Add support for "void line"

also abstract the rendering of a line item to separate class, so can
override later etc.

wuttapos/controls/txnitem.py

@@ -0,0 +1,93 @@
+# -*- coding: utf-8; -*-
+################################################################################
+#
+#  WuttaPOS -- Pythonic Point of Sale System
+#  Copyright © 2023 Lance Edgar
+#
+#  This file is part of WuttaPOS.
+#
+#  WuttaPOS is free software: you can redistribute it and/or modify it under the
+#  terms of the GNU General Public License as published by the Free Software
+#  Foundation, either version 3 of the License, or (at your option) any later
+#  version.
+#
+#  WuttaPOS is distributed in the hope that it will be useful, but WITHOUT ANY
+#  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+#  details.
+#
+#  You should have received a copy of the GNU General Public License along with
+#  WuttaPOS.  If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+"""
+WuttaPOS - txn item control
+"""
+
+import flet as ft
+
+from .base import WuttaControl
+
+
+class WuttaTxnItem(WuttaControl):
+    """
+    Control for displaying a transaction line item within main POS
+    items list.
+    """
+    font_size = 24
+
+    def __init__(self, config, row, *args, **kwargs):
+        super().__init__(config, *args, **kwargs)
+        self.row = row
+
+    def build(self):
+
+        kw = {}
+        if self.row.void:
+            kw['color'] = 'red'
+            kw['decoration'] = ft.TextDecoration.LINE_THROUGH
+
+        self.major_style = ft.TextStyle(size=self.font_size,
+                                        weight=ft.FontWeight.BOLD,
+                                        **kw)
+
+        self.minor_style = ft.TextStyle(size=int(self.font_size * 0.8),
+                                        italic=True,
+                                        **kw)
+
+        quantity = self.app.render_quantity(self.row.quantity)
+        pretty_price = self.app.render_currency(self.row.txn_price)
+
+        return ft.Row(
+            [
+                ft.Row([
+
+                    ft.Text(
+                        spans=[
+                            ft.TextSpan(f"{self.row.description}",
+                                        style=self.major_style),
+                            ft.TextSpan(f"× {quantity} @ {pretty_price}",
+                                        style=self.minor_style),
+                        ],
+                    ),
+                ]),
+                ft.Text(
+                    spans=[
+                        ft.TextSpan(self.app.render_currency(self.row.sales_total),
+                                    style=self.major_style),
+                    ],
+                ),
+
+            ],
+            alignment=ft.MainAxisAlignment.SPACE_BETWEEN,
+        )
+
+    def mark_void(self):
+
+        self.major_style.color = 'red'
+        self.major_style.decoration = ft.TextDecoration.LINE_THROUGH
+
+        self.minor_style.color = 'red'
+        self.minor_style.decoration = ft.TextDecoration.LINE_THROUGH
+
+        self.update()

wuttapos/views/pos.py

@@ -33,6 +33,7 @@ import flet as ft
 from .base import WuttaView
 from wuttapos.controls.custlookup import WuttaCustomerLookup
 from wuttapos.controls.itemlookup import WuttaProductLookup
+from wuttapos.controls.txnitem import WuttaTxnItem
 
 
 log = logging.getLogger(__name__)
@@ -63,22 +64,24 @@ class POSView(WuttaView):
         for control in self.informed_controls:
             control.informed_refresh()
 
-    def reset(self, e=None, clear_quantity=True, update=True):
+    def reset(self, e=None, clear_quantity=True):
         """
         This is a convenience method, meant only to clear the main
-        input and set focus to it.  Will also update() the page
+        input and set focus to it.  Will also update() the page.
-        by default.
 
         The ``e`` arg is ignored and accepted only so this method may
         be registered as an event handler, e.g. ``on_cancel``.
         """
+        # clear set (@) quantity
         if clear_quantity:
             self.set_quantity.data = None
             self.set_quantity.value = None
+
+        # clear/focus main input
         self.main_input.value = ''
         self.main_input.focus()
-        if update:
+
-            self.page.update()
+        self.page.update()
 
     def set_customer(self, customer, batch=None):
         session = self.app.get_session(customer)
@@ -137,7 +140,7 @@ class POSView(WuttaView):
         if row:
             session.commit()
             self.add_row_item(row)
-            self.items.scroll_to(offset=-1, duration=250)
+            self.items.scroll_to(offset=-1, duration=100)
             self.txn_total.value = self.app.render_currency(batch.get_balance())
             self.reset()
 
@@ -490,7 +493,9 @@ class POSView(WuttaView):
                                        text_style=ft.TextStyle(weight=ft.FontWeight.BOLD),
                                        autofocus=True)
 
+        self.selected_item = None
         self.items = ft.ListView(
+            item_extent=50,
             height=800,
         )
 
@@ -525,6 +530,9 @@ class POSView(WuttaView):
                 elif self.set_quantity.data is not None:
                     self.set_quantity.data = None
                     self.set_quantity.value = None
+                elif self.selected_item:
+                    self.selected_item.bgcolor = 'white'
+                    self.selected_item = None
                 self.main_input.focus()
                 self.page.update()
 
