CURA-5035 Don't show required plugins

Also renamed folder of UserAgreementPlugin to UserAgreement

plugins/UserAgreement/UserAgreement.py

@@ -0,0 +1,48 @@
+# Copyright (c) 2017 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+
+from UM.Extension import Extension
+from UM.Preferences import Preferences
+from UM.Application import Application
+from UM.PluginRegistry import PluginRegistry
+from UM.Logger import Logger
+
+from cura.CuraApplication import CuraApplication
+
+from PyQt5.QtCore import QObject, pyqtSlot
+
+import os.path
+
+class UserAgreement(QObject, Extension):
+    def __init__(self):
+        super(UserAgreement, self).__init__()
+        self._user_agreement_window = None
+        self._user_agreement_context = None
+        Application.getInstance().engineCreatedSignal.connect(self._onEngineCreated)
+        Preferences.getInstance().addPreference("general/accepted_user_agreement", False)
+
+    def _onEngineCreated(self):
+        if not Preferences.getInstance().getValue("general/accepted_user_agreement"):
+            self.showUserAgreement()
+
+    def showUserAgreement(self):
+        if not self._user_agreement_window:
+            self.createUserAgreementWindow()
+
+        self._user_agreement_window.show()
+
+    @pyqtSlot(bool)
+    def didAgree(self, user_choice):
+        if user_choice:
+            Logger.log("i", "User agreed to the user agreement")
+            Preferences.getInstance().setValue("general/accepted_user_agreement", True)
+            self._user_agreement_window.hide()
+        else:
+            Logger.log("i", "User did NOT agree to the user agreement")
+            Preferences.getInstance().setValue("general/accepted_user_agreement", False)
+            CuraApplication.getInstance().quit()
+        CuraApplication.getInstance().setNeedToShowUserAgreement(False)
+
+    def createUserAgreementWindow(self):
+        path = os.path.join(PluginRegistry.getInstance().getPluginPath(self.getPluginId()), "UserAgreement.qml")
+        self._user_agreement_window = Application.getInstance().createQmlComponent(path, {"manager": self})