Add support for opening files from the command line.

zxlive/app.py

@@ -16,11 +16,12 @@
 from __future__ import annotations
 
 from PySide6.QtWidgets import QApplication
+from PySide6.QtCore import QCommandLineParser
 import sys
+from .mainwindow import MainWindow
 
-sys.path.insert(0,'../pyzx') # So that it can find a local copy of pyzx
+sys.path.insert(0, '../pyzx')  # So that it can find a local copy of pyzx
 
-from .mainwindow import MainWindow
 
 class ZXLive(QApplication):
     """The main ZX Live application
@@ -32,10 +33,20 @@ def __init__(self) -> None:
         super().__init__(sys.argv)
         self.setApplicationName('ZX Live')
         self.setDesktopFileName('ZX Live')
+        self.setApplicationVersion('0.1')  # TODO: read this from pyproject.toml if possible
         self.main_window = MainWindow()
 
         self.lastWindowClosed.connect(self.quit)
 
+        parser = QCommandLineParser()
+        parser.setApplicationDescription("ZX Live - An interactive tool for the ZX calculus")
+        parser.addHelpOption()
+        parser.addVersionOption()
+        parser.addPositionalArgument("files", "File(s) to open.", "[files...]")
+        parser.process(self)
+        for f in parser.positionalArguments():
+            self.main_window.open_file_from_path(f)
+
 
 def main() -> None:
     """Main entry point for ZX Live"""

zxlive/dialogs.py

@@ -85,6 +85,7 @@ def show_error_msg(title: str, description: Optional[str] = None) -> None:
         msg.setInformativeText(description)
     msg.exec()
 
+
 def import_diagram_dialog(parent: QWidget) -> Optional[ImportGraphOutput | ImportProofOutput | ImportRuleOutput]:
     """Shows a dialog to import a diagram from disk.
 
@@ -98,9 +99,17 @@ def import_diagram_dialog(parent: QWidget) -> Optional[ImportGraphOutput | Impor
         # This happens if the user clicks on cancel
         return None
 
+    return import_diagram_from_file(file_path, selected_filter)
+
+
+def import_diagram_from_file(file_path: str, selected_filter: str = FileFormat.All.filter) -> \
+        Optional[ImportGraphOutput | ImportProofOutput | ImportRuleOutput]:
+    """Imports a diagram from a given file path.
+
+    Returns the imported graph or `None` if the import failed."""
     file = QFile(file_path)
     if not file.open(QIODevice.OpenModeFlag.ReadOnly | QIODevice.OpenModeFlag.Text):
-        show_error_msg("Could not open file")
+        show_error_msg(f"Could not open file: {file_path}.")
         return None
     stream = QTextStream(file)
     data = stream.readAll()
@@ -111,7 +120,7 @@ def import_diagram_dialog(parent: QWidget) -> Optional[ImportGraphOutput | Impor
         ext = file_path.split(".")[-1]
         selected_format = next(f for f in FileFormat if f.extension == ext)
 
-    # TODO: This would be nicer with match statements...
+    # TODO: This would be nicer with match statements (requires python 3.10 though)...
     try:
         if selected_format == FileFormat.ZXProof:
             return ImportProofOutput(selected_format, file_path, ProofModel.from_json(data))
@@ -135,11 +144,11 @@ def import_diagram_dialog(parent: QWidget) -> Optional[ImportGraphOutput | Impor
                     try:
                         return ImportGraphOutput(FileFormat.TikZ, file_path, GraphT.from_tikz(data))  # type: ignore
                     except:
-                        show_error_msg(f"Failed to import {selected_format.name} file", "Couldn't determine filetype.")
+                        show_error_msg(f"Failed to import {selected_format.name} file", f"Couldn't determine filetype: {file_path}.")
                         return None
 
     except Exception as e:
-        show_error_msg(f"Failed to import {selected_format.name} file", str(e))
+        show_error_msg(f"Failed to import {selected_format.name} file: {file_path}", str(e))
         return None
 
 def write_to_file(file_path: str, data: str) -> bool:

zxlive/mainwindow.py

@@ -36,7 +36,7 @@
                       ImportRuleOutput, create_new_rewrite,
                       export_diagram_dialog, export_proof_dialog,
                       export_rule_dialog, get_lemma_name_and_description,
-                      import_diagram_dialog, show_error_msg)
+                      import_diagram_dialog, import_diagram_from_file, show_error_msg)
 from zxlive.settings_dialog import open_settings_dialog
 
 from .edit_panel import GraphEditPanel
@@ -270,6 +270,14 @@ def _redo_changed(self) -> None:
     def open_file(self) -> None:
         out = import_diagram_dialog(self)
         if out is not None:
+            self._open_file_from_output(out)
+
+    def open_file_from_path(self, file_path: str) -> None:
+        out = import_diagram_from_file(file_path)
+        if out is not None:
+            self._open_file_from_output(out)
+
+    def _open_file_from_output(self, out: ImportGraphOutput | ImportProofOutput | ImportRuleOutput) -> None:
             name = QFileInfo(out.file_path).baseName()
             if isinstance(out, ImportGraphOutput):
                 self.new_graph(out.g, name)