[IMP] web_editor, website: introduce foldable zones in the editor UI

Now any set of widgets and rows can be placed in a we-collapse element
so that those elements can be foldable. The first element inside (or
the mentioned "string" on the we-collapse element itself) is used as the
always shown element (with a toggler on its left to toggle the
visibility of the other items).

we-collapse inside other we-collapse is supported as well.

Limitations / Other infos:

- The use of '⌙' and   characters is not automatic (yet?).
  Sometimes it actually make sense to use them without a we-collapse or
  to not use them in a we-collapse.

- The use of we-collapse is limited to widgets inside the same option.
  So unfortunately, there is no current way to add all bg image options
  in a folable section as those contain many different options. Maybe
  in the future.

Part of https://github.com/odoo/odoo/pull/56350

closes odoo/odoo#56350

Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

3 files changed, 137 insertions, 16 deletions

diff --git a/addons/web_editor/static/src/js/editor/snippets.options.js b/addons/web_editor/static/src/js/editor/snippets.options.js
index 7edee505ea1..23fe6ff1bfd 100644
--- a/addons/web_editor/static/src/js/editor/snippets.options.js
+++ b/addons/web_editor/static/src/js/editor/snippets.options.js
@@ -114,6 +114,41 @@ function _buildRowElement(title, options) {
     return groupEl;
 }
 /**
+ * Build the correct DOM for a we-collapse element.
+ *
+ * @param {string} [title] - @see _buildElement
+ * @param {Object} [options] - @see _buildElement
+ * @param {HTMLElement[]} [options.childNodes]
+ * @returns {HTMLElement}
+ */
+function _buildCollapseElement(title, options) {
+    const groupEl = _buildElement('we-collapse', title, options);
+    const titleEl = groupEl.querySelector('we-title');
+
+    const children = options && options.childNodes || [];
+    if (titleEl) {
+        titleEl.remove();
+        children.unshift(titleEl);
+    }
+    let i = 0;
+    for (i = 0; i < children.length; i++) {
+        groupEl.appendChild(children[i]);
+        if (children[i].nodeType === Node.ELEMENT_NODE) {
+            break;
+        }
+    }
+
+    const togglerEl = document.createElement('we-toggler');
+    togglerEl.classList.add('o_we_collapse_toggler');
+    groupEl.appendChild(togglerEl);
+
+    const containerEl = document.createElement('div');
+    children.slice(i + 1).forEach(node => containerEl.appendChild(node));
+    groupEl.appendChild(containerEl);
+
+    return groupEl;
+}
+/**
  * Creates a proxy for an object where one property is replaced by a different
  * value. This value is captured in the closure and can be read and written to.
  *
@@ -1729,6 +1764,9 @@ const userValueWidgetsRegistry = {
  */
 const SnippetOptionWidget = Widget.extend({
     tagName: 'we-customizeblock-option',
+    events: {
+        'click .o_we_collapse_toggler': '_onCollapseTogglerClick',
+    },
     custom_events: {
         'user_value_update': '_onUserValueUpdate',
         'user_value_widget_critical': '_onUserValueWidgetCritical',
@@ -2190,11 +2228,20 @@ const SnippetOptionWidget = Widget.extend({
 
         await Promise.all(proms);
 
-        // Hide rows which contains only hidden widgets
-        for (const rowEl of this.$el.find('we-row')) {
-            // TODO improve this, this is hackish to rely on DOM structure
-            // here. Rows should be handled as widgets or something like that.
-            rowEl.classList.toggle('d-none', $(rowEl).find('> div > .o_we_user_value_widget:not(.d-none)').length === 0);
+        // Hide layouting elements which contains only hidden widgets
+        // TODO improve this, this is hackish to rely on DOM structure here.
+        // Layouting elements should be handled as widgets or other.
+        for (const el of this.$el.find('we-row')) {
+            el.classList.toggle('d-none', !$(el).find('> div > .o_we_user_value_widget').not('.d-none').length);
+        }
+        for (const el of this.$el.find('we-collapse')) {
+            const $el = $(el);
+            el.classList.toggle('d-none', $el.children().first().hasClass('d-none'));
+            const hasNoVisibleElInCollapseMenu = !$el.children().last().children().not('.d-none').length;
+            if (hasNoVisibleElInCollapseMenu) {
+                this._toggleCollapseEl(el, false);
+            }
+            el.querySelector('.o_we_collapse_toggler').classList.toggle('d-none', hasNoVisibleElInCollapseMenu);
         }
     },
 
