Java tutorial
/** * 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 com.android.tests.usagestats; import android.app.ListActivity; import android.app.usage.UsageEvents; import android.app.usage.UsageStatsManager; import android.content.Context; import android.os.Bundle; import android.os.Handler; import android.support.v4.util.CircularArray; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.TextView; import java.util.ArrayList; public class UsageLogActivity extends ListActivity implements Runnable { private static final long USAGE_STATS_PERIOD = 1000 * 60 * 60 * 24 * 14; private UsageStatsManager mUsageStatsManager; private Adapter mAdapter; private Handler mHandler = new Handler(); private long mLastTime; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mUsageStatsManager = (UsageStatsManager) getSystemService(Context.USAGE_STATS_SERVICE); mLastTime = System.currentTimeMillis() - USAGE_STATS_PERIOD; mAdapter = new Adapter(); setListAdapter(mAdapter); } @Override protected void onResume() { super.onResume(); run(); } @Override protected void onPause() { super.onPause(); mHandler.removeCallbacks(this); } @Override public void run() { long now = System.currentTimeMillis(); UsageEvents events = mUsageStatsManager.queryEvents(mLastTime, now); long lastEventTime = mAdapter.update(events); if (lastEventTime >= 0) { mLastTime = lastEventTime + 1; } mHandler.postDelayed(this, 1000 * 5); } private class Adapter extends BaseAdapter { private static final int MAX_EVENTS = 50; private final CircularArray<UsageEvents.Event> mEvents = new CircularArray<>(MAX_EVENTS); public long update(UsageEvents results) { long lastTimeStamp = -1; while (results.hasNextEvent()) { UsageEvents.Event event = new UsageEvents.Event(); results.getNextEvent(event); lastTimeStamp = event.getTimeStamp(); if (mEvents.size() == MAX_EVENTS) { mEvents.popLast(); } mEvents.addFirst(event); } if (lastTimeStamp != 0) { notifyDataSetChanged(); } return lastTimeStamp; } @Override public int getCount() { return mEvents.size(); } @Override public UsageEvents.Event getItem(int position) { return mEvents.get(position); } @Override public long getItemId(int position) { return position; } @Override public int getItemViewType(int position) { final int eventType = getItem(position).getEventType(); if (eventType == UsageEvents.Event.CONFIGURATION_CHANGE) { return 1; } return 0; } @Override public View getView(int position, View convertView, ViewGroup parent) { final UsageEvents.Event event = getItem(position); final ViewHolder holder; if (convertView == null) { holder = new ViewHolder(); if (event.getEventType() == UsageEvents.Event.CONFIGURATION_CHANGE) { convertView = LayoutInflater.from(UsageLogActivity.this).inflate(R.layout.config_row_item, parent, false); holder.config = (TextView) convertView.findViewById(android.R.id.text1); } else { convertView = LayoutInflater.from(UsageLogActivity.this).inflate(R.layout.row_item, parent, false); holder.packageName = (TextView) convertView.findViewById(android.R.id.text1); holder.state = (TextView) convertView.findViewById(android.R.id.text2); } convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } if (holder.packageName != null) { holder.packageName.setText(event.getPackageName()); } if (holder.state != null) { holder.state.setText(eventToString(event.getEventType())); } if (holder.config != null && event.getEventType() == UsageEvents.Event.CONFIGURATION_CHANGE) { holder.config.setText(event.getConfiguration().toString()); } return convertView; } private String eventToString(int eventType) { switch (eventType) { case UsageEvents.Event.MOVE_TO_FOREGROUND: return "Foreground"; case UsageEvents.Event.MOVE_TO_BACKGROUND: return "Background"; case UsageEvents.Event.CONFIGURATION_CHANGE: return "Config change"; default: return "Unknown: " + eventType; } } } static class ViewHolder { public TextView packageName; public TextView state; public TextView config; } }