[IMP] sale: Apply discount on all SO lines onchage of first SO line

Purpose fo the task is to Allow changing a discount for the whole SO.

So in this commit, On a quotation, with "discount per line" option
enabled, if the user changes the discount on the first SO line, display
a pop-up requesting if they want to apply the change to all the lines
of the SO.
There is condition to open the confirmation dialog to change on all SO lines:
  1. There should be 3 or more lines in SO
  2. Happens only when changing the discount of the first SO line
  3. The initial discount is the same on all lines
For Ex: Example : a SO with a discount of 10% on all 6 SO lines.
The user clicks the discount field on the first so line, changes to 20%.
A pop-up "apply this discount to all quotation lines"
-> if yes, apply 20% to all SO lines.

closes odoo/odoo#54262

Taskid: 2276759
Closes: #54262
Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>

addons/sale/static/src/js/product_discount_widget.js

@@ -0,0 +1,37 @@
+odoo.define('sale.product_discount', function (require) {
+    "use strict";
+
+    const BasicFields = require('web.basic_fields');
+    const FieldsRegistry = require('web.field_registry');
+
+    /**
+     * The sale.product_discount widget is a simple widget extending FieldFloat
+     *
+     *
+     * !!! WARNING !!!
+     *
+     * This widget is only designed for sale_order_line creation/updates.
+     * !!! It should only be used on a discount field !!!
+     */
+    const ProductDiscountWidget = BasicFields.FieldFloat.extend({
+
+        /**
+         * Override changes at a discount.
+         *
+         * @override
+         * @param {OdooEvent} ev
+         *
+         */
+        async reset(record, ev) {
+            if (ev && ev.data.changes && ev.data.changes.discount >= 0) {
+               this.trigger_up('open_discount_wizard');
+            }
+            this._super(...arguments);
+        },
+    });
+
+    FieldsRegistry.add('product_discount', ProductDiscountWidget);
+
+    return ProductDiscountWidget;
+
+});

addons/sale/static/src/js/sale_order_view.js

@@ -0,0 +1,56 @@
+odoo.define('sale.SaleOrderView', function (require) {
+    "use strict";
+
+    const FormController = require('web.FormController');
+    const FormView = require('web.FormView');
+    const viewRegistry = require('web.view_registry');
+    const Dialog = require('web.Dialog');
+    const core = require('web.core');
+    const _t = core._t;
+
+    const SaleOrderFormController = FormController.extend({
+        custom_events: _.extend({}, FormController.prototype.custom_events, {
+            open_discount_wizard: '_onOpenDiscountWizard',
+        }),
+
+        // -------------------------------------------------------------------------
+        // Handlers
+        // -------------------------------------------------------------------------
+
+        /**
+         * Handler called if user changes the discount field in the sale order line.
+         * The wizard will open only if
+         *  (1) Sale order line is 3 or more
+         *  (2) First sale order line is changed to discount
+         *  (3) Discount is the same in all sale order line
+         */
+        _onOpenDiscountWizard(ev) {
+            const orderLines = this.renderer.state.data.order_line.data;
+            const recordData = ev.target.recordData;
+            const isEqualDiscount = orderLines.slice(1).every(line => line.data.discount === recordData.discount);
+            if (orderLines.length >= 3 && recordData.sequence === orderLines[0].data.sequence && isEqualDiscount) {
+                Dialog.confirm(this, _t("Do you want to apply this discount to all order lines?"), {
+                    confirm_callback: () => {
+                        orderLines.slice(1).forEach((line) => {
+                            this.trigger_up('field_changed', {
+                                dataPointID: this.renderer.state.id,
+                                changes: {order_line: {operation: "UPDATE", id: line.id, data: {discount: orderLines[0].data.discount}}},
+                            });
+                        });
+                    },
+                });
+            }
+        },
+    });
+
+    const SaleOrderView = FormView.extend({
+        config: _.extend({}, FormView.prototype.config, {
+            Controller: SaleOrderFormController,
+        }),
+    });
+
+    viewRegistry.add('sale_discount_form', SaleOrderView);
+
+    return SaleOrderView;
+
+});

addons/sale/views/assets.xml

@@ -9,6 +9,8 @@
             <script type="text/javascript" src="/sale/static/src/js/sale.js"></script>
             <script type="text/javascript" src="/sale/static/src/js/tours/sale.js"></script>
             <script type="text/javascript" src="/sale/static/src/js/product_configurator_widget.js"/>
+            <script type="text/javascript" src="/sale/static/src/js/sale_order_view.js"/>
+            <script type="text/javascript" src="/sale/static/src/js/product_discount_widget.js"/>
         </xpath>
     </template>
      <template id="report_assets_common_inherit_sale" inherit_id="web.report_assets_common" name="Sale report common assets">

addons/sale/views/sale_views.xml

@@ -259,7 +259,7 @@
             <field name="name">sale.order.form</field>
             <field name="model">sale.order</field>
             <field name="arch" type="xml">
-              <form string="Sales Order" class="o_sale_order">
+              <form string="Sales Order" class="o_sale_order" js_class="sale_discount_form">
                 <header>
                     <field name="authorized_transaction_ids" invisible="1"/>
                     <button name="payment_action_capture" type="object"
@@ -567,7 +567,7 @@
                                         attrs="{'readonly': [('qty_invoiced', '&gt;', 0)]}"
                                         optional="show"
                                     />
-                                    <field name="discount" string="Disc.%" groups="product.group_discount_per_so_line" optional="show"/>
+                                    <field name="discount" string="Disc.%" groups="product.group_discount_per_so_line" optional="show" widget="product_discount"/>
                                     <field name="price_subtotal" widget="monetary" groups="account.group_show_line_subtotals_tax_excluded"/>
                                     <field name="price_total" widget="monetary" groups="account.group_show_line_subtotals_tax_included"/>
                                     <field name="state" invisible="1"/>