added ShareSheet().view_file() method

Author: vesellov

Diff for: README.md

@@ -21,7 +21,7 @@ This package contains three classes, `SharedStorage`, `ShareSheet`, and `Chooser
 
  - `SharedStorage` allows copying files to and from shared storage with the `copy_to_shared()`, `copy_from_shared()`, and `delete_shared()` methods.
 
- - `ShareSheet` allows sending plain text, or a 'shared file' to another app. Using the `share_plain_text()`, `share_file()`, and `share_file_list()` methods, these create an Android ShareSheet used to select the target app.
+ - `ShareSheet` allows sending plain text, or a 'shared file' to another app. Using the `share_plain_text()`, `share_file()`, and `share_file_list()` methods, these create an Android ShareSheet used to select the target app. You can also call the `view_file()` method to open a 'shared file' in another app - Android will try to use default application available for that specific file type.
 
  - `Chooser` allows selecting a 'shared file' using the Android Chooser UI. The callback returns a list of one or more shared files.
 
@@ -138,6 +138,8 @@ Enables sending either plain_text, a file, or a file list to another app. The ta
     def share_file(self, shared_file, app = None):
 
     def share_file_list(self, shared_file_list, app = None):
+
+    def view_file(self, shared_file):
 ```
 
 `plain_text` is a string.

Diff for: src/androidstorage4kivy/sharesheet.py

@@ -65,6 +65,24 @@ def share_file(self, shared_file, app = None):
             Logger.warning('ShareSheet().share_file()')
             Logger.warning(str(e))
 
+    def view_file(self, shared_file):
+        try:
+            self._cleanup_legacy_uri_list()
+            if shared_file == None:
+                return
+            uri = self._legacy_create_uri(shared_file)
+            if uri == None:
+                return
+            cr =  mActivity.getContentResolver()
+            self.MIME = cr.getType(uri)
+            self.send = Intent()
+            self.send.setAction(Intent.ACTION_VIEW)
+            self.send.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+            self.send.setDataAndType(uri, self.MIME)
+            mActivity.startActivity(self.send)
+        except Exception as e:
+            Logger.warning('ShareSheet().view_file()')
+            Logger.warning(str(e))
 
     def share_file_list(self, shared_file_list, app = None):
         try: