Preferences, singletons

Create a Preference dialog for fonts and audio output devices

Turn Preferences and SoundOff into singletons.  No matter how many times
you request a new one, the same instance is returned.

Stop using singals on the parent() to access other instances, such as
sound and Preferences.

lib/preferences.py

@@ -0,0 +1,95 @@
+import json
+import os
+from PyQt6.QtCore import Qt, pyqtSlot
+from PyQt6.QtWidgets import QDialog, QListWidgetItem, QAbstractItemView
+from PyQt6.QtMultimedia import QMediaDevices
+from ui.Preferences import Ui_Dialog
+
+class Preferences(QDialog, Ui_Dialog):
+    _instance = None
+    def __new__(cls):
+        if cls._instance:
+            return cls._instance
+        cls._instance = super(Preferences, cls).__new__(cls)
+        return cls._instance
+    @pyqtSlot(int)
+    def done(self,r):
+        self.hide()
+        super().done(r)
+        return
+    @pyqtSlot()
+    def exec(self):
+        self.show()
+        super().exec()
+        return
+    @pyqtSlot()
+    def open(self):
+        self.show()
+        super().open()
+        return
+
+    def __init__(self, *args, **kwargs):
+        super(Preferences, self).__init__(*args, **kwargs)
+        self.setupUi(self)
+        self.hide()
+        #
+        # Overrides
+        #
+        self.alertList.setSelectionMode(QAbstractItemView.SelectionMode.MultiSelection)
+        self.playerList.setSelectionMode(QAbstractItemView.SelectionMode.MultiSelection)
+        self.readerCombo.setEditable(False)
+        self.phoneticsCombo.setEditable(False)
+        #
+        # End OverRides
+        #
+        for index, output in enumerate(QMediaDevices.audioOutputs()):
+            identifier = output.id().data().decode("utf-8")
+            description = output.description()
+            self.alertList.addItem(description)
+            self.playerList.addItem(description)
+        self.setCurrent()
+        return
+
+    def setCurrent(self):
+        if os.path.exists('preferences.json'):
+            with open('preferences.json','r') as f:
+                self.preferences = json.load(f)
+        else:
+            self.preferences = {
+                'readerFont': 'OpenDyslexic',
+                'phoneticFont': 'Gentium',
+                'alertOutputs': [ 'default' ],
+                'playerOutputs': [ 'Feed for virtual microphone' ]
+            }
+        for output in self.preferences['alertOutputs']:
+            if output == 'default':
+                output = QMediaDevices.defaultAudioOutput().description()
+            for item in self.alertList.findItems(output,Qt.MatchFlag.MatchExactly):
+                item.setSelected(True)
+        for output in self.preferences['playerOutputs']:
+            if output == 'default':
+                output = QMediaDevices.defaultAudioOutput().description()
+            for item in self.playerList.findItems(output,Qt.MatchFlag.MatchExactly ):
+                item.setSelected(True)
+        index = self.readerCombo.findText(self.preferences['readerFont'])
+        if index >= 0:
+            self.readerCombo.setCurrentIndex(index)
+        index = self.phoneticsCombo.findText(self.preferences['phoneticFont'])
+        if index >= 0:
+            self.phoneticsCombo.setCurrentIndex(index)
+        return
+
+    def get(self, name:str =None):
+        if not name:
+            return self.preferences
+        return self.preferences[name]
+    
+    def accept(self):
+        self.preferences['readerFont'] = self.readerCombo.currentFont().family()
+        self.preferences['phoneticFont'] =self.phoneticsCombo.currentFont().family()
+        self.preferences['alertOutputs'] = [ x.data(Qt.ItemDataRole.DisplayRole) for x in self.alertList.selectedItems() ]
+        self.preferences['playerOutputs'] = [ x.data(Qt.ItemDataRole.DisplayRole) for x in self.playerList.selectedItems() ]
+        with open('preferences.json','w') as f:
+            json.dump(self.preferences,f,indent=2)
+        super().accept()
+        return