Add helper adapter to AsyncFeedbackSource

Add a helper class to make extending AsyncFeedbackSource easy for the
common case.  This removes all of the work involving the AsyncTask,
status management, callback triggering, etc.

BUG=773403

Change-Id: Ic64a41dea7bf49cc005850418967a9f36da6df40
Reviewed-on: https://chromium-review.googlesource.com/811824
Commit-Queue: David Trainor <dtrainor@chromium.org>
Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522502}

chrome/android/java/src/org/chromium/chrome/browser/feedback/AsyncFeedbackSourceAdapter.java

+// Copyright 2017 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.feedback;
+
+import android.content.Context;
+import android.os.AsyncTask;
+import android.os.AsyncTask.Status;
+
+import org.chromium.base.ContextUtils;
+
+import java.util.concurrent.ExecutionException;
+
+/**
+ * A helper class to make implementing an AsyncFeedbackSource easier for the common case.  The bulk
+ * of the background work is meant to be done in {@link #doInBackground(Context)} and the result can
+ * be queried from {@link #getResult()}.  Subclasses are meant to override {@link #getFeedback()} or
+ * {@link #getLogs()} as necessary and use {@link #getResult()} if they need the result from the
+ * asynchronous work.
+ * @param <Result> The {@link Object} type that represents the result of doing the background work.
+ */
+public abstract class AsyncFeedbackSourceAdapter<Result> implements AsyncFeedbackSource {
+    private Worker mWorker;
+
+    private class Worker extends AsyncTask<Context, Void, Result> {
+        private final Runnable mCallback;
+
+        public Worker(Runnable callback) {
+            mCallback = callback;
+        }
+
+        // AsyncTask implementation.
+        @Override
+        protected Result doInBackground(Context... params) {
+            return AsyncFeedbackSourceAdapter.this.doInBackground(params[0]);
+        }
+
+        @Override
+        protected void onPostExecute(Result result) {
+            super.onPostExecute(result);
+
+            mCallback.run();
+        }
+    }
+
+    /**
+     * Meant to do the actual work in the background.  This method will be called from a thread in
+     * the {@link AsyncTask} thread pool.
+     * @param context The application {@link Context}.
+     * @return        The result of doing the work in the background or {@code null}.
+     */
+    protected abstract Result doInBackground(Context context);
+
+    /**
+     * @return The result of the background work if it has been started and finished.  This will be
+     *         null if the underlying background task has not finished yet (see {@link #isReady()})
+     *         or if {@link #doInBackground(Context)} returned {@code null}.
+     */
+    protected final Result getResult() {
+        try {
+            return mWorker != null && mWorker.getStatus() == Status.FINISHED ? mWorker.get() : null;
+        } catch (ExecutionException | InterruptedException e) {
+            return null;
+        }
+    }
+
+    // AsyncFeedbackSource implementation.
+    @Override
+    public final boolean isReady() {
+        return mWorker != null && mWorker.getStatus() == Status.FINISHED;
+    }
+
+    @Override
+    public final void start(Runnable callback) {
+        if (mWorker != null) return;
+        mWorker = new Worker(callback);
+        mWorker.executeOnExecutor(
+                AsyncTask.THREAD_POOL_EXECUTOR, ContextUtils.getApplicationContext());
+    }
+}
\ No newline at end of file

chrome/android/java/src/org/chromium/chrome/browser/feedback/SystemInfoFeedbackSource.java

@@ -4,8 +4,7 @@
 
 package org.chromium.chrome.browser.feedback;
 
-import android.os.AsyncTask;
-import android.os.AsyncTask.Status;
+import android.content.Context;
 import android.os.Environment;
 import android.os.StatFs;
 import android.util.Pair;
@@ -17,78 +16,19 @@ import org.chromium.base.annotations.JNINamespace;
 
 import java.io.File;
 import java.util.Map;
-import java.util.concurrent.ExecutionException;
 
