Added attribute queryAfterZeroResults to searchables.

As of now we are just reading it from the xml and not acting upon it, that would come in a subsequent change.

core/java/android/server/search/SearchableInfo.java

@@ -66,6 +66,7 @@ public final class SearchableInfo implements Parcelable {
     private final int mSearchInputType;
     private final int mSearchImeOptions;
     private final boolean mIncludeInGlobalSearch;
+    private final boolean mQueryAfterZeroResults;
     private final String mSuggestAuthority;
     private final String mSuggestPath;
     private final String mSuggestSelection;
@@ -276,6 +277,8 @@ public final class SearchableInfo implements Parcelable {
                 EditorInfo.IME_ACTION_SEARCH);
         mIncludeInGlobalSearch = a.getBoolean(
                 com.android.internal.R.styleable.Searchable_includeInGlobalSearch, false);
+        mQueryAfterZeroResults = a.getBoolean(
+                com.android.internal.R.styleable.Searchable_queryAfterZeroResults, false);
 
         mSuggestAuthority = a.getString(
                 com.android.internal.R.styleable.Searchable_searchSuggestAuthority);
@@ -636,6 +639,17 @@ public final class SearchableInfo implements Parcelable {
         return mIncludeInGlobalSearch;
     }
 
+    /**
+     * Checks whether this searchable activity should be invoked after a query returned zero
+     * results.
+     *
+     * @return The value of the <code>queryAfterZeroResults</code> attribute,
+     *         or <code>false</code> if the attribute is not set.
+     */
+    public boolean queryAfterZeroResults() {
+        return mQueryAfterZeroResults;
+    }
+
     /**
      * Support for parcelable and aidl operations.
      */
@@ -667,6 +681,7 @@ public final class SearchableInfo implements Parcelable {
         mSearchInputType = in.readInt();
         mSearchImeOptions = in.readInt();
         mIncludeInGlobalSearch = in.readInt() != 0;
+        mQueryAfterZeroResults = in.readInt() != 0;
 
         mSuggestAuthority = in.readString();
         mSuggestPath = in.readString();
@@ -702,6 +717,7 @@ public final class SearchableInfo implements Parcelable {
         dest.writeInt(mSearchInputType);
         dest.writeInt(mSearchImeOptions);
         dest.writeInt(mIncludeInGlobalSearch ? 1 : 0);
+        dest.writeInt(mQueryAfterZeroResults ? 1 : 0);
         
         dest.writeString(mSuggestAuthority);
         dest.writeString(mSuggestPath);

core/res/res/values/attrs.xml

@@ -2849,6 +2849,14 @@
              The default value is <code>false</code>. <i>Optional attribute.</i>. -->
         <attr name="includeInGlobalSearch" format="boolean" />
 
+        <!-- If provided and <code>true</code>, this searchable activity will be invoked for all
+             queries in a particular session. If set to <code>false</code> and the activity
+             returned zero results for a query, it will not be invoked again in that session for
+             supersets of that zero-results query. For example, if the activity returned zero
+             results for "bo", it would not be queried again for "bob".
+             The default value is <code>false</code>. <i>Optional attribute.</i>. -->
+        <attr name="queryAfterZeroResults" format="boolean" />
+
     </declare-styleable>
 
     <!-- In order to process special action keys during search, you must define them using