@@ -2399,12 +2446,14 @@ const SnippetOptionWidget = Widget.extend({
         await this._renderCustomXML(uiFragment);
 
         // Build layouting components first
-        uiFragment.querySelectorAll('we-row').forEach(el => {
-            const infos = this._extraInfoFromDescriptionElement(el);
-            const groupEl = _buildRowElement(infos.title, infos.options);
-            el.parentNode.insertBefore(groupEl, el);
-            el.parentNode.removeChild(el);
-        });
+        for (const [itemName, build] of [['we-row', _buildRowElement], ['we-collapse', _buildCollapseElement]]) {
+            uiFragment.querySelectorAll(itemName).forEach(el => {
+                const infos = this._extraInfoFromDescriptionElement(el);
+                const groupEl = build(infos.title, infos.options);
+                el.parentNode.insertBefore(groupEl, el);
+                el.parentNode.removeChild(el);
+            });
+        }
 
         // Load widgets
         await this._renderXMLWidgets(uiFragment);
@@ -2553,12 +2602,32 @@ const SnippetOptionWidget = Widget.extend({
         }
         return value;
     },
+    /**
+     * @private
+     * @param {HTMLElement} collapseEl
+     * @param {boolean|undefined} [show]
+     */
+    _toggleCollapseEl(collapseEl, show) {
+        collapseEl.classList.toggle('active', show);
+        collapseEl.querySelector('.o_we_collapse_toggler').classList.toggle('active', show);
+    },
 
     //--------------------------------------------------------------------------
     // Handlers
     //--------------------------------------------------------------------------
 
     /**
+     * @private
+     * @param {Event} ev
+     */
+    _onCollapseTogglerClick(ev) {
+        const currentCollapseEl = ev.currentTarget.parentNode;
+        this._toggleCollapseEl(currentCollapseEl);
+        for (const collapseEl of currentCollapseEl.querySelectorAll('we-collapse')) {
+            this._toggleCollapseEl(collapseEl, false);
+        }
+    },
+    /**
      * Called when a widget notifies a preview/change/reset.
      *
      * @private
@@ -4438,6 +4507,7 @@ return {
     buildElement: _buildElement,
     buildTitleElement: _buildTitleElement,
     buildRowElement: _buildRowElement,
+    buildCollapseElement: _buildCollapseElement,
 
     // Other names for convenience
     Class: SnippetOptionWidget,
diff --git a/addons/web_editor/static/src/scss/web_editor.variables.scss b/addons/web_editor/static/src/scss/web_editor.variables.scss
index ca8f9e6a080..add424313c0 100644
--- a/addons/web_editor/static/src/scss/web_editor.variables.scss
+++ b/addons/web_editor/static/src/scss/web_editor.variables.scss
@@ -117,8 +117,7 @@ $o-we-sidebar-content-main-title-font-size: 13px !default;
 
 $o-we-sidebar-content-block-spacing: 10px !default;
 
-$o-we-sidebar-content-fold-block-bg: $o-we-bg-dark !default;
-$o-we-sidebar-content-fold-block-inner-spacing: $o-we-sidebar-content-block-spacing !default;
+$o-we-sidebar-content-fold-block-bg: $o-we-bg-light !default;
 
