Add ProgressDialog to PySide upgrade action

activity_browser/actions/pyside_upgrade.py

@@ -2,46 +2,109 @@
 import os
 import sys
 import subprocess
+import time
 
+from activity_browser import application
 from activity_browser.actions.base import ABAction, exception_dialogs
-from activity_browser.ui.icons import qicons
+from activity_browser.ui import threading, icons
+
+from qtpy import QtWidgets
+from qtpy.QtCore import Signal, SignalInstance
 
 
 class PysideUpgrade(ABAction):
     """
-    ABAction to install all the default data: biosphere, IC's etcetera.
+    ABAction to install PySide6 through PyPI/pip. Installs PySide6, sets the environment variable for QtPy to use
+    PySide6 and then restarts the Activity Browser through a subprocess.
     """
 
-    icon = qicons.forward
+    icon = icons.qicons.forward
     text = "Upgrade installation to PySide6"
 
     @classmethod
     @exception_dialogs
     def run(cls):
+
+        # slot definition to update the progress dialog with thread updates
+        def update_dialog_slot(progress: int, label: str):
+            dialog.setValue(progress)
+            dialog.setLabelText(label)
+
         assert not qtpy.PYSIDE6, "Already running PySide6"
         assert cls.in_conda(), "Not inside a Conda environment"
 
-        cls.pypi_install()
-        cls.set_conda_env_var()
-        cls.restart()
+        # setup a progress dialog to show the user we're doing something
+        dialog = QtWidgets.QProgressDialog(application.main_window)
+        dialog.setWindowTitle("Upgrading GUI back-end")
+        dialog.setMaximum(0)
+        dialog.setCancelButton(None)
+
+        # messages can get quite long, so enable word-wrapping
+        lbl = dialog.findChild(QtWidgets.QLabel)
+        lbl.setWordWrap(True)
+
+        # initialize thread and connect signals
+        thread = PySideUpgradeThread(application)
+        thread.status.connect(update_dialog_slot)
+        thread.exit.connect(sys.exit)
 
+        thread.start()
+        dialog.exec_()
 
     @staticmethod
     def in_conda() -> bool:
+        """Returns true when the current shell is in a Conda environment."""
         return bool(os.environ.get("CONDA_DEFAULT_ENV", False))
 
-    @staticmethod
-    def pypi_install():
-        process = subprocess.run(["pip", "install", "pyside6"])
+
+class PySideUpgradeThread(threading.ABThread):
+    exit: SignalInstance = Signal()
+
+    def run_safely(self):
+        self.pip_installation()
+        self.set_conda_env_var()
+        self.restart()
+
+    def pip_installation(self):
+        """
+        Install PySide6 from PyPI using a subprocess.Popen call
+        """
+        self.status.emit(0, "Installing PySide6 through pip")
+
+        # open subprocess that installs PySide6
+        process = subprocess.Popen(["pip", "install", "pyside6"], stdout=subprocess.PIPE)
+
+        while process.poll() is None:  # block until the subprocess is finished
+            # format stdout
+            line = process.stdout.readline().decode().strip()
+            if not line:
+                continue
+
+            # redirect stdout to both console and progress dialog
+            print(line)
+            self.status.emit(0, line)
+
         assert process.returncode == 0, "Failed to install PySide6"
 
-    @staticmethod
-    def set_conda_env_var():
+    def set_conda_env_var(self):
+        """
+        Set the QT_API QtPy environment variable persistently for this conda environment
+        """
+        self.status.emit(0, "Setting QT_API environment variable")
+
         subprocess.run(["conda", "env", "config", "vars", "set", "QT_API=pyside6"])
-        os.environ["QT_API"] = "pyside6"
+        os.environ["QT_API"] = "pyside6"  # also set for the env directly for the restart
 
-    @staticmethod
-    def restart():
+    def restart(self):
+        """
+        Restarts the Activity Browser through a subprocess. Sleeps 5 seconds to allow the user to register
+        the restart.
+        """
+        self.status.emit(0, "Restarting the Activity Browser")
         subprocess.Popen(["python", "-c", "import activity_browser; activity_browser.run_activity_browser()"])
-        sys.exit()
+        time.sleep(5)
+
+        # signal restart through the exit signal as sys.exit needs to be called in the main thread.
+        self.exit.emit()
+