From fc617b0f936c1707a5e0f216de4cd884196bd61b Mon Sep 17 00:00:00 2001
From: Stefano Simonelli <16114781+s-simoncelli@users.noreply.github.com>
Date: Sat, 17 Feb 2024 13:57:07 +0000
Subject: [PATCH] Reload the editor if the JSON file is changed externally

---
 pywr_editor/app.py                |  2 --
 pywr_editor/main_window.py        | 35 ++++++++++++++++++++++++++++++-
 pywr_editor/model/model_config.py | 13 ++++++++++++
 3 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/pywr_editor/app.py b/pywr_editor/app.py
index d40d6b62..3d64d9a0 100644
--- a/pywr_editor/app.py
+++ b/pywr_editor/app.py
@@ -63,8 +63,6 @@ def app() -> None:
     QApplication.setHighDpiScaleFactorRoundingPolicy(
         Qt.HighDpiScaleFactorRoundingPolicy.PassThrough
     )
-    QApplication.setAttribute(Qt.AA_EnableHighDpiScaling)
-    QApplication.setAttribute(Qt.AA_UseHighDpiPixmaps)
 
     # create new model command
     if create_new is not None:
diff --git a/pywr_editor/main_window.py b/pywr_editor/main_window.py
index 73b46269..cb7d3e3f 100644
--- a/pywr_editor/main_window.py
+++ b/pywr_editor/main_window.py
@@ -5,7 +5,7 @@
 from typing import Literal
 
 import PySide6
-from PySide6.QtCore import Signal, Slot
+from PySide6.QtCore import QTimer, Signal, Slot
 from PySide6.QtGui import QAction, QKeySequence, Qt, QUndoStack
 from PySide6.QtWidgets import QFileDialog, QMainWindow, QMessageBox, QSplitter
 
@@ -93,6 +93,12 @@ def __init__(self, model_file: str | None = None):
             return
         self.model_config.model_changed.connect(self.on_model_change)
 
+        # listen for file changes
+        self.timer = QTimer(self)
+        # noinspection PyUnresolvedReferences
+        self.timer.timeout.connect(self.listen_for_changes)
+        self.timer.start(3000)
+
         self.editor_settings = Settings(model_file)
         # store recent files
         if model_file is not None:
@@ -1092,3 +1098,30 @@ def reload_model_file(self) -> None:
             self.prompt_unsaved_changes = False
             MainWindow(self.model_file)
             self.close()
+
+    @Slot()
+    def listen_for_changes(self) -> None:
+        """
+        Check whether the file is changed externally and reload the model.
+        :return: None
+        """
+        # do not refresh if the window has not focus
+        if not self.window().isActiveWindow():
+            return
+
+        # noinspection PyBroadException
+        try:
+            with open(self.model_file, "r") as file:
+                # only reload the editor if there are not changes made using the editor
+                if (
+                    file.read() != self.model_config.as_string
+                    and not self.model_config.has_changes
+                ):
+                    self.logger.debug(
+                        "Reloading model because it was changed externally"
+                    )
+                    self.timer.stop()
+                    self.close()
+                    MainWindow(self.model_file)
+        except Exception:
+            pass
diff --git a/pywr_editor/model/model_config.py b/pywr_editor/model/model_config.py
index ab11e616..fc8ea0d6 100644
--- a/pywr_editor/model/model_config.py
+++ b/pywr_editor/model/model_config.py
@@ -452,6 +452,19 @@ def reload_file_info(self) -> None:
         """
         self.file = ModelFileInfo(self.json_file)
 
+    @property
+    def as_string(self) -> str | bool:
+        """
+        Saves the model as JSON string.
+        :return: A string containing the model, or False if the model cannot be
+        converted to a string.
+        """
+        # noinspection PyBroadException
+        try:
+            return json.dumps(self.json, indent=2)
+        except Exception:
+            return False
+
     def save(self) -> bool | str:
         """
         Saves the JSON file.