diff -r 1f340f3597a8 -r ea92f4fe783d client/src/components/SlateEditor/CategoriesTooltip.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/client/src/components/SlateEditor/CategoriesTooltip.js	Mon Oct 08 18:35:47 2018 +0200
@@ -0,0 +1,71 @@
+import React, { Component } from 'react';
+
+class CategoriesTooltip extends Component {
+
+  state = {
+    activeCategory: null,
+    showCommentControl: false
+  }
+
+  componentDidUpdate = () => {
+    if (this.state.showCommentControl) {
+      this.commentControl.focus();
+    }
+  }
+
+  isCategoryActive = (category) => {
+    return this.state.activeCategory && this.state.activeCategory.key === category.key
+  }
+
+  onButtonClick = (category) => {
+    if (category.hasOwnProperty('hasComment') && category.hasComment === true) {
+      this.setState({
+        activeCategory: this.state.activeCategory ? null : category,
+        showCommentControl: !this.state.showCommentControl
+      })
+    } else {
+      if (typeof this.props.onCategoryClick === 'function') {
+        this.props.onCategoryClick(category)
+      }
+    }
+  }
+
+  onSubmit = (e) => {
+    e.preventDefault();
+    if (this.state.showCommentControl) {
+      const comment = this.commentControl.value;
+      const { activeCategory } = this.state;
+      Object.assign(activeCategory, { comment: comment });
+      if (typeof this.props.onCategoryClick === 'function') {
+        this.props.onCategoryClick(activeCategory)
+      }
+    }
+  }
+
+  render() {
+    return (
+      <div className="categories-tooltip">
+        <form onSubmit={ this.onSubmit }>
+          <div className="form-group buttons">
+          {this.props.categories.map((category) =>
+            <button type="button"
+              key={ category.key }
+              className="btn btn-sm text-secondary"
+              style={{ backgroundColor: category.color }}
+              active={ this.isCategoryActive(category)  }
+              onClick={ this.onButtonClick.bind(this, category) }>{ category.name }</button>
+          )}
+          </div>
+          {this.state.showCommentControl &&
+          <div className="form-group">
+            <input className="form-control"
+            // inputRef={(ref) => { this.commentControl = ref; }}
+            ref={(commentControl) => { this.commentControl = commentControl; }}/>
+          </div>}
+        </form>
+      </div>
+    );
+  }
+}
+
+export default CategoriesTooltip