document.blockingElements polyfill with inert

.gitignore

@@ -1 +1,2 @@
 node_modules
+bower_components

.travis.yml

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+language: node_js
+node_js: stable
+dist: trusty
+sudo: required
+addons:
+  firefox: latest
+  apt:
+    sources:
+    - google-chrome
+    packages:
+    - google-chrome-stable
+before_script:
+- npm install -g bower polylint web-component-tester
+- bower install
+- polylint
+script: xvfb-run wct

blocking-elements.html

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+<script src="blocking-elements.js"></script>

blocking-elements.js

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+/**
+ *
+ * Copyright 2016 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+(function(document) {
+
+  /* Symbols for blocking elements and already inert elements */
+  const BLOCKING_ELEMS = Symbol('blockingElements');
+  const ALREADY_INERT_ELEMS = Symbol('alreadyInertElements');
+
+  /* Symbols for static methods */
+  const TOP_CHANGED_FN = Symbol('topChanged');
+  const NOT_INERTABLE_FN = Symbol('notInertable');
+  const SET_SIBLINGS_INERT_FN = Symbol('setInertToSiblingsOfElement');
+  const GET_PARENTS_FN = Symbol('getParents');
+  const GET_DISTRIB_CHILDREN_FN = Symbol('getDistributedChildren');
+  const IS_INERT_FN = Symbol('isInert');
+  const SET_INERT_FN = Symbol('setInert');
+
+  /**
+   * `BlockingElements` manages a stack of elements that inert the interaction
+   * outside them. The top element is the interactive part of the document.
+   * The stack can be updated with the methods `push, remove, pop`.
+   * @class
+   */
+  class BlockingElements {
+    constructor() {
+      /**
+       * The blocking elements.
+       * @type {Array<HTMLElement>}
+       * @private
+       */
+      this[BLOCKING_ELEMS] = [];
+
+      /**
+       * Elements that are already inert before the first blocking element is pushed.
+       * @type {Set<HTMLElement>}
+       * @private
+       */
+      this[ALREADY_INERT_ELEMS] = new Set();
+    }
+
+    /**
+     * Call this whenever this object is about to become obsolete. This empties
+     * the blocking elements
+     */
+    destructor() {
+      // Loop from the last to first to gradually update the tree up to body.
+      const elems = this[BLOCKING_ELEMS];
+      for (let i = elems.length - 1; i >= 0; i--) {
+        BlockingElements[TOP_CHANGED_FN](elems[i - 1], elems[i], this[ALREADY_INERT_ELEMS]);
+      }
+      delete this[BLOCKING_ELEMS];
+      delete this[ALREADY_INERT_ELEMS];
+    }
+
+    /**
+     * A copy of the blocking elements.
+     * @type {Array<HTMLElement>}
+     */
+    get all() {
+      return Array.prototype.slice.call(this[BLOCKING_ELEMS]);
+    }
+
+    /**
+     * The top blocking element.
+     * @type {HTMLElement|null}
+     */
+    get top() {
+      const elems = this[BLOCKING_ELEMS];
+      return elems[elems.length - 1] || null;
+    }
+
+    /**
+     * Adds the element to the blocking elements.
+     * @param {!HTMLElement} element
+     */
+    push(element) {
+      const i = this[BLOCKING_ELEMS].indexOf(element);
+      if (i !== -1) {
+        console.warn('element already added in document.blockingElements');
+        return;
+      }
+      const oldTop = this.top;
+      this[BLOCKING_ELEMS].push(element);
+      BlockingElements[TOP_CHANGED_FN](element, oldTop, this[ALREADY_INERT_ELEMS]);
+    }
+
+    /**
+     * Removes the element from the blocking elements.
+     * @param {!HTMLElement} element
+     */
+    remove(element) {
+      const i = this[BLOCKING_ELEMS].indexOf(element);
+      if (i !== -1) {
+        this[BLOCKING_ELEMS].splice(i, 1);
+        // Top changed only if the removed element was the top element.
+        if (i === this[BLOCKING_ELEMS].length) {
+          BlockingElements[TOP_CHANGED_FN](this.top, element, this[ALREADY_INERT_ELEMS]);
+        }
+      }
+    }
+
+    /**
+     * Remove the top blocking element and returns it.
+     * @returns {HTMLElement|null} the removed element.
+     */
+    pop() {
+      const top = this.top;
+      top && this.remove(top);
+      return top;
+    }
+
+    /**
