LceAnimator.java

/*
 * Copyright 2015 Hannes Dorfmann.
 *
 * 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 com.hannesdorfmann.mosby3.mvp.lce;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.content.res.Resources;
import android.support.annotation.NonNull;
import android.view.View;
import com.hannesdorfmann.mosby3.mvp.lce.R;

/**
 * Little helper class for animating content, error and loading view
 *
 * @author Hannes Dorfmann
 * @since 1.0.0
 */
public class LceAnimator {

  private LceAnimator() {}

  /**
   * Show the loading view. No animations, because sometimes loading things is pretty fast (i.e.
   * retrieve data from memory cache).
   */
  public static void showLoading(@NonNull View loadingView, @NonNull View contentView,
      @NonNull View errorView) {

    contentView.setVisibility(View.GONE);
    errorView.setVisibility(View.GONE);
    loadingView.setVisibility(View.VISIBLE);
  }

  /**
   * Shows the error view instead of the loading view
   */
  public static void showErrorView(@NonNull final View loadingView, @NonNull final View contentView,
      final View errorView) {

    contentView.setVisibility(View.GONE);

    final Resources resources = loadingView.getResources();
    // Not visible yet, so animate the view in
    AnimatorSet set = new AnimatorSet();
    ObjectAnimator in = ObjectAnimator.ofFloat(errorView, View.ALPHA, 1f);
    ObjectAnimator loadingOut = ObjectAnimator.ofFloat(loadingView,  View.ALPHA, 0f);

    set.playTogether(in, loadingOut);
    set.setDuration(resources.getInteger(R.integer.lce_error_view_show_animation_time));

    set.addListener(new AnimatorListenerAdapter() {

      @Override public void onAnimationStart(Animator animation) {
        super.onAnimationStart(animation);
        errorView.setVisibility(View.VISIBLE);
      }

      @Override public void onAnimationEnd(Animator animation) {
        super.onAnimationEnd(animation);
        loadingView.setVisibility(View.GONE);
        loadingView.setAlpha(1f); // For future showLoading calls
      }
    });

    set.start();
  }

  /**
   * Display the content instead of the loadingView
   */
  public static void showContent(@NonNull final View loadingView, @NonNull final View contentView,
      @NonNull final View errorView) {

    if (contentView.getVisibility() == View.VISIBLE) {
      // No Changing needed, because contentView is already visible
      errorView.setVisibility(View.GONE);
      loadingView.setVisibility(View.GONE);
    } else {

      errorView.setVisibility(View.GONE);

      final Resources resources = loadingView.getResources();
      final int translateInPixels = resources.getDimensionPixelSize(R.dimen.lce_content_view_animation_translate_y);
      // Not visible yet, so animate the view in
      AnimatorSet set = new AnimatorSet();
      ObjectAnimator contentFadeIn = ObjectAnimator.ofFloat(contentView, View.ALPHA, 0f, 1f);
      ObjectAnimator contentTranslateIn = ObjectAnimator.ofFloat(contentView, View.TRANSLATION_Y,
              translateInPixels, 0);

      ObjectAnimator loadingFadeOut = ObjectAnimator.ofFloat(loadingView, View.ALPHA, 1f, 0f);
      ObjectAnimator loadingTranslateOut = ObjectAnimator.ofFloat(loadingView, View.TRANSLATION_Y, 0,
              -translateInPixels);

      set.playTogether(contentFadeIn, contentTranslateIn, loadingFadeOut, loadingTranslateOut);
      set.setDuration(resources.getInteger(R.integer.lce_content_view_show_animation_time));

      set.addListener(new AnimatorListenerAdapter() {

        @Override public void onAnimationStart(Animator animation) {
          contentView.setTranslationY(0);
          loadingView.setTranslationY(0);
          contentView.setVisibility(View.VISIBLE);
        }

        @Override public void onAnimationEnd(Animator animation) {
          loadingView.setVisibility(View.GONE);
          loadingView.setAlpha(1f); // For future showLoading calls
          contentView.setTranslationY(0);
          loadingView.setTranslationY(0);
        }
      });

      set.start();
    }
  }
}