autotune: improve combo box to be searchable

Author: bresch

autotune/data_selection_window.py

@@ -7,6 +7,7 @@
 import numpy as np
 
 from data_extractor import DataExtractor
+from searchable_combo_box import SearchableComboBox
 
 class DataSelectionWindow(QDialog):
     def __init__(self, filename):
@@ -39,15 +40,11 @@ def __init__(self, filename):
         self.combo_preset.currentIndexChanged.connect(self.selectPreset)
         in_out_group.addRow(QLabel("Preset:"), self.combo_preset)
 
-        self.combo_u = QComboBox()
-        self.combo_u.setEditable(True)
-        self.combo_u.setInsertPolicy(QComboBox.NoInsert)
+        self.combo_u = SearchableComboBox()
         self.combo_u.currentIndexChanged.connect(self.selectUData)
         in_out_group.addRow(QLabel("Input:"), self.combo_u)
 
-        self.combo_y = QComboBox()
-        self.combo_y.setEditable(True)
-        self.combo_y.setInsertPolicy(QComboBox.NoInsert)
+        self.combo_y = SearchableComboBox()
         self.combo_y.currentIndexChanged.connect(self.selectYData)
         in_out_group.addRow(QLabel("Output:"), self.combo_y)
         top_group.addLayout(in_out_group)

autotune/searchable_combo_box.py

@@ -0,0 +1,43 @@
+from PyQt5.QtCore import Qt, QSortFilterProxyModel
+from PyQt5.QtWidgets import QComboBox, QCompleter
+
+class SearchableComboBox(QComboBox):
+    def __init__(self, parent=None):
+        super(SearchableComboBox, self).__init__(parent)
+
+        self.setFocusPolicy(Qt.ClickFocus)
+        self.setEditable(True)
+
+        # prevent insertions into combobox
+        self.setInsertPolicy(QComboBox.NoInsert)
+
+        # filter model for matching items
+        self.pFilterModel = QSortFilterProxyModel(self)
+        self.pFilterModel.setFilterCaseSensitivity(Qt.CaseInsensitive)
+        self.pFilterModel.setSourceModel(self.model())
+
+        # completer that uses filter model
+        self.completer = QCompleter(self.pFilterModel, self)
+        self.completer.setCompletionMode(QCompleter.UnfilteredPopupCompletion)
+        self.setCompleter(self.completer)
+
+        # connect signals
+        self.lineEdit().textEdited[str].connect(self.pFilterModel.setFilterFixedString)
+        self.completer.activated.connect(self.on_completer_activated)
+
+    def on_completer_activated(self, text):
+        if text:
+            index = self.findText(text)
+            self.setCurrentIndex(index)
+            self.activated[str].emit(self.itemText(index))
+
+    def setModel(self, model):
+        super(SearchableComboBox, self).setModel(model)
+        self.pFilterModel.setSourceModel(model)
+        self.completer.setModel(self.pFilterModel)
+
+    def setModelColumn(self, column):
+        self.completer.setCompletionColumn(column)
+        self.pFilterModel.setFilterKeyColumn(column)
+        super(SearchableComboBox, self).setModelColumn(column)
+