kivy: password dialog and wizard fixes

gui/kivy/uix/dialogs/password_dialog.py

@@ -0,0 +1,84 @@
+from kivy.app import App
+from kivy.factory import Factory
+from kivy.properties import ObjectProperty
+from kivy.lang import Builder
+from decimal import Decimal
+
+Builder.load_string('''
+
+<PasswordDialog@Popup>
+    id: popup
+    title: _('Enter PIN Code')
+    size_hint: 0.9, 0.9
+
+    BoxLayout:
+
+        orientation: 'vertical'
+        size_hint: 0.8, 1
+
+        Label:
+            id: a
+            text: ' * '*len(kb.password) + ' o '*(6-len(kb.password))
+            size_hint: 1, None
+            height: '48dp'
+
+        GridLayout:
+            id: kb
+            update_amount: popup.update_password
+            password: ''
+            on_password: popup.on_password(self.password)
+            size_hint: 1, None
+            height: '300dp'
+            cols: 3
+            KButton:
+                text: '1'
+            KButton:
+                text: '2'
+            KButton:
+                text: '3'
+            KButton:
+                text: '4'
+            KButton:
+                text: '5'
+            KButton:
+                text: '6'
+            KButton:
+                text: '7'
+            KButton:
+                text: '8'
+            KButton:
+                text: '9'
+            KButton:
+                text: 'Clear'
+            KButton:
+                text: '0'
+            KButton:
+                text: '<'
+
+        Widget:
+            size_hint: 1, 1
+''')
+
+
+class PasswordDialog(Factory.Popup):
+
+    def __init__(self, title, cb):
+        Factory.Popup.__init__(self)
+        self.title = title
+        self.callback = cb
+
+    def update_password(self, c):
+        kb = self.ids.kb
+        text = kb.password
+        if c == '<':
+            text = text[:-1]
+        elif c == 'Clear':
+            text = ''
+        else:
+            text += c
+        kb.password = text
+
+    def on_password(self, pw):
+        if len(pw) == 6:
+            self.dismiss()
+            self.callback(pw)