Instantiate documents with a filename

Avoid setting document's filename via document.filename and instead
do it via object instantiation where possible.

Incidentally this has to change some window logic. When
select_document() is called it no longer checks if there is already an
open window with no document selected yet. The user can open as many
windows with unselected documents as they want.

dangerzone/cli.py

@@ -28,7 +28,6 @@ def cli_main(
 ) -> None:
     setup_logging()
     global_common = GlobalCommon()
-    document = Document()
 
     display_banner()
 
@@ -44,7 +43,7 @@ def cli_main(
         click.echo("Invalid filename")
         exit(1)
 
-    document.input_filename = os.path.abspath(filename)
+    document = Document(os.path.abspath(filename))
 
     # Validate safe PDF output filename
     if output_filename:

dangerzone/document.py

@@ -14,11 +14,13 @@ class Document:
     document, and validating its info.
     """
 
-    def __init__(self) -> None:
-        # Name of input and out files
+    def __init__(self, input_filename: str = None) -> None:
         self._input_filename: Optional[str] = None
         self._output_filename: Optional[str] = None
 
+        if input_filename:
+            self.input_filename = input_filename
+
     @property
     def input_filename(self) -> str:
         if self._input_filename is None:

dangerzone/gui/__init__.py

@@ -10,6 +10,7 @@ import click
 import colorama
 from PySide2 import QtCore, QtGui, QtWidgets
 
+from ..document import Document
 from ..global_common import GlobalCommon
 from .common import GuiCommon
 from .main_window import MainWindow
@@ -86,16 +87,11 @@ def gui_main(filename: Optional[str]) -> bool:
 
     # Open a document in a window
     def select_document(filename: Optional[str] = None) -> bool:
-        if (
-            len(windows) == 1
-            and windows[list(windows.keys())[0]].document.input_filename == None
-        ):
-            window = windows[list(windows.keys())[0]]
-        else:
-            window_id = uuid.uuid4().hex
-            window = MainWindow(global_common, gui_common, window_id)
-            window.delete_window.connect(delete_window)
-            windows[window_id] = window
+        document = Document(filename)
+        window_id = uuid.uuid4().hex
+        window = MainWindow(global_common, gui_common, window_id)
+        window.delete_window.connect(delete_window)
+        windows[window_id] = window
 
         if filename:
             # Validate filename

dangerzone/gui/main_window.py

@@ -24,13 +24,17 @@ class MainWindow(QtWidgets.QMainWindow):
     delete_window = QtCore.Signal(str)
 
     def __init__(
-        self, global_common: GlobalCommon, gui_common: GuiCommon, window_id: str
+        self,
+        global_common: GlobalCommon,
+        gui_common: GuiCommon,
+        window_id: str,
+        document: Document,
     ) -> None:
         super(MainWindow, self).__init__()
         self.global_common = global_common
         self.gui_common = gui_common
         self.window_id = window_id
-        self.document = Document()
+        self.document = document
 
         self.setWindowTitle("Dangerzone")
         self.setWindowIcon(self.gui_common.get_window_icon())