+     * Sets `inert` to all document elements except the new top element, its parents,
+     * and its distributed content. Pass `oldTop` to limit element updates (will look
+     * for common parents and avoid setting them twice).
+     * When the first blocking element is added (`newTop = null`), it saves the elements
+     * that are already inert into `alreadyInertElems`. When the last blocking element
+     * is removed (`oldTop = null`), `alreadyInertElems` are kept inert.
+     * @param {HTMLElement} newTop If null, it means the last blocking element was removed.
+     * @param {HTMLElement} oldTop If null, it means the first blocking element was added.
+     * @param {!Set<HTMLElement>} alreadyInertElems Elements to be kept inert.
+     * @private
+     */
+    static[TOP_CHANGED_FN](newTop, oldTop, alreadyInertElems) {
+      const oldElParents = oldTop ? this[GET_PARENTS_FN](oldTop) : [];
+      const newElParents = newTop ? this[GET_PARENTS_FN](newTop) : [];
+      const elemsToSkip = newTop && newTop.shadowRoot ?
+        this[GET_DISTRIB_CHILDREN_FN](newTop.shadowRoot) : null;
+      // Loop from top to deepest elements, so we find the common parents and
+      // avoid setting them twice.
+      while (oldElParents.length || newElParents.length) {
+        const oldElParent = oldElParents.pop();
+        const newElParent = newElParents.pop();
+        if (oldElParent === newElParent) {
+          continue;
+        }
+        // Same parent, set only these 2 children.
+        if (oldElParent && newElParent &&
+          oldElParent.parentNode === newElParent.parentNode) {
+          if (!oldTop && this[IS_INERT_FN](oldElParent)) {
+            alreadyInertElems.add(oldElParent);
+          }
+          this[SET_INERT_FN](oldElParent, true);
+          this[SET_INERT_FN](newElParent, alreadyInertElems.has(newElParent));
+        } else {
+          oldElParent && this[SET_SIBLINGS_INERT_FN](oldElParent, false, elemsToSkip,
+            alreadyInertElems);
+          // Collect the already inert elements only if it is the first blocking
+          // element (if oldTop = null)
+          newElParent && this[SET_SIBLINGS_INERT_FN](newElParent, true, elemsToSkip,
+            oldTop ? null : alreadyInertElems);
+        }
+      }
+      if (!newTop) {
+        alreadyInertElems.clear();
+      }
+    }
+
+    /**
+     * Returns if the element is not inertable.
+     * @param {!HTMLElement} element
+     * @returns {boolean}
+     * @private
+     */
+    static[NOT_INERTABLE_FN](element) {
+      return /^(style|template|script)$/.test(element.localName);
+    }
+
+    /**
+     * Sets `inert` to the siblings of the element except the elements to skip.
+     * If `inert = true`, already inert elements are added into `alreadyInertElems`.
+     * If `inert = false`, siblings that are contained in `alreadyInertElems` will
+     * be kept inert.
+     * @param {!HTMLElement} element
+     * @param {boolean} inert
+     * @param {Set<HTMLElement>} elemsToSkip
+     * @param {Set<HTMLElement>} alreadyInertElems
+     * @private
+     */
+    static[SET_SIBLINGS_INERT_FN](element, inert, elemsToSkip, alreadyInertElems) {
+      // Previous siblings.
+      let sibling = element;
+      while ((sibling = sibling.previousElementSibling)) {
+        // If not inertable or to be skipped, skip.
+        if (this[NOT_INERTABLE_FN](sibling) || (elemsToSkip && elemsToSkip.has(sibling))) {
+          continue;
+        }
+        // Should be collected since already inerted.
+        if (alreadyInertElems && inert && this[IS_INERT_FN](sibling)) {
+          alreadyInertElems.add(sibling);
+        }
+        // Should be kept inert if it's in `alreadyInertElems`.
+        this[SET_INERT_FN](sibling, inert || (alreadyInertElems && alreadyInertElems.has(sibling)));
+      }
+      // Next siblings.
+      sibling = element;
+      while ((sibling = sibling.nextElementSibling)) {
+        // If not inertable or to be skipped, skip.
+        if (this[NOT_INERTABLE_FN](sibling) || (elemsToSkip && elemsToSkip.has(sibling))) {
+          continue;
+        }
+        // Should be collected since already inerted.
