Move Utils#getApkUrl(String repoAddress, Apk apk) to Apk#getUrl()

Added assertions that both apkName and repoAddress need to be populated
in order to call `getUrl()`. Also verified that this is the case for all
usages of this method, which it should be. All `Apk` objects which currently
have `getUrl()` called on them are loaded using the `ApkProvider.Helper.findById()`
method without specifying which columns to load (which defaults to all).

app/src/main/java/org/fdroid/fdroid/AppDetails.java

@@ -815,9 +815,6 @@ public class AppDetails extends AppCompatActivity {
             return;
         }
 
-        final String repoaddress = getRepoAddress(apk);
-        if (repoaddress == null) return;
-
         if (!apk.compatible) {
             AlertDialog.Builder builder = new AlertDialog.Builder(this);
             builder.setMessage(R.string.installIncompatible);
@@ -826,7 +823,7 @@ public class AppDetails extends AppCompatActivity {
                         @Override
                         public void onClick(DialogInterface dialog,
                                 int whichButton) {
-                            startDownload(apk, repoaddress);
+                            startDownload(apk);
                         }
                     });
             builder.setNegativeButton(R.string.no,
@@ -855,21 +852,11 @@ public class AppDetails extends AppCompatActivity {
             alert.show();
             return;
         }
-        startDownload(apk, repoaddress);
+        startDownload(apk);
     }
 
-    @Nullable
+    private void startDownload(Apk apk) {
-    private String getRepoAddress(Apk apk) {
+        activeDownloadUrlString = apk.getUrl();
-        final String[] projection = {RepoProvider.DataColumns.ADDRESS};
-        Repo repo = RepoProvider.Helper.findById(this, apk.repo, projection);
-        if (repo == null || repo.address == null) {
-            return null;
-        }
-        return repo.address;
-    }
-
-    private void startDownload(Apk apk, String repoAddress) {
-        activeDownloadUrlString = Utils.getApkUrl(repoAddress, apk);
         registerDownloaderReceivers();
         headerFragment.startProgress();
         DownloaderService.queue(this, apk.packageName, activeDownloadUrlString);

app/src/main/java/org/fdroid/fdroid/UpdateService.java

@@ -393,7 +393,7 @@ public class UpdateService extends IntentService implements ProgressListener {
 
                 // now that downloading the index is done, start downloading updates
                 if (changes && fdroidPrefs.isAutoDownloadEnabled()) {
-                    autoDownloadUpdates(repo.address);
+                    autoDownloadUpdates();
                 }
             }
 
@@ -485,7 +485,7 @@ public class UpdateService extends IntentService implements ProgressListener {
         return inboxStyle;
     }
 
-    private void autoDownloadUpdates(String repoAddress) {
+    private void autoDownloadUpdates() {
         Cursor cursor = getContentResolver().query(
                 AppProvider.getCanUpdateUri(),
                 new String[]{
@@ -496,10 +496,8 @@ public class UpdateService extends IntentService implements ProgressListener {
             cursor.moveToFirst();
             for (int i = 0; i < cursor.getCount(); i++) {
                 App app = new App(cursor);
-                Apk apk = ApkProvider.Helper.find(this, app.packageName, app.suggestedVersionCode, new String[]{
+                Apk apk = ApkProvider.Helper.find(this, app.packageName, app.suggestedVersionCode);
-                        ApkProvider.DataColumns.NAME,
+                String urlString = apk.getUrl();
-                });
-                String urlString = Utils.getApkUrl(repoAddress, apk);
                 DownloaderService.queue(this, app.packageName, urlString);
                 cursor.moveToNext();
             }

app/src/main/java/org/fdroid/fdroid/Utils.java

@@ -39,7 +39,6 @@ import com.nostra13.universalimageloader.utils.StorageUtils;
 
 import org.apache.commons.io.FileUtils;
 import org.fdroid.fdroid.compat.FileCompat;
-import org.fdroid.fdroid.data.Apk;
 import org.fdroid.fdroid.data.Repo;
 import org.fdroid.fdroid.data.SanitizedFile;
 import org.xml.sax.XMLReader;
@@ -434,10 +433,6 @@ public final class Utils {
         return new Locale(languageTag);
     }
 
-    public static String getApkUrl(String repoAddress, Apk apk) {
-        return repoAddress + "/" + apk.apkName.replace(" ", "%20");
-    }
-
     public static final class CommaSeparatedList implements Iterable<String> {
         private final String value;
 

app/src/main/java/org/fdroid/fdroid/data/Apk.java

@@ -121,6 +121,13 @@ public class Apk extends ValueObject implements Comparable<Apk> {
         }
     }
 
+    public String getUrl() {
+        if (repoAddress == null || apkName == null) {
+            throw new IllegalStateException("Apk needs to have both ApkProvider.DataColumns.REPO_ADDRESS and ApkProvider.DataColumns.NAME set in order to calculate URL.");
+        }
+        return repoAddress + "/" + apkName.replace(" ", "%20");
+    }
+
     @Override
     public String toString() {
         return packageName + " (version " + versionCode + ")";

app/src/main/java/org/fdroid/fdroid/views/swap/SwapAppsView.java

@@ -297,7 +297,7 @@ public class SwapAppsView extends ListView implements
                 // TODO: Unregister receivers correctly...
 
                 Apk apk = getApkToInstall();
-                String url = Utils.getApkUrl(apk.repoAddress, apk);
+                String url = apk.getUrl();
 
                 localBroadcastManager = LocalBroadcastManager.getInstance(getActivity());
                 localBroadcastManager.registerReceiver(appListViewResetReceiver,

app/src/main/java/org/fdroid/fdroid/views/swap/SwapWorkflowActivity.java

@@ -778,7 +778,7 @@ public class SwapWorkflowActivity extends AppCompatActivity {
 
     public void install(@NonNull final App app) {
         final Apk apk = ApkProvider.Helper.find(this, app.packageName, app.suggestedVersionCode);
-        String urlString = Utils.getApkUrl(apk.repoAddress, apk);
+        String urlString = apk.getUrl();
         downloadCompleteReceiver = new BroadcastReceiver() {
             @Override
             public void onReceive(Context context, Intent intent) {