Added Storage permission handling on the Android Viewer

This patch prevents document browsing and creating
a new document from happening when write external
storage permission is denied by the user.
Signed-off-by: Mert Tümer <merttumer7@gmail.com>

Change-Id: Idf39a291a15a9dac023f4318329baed1baa90e14
Reviewed-on: https://gerrit.libreoffice.org/52868Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

android/source/res/layout/activity_document_browser.xml

@@ -125,6 +125,7 @@
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:clickable="true"
+        android:visibility="invisible"
         app:backgroundTint="@color/background_normal"
         app:fabSize="normal"
         app:layout_constraintBottom_toBottomOf="parent"

android/source/src/java/org/libreoffice/storage/external/ExtsdDocumentsProvider.java

 package org.libreoffice.storage.external;
 
+import android.Manifest;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
+import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Environment;
@@ -160,7 +162,7 @@ public class ExtsdDocumentsProvider implements IExternalDocumentProvider,
         // getExternalStorageState().equals(Environment.MEDIA_MOUNTED) && isExternalStorageRemovable()
         // but they refer to the primary external storage anyway, so what currently is covered by the
         // "LocalDocumentsProvider"
-        return rootPathURI!=null;
+        return rootPathURI!=null && ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
     }
 
     @Override

android/source/src/java/org/libreoffice/storage/external/OTGDocumentsProvider.java

@@ -85,6 +85,6 @@ public class OTGDocumentsProvider implements IExternalDocumentProvider,
     @Override
     public boolean checkProviderAvailability(Context context) {
         // check if system supports USB Host
-        return context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_USB_HOST);
+        return rootPathURI.length()>0 && context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_USB_HOST);
     }
 }

android/source/src/java/org/libreoffice/storage/local/LocalDocumentsDirectoryProvider.java

@@ -71,6 +71,6 @@ public class LocalDocumentsDirectoryProvider extends LocalDocumentsProvider {
     @Override
     public boolean checkProviderAvailability(Context context) {
         File documentsDirectory = getDocumentsDir();
-        return documentsDirectory.exists() || ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
+        return documentsDirectory.exists() && ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
     }
 }

android/source/src/java/org/libreoffice/storage/local/LocalDocumentsProvider.java

@@ -16,8 +16,11 @@ import org.libreoffice.storage.IFile;
 
 import org.libreoffice.R;
 
+import android.Manifest;
 import android.content.Context;
+import android.content.pm.PackageManager;
 import android.os.Environment;
+import android.support.v4.content.ContextCompat;
 
 /**
  * Implementation of IDocumentProvider for the local file system.
@@ -52,6 +55,6 @@ public class LocalDocumentsProvider implements IDocumentProvider {
 
     @Override
     public boolean checkProviderAvailability(Context context) {
-        return true;
+        return ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
     }
 }

android/source/src/java/org/libreoffice/storage/owncloud/OwnCloudProvider.java

@@ -38,6 +38,7 @@ public class OwnCloudProvider implements IDocumentProvider,
     private String serverUrl;
     private String userName;
     private String password;
+    private RemoteOperationResult result;
 
     public OwnCloudProvider(int id, Context context) {
         this.id = id;
@@ -80,7 +81,7 @@ public class OwnCloudProvider implements IDocumentProvider,
     public IFile createFromUri(Context context, URI uri) {
         ReadRemoteFileOperation refreshOperation = new ReadRemoteFileOperation(
                 uri.getPath());
-        RemoteOperationResult result = refreshOperation.execute(client);
+        this.result = refreshOperation.execute(client);
         if (!result.isSuccess()) {
             throw buildRuntimeExceptionForResultCode(result.getCode());
         }
@@ -180,6 +181,6 @@ public class OwnCloudProvider implements IDocumentProvider,
 
     @Override
     public boolean checkProviderAvailability(Context context) {
-        return true;
+        return result != null && this.result.isSuccess();
     }
 }

android/source/src/java/org/libreoffice/ui/LibreOfficeUIActivity.java

@@ -65,6 +65,7 @@ import android.widget.TextView;
 import android.widget.Toast;
 
 import org.libreoffice.AboutDialogFragment;
+import org.libreoffice.LOKitShell;
 import org.libreoffice.LibreOfficeMainActivity;
 import org.libreoffice.R;
 import org.libreoffice.SettingsActivity;
@@ -95,7 +96,7 @@ public class LibreOfficeUIActivity extends AppCompatActivity implements Settings
     private int sortMode;
     private boolean showHiddenFiles;
     // dynamic permissions IDs
-    private static int PERMISSION_READ_EXTERNAL_STORAGE = 0;
+    private static final int PERMISSION_READ_EXTERNAL_STORAGE = 0;
 
