Removed unneeded todo's, add docs.

src/org/fdroid/fdroid/net/ApkDownloader.java

@@ -31,6 +31,11 @@ import java.io.IOException;
 import java.net.MalformedURLException;
 import java.security.NoSuchAlgorithmException;
 
+/**
+ * Downloads and verifies (against the Apk.hash) the apk file.
+ * If the file has previously been downloaded, it will make use of that
+ * instead, without going to the network to download a new one.
+ */
 public class ApkDownloader implements AsyncDownloadWrapper.Listener {
 
     private static final String TAG = "org.fdroid.fdroid.net.ApkDownloader";
@@ -71,7 +76,9 @@ public class ApkDownloader implements AsyncDownloadWrapper.Listener {
         localFile = new File(destDir, curApk.apkName);
     }
 
-    // The downloaded APK. Valid only when getStatus() has returned STATUS.DONE.
+    /**
+     * The downloaded APK. Valid only when getStatus() has returned STATUS.DONE.
+     */
     public File localFile() {
         return localFile;
     }

src/org/fdroid/fdroid/net/AsyncDownloadWrapper.java

@@ -8,6 +8,13 @@ import org.fdroid.fdroid.ProgressListener;
 
 import java.io.IOException;
 
+/**
+ * Given a {@link org.fdroid.fdroid.net.Downloader}, this wrapper will conduct the download operation on a
+ * separate thread. All progress/status/error/etc events will be forwarded from that thread to the thread
+ * that {@link AsyncDownloadWrapper#download()} was invoked on. If you want to respond with UI feedback
+ * to these events, it is important that you execute the download method of this class from the UI thread.
+ * That way, all forwarded events will be handled on that thread.
+ */
 public class AsyncDownloadWrapper extends Handler {
 
     private static final String TAG = "org.fdroid.fdroid.net.AsyncDownloadWrapper";
@@ -71,6 +78,11 @@ public class AsyncDownloadWrapper extends Handler {
         downloadThread.interrupt();
     }
 
+    /**
+     * Receives "messages" from the download thread, and passes them onto the
+     * relevant {@link org.fdroid.fdroid.net.AsyncDownloadWrapper.Listener}
+     * @param message
+     */
     public void handleMessage(Message message) {
         if (message.arg1 == MSG_PROGRESS) {
             Bundle data = message.getData();

src/org/fdroid/fdroid/net/Downloader.java

@@ -47,15 +47,6 @@ public abstract class Downloader {
         outputStream = new FileOutputStream(outputFile);
     }
 
-    /**
-     * Downloads to a temporary file, which *you must delete yourself when
-     * you are done*.
-     * @see org.fdroid.fdroid.net.Downloader#getFile()
-     */
-    public Downloader(File destFile, Context ctx) throws IOException {
-        // TODO: Reimplement (is it still necessary? In what context was it being used before?)
-    }
-
     public Downloader(OutputStream output)
             throws MalformedURLException {
         outputStream = output;
@@ -158,8 +149,6 @@ public abstract class Downloader {
      */
     private void throwExceptionIfInterrupted() throws InterruptedException {
         if (Thread.interrupted()) {
-            // TODO: Do we need to provide more information to whoever needs it,
-            // so they can, for example, remove any partially created files?
             Log.d(TAG, "Received interrupt, cancelling download");
             throw new InterruptedException();
         }