Add InstallerDelegate for watching that a package gets installed

chrome/android/java/src/org/chromium/chrome/browser/banners/InstallerDelegate.java

Index: chrome/android/java/src/org/chromium/chrome/browser/banners/InstallerDelegate.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/banners/InstallerDelegate.java b/chrome/android/java/src/org/chromium/chrome/browser/banners/InstallerDelegate.java
new file mode 100644
index 0000000000000000000000000000000000000000..c38de8b7307cb4cd70af0c9395338772185b9801
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/banners/InstallerDelegate.java
@@ -0,0 +1,137 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.banners;
+
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.os.Handler;
+import android.os.Looper;
+import android.os.SystemClock;
+import android.text.TextUtils;
+
+import java.util.List;
+
+/**
+ * Monitors the PackageManager to see when an app has been installed.
+ */
+public class InstallerDelegate implements Runnable {
+    /**
+     * Callback for when the app install has completed.
+     */
+    public static interface Observer {
+        /**
+         * Called when the task has finished.
+         * @param delegate Instance of the class that finished.
+         * @param success  Whether or not the package was successfully installed.
+         */
+        public void onInstallFinished(InstallerDelegate delegate, boolean success);
+    }
+
+    private static final long DEFAULT_MS_BETWEEN_RUNS = 1000;
+    private static final long DEFAULT_MS_MAXIMUM_WAITING_TIME = 3 * 60 * 1000;
+
+    /** Message loop to post the Runnable to. */
+    private final Handler mHandler;
+
+    /** PackageManager that the Runnable is monitoring. */
+    private final PackageManager mPackageManager;
+
+    /** Object that is notified when the PackageManager has finished. */
+    private final Observer mObserver;
+
+    /** Name of the package that we need to see the PackageManager has finished installing. */
+    private final String mPackageName;
+
+    /** Whether or not the Runnable is currently looping. */
+    private boolean mIsRunning;
+
+    /** Number of milliseconds to wait between calls to run(). */
+    private long mMsBetweenRuns;
+
+    /** Maximum number of milliseconds to wait before giving up. */
+    private long mMsMaximumWaitingTime;
+
+    /** Timestamp of when we first started. */
+    private long mTimestampStarted;
+
+    /**
+     * Constructs the InstallerDelegate.
+     * @param looper         Thread to run the Runnable on.
+     * @param packageManager Provides access to the list of installed apps.
+     * @param observer       Alerted when the package has been completely installed.
+     * @param packageName    Name of the package for the app to monitor.
+     */
+    InstallerDelegate(
+            Looper looper, PackageManager packageManager, Observer observer, String packageName) {
+        mHandler = new Handler(looper);
+        mPackageManager = packageManager;
+        mObserver = observer;
+        mPackageName = packageName;
+        mMsBetweenRuns = DEFAULT_MS_BETWEEN_RUNS;
+        mMsMaximumWaitingTime = DEFAULT_MS_MAXIMUM_WAITING_TIME;
+    }
+
+    /**
+     * Begin monitoring the PackageManager to see if it completes installing the package.
+     */
+    public void start() {
+        mTimestampStarted = SystemClock.elapsedRealtime();
+        mIsRunning = true;
+        run();
+    }
+
+    /**
+     * Don't call this directly; instead, call {@link #start()}.
+     */
+    @Override
+    public void run() {
+        boolean isInstalled = isInstalled();
+        boolean waitedTooLong =
+                (SystemClock.elapsedRealtime() - mTimestampStarted) > mMsMaximumWaitingTime;
+        if (isInstalled || !mIsRunning || waitedTooLong) {
+            mObserver.onInstallFinished(this, isInstalled);
+            mIsRunning = false;
+        } else {
+            mHandler.postDelayed(this, mMsBetweenRuns);
+        }
+    }
+
+    /**
+     * Checks if the app has been installed on the system.
+     * @return True if the PackageManager reports that the app is installed, false otherwise.
+     */
+    private boolean isInstalled() {
+        List<PackageInfo> packs = mPackageManager.getInstalledPackages(0);
+        for (int i = 0; i < packs.size(); i++) {
+            if (TextUtils.equals(packs.get(i).packageName, mPackageName)) return true;
+        }
+        return false;
+    }
+
+    /**
+     * Prevent rescheduling the Runnable.
+     */
+    void cancel() {
+        mIsRunning = false;
+    }
+
+    /**
+     * Checks to see if the Runnable will continue scheduling itself.
+     * @return True if the runnable is still being scheduled.
+     */
+    boolean isRunning() {
+        return mIsRunning;
+    }
+
+    /**
+     * Set how often the handler will check the PackageManager.
+     * @param msBetween How long to wait between executions of the Runnable.
+     * @param msMax     How long to wait before giving up.
+     */
+    void setTimingForTests(long msBetween, long msMax) {
+        mMsBetweenRuns = msBetween;
+        mMsMaximumWaitingTime = msMax;
+    }
+}