Allow cancellation of track write

MyTracks/src/com/google/android/apps/mytracks/WriteProgressController.java

@@ -20,6 +20,7 @@ import com.google.android.maps.mytracks.R;
 
 import android.app.Activity;
 import android.app.ProgressDialog;
+import android.content.DialogInterface;
 
 /**
  * Given a {@link TrackWriter}, this class manages the process of writing the
@@ -66,6 +67,7 @@ class WriteProgressController {
     dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
     dialog.setMessage(activity.getString(R.string.write_progress_message));
     dialog.setIndeterminate(true);
+    dialog.setOnCancelListener(dialogCancelListener);
 
     writer.setOnCompletionListener(writerCompleteListener);
     writer.setOnWriteListener(writerWriteListener);
@@ -87,6 +89,14 @@ class WriteProgressController {
     return dialog;
   }
 
+  private final DialogInterface.OnCancelListener dialogCancelListener =
+    new DialogInterface.OnCancelListener() {
+      @Override
+      public void onCancel(DialogInterface dialog) {
+        writer.stopWriteTrack();
+      }
+    };
+
   private final TrackWriter.OnCompletionListener writerCompleteListener =
       new TrackWriter.OnCompletionListener() {
         @Override

MyTracks/src/com/google/android/apps/mytracks/io/file/TrackFormatWriter.java

@@ -1,12 +1,12 @@
 /*
  * Copyright 2010 Google Inc.
- * 
+ *
  * 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
@@ -54,7 +54,7 @@ public interface TrackFormatWriter {
   void prepare(Track track, OutputStream out);
 
   /**
-   * @return The file extentsion (i.e. gpx, kml, ...)
+   * @return The file extension (i.e. gpx, kml, ...)
    */
   String getExtension();
 
@@ -77,7 +77,7 @@ public interface TrackFormatWriter {
    *
    * @param location the location to write
    */
-  void writeLocation(Location location);
+  void writeLocation(Location location) throws InterruptedException;
 
   /**
    * Write a way point.

MyTracks/src/com/google/android/apps/mytracks/io/file/TrackWriter.java

@@ -75,6 +75,11 @@ public interface TrackWriter {
    */
   void writeTrack();
 
+  /**
+   * Stop any in-progress writes
+   */
+  void stopWriteTrack();
+
   /**
    * Returns true if the write completed successfully.
    */

MyTracks/src/com/google/android/apps/mytracks/io/file/TrackWriterImpl.java

@@ -57,6 +57,7 @@ class TrackWriterImpl implements TrackWriter {
   private File file = null;
   private OnCompletionListener onCompletionListener;
   private OnWriteListener onWriteListener;
+  private Thread writeThread;
 
   TrackWriterImpl(Context context, MyTracksProviderUtils providerUtils,
       Track track, TrackFormatWriter writer) {
@@ -89,28 +90,60 @@ class TrackWriterImpl implements TrackWriter {
 
   @Override
   public void writeTrackAsync() {
-    Thread t = new Thread() {
+    writeThread = new Thread() {
       @Override
       public void run() {
-        writeTrack();
+        doWriteTrack();
       }
     };
-    t.start();
+    writeThread.start();
   }
 
   @Override
   public void writeTrack() {
+    writeTrackAsync();
+    try {
+      writeThread.join();
+    } catch (InterruptedException e) {
+      Log.e(Constants.TAG, "Interrupted waiting for write to complete", e);
+    }
+  }
+
+  private void doWriteTrack() {
     // Open the input and output
     success = false;
     errorMessage = R.string.error_track_does_not_exist;
     if (track != null) {
       if (openFile()) {
-        writeDocument();
+        try {
+          writeDocument();
+        } catch (InterruptedException e) {
+          Log.i(Constants.TAG, "The track write was interrupted");
+          if (file != null) {
+            file.delete();
+          }
+          success = false;
+          errorMessage = R.string.error_operation_cancelled;
+        }
       }
     }
     finished();
   }
 
+  public void stopWriteTrack() {
+    if (writeThread != null && writeThread.isAlive()) {
+      Log.i(Constants.TAG, "Attempting to stop track write");
+      writeThread.interrupt();
+
+      try {
+        writeThread.join();
+        Log.i(Constants.TAG, "Track write stopped");
+      } catch (InterruptedException e) {
+        Log.e(Constants.TAG, "Failed to wait for writer to stop", e);
+      }
+    }
+  }
+
   @Override
   public int getErrorMessage() {
     return errorMessage;
@@ -253,7 +286,7 @@ class TrackWriterImpl implements TrackWriter {
   /**
    * Does the actual work of writing the track to the now open file.
    */
-  void writeDocument() {
+  void writeDocument() throws InterruptedException {
     Log.d(Constants.TAG, "Started writing track.");
     writer.writeHeader();
     writeWaypoints(track.getId());
@@ -265,7 +298,7 @@ class TrackWriterImpl implements TrackWriter {
     errorMessage = R.string.io_write_finished;
   }
 
-  private void writeLocations() {
+  private void writeLocations() throws InterruptedException {
     boolean wroteFirst = false;
     boolean segmentOpen = false;
     boolean isLastValid = false;
@@ -303,6 +336,9 @@ class TrackWriterImpl implements TrackWriter {
       int pointNumber = 0;
       while (it.hasNext()) {
         Location loc = it.next();
+        if (Thread.interrupted()) {
+          throw new InterruptedException();
+        }
 
         pointNumber++;