content: /*
   * Copyright (C) 2006 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 android.widget;
  
  
  import android.content.Context;
  import android.util.AttributeSet;
  import android.view.View;
  import android.view.ViewGroup;
  
  /**
   * Specialized {@link android.widget.ViewSwitcher} that contains
   * only children of type {@link android.widget.TextView}.
   *
   * A TextSwitcher is useful to animate a label on screen. Whenever
   * {@link #setText(CharSequence)} is called, TextSwitcher animates the current text
   * out and animates the new text in. 
   */
  public class TextSwitcher extends ViewSwitcher {
      /**
       * Creates a new empty TextSwitcher.
       *
       * @param context the application's environment
       */
      public TextSwitcher(Context context) {
          super(context);
      }
  
      /**
       * Creates a new empty TextSwitcher for the given context and with the
       * specified set attributes.
       *
       * @param context the application environment
       * @param attrs a collection of attributes
       */
      public TextSwitcher(Context context, AttributeSet attrs) {
          super(context, attrs);
      }
  
      /**
       * {@inheritDoc}
       *
       * @throws IllegalArgumentException if child is not an instance of
       *         {@link android.widget.TextView}
       */
      @Override
      public void addView(View child, int index, ViewGroup.LayoutParams params) {
          if (!(child instanceof TextView)) {
              throw new IllegalArgumentException(
                      "TextSwitcher children must be instances of TextView");
          }
  
          super.addView(child, index, params);
      }
  
      /**
       * Sets the text of the next view and switches to the next view. This can
       * be used to animate the old text out and animate the next text in.
       *
       * @param text the new text to display
       */
      public void setText(CharSequence text) {
          final TextView t = (TextView) getNextView();
          t.setText(text);
          showNext();
      }
  
      /**
       * Sets the text of the text view that is currently showing.  This does
       * not perform the animations.
       *
       * @param text the new text to display
       */
      public void setCurrentText(CharSequence text) {
          ((TextView)getCurrentView()).setText(text);
      }
  
      @Override
      public CharSequence getAccessibilityClassName() {
          return TextSwitcher.class.getName();
      }
  }
  