Add behavior for "long backspace" press in keyboard

what this actually does must be specified by parent i guess, so far
that is in 2 places.  if many more would be nice to standardize that a
bit more somehow

wuttapos/controls/custlookup.py

@@ -117,7 +117,8 @@ class WuttaCustomerLookup(WuttaControl):
                     ],
                 ),
                 ft.Divider(),
-                WuttaKeyboard(self.config, on_keypress=self.keypress),
+                WuttaKeyboard(self.config, on_keypress=self.keypress,
+                              on_long_backspace=self.long_backspace),
                 ft.Divider(),
                 ft.Row(
                     [
@@ -162,6 +163,11 @@ class WuttaCustomerLookup(WuttaControl):
             self.searchbox.focus()
             self.update()
 
+    def long_backspace(self):
+        self.searchbox.value = self.searchbox.value[:-10]
+        self.searchbox.focus()
+        self.update()
+
     def lookup(self, e=None):
         entry = self.searchbox.value
         if not entry:

wuttapos/controls/feedback.py

@@ -71,7 +71,8 @@ class WuttaFeedback(WuttaControl):
                         ft.Divider(),
                         self.message,
                         ft.Divider(),
-                        WuttaKeyboard(self.config, on_keypress=self.keypress),
+                        WuttaKeyboard(self.config, on_keypress=self.keypress,
+                                      on_long_backspace=self.long_backspace),
                     ],
                     expand=True,
                 ),
@@ -121,6 +122,11 @@ class WuttaFeedback(WuttaControl):
         self.message.focus()
         self.update()
 
+    def long_backspace(self):
+        self.message.value = self.message.value[:-10]
+        self.message.focus()
+        self.update()
+
     def cancel(self, e):
         self.dlg.open = False
         self.page.update()

wuttapos/controls/keyboard.py

@@ -36,6 +36,7 @@ class WuttaKeyboard(WuttaControl):
 
     def __init__(self, *args, **kwargs):
         self.on_keypress = kwargs.pop('on_keypress', None)
+        self.on_long_backspace = kwargs.pop('on_long_backspace', None)
 
         super().__init__(*args, **kwargs)
 
@@ -127,10 +128,16 @@ class WuttaKeyboard(WuttaControl):
         if self.shift:
             self.update_shift(False)
 
+    def long_backspace(self, e):
+        if self.on_long_backspace:
+            self.on_long_backspace()
+
     def build(self):
         self.keys = {}
 
-        def make_key(key, data=None, on_click=self.simple_keypress,
+        def make_key(key, data=None,
+                     on_click=self.simple_keypress,
+                     on_long_press=None,
                      width=self.default_button_size,
                      bgcolor=None):
             button = ft.Container(content=ft.Text(key, size=self.default_font_size,
@@ -139,6 +146,7 @@ class WuttaKeyboard(WuttaControl):
                                   height=self.default_button_size,
                                   width=width,
                                   on_click=on_click,
+                                  on_long_press=on_long_press,
                                   alignment=ft.alignment.center,
                                   border=ft.border.all(1, 'black'),
                                   border_radius=ft.border_radius.all(5),
@@ -162,7 +170,8 @@ class WuttaKeyboard(WuttaControl):
             self.shift_key.bgcolor = 'blue'
 
         rows = [
-            [make_key(k) for k in "`1234567890-="] + [make_key('⌫', bgcolor='yellow')],
+            [make_key(k) for k in "`1234567890-="] + [make_key('⌫', bgcolor='yellow',
+                                                               on_long_press=self.long_backspace)],
             [make_key(k) for k in "qwertyuiop[]\\"],
             [self.caps_key] + [make_key(k) for k in "asdfghjkl;'"] + [make_key('⏎', bgcolor='blue')],
             [self.shift_key] + [make_key(k) for k in "zxcvbnm,./"],