New extensions: side panel and outliner (#284)

* upload side panel core

* upload outliner extension

* add onLoad, onSwitch, and onResize functions to panel extensions

* Update panel.js

* Add onLock and onUnlock functions to panel extensions

* Reordered side panel content loading

* change panel switcher font color

* fix loading last opened panel

* use svg icon files instead of defining them inline

* outliner: add full height option

repo/outliner/app.css

@@ -0,0 +1,51 @@
+/*
+ * outliner
+ * (c) 2020 dragonwocky <thedragonring.bod@gmail.com> (https://dragonwocky.me/)
+ * (c) 2020 CloudHill
+ * under the MIT license
+ */
+
+.outliner {
+  max-height: 100%;
+  overflow: hidden auto;
+}
+
+.outline-header {
+  display: flex;
+  align-items: center;
+  height: 2.2em;
+  cursor: pointer;
+  user-select: none;
+  transition: background 20ms ease-in;
+}
+.outline-header:hover {
+  background: var(--theme--interactive_hover);
+}
+
+.outline-header a {
+  width: 100%;
+  height: 100%;
+  padding: 0 14px;
+  line-height: 2.2;
+  color: inherit;
+  text-decoration: none;
+
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.outline-header a:empty:before {
+  color: var(--theme--text_ui_info);
+  content: attr(placeholder);
+  display: block;
+}
+.outline-header.notion-header-block a {
+  text-indent: 0;
+}
+.outline-header.notion-sub_header-block a {
+  text-indent: 18px;
+}
+.outline-header.notion-sub_sub_header-block a {
+  text-indent: 36px;
+}

repo/outliner/mod.js

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+/*
+ * outliner
+ * (c) 2020 dragonwocky <thedragonring.bod@gmail.com> (https://dragonwocky.me/)
+ * (c) 2020 CloudHill
+ * under the MIT license
+ */
+
+'use strict';
+
+const store = require("../../pkg/store");
+
+module.exports = {
+  id: '87e077cc-5402-451c-ac70-27cc4ae65546',
+  tags: ['extension', 'panel'],
+  name: 'outliner',
+  desc: 'table of contents.',
+  version: '1.0.0',
+  author: 'CloudHill',
+  options: [
+    {
+      key: 'fullHeight',
+      label: 'full height',
+      type: 'toggle',
+      value: false
+    }
+  ],
+  panel: {
+    html: "panel.html",
+    name: "Outline",
+    icon: "icon.svg",
+    js: "panel.js",
+    fullHeight: store('87e077cc-5402-451c-ac70-27cc4ae65546').fullHeight
+  }
+};

repo/outliner/panel.html

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+<div class="outliner"></div>

repo/outliner/panel.js

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+/*
+ * outliner
+ * (c) 2020 dragonwocky <thedragonring.bod@gmail.com> (https://dragonwocky.me/)
+ * (c) 2020 CloudHill
+ * under the MIT license
+ */
+
+'use strict';
+
+const { createElement } = require("../../pkg/helpers");
+
+module.exports = (store) => {   
+  // Observe for page changes
+  const pageObserver = new MutationObserver((list, observer) => {
+    for ( let { addedNodes } of list) {
+      if (addedNodes[0]) {
+        if (addedNodes[0].className === 'notion-page-content') {
+          startContentObserver();
+        }
+        // Clear outline on database pages
+        else if (addedNodes[0].className === 'notion-scroller') {
+          contentObserver.disconnect();
+          const outline = document.querySelector('.outliner');
+          if (outline) outline.textContent = '';
+        }
+      } 
+    }
+  });
+
+  // Observe for header changes
+  const contentObserver = new MutationObserver((list, observer) => {
+    list.forEach(m => {
+      if (
+        (
+          m.type === 'childList' &&
+          (
+            isHeaderElement(m.target) ||
+            isHeaderElement(m.addedNodes[0]) ||
+            isHeaderElement(m.removedNodes[0])
+          )
+        ) ||
+        (
+          m.type === 'characterData' &&
+          isHeaderElement(m.target.parentElement)
+        )
+      ) findHeaders();
+    })
+  });
+
+  function startContentObserver() {
+    findHeaders();
+    contentObserver.disconnect();
+    contentObserver.observe(
+      document.querySelector('.notion-page-content'),
+      {
+        childList: true,
+        subtree: true,
+        characterData: true,
+      }
+    );
+  }
+
+  function findHeaders() {
+    const outline = document.querySelector('.outliner');
+    if (!outline) return;
+    outline.textContent = '';
+
+    const pageContent = document.querySelector('.notion-page-content');
+    const headerBlocks = pageContent.querySelectorAll('[class*="header-block"]');
+
+    headerBlocks.forEach(block => {
+      const blockId = block.dataset.blockId.replace(/-/g, '');
+      const placeholder = block.querySelector('[placeholder]').getAttribute('placeholder');
+      const header = createElement(`
+        <div class="outline-header ${block.classList[1]}">
+          <a href="${window.location.pathname}#${blockId}"
+            placeholder="${placeholder}">${block.innerText}</a>
+        </div>
+      `);
+
+      outline.append(header);
+    })
+  }
+
+  function isHeaderElement(el) {
+    let placeholder;
+    if (el) {
+      if (
+        el.querySelector && 
+        el.querySelector('[placeholder]')
+      ) {
+        placeholder = el.querySelector('[placeholder]').getAttribute('placeholder')
+      } else if (el.getAttribute) {
+        placeholder = el.getAttribute('placeholder');
+      } 
+    }
+    if (!placeholder) placeholder = '';
+    return placeholder.includes('Heading');
+  }
+
+  return {
+    onLoad() {
+      // Find headers when switching panels
+      if (document.querySelector('.notion-page-content')) {
+        startContentObserver();
+      };    
+      pageObserver.observe(document.body, {
+        childList: true,
+        subtree: true,
+      });
+    },
+    onSwitch() {
+      pageObserver.disconnect();
+      contentObserver.disconnect();
+    }
+  }
+}