Move MIME type declarations into constructors of readers

So that if you disable the plug-in, the MIME type declaration is also not added.

Fixes #4151.

plugins/GCodeGzReader/GCodeGzReader.py

@@ -7,20 +7,19 @@ from UM.Mesh.MeshReader import MeshReader #The class we're extending/implementin
 from UM.MimeTypeDatabase import MimeTypeDatabase, MimeType #To add the .gcode.gz files to the MIME type database.
 from UM.PluginRegistry import PluginRegistry
 
-MimeTypeDatabase.addMimeType(
-    MimeType(
-        name = "application/x-cura-compressed-gcode-file",
-        comment = "Cura Compressed GCode File",
-        suffixes = ["gcode.gz"]
-    )
-)
-
 ##  A file reader that reads gzipped g-code.
 #
 #   If you're zipping g-code, you might as well use gzip!
 class GCodeGzReader(MeshReader):
     def __init__(self) -> None:
         super().__init__()
+        MimeTypeDatabase.addMimeType(
+            MimeType(
+                name = "application/x-cura-compressed-gcode-file",
+                comment = "Cura Compressed GCode File",
+                suffixes = ["gcode.gz"]
+            )
+        )
         self._supported_extensions = [".gcode.gz"]
 
     def _read(self, file_name):

plugins/GCodeReader/GCodeReader.py

@@ -12,13 +12,7 @@ catalog = i18nCatalog("cura")
 from . import MarlinFlavorParser, RepRapFlavorParser
 
 
-MimeTypeDatabase.addMimeType(
+
-    MimeType(
-        name = "application/x-cura-gcode-file",
-        comment = "Cura GCode File",
-        suffixes = ["gcode"]
-    )
-)
 
 
 # Class for loading and parsing G-code files
@@ -30,7 +24,15 @@ class GCodeReader(MeshReader):
 
     def __init__(self) -> None:
         super().__init__()
+        MimeTypeDatabase.addMimeType(
+            MimeType(
+                name = "application/x-cura-gcode-file",
+                comment = "Cura GCode File",
+                suffixes = ["gcode"]
+            )
+        )
         self._supported_extensions = [".gcode", ".g"]
+
         self._flavor_reader = None
 
         Application.getInstance().getPreferences().addPreference("gcodereader/show_caution", True)

plugins/UFPWriter/UFPWriter.py

@@ -1,5 +1,6 @@
 #Copyright (c) 2018 Ultimaker B.V.
 #Cura is released under the terms of the LGPLv3 or higher.
+
 from typing import cast
 
 from Charon.VirtualFile import VirtualFile #To open UFP files.
@@ -9,6 +10,7 @@ from io import StringIO #For converting g-code to bytes.
 from UM.Application import Application
 from UM.Logger import Logger
 from UM.Mesh.MeshWriter import MeshWriter #The writer we need to implement.
+from UM.MimeTypeDatabase import MimeTypeDatabase, MimeType
 from UM.PluginRegistry import PluginRegistry #To get the g-code writer.
 from PyQt5.QtCore import QBuffer
 
@@ -22,6 +24,15 @@ catalog = i18nCatalog("cura")
 class UFPWriter(MeshWriter):
     def __init__(self):
         super().__init__(add_to_recent_files = False)
+
+        MimeTypeDatabase.addMimeType(
+            MimeType(
+                name = "application/x-cura-stl-file",
+                comment = "Cura UFP File",
+                suffixes = ["ufp"]
+            )
+        )
+
         self._snapshot = None
         Application.getInstance().getOutputDeviceManager().writeStarted.connect(self._createSnapshot)
 

plugins/UFPWriter/__init__.py

@@ -11,16 +11,6 @@ except ImportError:
 
 from UM.i18n import i18nCatalog #To translate the file format description.
 from UM.Mesh.MeshWriter import MeshWriter #For the binary mode flag.
-from UM.MimeTypeDatabase import MimeTypeDatabase, MimeType
-
-
-MimeTypeDatabase.addMimeType(
-    MimeType(
-        name = "application/x-cura-stl-file",
-        comment = "Cura UFP File",
-        suffixes = ["ufp"]
-    )
-)
 
 i18n_catalog = i18nCatalog("cura")