1 /** 2 * Copyright (c) 2011, Google Inc. 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 package com.android.mail; 17 18 import android.content.Context; 19 import android.os.Handler; 20 import android.util.AttributeSet; 21 import android.view.View; 22 import android.widget.ProgressBar; 23 24 /** 25 * MinTimeProgressView implements a ProgressBar that waits MIN_DELAY ms to be 26 * dismissed before showing. Once visible, the progress bar will be visible for 27 * at least MIN_SHOW_TIME to avoid "flashes" in the UI when an event could take 28 * a largely variable time to complete (from none, to a user perceivable amount) 29 * 30 * @author mindyp 31 */ 32 public class MinTimeProgressView extends ProgressBar { 33 private static int sMinShowTime; 34 35 private static int sMinDelay; 36 37 private long mStartTime = -1; 38 39 private final Handler mHandler = new Handler(); 40 41 private boolean mDismissed = false; 42 MinTimeProgressView(Context context)43 public MinTimeProgressView(Context context) { 44 this(context, null); 45 } 46 MinTimeProgressView(Context context, AttributeSet attrs)47 public MinTimeProgressView(Context context, AttributeSet attrs) { 48 super(context, attrs, R.style.MinTimeProgressViewStyle); 49 sMinShowTime = context.getResources() 50 .getInteger(R.integer.html_conv_progress_display_time); 51 sMinDelay = context.getResources() 52 .getInteger(R.integer.html_conv_progress_wait_time); 53 } 54 55 private final Runnable mDelayedHide = new Runnable() { 56 @Override 57 public void run() { 58 MinTimeProgressView.super.setVisibility(View.GONE); 59 } 60 }; 61 62 private final Runnable mDelayedShow = new Runnable() { 63 @Override 64 public void run() { 65 if (!mDismissed) { 66 mStartTime = System.currentTimeMillis(); 67 MinTimeProgressView.super.setVisibility(View.VISIBLE); 68 } 69 } 70 }; 71 hide()72 private void hide() { 73 mDismissed = true; 74 long diff = System.currentTimeMillis() - mStartTime; 75 if (diff >= sMinShowTime || mStartTime == -1) { 76 // The progress spinner has been shown long enough 77 // OR was not shown yet. If it wasn't shown yet, 78 // it will just never be shown. 79 MinTimeProgressView.super.setVisibility(View.GONE); 80 } else { 81 // The progress spinner is shown, but not long enough, 82 // so put a delayed message in to hide it when its been 83 // shown long enough. 84 mHandler.postDelayed(mDelayedHide, sMinShowTime - diff); 85 } 86 } 87 show()88 private void show() { 89 // Reset the start time. 90 mStartTime = -1; 91 mHandler.postDelayed(mDelayedShow, sMinDelay); 92 } 93 94 @Override setVisibility(int visibility)95 public void setVisibility(int visibility) { 96 // Whenever the visibility gets changed, clear dismissed 97 // state. 98 mDismissed = false; 99 switch (visibility) { 100 case View.VISIBLE: 101 show(); 102 break; 103 case View.GONE: 104 hide(); 105 break; 106 default: 107 super.setVisibility(visibility); 108 } 109 } 110 } 111