 /** Grabs feedback about the current system. */
 @JNINamespace("chrome::android")
-public class SystemInfoFeedbackSource implements AsyncFeedbackSource {
-    private StorageTask mStorageTask;
-
-    private static class StorageTask extends AsyncTask<Void, Void, StatFs> {
-        private Runnable mCallback;
-
-        public StorageTask(Runnable callback) {
-            mCallback = callback;
-        }
-
-        Long getAvailableSpaceMB() {
-            if (getStatus() != Status.FINISHED) return null;
-
-            try {
-                StatFs statFs = get();
-                if (statFs == null) return null;
-                long blockSize = ApiCompatibilityUtils.getBlockSize(statFs);
-                return ApiCompatibilityUtils.getAvailableBlocks(statFs) * blockSize / 1024 / 1024;
-            } catch (ExecutionException | InterruptedException e) {
-                return null;
-            }
-        }
-
-        Long getTotalSpaceMB() {
-            if (getStatus() != Status.FINISHED) return null;
-
-            try {
-                StatFs statFs = get();
-                if (statFs == null) return null;
-                long blockSize = ApiCompatibilityUtils.getBlockSize(statFs);
-                return ApiCompatibilityUtils.getBlockCount(statFs) * blockSize / 1024 / 1024;
-            } catch (ExecutionException | InterruptedException e) {
-                return null;
-            }
-        }
-
-        // AsyncTask implementation.
+public class SystemInfoFeedbackSource extends AsyncFeedbackSourceAdapter<StatFs> {
+    // AsyncFeedbackSourceAdapter implementation.
     @Override
-        protected StatFs doInBackground(Void... params) {
+    protected StatFs doInBackground(Context context) {
         File directory = Environment.getDataDirectory();
-
         if (!directory.exists()) return null;
 
         return new StatFs(directory.getPath());
     }
 
-        @Override
-        protected void onPostExecute(StatFs result) {
-            super.onPostExecute(result);
-            mCallback.run();
-        }
-    }
-
-    SystemInfoFeedbackSource() {}
-
-    // AsyncFeedbackSource implementation.
-    @Override
-    public boolean isReady() {
-        return mStorageTask != null && mStorageTask.getStatus() == Status.FINISHED;
-    }
-
-    @Override
-    public void start(Runnable callback) {
-        if (mStorageTask != null) return;
-        mStorageTask = new StorageTask(callback);
-        mStorageTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
-    }
-
     @Override
     public Map<String, String> getFeedback() {
         Map<String, String> feedback = CollectionUtil.newHashMap(
@@ -100,12 +40,15 @@ public class SystemInfoFeedbackSource implements AsyncFeedbackSource {
                 Pair.create("GPU Model", nativeGetGpuModel()),
                 Pair.create("UI Locale", LocaleUtils.getDefaultLocaleString()));
 
-        if (isReady()) {
-            Long availSpace = mStorageTask.getAvailableSpaceMB();
-            Long totalSpace = mStorageTask.getTotalSpaceMB();
+        StatFs statFs = getResult();
+        if (statFs != null) {
+            long blockSize = ApiCompatibilityUtils.getBlockSize(statFs);
+            long availSpace =
+                    ApiCompatibilityUtils.getAvailableBlocks(statFs) * blockSize / 1024 / 1024;
+            long totalSpace = ApiCompatibilityUtils.getBlockCount(statFs) * blockSize / 1024 / 1024;
 
-            if (availSpace != null) feedback.put("Available Storage (MB)", availSpace.toString());
-            if (totalSpace != null) feedback.put("Total Storage (MB)", totalSpace.toString());
+            feedback.put("Available Storage (MB)", Long.toString(availSpace));
+            feedback.put("Total Storage (MB)", Long.toString(totalSpace));
         }
 
         return feedback;

chrome/android/java_sources.gni

@@ -409,6 +409,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/feature_engagement/ScreenshotMonitor.java",
   "java/src/org/chromium/chrome/browser/feature_engagement/ScreenshotMonitorDelegate.java",
   "java/src/org/chromium/chrome/browser/feedback/AsyncFeedbackSource.java",
+  "java/src/org/chromium/chrome/browser/feedback/AsyncFeedbackSourceAdapter.java",
   "java/src/org/chromium/chrome/browser/feedback/ChromeHomeFeedbackSource.java",
   "java/src/org/chromium/chrome/browser/feedback/ConnectivityChecker.java",
   "java/src/org/chromium/chrome/browser/feedback/ConnectivityFeedbackSource.java",