content: /*
   * Copyright (C) 2014 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.transition;
  
  import android.view.View;
  
  /**
   * Base class for <code>TransitionPropagation</code>s that care about
   * View Visibility and the center position of the View.
   */
  public abstract class VisibilityPropagation extends TransitionPropagation {
  
      /**
       * The property key used for {@link android.view.View#getVisibility()}.
       */
      private static final String PROPNAME_VISIBILITY = "android:visibilityPropagation:visibility";
  
      /**
       * The property key used for the center of the View in screen coordinates. This is an
       * int[2] with the index 0 taking the x coordinate and index 1 taking the y coordinate.
       */
      private static final String PROPNAME_VIEW_CENTER = "android:visibilityPropagation:center";
  
      private static final String[] VISIBILITY_PROPAGATION_VALUES = {
              PROPNAME_VISIBILITY,
              PROPNAME_VIEW_CENTER,
      };
  
      @Override
      public void captureValues(TransitionValues values) {
          View view = values.view;
          Integer visibility = (Integer) values.values.get(Visibility.PROPNAME_VISIBILITY);
          if (visibility == null) {
              visibility = view.getVisibility();
          }
          values.values.put(PROPNAME_VISIBILITY, visibility);
          int[] loc = new int[2];
          view.getLocationOnScreen(loc);
          loc[0] += Math.round(view.getTranslationX());
          loc[0] += view.getWidth() / 2;
          loc[1] += Math.round(view.getTranslationY());
          loc[1] += view.getHeight() / 2;
          values.values.put(PROPNAME_VIEW_CENTER, loc);
      }
  
      @Override
      public String[] getPropagationProperties() {
          return VISIBILITY_PROPAGATION_VALUES;
      }
  
      /**
       * Returns {@link android.view.View#getVisibility()} for the View at the time the values
       * were captured.
       * @param values The TransitionValues captured at the start or end of the Transition.
       * @return {@link android.view.View#getVisibility()} for the View at the time the values
       * were captured.
       */
      public int getViewVisibility(TransitionValues values) {
          if (values == null) {
              return View.GONE;
          }
          Integer visibility = (Integer) values.values.get(PROPNAME_VISIBILITY);
          if (visibility == null) {
              return View.GONE;
          }
          return visibility;
      }
  
      /**
       * Returns the View's center x coordinate, relative to the screen, at the time the values
       * were captured.
       * @param values The TransitionValues captured at the start or end of the Transition.
       * @return the View's center x coordinate, relative to the screen, at the time the values
       * were captured.
       */
      public int getViewX(TransitionValues values) {
          return getViewCoordinate(values, 0);
      }
  
      /**
       * Returns the View's center y coordinate, relative to the screen, at the time the values
       * were captured.
       * @param values The TransitionValues captured at the start or end of the Transition.
       * @return the View's center y coordinate, relative to the screen, at the time the values
       * were captured.
       */
      public int getViewY(TransitionValues values) {
          return getViewCoordinate(values, 1);
      }
  
      private static int getViewCoordinate(TransitionValues values, int coordinateIndex) {
          if (values == null) {
              return -1;
          }
  
          int[] coordinates = (int[]) values.values.get(PROPNAME_VIEW_CENTER);
          if (coordinates == null) {
              return -1;
          }
  
          return coordinates[coordinateIndex];
      }
  }
  