Don't show progress in AppDetails when using a cached download.

The ApkDownloader now returns true or false depending on whether it
is using a cached version on disk, or hitting the network.
I was also a little more defensive about checking for if downloadHandler
is null before deciding to show a progress dialog.

src/org/fdroid/fdroid/AppDetails.java

@@ -425,7 +425,6 @@ public class AppDetails extends ListActivity implements ProgressListener {
 
     @Override
     protected void onResume() {
-        Log.d(TAG, "onresume");
         super.onResume();
         
         // register observer to know when install status changes
@@ -1021,9 +1020,10 @@ public class AppDetails extends ListActivity implements ProgressListener {
     private void startDownload(Apk apk, String repoAddress) {
         downloadHandler = new ApkDownloader(apk, repoAddress, Utils.getApkCacheDir(getBaseContext()));
         downloadHandler.setProgressListener(this);
-        downloadHandler.download();
+        if (downloadHandler.download()) {
             updateProgressDialog();
         }
+    }
     private void installApk(File file, String packageName) {
         setProgressBarIndeterminateVisibility(true);
 
@@ -1052,10 +1052,6 @@ public class AppDetails extends ListActivity implements ProgressListener {
                 @Override
                 public void run() {                    
                     if (operation == Installer.InstallerCallback.OPERATION_INSTALL) {
-                        if (downloadHandler != null) {
-                            downloadHandler = null;
-                        }
-
                         PackageManagerCompat.setInstaller(mPm, app.id);
                     }
 
@@ -1121,8 +1117,13 @@ public class AppDetails extends ListActivity implements ProgressListener {
             pd.setOnCancelListener(new DialogInterface.OnCancelListener() {
                 @Override
                 public void onCancel(DialogInterface dialog) {
+                    Log.d(TAG, "User clicked 'cancel' on download, attempting to interrupt download thread.");
+                    if (downloadHandler !=  null) {
                         downloadHandler.cancel();
                         downloadHandler = null;
+                    } else {
+                        Log.e(TAG, "Tried to cancel, but the downloadHandler doesn't exist.");
+                    }
                     progressDialog = null;
                     Toast.makeText(AppDetails.this, getString(R.string.download_cancelled), Toast.LENGTH_LONG).show();
                 }
@@ -1148,10 +1149,13 @@ public class AppDetails extends ListActivity implements ProgressListener {
      * {@link org.fdroid.fdroid.ProgressListener.Event}.
      */
     private void updateProgressDialog() {
+        if (downloadHandler != null) {
             updateProgressDialog(downloadHandler.getProgress(), downloadHandler.getTotalSize());
         }
+    }
 
     private void updateProgressDialog(int progress, int total) {
+        if (downloadHandler != null) {
             ProgressDialog pd = getProgressDialog(downloadHandler.getRemoteAddress());
             if (total > 0) {
                 pd.setIndeterminate(false);
@@ -1162,8 +1166,12 @@ public class AppDetails extends ListActivity implements ProgressListener {
                 pd.setProgress(progress);
                 pd.setMax(0);
             }
+            if (!pd.isShowing()) {
+                Log.d(TAG, "Showing progress dialog for download.");
                 pd.show();
             }
+        }
+    }
 
     @Override
     public void onProgress(Event event) {

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

@@ -131,12 +131,17 @@ public class ApkDownloader implements AsyncDownloadWrapper.Listener {
         }
     }
 
-    public void download() {
+    /**
+     * If the download successfully spins up a new thread to start downloading, then we return
+     * true, otherwise false. This is useful, e.g. when we use a cached version, and so don't
+     * want to bother with progress dialogs et al.
+     */
+    public boolean download() {
 
         // Can we use the cached version?
         if (verifyOrDeleteCachedVersion()) {
             sendMessage(EVENT_APK_DOWNLOAD_COMPLETE);
-            return;
+            return false;
         }
 
         String remoteAddress = getRemoteAddress();
@@ -147,12 +152,15 @@ public class ApkDownloader implements AsyncDownloadWrapper.Listener {
             Downloader downloader = new HttpDownloader(remoteAddress, localFile);
             dlWrapper = new AsyncDownloadWrapper(downloader, this);
             dlWrapper.download();
+            return true;
 
         } catch (MalformedURLException e) {
             onErrorDownloading(e.getLocalizedMessage());
         } catch (IOException e) {
             onErrorDownloading(e.getLocalizedMessage());
         }
+
+        return false;
     }
 
     private void sendMessage(String type) {