+        if (alreadyInertElems && inert && this[IS_INERT_FN](sibling)) {
+          alreadyInertElems.add(sibling);
+        }
+        // Should be kept inert if it's in `alreadyInertElems`.
+        this[SET_INERT_FN](sibling, inert || (alreadyInertElems && alreadyInertElems.has(sibling)));
+      }
+    }
+
+    /**
+     * Returns the list of parents of an element, starting from element (included)
+     * up to `document.body` (excluded).
+     * @param {!HTMLElement} element
+     * @returns {Array<HTMLElement>}
+     * @private
+     */
+    static[GET_PARENTS_FN](element) {
+      const parents = [];
+      let current = element;
+      // Stop to body.
+      while (current && current !== document.body) {
+        // Skip shadow roots.
+        if (current.nodeType === Node.ELEMENT_NODE) {
+          parents.push(current);
+        }
+        // ShadowDom v1
+        if (current.assignedSlot) {
+          // Collect slots from deepest slot to top.
+          while ((current = current.assignedSlot)) {
+            parents.push(current);
+          }
+          // Continue the search on the top slot.
+          current = parents.pop();
+          continue;
+        }
+        // ShadowDom v0
+        const insertionPoints = current.getDestinationInsertionPoints ?
+          current.getDestinationInsertionPoints() : [];
+        if (insertionPoints.length) {
+          for (let i = 0; i < insertionPoints.length - 1; i++) {
+            parents.push(current);
+          }
+          // Continue the search on the top content.
+          current = insertionPoints[insertionPoints.length - 1];
+          continue;
+        }
+        current = current.parentNode || current.host;
+      }
+      return parents;
+    }
+
+    /**
+     * Returns the distributed children of a shadow root.
+     * @param {!DocumentFragment} shadowRoot
+     * @returns {Set<HTMLElement>}
+     * @private
+     */
+    static[GET_DISTRIB_CHILDREN_FN](shadowRoot) {
+      const result = new Set();
+      // ShadowDom v1
+      const slots = shadowRoot.querySelectorAll('slot');
+      for (let i = 0; i < slots.length; i++) {
+        const nodes = slots[i].assignedNodes({
+          flatten: true
+        });
+        for (let j = 0; j < nodes.length; j++) {
+          if (nodes[j].nodeType === Node.ELEMENT_NODE) {
+            result.add(nodes[j]);
+          }
+        }
+      }
+      // ShadowDom v0
+      const contents = shadowRoot.querySelectorAll('content');
+      for (let i = 0; i < contents.length; i++) {
+        const nodes = contents[i].getDistributedNodes();
+        for (let j = 0; j < nodes.length; j++) {
+          if (nodes[j].nodeType === Node.ELEMENT_NODE) {
+            result.add(nodes[j]);
+          }
+        }
+      }
+      return result;
+    }
+
+    /**
+     * Returns if an element is inert.
+     * @param {!HTMLElement} element
+     * @returns {boolean}
+     * @private
+     */
+    static[IS_INERT_FN](element) {
+      return !!element.inert;
+    }
+
+    /**
+     * Sets inert to an element.
+     * @param {!HTMLElement} element
+     * @param {boolean} inert
+     * @private
+     */
+    static[SET_INERT_FN](element, inert) {
+      // Update JS property.
+      element.inert = inert;
+    }
+  }
+
+  document.$blockingElements = new BlockingElements();
+
+})(document);

bower.json

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+{
+  "name": "blockingElements",
+  "description": "A polyfill for the proposed blocking elments stack API",
+  "main": "blocking-elements.html",
+  "authors": [
+    "Valdrin Koshi <[email protected]>"
+  ],
+  "license": "Apache-2.0",
+  "keywords": [
+    "blocking",
+    "elements",
+    "polyfill",
+    "browser"
+  ],
+  "homepage": "https://github.com/PolymerLabs/blockingElements",
+  "private": true,
+  "ignore": [
+    "**/.*",
+    "node_modules",
+    "bower_components",
+    "test",
+    "tests"
+  ],
+  "devDependencies": {
+    "test-fixture": "PolymerElements/test-fixture#ce-v1",
+    "inert": "WICG/inert#master",
+    "web-component-tester": "^4.0.0",
+    "webcomponentsjs": "webcomponents/webcomponentsjs#v1-polymer-edits"
+  },
+  "resolutions": {
+    "test-fixture": "ce-v1"
+  }
+}