Pad improvements:

- qty change gross weight;
- accept qty <= 0, shows  warning at checkout time.

pos_tare/models/pos_config.py

@@ -4,7 +4,8 @@ from odoo import api, models, fields
 class PosConfig(models.Model):
     _inherit = "pos.config"
 
-    iface_tare_method = fields.Selection([
+    iface_tare_method = fields.Selection(
+        [
             ("manual", "Input the tare manually"),
             ("barcode", "Scan a barcode to set the tare"),
             ("both", "Manual input and barcode"),
@@ -18,7 +19,8 @@ class PosConfig(models.Model):
         "* 'both' : manual input and barcode methods are enabled;",
     )
 
-    iface_gross_weight_method = fields.Selection([
+    iface_gross_weight_method = fields.Selection(
+        [
             ("manual", "Input the Gross Weight manually"),
             ("scale", "Input Gross Weight via Scale")
         ],

pos_tare/static/src/js/models.js

@@ -4,35 +4,8 @@ odoo.define('pos_tare.models', function (require) {
     var core = require('web.core');
     var models = require('point_of_sale.models');
     var pos_tare_tools = require('pos_tare.tools');
-
     var _t = core._t;
 
-    class ValidationError extends Error {
-        constructor(message, gui) {
-            super(message); // (1)
-            this.name = "ValidationError"; // (2)
-            this.gui = gui;
-        }
-    }
-
-    var _NumpadState_ = models.NumpadState.prototype;
-    var NumpadState = models.NumpadState.extend({
-        appendNewChar: function (newChar) {
-            try {
-                _NumpadState_.appendNewChar.call(this, newChar);
-            } catch (error) {
-                if (error instanceof ValidationError) {
-                    var title = _t("Error while applying the numpad action");
-                    var popup = {title: title, body: error.message};
-                    error.gui.show_popup('error', popup);
-                    _NumpadState_.deleteLastChar.call(this);
-                } else {
-                  throw error;
-                }
-            }
-        },
-    });
-
     var _super_ = models.Orderline.prototype;
     var OrderLineWithTare = models.Orderline.extend({
 
@@ -95,16 +68,6 @@ odoo.define('pos_tare.models', function (require) {
                 this.pos, tare_in_product_uom, line_unit);
             if (update_net_weight) {
                 var net_quantity = this.get_quantity() - tare_in_product_uom;
-                // This method fails when the net weight is negative.
-                if (net_quantity <= 0) {
-                    throw new ValidationError(_.str.sprintf(
-                        _t("The tare weight is %s %s, it's greater or equal" +
-                        " to the gross weight %s. To apply this tare would" +
-                        " result in a negative net weight and a negative" +
-                        " price. This tare can not be applied to this item."),
-                        tare_in_product_uom_string, line_unit.name,
-                        this.get_quantity_str_with_unit()), this.pos.gui);
-                }
                 // Update the quantity with the new weight net of tare quantity.
                 this.set_quantity(net_quantity);
             }
@@ -148,8 +111,6 @@ odoo.define('pos_tare.models', function (require) {
 
     });
 
-
-    models.NumpadState = NumpadState;
     models.Orderline = OrderLineWithTare;
 
 });

pos_tare/static/src/js/screens.js

@@ -7,6 +7,7 @@ odoo.define('pos_tare.screens', function (require) {
 
     var _t = core._t;
     var round_pr = utils.round_precision;
+    var leq_zero_qty = (ol) => ol.get_quantity() <= 0;
 
     // This configures read action for tare barcode. A tare barcode contains a
     // fake product ID and the weight to be subtracted from the product in the
@@ -133,13 +134,44 @@ odoo.define('pos_tare.screens', function (require) {
 
     });
 
+    screens.PaymentScreenWidget.include({
+        validate_order: function(options) {
+            var order = this.pos.get_order();
+            var orderlines = Array.from(order.get_orderlines());
+
+            if (orderlines.some(leq_zero_qty)) {
+                var _super_validate_order = this._super.bind(this);
+                var wrong_orderline = orderlines.find(leq_zero_qty);
+                var wrong_product = wrong_orderline.get_product().display_name;
+                this.gui.show_popup('confirm', {
+                    title: _t('Quantity lower or equal to zero'),
+                    body:  _.str.sprintf(
+                        _t("The quantity for \"%s\" is lower or equal to" +
+                        " zero. Call for help unless your perfectly sure " +
+                        " about what you are doing."), wrong_product),
+                    confirm: function() {
+                        _super_validate_order();
+                    },
+                });
+                return;
+            }
+            return this._super(options);
+        },
+    });
+
     screens.OrderWidget.include({
         set_value: function (val) {
             var order = this.pos.get_order();
             if (order.get_selected_orderline()) {
                 var mode = this.numpad_state.get('mode');
                 if (mode === 'quantity') {
-                    order.get_selected_orderline().set_quantity(val);
+                    var orderline = order.get_selected_orderline();
+                    var tare = orderline.get_tare();
+                    orderline.reset_tare();
+                    orderline.set_quantity(val);
+                    if (tare > 0) {
+                      orderline.set_tare(tare, true);
+                    }
                 } else if (mode === 'discount') {
                     order.get_selected_orderline().set_discount(val);
                 } else if (mode === 'price') {
@@ -155,7 +187,13 @@ odoo.define('pos_tare.screens', function (require) {
                                 ' you have to change the tare input method' +
                                 ' in the POS configuration.')});
                     } else {
-                        order.get_selected_orderline().set_tare(val, true);
+                        try {
+                            order.get_selected_orderline().set_tare(val, true);
+                        } catch (error) {
+                            var title = _t("We can not apply this tare.");
+                            var popup = {title: title, body: error.message};
+                            this.gui.show_popup('error', popup);
+                        }
                     }
                 }
             }