Improve the device selection list

While typing the combobox text, the validator adapts the contents of
the dropdown menu to only those entries that match the text typed.
So one can enter "64", and will only be presented all device that
have a 64 in their name (which are a few more than just those with
64 KiB of flash).

src/python/adgui.py

@@ -434,10 +434,11 @@ def get_entries(self):
 
 class listValidator(QValidator):
 
-    def __init__(self, liste, buttonbox):
+    def __init__(self, liste, buttonbox, combobox):
         super().__init__()
         self.list = liste
         self.buttonbox = buttonbox
+        self.combobox = combobox
 
     def validate(self, string, position):
         if string == "":
@@ -455,9 +456,21 @@ def validate(self, string, position):
                 self.buttonbox.button(QDialogButtonBox.Ok).setEnabled(True)
                 return QValidator.Acceptable, string, position
 
+        for i in self.list:
+            i = i.lower()
+
             if i.find(s) != -1:
                 # could become a real match some day
                 self.buttonbox.button(QDialogButtonBox.Ok).setEnabled(False)
+                # adjust the elements visible in the dropdown list
+                self.combobox.setEditable(False)
+                self.combobox.clear()
+                for j in self.list:
+                    if j.lower().find(s) != -1:
+                        self.combobox.addItem(j)
+                self.combobox.setEditable(True)
+                self.combobox.setEditText(s)
+                self.combobox.setValidator(self)
                 return QValidator.Intermediate, string, position
 
         # no match at all, invalid input
@@ -798,7 +811,7 @@ def update_device_cb(self):
                 for d in self.devices[f]:
                     self.device.devices.addItem(d)
                     l.append(d)
-        self.dev_validator = listValidator(l, self.device.buttonBox)
+        self.dev_validator = listValidator(l, self.device.buttonBox, self.device.devices)
         self.device.devices.setValidator(self.dev_validator)
 
     def update_programmer_cb(self):