'Copy to Clipboard' functionality (#163)

* Adds 'Copy to Clipboard' functionality to all code blocks in readOnly

* Show on hover, move to SC

* 💚

* PR feedback

frontend/components/Editor/components/Code.js

@@ -1,13 +1,40 @@
 // @flow
 import React from 'react';
+import styled from 'styled-components';
+import CopyButton from './CopyButton';
+import { color } from 'styles/constants';
 import type { Props } from '../types';
 
-export default function Code({ children, attributes }: Props) {
+export default function Code({ children, node, readOnly, attributes }: Props) {
   return (
-    <pre>
-      <code {...attributes}>
-        {children}
-      </code>
-    </pre>
+    <Container>
+      {readOnly && <CopyButton text={node.text} />}
+      <Pre>
+        <code {...attributes}>
+          {children}
+        </code>
+      </Pre>
+    </Container>
   );
 }
+
+const Pre = styled.pre`
+  padding: .5em 1em;
+  background: ${color.smoke};
+  border-radius: 4px;
+  border: 1px solid ${color.smokeDark};
+
+  code {
+    padding: 0;
+  }
+`;
+
+const Container = styled.div`
+  position: relative;
+
+  &:hover {
+    > span {
+      opacity: 1;
+    }
+  }
+`;

frontend/components/Editor/components/CopyButton.js

@@ -0,0 +1,49 @@
+// @flow
+import React, { Component } from 'react';
+import { observable } from 'mobx';
+import { observer } from 'mobx-react';
+import { color } from 'styles/constants';
+import styled from 'styled-components';
+import CopyToClipboard from 'components/CopyToClipboard';
+
+@observer class CopyButton extends Component {
+  @observable copied: boolean = false;
+  copiedTimeout: ?number;
+
+  componentWillUnmount() {
+    clearTimeout(this.copiedTimeout);
+  }
+
+  handleCopy = () => {
+    this.copied = true;
+    this.copiedTimeout = setTimeout(() => (this.copied = false), 3000);
+  };
+
+  render() {
+    return (
+      <StyledCopyToClipboard onCopy={this.handleCopy} {...this.props}>
+        <span>{this.copied ? 'Copied!' : 'Copy to clipboard'}</span>
+      </StyledCopyToClipboard>
+    );
+  }
+}
+
+const StyledCopyToClipboard = styled(CopyToClipboard)`
+  position: absolute;
+  top: 0;
+  right: 0;
+
+  opacity: 0;
+  transition: opacity 50ms ease-in-out;
+  z-index: 1;
+  font-size: 12px;
+  background: ${color.slateLight};
+  border-radius: 2px;
+  padding: 1px 6px;
+
+  &:hover {
+    background: ${color.slate};
+  }
+`;
+
+export default CopyButton;

frontend/components/Editor/components/InlineCode.js

@@ -0,0 +1,12 @@
+// @flow
+import styled from 'styled-components';
+import { color } from 'styles/constants';
+
+const InlineCode = styled.code`
+  padding: .25em;
+  background: ${color.smoke};
+  border-radius: 4px;
+  border: 1px solid ${color.smokeDark};
+`;
+
+export default InlineCode;