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      1 /*
      2  * Copyright (C) 2010 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.email.activity;
     18 
     19 import android.animation.Animator;
     20 import android.animation.ObjectAnimator;
     21 import android.animation.PropertyValuesHolder;
     22 import android.animation.TimeInterpolator;
     23 import android.content.Context;
     24 import android.view.ViewGroup;
     25 import android.view.animation.DecelerateInterpolator;
     26 import android.widget.TextView;
     27 
     28 /**
     29  * Class to hide/show a banner.
     30  */
     31 public class BannerController {
     32     private static final int ANIMATION_DURATION = 100;
     33     private static final TimeInterpolator INTERPOLATOR = new DecelerateInterpolator(1.5f);
     34 
     35     private final TextView mBannerView;
     36     private final int mBannerHeight;
     37 
     38     private boolean mShown;
     39 
     40     /** Hold last animator to cancel. */
     41     private Animator mLastAnimator;
     42 
     43     public BannerController(Context context, TextView bannerView, int bannerHeight) {
     44         mBannerView = bannerView;
     45         mBannerHeight = bannerHeight;
     46 
     47         setBannerYAnim(-mBannerHeight); // hide by default.
     48     }
     49 
     50     /**
     51      * @return the current y position of the banner.
     52      */
     53     private int getBannerY() {
     54         return ((ViewGroup.MarginLayoutParams) mBannerView.getLayoutParams()).topMargin;
     55     }
     56 
     57     private static final String PROP_SET_BANNER_Y = "bannerYAnim";
     58 
     59     /**
     60      * Set the Y position of the banner.  public, but should only be used by animators.
     61      */
     62     public void setBannerYAnim(int y) {
     63         ((ViewGroup.MarginLayoutParams) mBannerView.getLayoutParams()).topMargin = y;
     64         mBannerView.requestLayout();
     65     }
     66 
     67     /**
     68      * Show a banner with a message.
     69      *
     70      * @return false if a banner is already shown, in which case the message won't be updated.
     71      */
     72     public boolean show(String message) {
     73         if (mShown) {
     74             return false; // If already shown, don't change the message, to avoid flicker.
     75         }
     76         mShown = true;
     77         mBannerView.setText(message);
     78         slideBanner(0);
     79         return true;
     80     }
     81 
     82     /**
     83      * Dismiss a banner.
     84      */
     85     public void dismiss() {
     86         if (!mShown) {
     87             return; // Always hidden, or hiding.
     88         }
     89         mShown = false;
     90         slideBanner(-mBannerHeight); // Slide up to hide.
     91     }
     92 
     93     private void slideBanner(int toY) {
     94         if (mLastAnimator != null) {
     95             mLastAnimator.cancel();
     96         }
     97 
     98         final PropertyValuesHolder[] values = {
     99                 PropertyValuesHolder.ofInt(PROP_SET_BANNER_Y, getBannerY(), toY) };
    100         final ObjectAnimator animator = ObjectAnimator.ofPropertyValuesHolder(
    101                 this, values).setDuration(ANIMATION_DURATION);
    102         animator.setInterpolator(INTERPOLATOR);
    103         mLastAnimator = animator;
    104         animator.start();
    105     }
    106 }
    107