android: Suggest file name for PDF export

When using the PDF export feature in Android Viewer,
suggest a file name for the PDF file that matches
the current display name (which is usually the
file name, or "untitled" for a newly created doc
that hasn't been saved yet).

This can be achieved by setting `Intent.EXTRA_TITLE`
for the `ACTION_CREATE_DOCUMENT`. [1]

The `DocumentsContract.EXTRA_INITIAL_URI` already
set previously already results in the same
directory as the doc being preselected in the
file chooser:

> Callers can set a document URI through
> DocumentsContract#EXTRA_INITIAL_URI to indicate the initial location of
> documents navigator. System will do its best to launch the navigator in
> the specified document if it's a folder, or the folder that contains the
> specified document if not.

Filling in the current file name was suggested
in a Google Play review comment for the app.

[1] https://developer.android.com/reference/android/content/Intent#ACTION_CREATE_DOCUMENT

Change-Id: Idbd4a89416089f927e0232ce65161b43059ca46d
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/159959
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

2 files changed, 9 insertions, 0 deletions

diff --git a/android/source/src/java/org/libreoffice/LibreOfficeMainActivity.java b/android/source/src/java/org/libreoffice/LibreOfficeMainActivity.java
index b21ad02383d7..ba371bfd9c8a 100644
--- a/android/source/src/java/org/libreoffice/LibreOfficeMainActivity.java
+++ b/android/source/src/java/org/libreoffice/LibreOfficeMainActivity.java
@@ -350,7 +350,11 @@ public class LibreOfficeMainActivity extends AppCompatActivity implements Settin
         Intent intent = new Intent(Intent.ACTION_CREATE_DOCUMENT);
         intent.addCategory(Intent.CATEGORY_OPENABLE);
         intent.setType(FileUtilities.MIMETYPE_PDF);
+        // suggest directory and file name based on the doc
         intent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, mDocumentUri);
+        final String displayName = toolbarTop.getTitle().toString();
+        final String suggestedFileName = FileUtilities.stripExtensionFromFileName(displayName) + ".pdf";
+        intent.putExtra(Intent.EXTRA_TITLE, suggestedFileName);
 
         startActivityForResult(intent, REQUEST_CODE_EXPORT_TO_PDF);
     }
diff --git a/android/source/src/java/org/libreoffice/ui/FileUtilities.java b/android/source/src/java/org/libreoffice/ui/FileUtilities.java
index 902b30ed7794..7fc8c3c84eb1 100644
--- a/android/source/src/java/org/libreoffice/ui/FileUtilities.java
+++ b/android/source/src/java/org/libreoffice/ui/FileUtilities.java
@@ -124,6 +124,11 @@ public class FileUtilities {
         return mimeType != null && mimeType.endsWith("template");
     }
 
+    public static String stripExtensionFromFileName(final String fileName)
+    {
+        return fileName.split("\\.[A-Za-z0-9]*$")[0];
+    }
+
     /**
      * Tries to retrieve the display (which should be the document name)
      * for the given URI using the given resolver.