when
more than 3 items can be seen at a time without it.

Don't let a ListPopupWindow that is expanding in response to touch
scroll the anchor view within its parent and slide the dropdown out
from under the user's finger.

Change-Id: I009accfd4e841c9a5e1072735d8a0b067a0bc06a

core/java/android/widget/AutoCompleteTextView.java

@@ -92,6 +92,8 @@ public class AutoCompleteTextView extends EditText implements Filter.FilterListe
     static final boolean DEBUG = false;
     static final String TAG = "AutoCompleteTextView";
 
+    static final int EXPAND_MAX = 3;
+
     private CharSequence mHintText;
     private TextView mHintView;
     private int mHintResource;
@@ -1057,8 +1059,10 @@ public class AutoCompleteTextView extends EditText implements Filter.FilterListe
         if (!isPopupShowing()) {
             // Make sure the list does not obscure the IME when shown for the first time.
             mPopup.setInputMethodMode(ListPopupWindow.INPUT_METHOD_NEEDED);
+            mPopup.setListItemExpandMax(EXPAND_MAX);
         }
         mPopup.show();
+        mPopup.getListView().setOverScrollMode(View.OVER_SCROLL_ALWAYS);
     }
     
     /**

core/java/android/widget/ListPopupWindow.java

@@ -65,6 +65,7 @@ public class ListPopupWindow {
 
     private boolean mDropDownAlwaysVisible = false;
     private boolean mForceIgnoreOutsideTouch = false;
+    int mListItemExpandMaximum = Integer.MAX_VALUE;
 
     private View mPromptView;
     private int mPromptPosition = POSITION_PROMPT_ABOVE;
@@ -519,6 +520,7 @@ public class ListPopupWindow {
         int heightSpec = 0;
 
         boolean noInputMethod = isInputMethodNotNeeded();
+        mPopup.setAllowScrollingAnchorParent(!noInputMethod);
 
         if (mPopup.isShowing()) {
             if (mDropDownWidth == ViewGroup.LayoutParams.MATCH_PARENT) {
@@ -774,6 +776,16 @@ public class ListPopupWindow {
         return mDropDownList;
     }
 
+    /**
+     * The maximum number of list items that can be visible and still have
+     * the list expand when touched.
+     *
+     * @param max Max number of items that can be visible and still allow the list to expand.
+     */
+    void setListItemExpandMax(int max) {
+        mListItemExpandMaximum = max;
+    }
+
     /**
      * Filter key down events. By forwarding key down events to this function,
      * views using non-modal ListPopupWindow can have it handle key selection of items.
@@ -1210,8 +1222,11 @@ public class ListPopupWindow {
 
     private class ResizePopupRunnable implements Runnable {
         public void run() {
-            mPopup.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
-            show();
+            if (mDropDownList != null && mDropDownList.getCount() > mDropDownList.getChildCount() &&
+                    mDropDownList.getChildCount() <= mListItemExpandMaximum) {
+                mPopup.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
+                show();
+            }
         }
     }
 

core/java/android/widget/PopupWindow.java

@@ -90,6 +90,7 @@ public class PopupWindow {
     private int mSplitTouchEnabled = -1;
     private boolean mLayoutInScreen;
     private boolean mClipToScreen;
+    private boolean mAllowScrollingAnchorParent = true;
 
     private OnTouchListener mTouchInterceptor;
     
@@ -592,6 +593,16 @@ public class PopupWindow {
         mClipToScreen = enabled;
         setClippingEnabled(!enabled);
     }
+
+    /**
+     * Allow PopupWindow to scroll the anchor's parent to provide more room
+     * for the popup. Enabled by default.
+     *
+     * @param enabled True to scroll the anchor's parent when more room is desired by the popup.
+     */
+    void setAllowScrollingAnchorParent(boolean enabled) {
+        mAllowScrollingAnchorParent = enabled;
+    }
     
     /**
      * <p>Indicates whether the popup window supports splitting touches.</p>
@@ -1045,7 +1056,8 @@ public class PopupWindow {
         anchor.getWindowVisibleDisplayFrame(displayFrame);
         
         final View root = anchor.getRootView();
-        if (p.y + mPopupHeight > displayFrame.bottom || p.x + mPopupWidth - root.getWidth() > 0) {
+        if (mAllowScrollingAnchorParent && (p.y + mPopupHeight > displayFrame.bottom ||
+                p.x + mPopupWidth - root.getWidth() > 0)) {
             // if the drop down disappears at the bottom of the screen. we try to
             // scroll a parent scrollview or move the drop down back up on top of
             // the edit box