 $o-we-sidebar-content-field-spacing: $o-we-item-spacing !default;
 $o-we-sidebar-content-field-color: $o-we-fg-darker !default;
diff --git a/addons/web_editor/static/src/scss/wysiwyg_snippets.scss b/addons/web_editor/static/src/scss/wysiwyg_snippets.scss
index 01963484889..5419eb8a133 100644
--- a/addons/web_editor/static/src/scss/wysiwyg_snippets.scss
+++ b/addons/web_editor/static/src/scss/wysiwyg_snippets.scss
@@ -427,14 +427,13 @@ body.editor_enable.editor_has_snippets {
         we-customizeblock-options {
             position: relative;
             display: block;
-            padding: 0 $o-we-sidebar-content-padding-base $o-we-sidebar-content-block-spacing * 1.5 $o-we-sidebar-content-indent;
+            padding: 0 0 ($o-we-sidebar-content-block-spacing * 1.5) 0;
             background-color: $o-we-bg-lighter;
             box-shadow: $o-we-item-standup-bottom rgba($o-we-item-standup-color-dark, 0.8);
 
             > we-title {
                 display: flex;
                 align-items: center;
-                margin: 0 (-$o-we-sidebar-content-padding-base) 0 (-$o-we-sidebar-content-indent);
                 padding: $o-we-sidebar-content-block-spacing * .3 $o-we-sidebar-content-padding-base 0 $o-we-sidebar-content-indent;
                 background-color: $o-we-bg-light;
                 box-shadow: $o-we-item-standup-top rgba($o-we-item-standup-color-light, .2), $o-we-item-standup-bottom rgba($o-we-item-standup-color-dark, .5);
@@ -454,7 +453,9 @@ body.editor_enable.editor_has_snippets {
                     .oe_snippet_remove {
                         font-size: 1.2em;
                     }
-
+                    we-customizeblock-option {
+                        padding: 0;
+                    }
                     we-button {
                         margin-left: $o-we-sidebar-content-field-multi-spacing;
                         padding: 0 $o-we-sidebar-content-field-multi-spacing;
@@ -470,6 +471,7 @@ body.editor_enable.editor_has_snippets {
         we-customizeblock-option {
             position: relative;
             display: block;
+            padding: 0 $o-we-sidebar-content-padding-base 0 $o-we-sidebar-content-indent;
 
             .dropdown-menu {
                 // FIXME temporary fix for m2o option for example
@@ -1063,6 +1065,56 @@ body.editor_enable.editor_has_snippets {
             }
         }
 
+        we-collapse {
+            position: relative;
+            display: block;
+            padding-left: $o-we-sidebar-content-indent;
+            padding-right: $o-we-sidebar-content-padding-base;
+            margin-right: -$o-we-sidebar-content-padding-base;
+            margin-left: -$o-we-sidebar-content-indent;
+            // Allow inner margin to be considered inside the block + Visual space after/before previous/next widget + No flickering on opening
+            $-inner-spacing: ceil($o-we-sidebar-content-field-spacing / 2);
+            border-top: ($o-we-sidebar-content-field-spacing - $-inner-spacing) solid transparent;
+            padding-bottom: ($o-we-sidebar-content-field-spacing - $-inner-spacing);
+            margin-bottom: -($o-we-sidebar-content-field-spacing - $-inner-spacing);
+            background-clip: padding-box;
+
+            > :first-child, .o_we_collapse_toggler {
+                margin-top: $-inner-spacing;
+            }
+            .o_we_collapse_toggler {
+                @include o-position-absolute($top: 0, $left: 0);
+                width: $o-we-sidebar-content-indent;
+                height: $o-we-sidebar-content-field-height;
+                display: flex;
+                align-items: center;
+                justify-content: center;
+                padding: 0;
+                background: none;
+                border: none;
+
+                &::after {
+                    content: '\f0da';
+                    position: static;
+                    transform: none;
+                }
+                &.active {
+
+                    &::after {
+                        content: '\f0d7';
+                    }
+                    + * {
+                        background: none;
+                        border: none;
+                        box-shadow: none;
+                    }
+                }
+            }
+            &.active {
+                background-color: $o-we-sidebar-content-fold-block-bg;
+            }
+        }
+
         .o_we_image_weight {
             display: flex;
             justify-content: flex-end;