[ADD] web_tree_column_width_remember: Remember the tree view columns' widths

Remember the tree columns' widths across sessions, and after filtering, grouping, or reordering.

web_remember_tree_column_width/static/src/js/list_renderer.js

@@ -0,0 +1,69 @@
+odoo.define("remember_tree_column_width.ListRenderer", function (require) {
+    "use strict";
+
+    const ListRenderer = require("web.ListRenderer");
+    ListRenderer.include({
+        events: Object.assign({}, ListRenderer.prototype.events, {
+            "pointerdown th .o_resize": "_onMouseDownResize",
+            mouseup: "_onMouseUpResize",
+        }),
+        _onMouseDownResize: function () {
+            this.resizeInProgress = true;
+        },
+        _getLocalStorageWidthColumnName: function (model, field) {
+            return "odoo.columnWidth." + model + "." + field;
+        },
+        _onMouseUpResize: function (ev) {
+            if (this.resizeInProgress) {
+                this.resizeInProgress = false;
+                const target = $(ev.target);
+                const $th = target.is("th") ? target : target.parent("th");
+                const fieldName = $th.length ? $th.data("name") : undefined;
+                if (
+                    this.state &&
+                    this.state.model &&
+                    fieldName &&
+                    window.localStorage
+                ) {
+                    window.localStorage.setItem(
+                        this._getLocalStorageWidthColumnName(
+                            this.state.model,
+                            fieldName
+                        ),
+                        parseInt(($th[0].style.width || "0").replace("px", "")) || 0
+                    );
+                }
+            }
+        },
+        _squeezeTable: function () {
+            const columnWidths = this._super.apply(this, arguments);
+
+            const table = this.el.getElementsByTagName("table")[0];
+            const thead = table.getElementsByTagName("thead")[0];
+            const thElements = [...thead.getElementsByTagName("th")];
+
+            const self = this;
+            thElements.forEach(function (el, elIndex) {
+                const fieldName = $(el).data("name");
+                if (
+                    self.state &&
+                    self.state.model &&
+                    fieldName &&
+                    window.localStorage
+                ) {
+                    const storedWidth = window.localStorage.getItem(
+                        self._getLocalStorageWidthColumnName(
+                            self.state.model,
+                            fieldName
+                        )
+                    );
+                    if (storedWidth) {
+                        columnWidths[elIndex] = parseInt(storedWidth);
+                    }
+                }
+            });
+
+            return columnWidths;
+        },
+    });
+});

web_remember_tree_column_width/static/src/scss/main.scss

@@ -0,0 +1,8 @@
+th.o_column_sortable {
+    max-width: none !important;
+    min-width: 0 !important;
+}
+
+.o_optional_columns_dropdown_toggle {
+    height: 25px;
+}