Android: reimplement DocumentProviderFactory as a singleton

The factory will require some objects that are not available from a
static context.

Change-Id: Idf852f5b9ab3023644b1a9577951a94c4f21c4e9

2 files changed, 38 insertions, 9 deletions

diff --git a/android/experimental/LOAndroid3/src/java/org/libreoffice/storage/DocumentProviderFactory.java b/android/experimental/LOAndroid3/src/java/org/libreoffice/storage/DocumentProviderFactory.java
index 57b0437b5ab5..2ec0dc9514fd 100644
--- a/android/experimental/LOAndroid3/src/java/org/libreoffice/storage/DocumentProviderFactory.java
+++ b/android/experimental/LOAndroid3/src/java/org/libreoffice/storage/DocumentProviderFactory.java
@@ -16,22 +16,47 @@ import org.libreoffice.storage.local.LocalDocumentsProvider;
  * Keeps the instances of the available IDocumentProviders in the system.
  * Instances are maintained in a sorted list and providers have to be
  * accessed from their position.
+ *
+ * The factory follows the Singleton pattern, there is only one instance of it
+ * in the application and it must be retrieved with
+ * DocumentProviderFactory.getInstance().
  */
-public class DocumentProviderFactory {
+public final class DocumentProviderFactory {
+
+    /**
+     * Private factory instance for the Singleton pattern.
+     */
+    private static DocumentProviderFactory instance = null;
 
-    private static IDocumentProvider[] providers = {
+    private IDocumentProvider[] providers = {
             new LocalDocumentsDirectoryProvider(), new LocalDocumentsProvider() };
 
-    private static String[] providerNames = {
+    private String[] providerNames = {
             "Local documents", "Local file system" };
 
+    private DocumentProviderFactory() {
+        // private to prevent external instances of the factory
+    }
+
+    /**
+     * Retrieve the unique instance of the factory.
+     *
+     * @return the unique factory object.
+     */
+    public static DocumentProviderFactory getInstance() {
+        if (instance == null) {
+            instance = new DocumentProviderFactory();
+        }
+        return instance;
+    }
+
     /**
      * Retrieve the provider associated to a certain position.
      *
      * @param position
      * @return document provider in that position.
      */
-    public static IDocumentProvider getProvider(int position) {
+    public IDocumentProvider getProvider(int position) {
         return providers[position];
     }
 
@@ -41,7 +66,7 @@ public class DocumentProviderFactory {
      *
      * @return Array with the names of the available providers.
      */
-    public static String[] getNames() {
+    public String[] getNames() {
         return providerNames;
     }
 
@@ -50,7 +75,7 @@ public class DocumentProviderFactory {
      *
      * @return default provider.
      */
-    public static IDocumentProvider getDefaultProvider() {
+    public IDocumentProvider getDefaultProvider() {
         return providers[0];
     }
 }
diff --git a/android/experimental/LOAndroid3/src/java/org/libreoffice/ui/LibreOfficeUIActivity.java b/android/experimental/LOAndroid3/src/java/org/libreoffice/ui/LibreOfficeUIActivity.java
index 041eda83a438..1ee88bf86000 100644
--- a/android/experimental/LOAndroid3/src/java/org/libreoffice/ui/LibreOfficeUIActivity.java
+++ b/android/experimental/LOAndroid3/src/java/org/libreoffice/ui/LibreOfficeUIActivity.java
@@ -78,6 +78,7 @@ public class LibreOfficeUIActivity extends LOAbout implements ActionBar.OnNaviga
     FileFilter fileFilter;
     FilenameFilter filenameFilter;
     private List<IFile> filePaths;
+    private DocumentProviderFactory documentProviderFactory;
     private IDocumentProvider documentProvider;
     private IFile homeDirectory;
     private IFile currentDirectory;
@@ -105,8 +106,11 @@ public class LibreOfficeUIActivity extends LOAbout implements ActionBar.OnNaviga
 
         super.onCreate(savedInstanceState);
         Log.d(tag, "onCreate - tweaked - meeks !");
+
+        documentProviderFactory = DocumentProviderFactory.getInstance();
+
         //Set the "home" - top level - directory.
-        documentProvider = DocumentProviderFactory.getDefaultProvider();
+        documentProvider = documentProviderFactory.getDefaultProvider();
         homeDirectory = documentProvider.getRootDirectory();
         currentDirectory = homeDirectory;
         //Load default settings
@@ -177,13 +181,13 @@ public class LibreOfficeUIActivity extends LOAbout implements ActionBar.OnNaviga
 
         // Set the adapter for the list view
         drawerList.setAdapter(new ArrayAdapter<String>(this,
-                R.layout.item_in_drawer, DocumentProviderFactory.getNames()));
+                R.layout.item_in_drawer, documentProviderFactory.getNames()));
         // Set the list's click listener
         drawerList.setOnItemClickListener(new ListView.OnItemClickListener() {
             @Override
             public void onItemClick(AdapterView parent, View view,
                     int position, long id) {
-                documentProvider = DocumentProviderFactory.getProvider(position);
+                documentProvider = documentProviderFactory.getProvider(position);
                 homeDirectory = documentProvider.getRootDirectory();
                 currentDirectory = homeDirectory;
                 createUI();