I173 print help doc in pdf

closes #173 (closed)

Note: the images in help document must be less than 11in/1584px in width to fit in the saved pdf document.

sohstationviewer/view/help_view.py

@@ -108,7 +108,11 @@ class HelpBrowser(QtWidgets.QWidget):
         """
         self.search_results_path: Path = self.docdir_path.joinpath(
             'Search Results.md')
-
+        """
+        default_pdf_file_name: the default name for pdf file when the current
+        help document is saved
+        """
+        self.default_pdf_file_name: str = ''
         # Get screen dimensions
         geom = QtGui.QGuiApplication.screens()[0].availableGeometry()
         self.setGeometry(10, 10,
@@ -373,10 +377,20 @@ class HelpBrowser(QtWidgets.QWidget):
         Load file from file_path to help_view
 
         :param file_path:  absolute path to a document
-        :type file_path: str
         """
         url = QtCore.QUrl.fromLocalFile(file_path)
         self.help_view.setSource(url)
+        self._set_default_pdf_file_name(file_path)
+
+    def _set_default_pdf_file_name(self, file_path: str) -> str:
+        """
+        Set the default_pdf_file_name for the current help document
+
+        :param file_path:  absolute path to a document
+        """
+        file_name = file_path.split(' _ ')[1]
+        file_name = "SOHViewer Help - " + file_name
+        self.default_pdf_file_name = file_name.replace('.help.md', '')
 
     @QtCore.Slot()
     def on_tree_view_item_clicked(self, index: QtCore.QModelIndex):
@@ -541,15 +555,22 @@ class HelpBrowser(QtWidgets.QWidget):
     def save_to_pdf(self):
         """
         Save the current document to pdf file.
+
+        A3 size is selected because the current font look well in that. After
+        the document is saved, user can print it in the size they want. The
+        size of A3 is 11.7 x 16.5. So the width of pictures in the document
+        will be cut off if greater than (11.7 - margins).
+
         Note: the pictures' width in the document must be smaller than 11 in/
             1584px or its content will be cut off.
         """
         home_path = Path.home()
         doc_path = home_path.joinpath("Documents")
-        save_file = QtWidgets.QFileDialog.getSaveFileName(self, 'Save to PDF',
-                                                          doc_path.as_posix())
-        if save_file:
-            filename = save_file[0]
+        file_path = doc_path.joinpath(self.default_pdf_file_name)
+        save_file = QtWidgets.QFileDialog.getSaveFileName(
+            self, 'Save to PDF', file_path.as_posix())[0]
+        if save_file != "":
+            filename = save_file
             if not filename.endswith('.pdf'):
                 filename = filename + '.pdf'
             printer = QPrinter(
@@ -560,6 +581,8 @@ class HelpBrowser(QtWidgets.QWidget):
             printer.setOutputFormat(QPrinter.OutputFormat.PdfFormat)
             printer.setOutputFileName(filename)
             self.help_view.document().print_(printer)
+            msg = f"The current help document has been saved at {filename}"
+            QtWidgets.QMessageBox.information(self, "Document Saved", msg)
 
 
 def main():