     FileFilter fileFilter;
     FilenameFilter filenameFilter;
@@ -166,16 +167,15 @@ public class LibreOfficeUIActivity extends AppCompatActivity implements Settings
         registerReceiver(mUSBReceiver, filter);
         // init UI and populate with contents from the provider
         if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
-            // TODO: remove local document providers if really is denied, code right now assumes it is granted/
-            // there is no onRequestPermissionsResult evaluating the callback
-            // without the read permissions, LO could only load documents passed via intent from other apps
             Log.i(LOGTAG, "no permission to read external storage - asking for permission");
             ActivityCompat.requestPermissions(this,
                     new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
                     PERMISSION_READ_EXTERNAL_STORAGE);
+        } else {
+            switchToDocumentProvider(documentProviderFactory.getDefaultProvider());
+            setEditFABVisibility(View.VISIBLE);
         }
 
-        switchToDocumentProvider(documentProviderFactory.getDefaultProvider());
         createUI();
         fabOpenAnimation = AnimationUtils.loadAnimation(this, R.anim.fab_open);
         fabCloseAnimation = AnimationUtils.loadAnimation(this, R.anim.fab_close);
@@ -215,6 +215,7 @@ public class LibreOfficeUIActivity extends AppCompatActivity implements Settings
         final ArrayList<IFile> recentFiles = new ArrayList<IFile>();
         for (String recentFileString : recentFileStrings) {
             try {
+                if(documentProvider != null)
                     recentFiles.add(documentProvider.createFromUri(this, new URI(recentFileString)));
             } catch (URISyntaxException e) {
                 e.printStackTrace();
@@ -347,7 +348,7 @@ public class LibreOfficeUIActivity extends AppCompatActivity implements Settings
 
     private void refreshView() {
         // enable home icon as "up" if required
-        if (!currentDirectory.equals(homeDirectory)) {
+        if (currentDirectory != null && homeDirectory != null && !currentDirectory.equals(homeDirectory)) {
             drawerToggle.setDrawerIndicatorEnabled(false);
         } else {
             drawerToggle.setDrawerIndicatorEnabled(true);
@@ -371,7 +372,7 @@ public class LibreOfficeUIActivity extends AppCompatActivity implements Settings
             if (isFabMenuOpen) {
                 collapseFabMenu();
             }
-        } else if (!currentDirectory.equals(homeDirectory)) {
+        } else if (currentDirectory != null && homeDirectory != null && !currentDirectory.equals(homeDirectory)) {
             // navigate upwards in directory hierarchy
             openParentDirectory();
         } else if (isFabMenuOpen) {
@@ -864,13 +865,18 @@ public class LibreOfficeUIActivity extends AppCompatActivity implements Settings
     protected void onSaveInstanceState(Bundle outState) {
         // TODO Auto-generated method stub
         super.onSaveInstanceState(outState);
+
+        if(currentDirectory != null) {
             outState.putString(CURRENT_DIRECTORY_KEY, currentDirectory.getUri().toString());
+            Log.d(LOGTAG, currentDirectory.toString() + Integer.toString(filterMode) + Integer.toString(viewMode));
+        }
         outState.putInt(FILTER_MODE_KEY, filterMode);
         outState.putInt(EXPLORER_VIEW_TYPE_KEY , viewMode);
+        if(documentProvider != null)
             outState.putInt(DOC_PROVIDER_KEY, documentProvider.getId());
+
         outState.putBoolean(ENABLE_SHOW_HIDDEN_FILES_KEY , showHiddenFiles);
 
-        Log.d(LOGTAG, currentDirectory.toString() + Integer.toString(filterMode) + Integer.toString(viewMode));
         //prefs.edit().putInt(EXPLORER_VIEW_TYPE, viewType).commit();
         Log.d(LOGTAG, "savedInstanceState");
     }
@@ -1165,6 +1171,31 @@ public class LibreOfficeUIActivity extends AppCompatActivity implements Settings
             }
         }
     }
+
+    private void setEditFABVisibility(final int visibility){
+        LOKitShell.getMainHandler().post(new Runnable() {
+            @Override
+            public void run() {
+                editFAB.setVisibility(visibility);
+            }
+        });
+    }
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
+        switch(requestCode){
+            case PERMISSION_READ_EXTERNAL_STORAGE:
+                if(permissions.length>0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
+                    switchToDocumentProvider(documentProviderFactory.getDefaultProvider());
+                    setEditFABVisibility(View.VISIBLE);
+                } else {
+                    setEditFABVisibility(View.INVISIBLE);
+                }
+                break;
+                default:
+                    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        }
+    }
 }
 
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