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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.tv.ui;
     18 
     19 import android.animation.Animator;
     20 import android.animation.ValueAnimator;
     21 import android.util.Log;
     22 import android.view.View;
     23 import android.view.ViewGroup.LayoutParams;
     24 import java.lang.reflect.InvocationTargetException;
     25 import java.lang.reflect.Method;
     26 
     27 /** A class that includes convenience methods for view classes. */
     28 public class ViewUtils {
     29     private static final String TAG = "ViewUtils";
     30 
     31     private ViewUtils() {
     32         // Prevent instantiation.
     33     }
     34 
     35     public static void setTransitionAlpha(View v, float alpha) {
     36         Method method;
     37         try {
     38             method = View.class.getDeclaredMethod("setTransitionAlpha", Float.TYPE);
     39             method.invoke(v, alpha);
     40         } catch (NoSuchMethodException
     41                 | IllegalAccessException
     42                 | IllegalArgumentException
     43                 | InvocationTargetException e) {
     44             Log.e(TAG, "Fail to call View.setTransitionAlpha", e);
     45         }
     46     }
     47 
     48     /**
     49      * Creates an animator in view's height
     50      *
     51      * @param target the {@link view} animator performs on.
     52      */
     53     public static Animator createHeightAnimator(
     54             final View target, int initialHeight, int targetHeight) {
     55         ValueAnimator animator = ValueAnimator.ofInt(initialHeight, targetHeight);
     56         animator.addUpdateListener(
     57                 new ValueAnimator.AnimatorUpdateListener() {
     58                     @Override
     59                     public void onAnimationUpdate(ValueAnimator animation) {
     60                         int value = (Integer) animation.getAnimatedValue();
     61                         if (value == 0) {
     62                             if (target.getVisibility() != View.GONE) {
     63                                 target.setVisibility(View.GONE);
     64                             }
     65                         } else {
     66                             if (target.getVisibility() != View.VISIBLE) {
     67                                 target.setVisibility(View.VISIBLE);
     68                             }
     69                             setLayoutHeight(target, value);
     70                         }
     71                     }
     72                 });
     73         return animator;
     74     }
     75 
     76     /** Gets view's layout height. */
     77     public static int getLayoutHeight(View view) {
     78         LayoutParams layoutParams = view.getLayoutParams();
     79         return layoutParams.height;
     80     }
     81 
     82     /** Sets view's layout height. */
     83     public static void setLayoutHeight(View view, int height) {
     84         LayoutParams layoutParams = view.getLayoutParams();
     85         if (height != layoutParams.height) {
     86             layoutParams.height = height;
     87             view.setLayoutParams(layoutParams);
     88         }
     89     }
     90 }
     91