Revamp of the NumberPicker widget.

1. The number picker no longer shows up and down arrows, it
   has only three touch targets which are the currently selected number
   in the middle with a lesser one above and greater below, now what
   you touch is what you get, flingability and long press are still
   supported.

2. Removed the restriction for a View with an AccessibilityNodeProvider
   to not have any concrete children. If the View has a provider, then
   this provider is responsible for creating the AccessibilityNodeInfos
   for all its descendants, concrete and virtual. The number picker is
   a good example for such a case - it has a concrete input view and
   two virtual buttons as its children. This is a safe change since
   this behavior has not been released.

3. This patch also fixes bug where the number picker is stretched too
   much in the Theme theme.

bug:6177794
bug:5728294

Change-Id: Id8c0b3549174b9599f971d6e3086ca427cfbaa39

Author: sganov

api/current.txt

@@ -26924,7 +26924,6 @@ package android.widget {
     method public void setOnValueChangedListener(android.widget.NumberPicker.OnValueChangeListener);
     method public void setValue(int);
     method public void setWrapSelectorWheel(boolean);
-    field public static final int SELECTOR_WHEEL_ITEM_COUNT = 5; // 0x5
   }
 
   public static abstract interface NumberPicker.Formatter {

core/java/android/view/ViewGroup.java

@@ -2679,15 +2679,6 @@ protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
         return child.draw(canvas, this, drawingTime);
     }
 
-    @Override
-    public void requestLayout() {
-        if (mChildrenCount > 0 && getAccessibilityNodeProvider() != null) {
-            throw new IllegalStateException("Views with AccessibilityNodeProvider"
-                    + " can't have children.");
-        }
-        super.requestLayout();
-    }
-
     /**
      * 
      * @param enabled True if children should be drawn with layers, false otherwise.
@@ -3109,11 +3100,6 @@ protected void cleanupLayoutState(View child) {
     private void addViewInner(View child, int index, LayoutParams params,
             boolean preventRequestLayout) {
 
-        if (getAccessibilityNodeProvider() != null) {
-            throw new IllegalStateException("Views with AccessibilityNodeProvider"
-                    + " can't have children.");
-        }
-
         if (mTransition != null) {
             // Don't prevent other add transitions from completing, but cancel remove
             // transitions to let them complete the process before we add to the container

core/java/android/widget/DatePicker.java

@@ -29,8 +29,8 @@
 import android.util.Log;
 import android.util.SparseArray;
 import android.view.LayoutInflater;
+import android.view.View;
 import android.view.accessibility.AccessibilityEvent;
-import android.view.accessibility.AccessibilityManager;
 import android.view.accessibility.AccessibilityNodeInfo;
 import android.view.inputmethod.EditorInfo;
 import android.view.inputmethod.InputMethodManager;
@@ -280,9 +280,7 @@ public void onSelectedDayChange(CalendarView view, int year, int month, int mont
         reorderSpinners();
 
         // set content descriptions
-        if (AccessibilityManager.getInstance(mContext).isEnabled()) {
-            setContentDescriptions();
-        }
+        setContentDescriptions();
     }
 
     /**
@@ -717,20 +715,27 @@ private void setImeOptions(NumberPicker spinner, int spinnerCount, int spinnerIn
 
     private void setContentDescriptions() {
         // Day
-        String text = mContext.getString(R.string.date_picker_increment_day_button);
-        mDaySpinner.findViewById(R.id.increment).setContentDescription(text);
-        text = mContext.getString(R.string.date_picker_decrement_day_button);
-        mDaySpinner.findViewById(R.id.decrement).setContentDescription(text);
+        trySetContentDescription(mDaySpinner, R.id.increment,
+                R.string.date_picker_increment_day_button);
+        trySetContentDescription(mDaySpinner, R.id.decrement,
+                R.string.date_picker_decrement_day_button);
         // Month
-        text = mContext.getString(R.string.date_picker_increment_month_button);
-        mMonthSpinner.findViewById(R.id.increment).setContentDescription(text);
-        text = mContext.getString(R.string.date_picker_decrement_month_button);
-        mMonthSpinner.findViewById(R.id.decrement).setContentDescription(text);
+        trySetContentDescription(mMonthSpinner, R.id.increment,
+                R.string.date_picker_increment_month_button);
+        trySetContentDescription(mMonthSpinner, R.id.decrement,
+                R.string.date_picker_decrement_month_button);
         // Year
-        text = mContext.getString(R.string.date_picker_increment_year_button);
-        mYearSpinner.findViewById(R.id.increment).setContentDescription(text);
-        text = mContext.getString(R.string.date_picker_decrement_year_button);
-        mYearSpinner.findViewById(R.id.decrement).setContentDescription(text);
+        trySetContentDescription(mYearSpinner, R.id.increment,
+                R.string.date_picker_increment_year_button);
+        trySetContentDescription(mYearSpinner, R.id.decrement,
+                R.string.date_picker_decrement_year_button);
+    }
+
+    private void trySetContentDescription(View root, int viewId, int contDescResId) {
+        View target = root.findViewById(viewId);
+        if (target != null) {
+            target.setContentDescription(mContext.getString(contDescResId));
+        }
     }
 
     private void updateInputState() {