@@ -566,12 +574,30 @@ class POSView(WuttaView):
 
                 self.page.update()
 
-            elif value == '↑':
+            elif value == '↑':  # UP
-                self.items.scroll_to(delta=-50, duration=250)
+
+                # select previous item, if selection in progress
+                if self.selected_item:
+                    i = self.items.controls.index(self.selected_item)
+                    if i > 0:
+                        self.items.scroll_to(delta=-50, duration=100)
+                        self.select_txn_item(self.items.controls[i - 1])
+                        return
+
+                self.items.scroll_to(delta=-50, duration=100)
                 self.page.update()
 
             elif value == '↓':
-                self.items.scroll_to(delta=50, duration=250)
+
+                # select next item, if selection in progress
+                if self.selected_item:
+                    i = self.items.controls.index(self.selected_item)
+                    if (i + 1) < len(self.items.controls):
+                        self.items.scroll_to(delta=50, duration=100)
+                        self.select_txn_item(self.items.controls[i + 1])
+                        return
+
+                self.items.scroll_to(delta=50, duration=100)
                 self.page.update()
 
             else:
@@ -580,11 +606,11 @@ class POSView(WuttaView):
                 self.page.update()
 
         def up_long_press(e):
-            self.items.scroll_to(delta=-500, duration=250)
+            self.items.scroll_to(delta=-500, duration=100)
             self.page.update()
 
         def down_long_press(e):
-            self.items.scroll_to(delta=500, duration=250)
+            self.items.scroll_to(delta=500, duration=100)
             self.page.update()
 
         tenkey_button_size = self.default_button_size
@@ -894,25 +920,26 @@ class POSView(WuttaView):
         if row.row_type not in ('sell',):
             return
 
-        quantity = self.app.render_quantity(row.quantity)
-        pretty_price = self.app.render_currency(row.txn_price)
         self.items.controls.append(
             ft.Container(
-                content=ft.Row(
+                content=WuttaTxnItem(self.config, row),
-                    [
-                        ft.Row([
-                            self.make_text(f"{row.description}"),
-                            self.make_text(f"× {quantity} @ {pretty_price}",
-                                           weight=None, italic=True, size=20),
-                        ]),
-                        self.make_text(self.app.render_currency(row.sales_total)),
-                    ],
-                    alignment=ft.MainAxisAlignment.SPACE_BETWEEN,
-                ),
                 border=ft.border.only(bottom=ft.border.BorderSide(1, 'gray')),
                 padding=ft.padding.only(0, 5, 0, 5),
+                on_click=self.list_item_click,
+                data={'row': row},
+                key=row.uuid,
             ))
 
+    def list_item_click(self, e):
+        self.select_txn_item(e.control)
+
+    def select_txn_item(self, item):
+        if self.selected_item:
+            self.selected_item.bgcolor = 'white'
+
+        item.bgcolor = 'blue'
+        self.selected_item = item
+        self.page.update()
 
     def void_click(self, e):
 
@@ -924,12 +951,39 @@ class POSView(WuttaView):
             user = self.get_current_user(session)
             batch = handler.get_current_batch(user, create=True)
 
-            # void current batch
+            if self.selected_item:
-            handler.void_batch(batch, user)
+
+                # void line
+                row = self.selected_item.data['row']
+                if not row.void:
+                    row = session.get(row.__class__, row.uuid)
+                    handler.void_row(row, user)
+                    self.selected_item.data['row'] = row
+                    self.selected_item.content.mark_void()
+                    self.selected_item.bgcolor = 'white'
+                    self.selected_item = None
+
+                    # update screen to reflect new balance
+                    self.txn_total.value = self.app.render_currency(batch.get_balance())
+
+
+                else:
+                    self.page.snack_bar = ft.SnackBar(ft.Text("LINE ALREADY VOID",
+                                                              color='black',
+                                                              size=20,
+                                                              weight=ft.FontWeight.BOLD),
+                                                      bgcolor='yellow',
+                                                      duration=1500)
+                    self.page.snack_bar.open = True
+
+
+            else:
+                # void txn
+                handler.void_batch(batch, user)
+                self.clear_all()
+
             session.commit()
             session.close()
-
-            self.clear_all()
             self.reset()
 
         def cancel(e):
@@ -942,11 +996,13 @@ class POSView(WuttaView):
 
         if batch:
 
+            # prompt to void something
+            target = 'LINE' if self.selected_item else 'TXN'
             dlg = ft.AlertDialog(
                 title=ft.Text("Confirm VOID"),
-                content=ft.Text("Really VOID this transaction?"),
+                content=ft.Text(f"Really VOID {target}?"),
                 actions=[
-                    ft.Container(content=ft.Text("Yes, VOID",
+                    ft.Container(content=ft.Text(f"VOID {target}",
                                                  size=self.default_font_size,
                                                  color='black',
                                                  weight=ft.FontWeight.BOLD),