[IMP] website, *: move page scrollbar to #wrapwrap

*: web, web_editor, portal, account, website_blog, website_forum

This is probably not ideal to move the scrolling behavior out of the
html element but this will be needed for the editor to not have a double
scrollbar on the right. This is actually also useful for the scrollbar
to appear under the purple odoo menu instead of its right.

This commit, if to be reverted in the future, however contains many
improvements to make the transition easier that should be kept: jQuery
and Odoo functions to be able to scrollTo a specific element, get the
top scrollable element, check if an element is scrollable, etc. Also,
some magic was done: if some code tries to scroll to a specific scroll
position via jQuery's scrollTop or animate functions on the html/body
element, those will still work as intended (obviously, using the new
utils to do that is however recommended).

This commit also reviews our scroll behaviors to make them more robust
and share the code.

Part of https://github.com/odoo/odoo/pull/57975
task-2344227

1 files changed, 101 insertions, 0 deletions

diff --git a/addons/web/static/src/js/core/dom.js b/addons/web/static/src/js/core/dom.js
index 716593eb558..f4aba50be8a 100644
--- a/addons/web/static/src/js/core/dom.js
+++ b/addons/web/static/src/js/core/dom.js
@@ -142,6 +142,12 @@ var dom = {
         }
     },
     /**
+     * @return {HTMLElement}
+     */
+    closestScrollable(el) {
+        return $(el).closestScrollable()[0];
+    },
+    /**
      * jQuery find function behavior is::
      *
      *      $('A').find('A B') <=> $('A A B')
@@ -229,6 +235,26 @@ var dom = {
         return position;
     },
     /**
+     * @returns {HTMLElement}
+     */
+    getScrollingElement() {
+        return $().getScrollingElement()[0];
+    },
+    /**
+     * @param {HTMLElement} el
+     * @returns {boolean}
+     */
+    hasScrollableContent(el) {
+        return $(el).hasScrollableContent();
+    },
+    /**
+     * @param {HTMLElement} el
+     * @returns {boolean}
+     */
+    isScrollable(el) {
+        return $(el).isScrollable();
+    },
+    /**
      * Protects a function which is to be used as a handler by preventing its
      * execution for the duration of a previous call to it (including async
      * parts of that call).
@@ -455,6 +481,81 @@ var dom = {
         }
     },
     /**
+     * Computes the size by which a scrolling point should be decreased so that
+     * the top fixed elements of the page appear above that scrolling point.
+     *
+     * @returns {number}
+     */
+    scrollFixedOffset() {
+        let size = 0;
+        for (const el of $('.o_top_fixed_element')) {
+            size += $(el).outerHeight();
+        }
+        return size;
+    },
+    /**
+     * @param {HTMLElement} el - the element to stroll to
+     * @param {number} [options] - same as animate of jQuery
+     * @param {number} [options.extraOffset=0]
+     *      extra offset to add on top of the automatic one (the automatic one
+     *      being computed based on fixed header sizes)
+     * @param {number} [options.forcedOffset]
+     *      offset used instead of the automatic one (extraOffset will be
+     *      ignored too)
+     * @return {Promise}
+     */
+    scrollTo(el, options = {}) {
+        const $el = $(el);
+        const $scrollable = $el.parent().closestScrollable();
+        const $topLevelScrollable = $().getScrollingElement();
+        const isTopScroll = $scrollable.is($topLevelScrollable);
+
+        function _computeScrollTop() {
+            const elPosition = $scrollable[0].scrollTop + ($el.offset().top - $scrollable.offset().top);
+            let offset = options.forcedOffset;
+            if (offset === undefined) {
+                offset = (isTopScroll ? dom.scrollFixedOffset() : 0) + (options.extraOffset || 0);
+            }
+            return Math.max(0, elPosition - offset);
+        }
+
+        const originalScrollTop = _computeScrollTop();
+
+        return new Promise(resolve => {
+            const clonedOptions = Object.assign({}, options);
+
+            // During the animation, detect any change needed for the scroll
+            // offset. If any occurs, stop the animation and continuing it to
+            // the new scroll point for the remaining time.
+            // Note: limitation, the animation won't be as fluid as possible if
+            // the easing mode is different of 'linear'.
+            clonedOptions.progress = function (a, b, remainingMs) {
+                if (options.progress) {
+                    options.progress.apply(this, ...arguments);
+                }
+                const newScrollTop = _computeScrollTop();
+                if (Math.abs(newScrollTop - originalScrollTop) <= 1.0) {
+                    return;
+                }
+                $scrollable.stop();
+                dom.scrollTo(el, Object.assign({}, options, {
+                    duration: remainingMs,
+                })).then(() => resolve());
+            };
+
+            // Detect the end of the animation to be able to indicate it to
+            // the caller via the returned Promise.
+            clonedOptions.complete = function () {
+                if (options.complete) {
+                    options.complete.apply(this, ...arguments);
+                }
+                resolve();
+            };
+
+            $scrollable.animate({scrollTop: originalScrollTop}, clonedOptions);
+        });
+    },
+    /**
      * Creates an automatic 'more' dropdown-menu for a set of navbar items.
      *
      * @param {jQuery} $el