Initial commit

lib/src/main/java/com/king/zxing/InactivityTimer.java

@@ -0,0 +1,123 @@
+package com.king.zxing;
+
+/*
+ * Copyright (C) 2010 ZXing authors
+ *
+ * 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.
+ */
+
+
+import android.app.Activity;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.os.AsyncTask;
+import android.os.BatteryManager;
+import android.util.Log;
+
+import java.util.concurrent.RejectedExecutionException;
+
+/**
+ * Finishes an activity after a period of inactivity if the device is on battery power.
+ */
+final class InactivityTimer {
+
+    private static final String TAG = InactivityTimer.class.getSimpleName();
+
+    private static final long INACTIVITY_DELAY_MS = 5 * 60 * 1000L;
+
+    private final Activity activity;
+    private final BroadcastReceiver powerStatusReceiver;
+    private boolean registered;
+    private AsyncTask<Object,Object,Object> inactivityTask;
+
+    InactivityTimer(Activity activity) {
+        this.activity = activity;
+        powerStatusReceiver = new PowerStatusReceiver();
+        registered = false;
+        onActivity();
+    }
+
+    synchronized void onActivity() {
+        cancel();
+        inactivityTask = new InactivityAsyncTask();
+        try {
+            inactivityTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+        } catch (RejectedExecutionException ree) {
+            Log.w(TAG, "Couldn't schedule inactivity task; ignoring");
+        }
+    }
+
+    synchronized void onPause() {
+        cancel();
+        if (registered) {
+            activity.unregisterReceiver(powerStatusReceiver);
+            registered = false;
+        } else {
+            Log.w(TAG, "PowerStatusReceiver was never registered?");
+        }
+    }
+
+    synchronized void onResume() {
+        if (registered) {
+            Log.w(TAG, "PowerStatusReceiver was already registered?");
+        } else {
+            activity.registerReceiver(powerStatusReceiver, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
+            registered = true;
+        }
+        onActivity();
+    }
+
+    private synchronized void cancel() {
+        AsyncTask<?,?,?> task = inactivityTask;
+        if (task != null) {
+            task.cancel(true);
+            inactivityTask = null;
+        }
+    }
+
+    void shutdown() {
+        cancel();
+    }
+
+    private final class PowerStatusReceiver extends BroadcastReceiver {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            if (Intent.ACTION_BATTERY_CHANGED.equals(intent.getAction())) {
+                // 0 indicates that we're on battery
+                boolean onBatteryNow = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1) <= 0;
+                if (onBatteryNow) {
+                    InactivityTimer.this.onActivity();
+                } else {
+                    InactivityTimer.this.cancel();
+                }
+            }
+        }
+    }
+
+    private final class InactivityAsyncTask extends AsyncTask<Object,Object,Object> {
+        @Override
+        protected Object doInBackground(Object... objects) {
+            try {
+                Thread.sleep(INACTIVITY_DELAY_MS);
+                Log.i(TAG, "Finishing activity due to inactivity");
+                activity.finish();
+            } catch (InterruptedException e) {
+                // continue without killing
+            }
+            return null;
+        }
+    }
+
+}