Create InstallMissingPackageDialog with newly-exposed function from Marketplace

This adds a new function to the API of the Marketplace plug-in.
It's not pretty, but it's going to be how it is for a while.

Done to fix a critical build issue. The 'import plugins' thing works from source but not on the build.

plugins/3MFReader/WorkspaceDialog.py

@@ -1,19 +1,20 @@
-# Copyright (c) 2020 Ultimaker B.V.
+# Copyright (c) 2022 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
-from typing import List, Optional, Dict, cast
 
 from PyQt6.QtCore import pyqtSignal, QObject, pyqtProperty, QCoreApplication, QUrl
 from PyQt6.QtGui import QDesktopServices
+from typing import List, Optional, Dict, cast
 
-from UM.FlameProfiler import pyqtSlot
-from UM.PluginRegistry import PluginRegistry
+from cura.Settings.GlobalStack import GlobalStack
 from UM.Application import Application
+from UM.FlameProfiler import pyqtSlot
 from UM.i18n import i18nCatalog
+from UM.Logger import Logger
+from UM.Message import Message
+from UM.PluginRegistry import PluginRegistry
 from UM.Settings.ContainerRegistry import ContainerRegistry
-from cura.Settings.GlobalStack import GlobalStack
-from plugins.Marketplace.InstallMissingPackagesDialog import InstallMissingPackageDialog
+
 from .UpdatableMachinesModel import UpdatableMachinesModel
-from UM.Message import Message
 
 import os
 import threading
@@ -292,8 +293,10 @@ class WorkspaceDialog(QObject):
 
     @pyqtSlot()
     def installMissingPackages(self) -> None:
-        self._install_missing_package_dialog = InstallMissingPackageDialog(self._missing_package_metadata, self.showMissingMaterialsWarning)
-        self._install_missing_package_dialog.show()
+        marketplace_plugin = PluginRegistry.getInstance().getPluginObject("Marketplace")
+        if not marketplace_plugin:
+            Logger.warning("Could not show dialog to install missing plug-ins. Is Marketplace plug-in not available?")
+        marketplace_plugin.showInstallMissingPackageDialog(self._missing_package_metadata, self.showMissingMaterialsWarning)  # type: ignore
 
     def getResult(self) -> Dict[str, Optional[str]]:
         if "machine" in self._result and self.updatableMachinesModel.count <= 1:

plugins/Marketplace/Marketplace.py

@@ -3,15 +3,15 @@
 
 import os.path
 from PyQt6.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject
-from typing import Optional, cast
+from typing import Callable, cast, Dict, List, Optional
 
 from cura.CuraApplication import CuraApplication  # Creating QML objects and managing packages.
-
 from UM.Extension import Extension  # We are implementing the main object of an extension here.
 from UM.PluginRegistry import PluginRegistry  # To find out where we are stored (the proper way).
 
-from .RemotePackageList import RemotePackageList  # To register this type with QML.
+from .InstallMissingPackagesDialog import InstallMissingPackageDialog  # To allow creating this dialogue from outside of the plug-in.
 from .LocalPackageList import LocalPackageList  # To register this type with QML.
+from .RemotePackageList import RemotePackageList  # To register this type with QML.
 
 
 class Marketplace(Extension, QObject):
@@ -118,3 +118,15 @@ class Marketplace(Extension, QObject):
     @pyqtProperty(bool, notify=showRestartNotificationChanged)
     def showRestartNotification(self) -> bool:
         return self._restart_needed
+
+    def showInstallMissingPackageDialog(self, packages_metadata: List[Dict[str, str]], ignore_warning_callback: Callable[[], None]) -> None:
+        """
+        Show a dialog that prompts the user to install certain packages.
+
+        The dialog is worded for packages that are missing and required for a certain operation.
+        :param packages_metadata: The metadata of the packages that are missing.
+        :param ignore_warning_callback: A callback that gets executed when the user ignores the pop-up, to show them a
+        warning.
+        """
+        dialog = InstallMissingPackageDialog(packages_metadata, ignore_warning_callback)
+        dialog.show()