fix(Modal): Lock focus

src/Modal/Modal.dropdownExample.js

@@ -0,0 +1,65 @@
+import React from 'react';
+import Modal from './Modal';
+import Button from '../Button';
+import Input from '../Form/Input';
+import Dropdown from '../Dropdown';
+
+export default class ModalDropdownDemo extends React.Component {
+  state = {
+    isModalOpen: false,
+  };
+
+  toggle = () => {
+    this.setState({ isModalOpen: !this.state.isModalOpen });
+  };
+
+  onCancel = () => {
+    this.toggle();
+
+    setTimeout(() => {
+      alert('Oh no! It has been canceled.');
+    }, 500);
+  };
+
+  render() {
+    const { body, ...props } = this.props;
+
+    return (
+      <div>
+        <Dropdown placement="top" width={250} trigger={<Button variant="success">Open Dropdown</Button>}>
+          <Dropdown.Header title="Dropdown" />
+
+          <Dropdown.Body>
+            <Dropdown.SectionTitle>Section One</Dropdown.SectionTitle>
+            <Dropdown.Item onClick={this.toggle} as="button">
+              Open Modal
+            </Dropdown.Item>
+          </Dropdown.Body>
+
+          <Dropdown.Footer>Footer</Dropdown.Footer>
+        </Dropdown>
+
+        <Modal
+          open={this.state.isModalOpen}
+          onClose={this.toggle}
+          title="Example Dropdown Modal"
+          {...props}>
+          <Modal.Body>
+            <>
+              {body}
+              <Input autoFocus name="password" label="Password" />
+            </>
+          </Modal.Body>
+
+          <Modal.Footer>
+            <Button.Group justifyContent="flex-end">
+              <Button variant="gray" onClick={this.onCancel}>
+                Cancel
+              </Button>
+            </Button.Group>
+          </Modal.Footer>
+        </Modal>
+      </div>
+    );
+  }
+}

src/Modal/Modal.example.js

@@ -1,7 +1,7 @@
 import React from 'react';
 import Modal from './Modal';
 import Button from '../Button';
-import Box from '../Box';
+import Input from '../Form/Input';
 
 export default class ModalDemo extends React.Component {
   state = {
@@ -32,11 +32,22 @@ export default class ModalDemo extends React.Component {
       <div>
         <Button onClick={this.toggle}>Open Modal</Button>
 
-        <Modal open={this.state.isModalOpen} onClose={this.toggle} title="Example Modal" {...props}>
+        <Modal
+          open={this.state.isModalOpen}
+          onClose={this.toggle}
+          title="Example Modal"
+          {...props}>
           <Modal.Body>
-            {body}
+            <>
+              {body}
+              <Input autoFocus name="password" label="Password" />
+            </>
 
-            <Modal open={this.state.isModalTwoOpen} onClose={this.toggleModalTwo} title="Example Modal Two" {...props}>
+            <Modal
+              open={this.state.isModalTwoOpen}
+              onClose={this.toggleModalTwo}
+              title="Example Modal Two"
+              {...props}>
               <Modal.Body>{bodyTwo}</Modal.Body>
 
               <Modal.Footer>

src/Modal/Modal.js

@@ -3,6 +3,7 @@ import PropTypes from 'prop-types';
 import { keyframes, css } from 'styled-components';
 import * as animations from 'react-animations';
 import { Transition } from 'react-transition-group';
+import FocusLock from 'react-focus-lock';
 import Portal from '../Portal';
 import Flex from '../Flex';
 import Box from '../Box';
@@ -105,10 +106,12 @@ function Modal({ children, title, animationDuration, showClose, onClose, open, .
         <Transition in={isOpen} timeout={animationDuration}>
           {state => (
             <Backdrop transitionState={state} onClick={handleBackdropClick}>
-              <ModalContent transitionState={state} onClick={handleContentClick} {...props}>
-                {title && <Modal.Header title={title} showClose={showClose} />}
-                {children}
-              </ModalContent>
+              <FocusLock lockProps={{ style: { maxHeight: '100%' } }} disabled={!isOpen}>
+                <ModalContent transitionState={state} onClick={handleContentClick} {...props}>
+                  {title && <Modal.Header title={title} showClose={showClose} />}
+                  {children}
+                </ModalContent>
+              </FocusLock>
             </Backdrop>
           )}
         </Transition>

src/Modal/Modal.mdx

@@ -6,6 +6,7 @@ name: Modal
 import { Playground, PropsTable } from 'docz'
 import Modal from './Modal'
 import ModalExample from './Modal.example'
+import ModalDropdownExample from './Modal.dropdownexample'
 
 # Modal
 
@@ -29,3 +30,11 @@ When modals become too long for the user’s viewport or device, they scroll ind
 <Playground>
   <ModalExample body={<div>{new Array(50).fill(null).map((_, i) => <p key={i}>I'm really long annoying content.</p>)}</div>} />
 </Playground>
+
+## Handling Dropdown Triggered Content
+
+When modals are triggered by dropdowns with returnFocus set to true, modals still receive focus. 
+
+<Playground>
+  <ModalDropdownExample body="I'm triggered by a dropdown" />
+</Playground>