From 8dcde696d1996d892b3c241766984617405e564e Mon Sep 17 00:00:00 2001
From: David Yonge-Mallo <dlyongemallo@users.noreply.github.com>
Date: Sun, 10 Dec 2023 09:59:23 +0100
Subject: [PATCH] Enable "File|Export to tikz" only if active panel is a proof.

---
 test/test_mainwindow.py | 18 ++++++++++++++++++
 zxlive/mainwindow.py    |  6 ++++++
 2 files changed, 24 insertions(+)

diff --git a/test/test_mainwindow.py b/test/test_mainwindow.py
index f63ece63..793c8cde 100644
--- a/test/test_mainwindow.py
+++ b/test/test_mainwindow.py
@@ -66,8 +66,26 @@ def test_undo_redo_actions(app: MainWindow) -> None:
 
 
 def test_start_derivation(app: MainWindow, qtbot: QtBot) -> None:
+    # Demo graph is not a proof, so export to tikz should be disabled.
     assert app.active_panel is not None
     assert isinstance(app.active_panel, GraphEditPanel)
+    assert not app.export_tikz_proof.isEnabled()
+
+    # Start a derivation. Export to tikz is enabled.
     qtbot.mouseClick(app.active_panel.start_derivation, QtCore.Qt.MouseButton.LeftButton)
     assert app.tab_widget.count() == 2
     assert isinstance(app.active_panel, ProofPanel)
+    assert app.export_tikz_proof.isEnabled()
+
+    # Switch to the demo graph tab. Export to tikz is disabled.
+    app.tab_widget.setCurrentIndex(0)
+    assert not app.export_tikz_proof.isEnabled()
+
+    # Switch back to the proof tab. Export to tikz is enabled.
+    app.tab_widget.setCurrentIndex(1)
+    assert app.export_tikz_proof.isEnabled()
+
+    # Close the proof tab. Export to tikz is disabled.
+    app.close_action.trigger()
+    assert app.tab_widget.count() == 1
+    assert not app.export_tikz_proof.isEnabled()
diff --git a/zxlive/mainwindow.py b/zxlive/mainwindow.py
index 55111ac4..73097ecc 100644
--- a/zxlive/mainwindow.py
+++ b/zxlive/mainwindow.py
@@ -181,6 +181,9 @@ def _reset_menus(self, has_active_tab: bool) -> None:
         self.fit_view_action.setEnabled(has_active_tab)
         self.show_matrix_action.setEnabled(has_active_tab)
 
+        # Export to tikz is enabled only if there is a proof in the active tab.
+        self.export_tikz_proof.setEnabled(has_active_tab and isinstance(self.active_panel, ProofPanel))
+
         # Paste is enabled only if there is something in the clipboard.
         self.paste_action.setEnabled(has_active_tab and self.copied_graph is not None)
 
@@ -253,6 +256,7 @@ def tab_changed(self, i: int) -> None:
         self._redo_changed()
         if self.active_panel:
             self.active_panel.update_colors()
+            self._reset_menus(True)
 
     def _undo_changed(self) -> None:
         if self.active_panel:
@@ -318,6 +322,8 @@ def close_tab(self, i: int) -> bool:
         self.tab_widget.removeTab(i)
         if self.tab_widget.count() == 0:
             self._reset_menus(False)
+        else:
+            self._reset_menus(True)
         return True
 
     def handle_save_file_action(self) -> bool: