Add EuiDelayHide component

.gitignore

@@ -4,6 +4,7 @@ reports/
 tmp/
 dist/
 lib/
+.vscode/
 .DS_Store
 .eslintcache
 .yo-rc.json

CHANGELOG.md

@@ -1,5 +1,6 @@
 # [`master`](https://github.com/elastic/eui/tree/master)
 
+- Added `EuiDelayHide` component. [#412](https://github.com/elastic/eui/pull/412)
 - Decreased overall size of checkbox, radio, and switches as well as better styles for the different states. ([#407](https://github.com/elastic/eui/pull/407))
 
 **Bug fixes**
@@ -21,7 +22,7 @@
 - Added importAction and exportAction icons ([#394](https://github.com/elastic/eui/pull/394))
 - Added `EuiCard` for UI patterns that need an icon/image, title and description with some sort of action. ([#380](https://github.com/elastic/eui/pull/380))
 - Add TypeScript definitions for the `<EuiHealth>` component. ([#403](https://github.com/elastic/eui/pull/403))
-- Added `SearchBar` component - introduces a simple yet rich query language to search for objects + search box and filter controls to construct/manipulate it. ([#379](https://github.com/elastic/eui/pull/379))  
+- Added `SearchBar` component - introduces a simple yet rich query language to search for objects + search box and filter controls to construct/manipulate it. ([#379](https://github.com/elastic/eui/pull/379))
 
 **Bug fixes**
 

src-docs/src/routes.js

@@ -64,6 +64,9 @@ import { ColorPickerExample }
 import { ContextMenuExample }
   from './views/context_menu/context_menu_example';
 
+import { DelayHideExample }
+  from './views/delay_hide/delay_hide_example';
+
 import { DescriptionListExample }
   from './views/description_list/description_list_example';
 
@@ -226,6 +229,7 @@ const components = [
   CodeExample,
   ColorPickerExample,
   ContextMenuExample,
+  DelayHideExample,
   DescriptionListExample,
   ErrorBoundaryExample,
   ExpressionExample,

src-docs/src/views/delay_hide/delay_hide.js

@@ -0,0 +1,55 @@
+import React, { Component, Fragment } from 'react';
+import {
+  EuiDelayHide,
+  EuiFlexItem,
+  EuiCheckbox,
+  EuiFormRow,
+  EuiFieldNumber,
+  EuiLoadingSpinner
+} from '../../../../src/components';
+
+export default class extends Component {
+  state = {
+    minimumDuration: 3000,
+    hide: false
+  };
+
+  onChangeMinimumDuration = event => {
+    this.setState({ minimumDuration: parseInt(event.target.value, 10) });
+  };
+
+  onChangeHide = event => {
+    this.setState({ hide: event.target.checked });
+  };
+
+  render() {
+    return (
+      <Fragment>
+        <EuiFlexItem>
+          <EuiFormRow>
+            <EuiCheckbox
+              id="dummy-id"
+              checked={this.state.hide}
+              onChange={this.onChangeHide}
+              label="Hide child"
+            />
+          </EuiFormRow>
+          <EuiFormRow label="Minimum duration">
+            <EuiFieldNumber
+              value={this.state.minimumDuration}
+              onChange={this.onChangeMinimumDuration}
+            />
+          </EuiFormRow>
+
+          <EuiFormRow label="Child to render">
+            <EuiDelayHide
+              hide={this.state.hide}
+              minimumDuration={this.state.minimumDuration}
+              render={() => <EuiLoadingSpinner size="m"/>}
+            />
+          </EuiFormRow>
+        </EuiFlexItem>
+      </Fragment>
+    );
+  }
+}

src-docs/src/views/delay_hide/delay_hide_example.js

@@ -0,0 +1,38 @@
+import React from 'react';
+import DelayHide from './delay_hide';
+import { GuideSectionTypes } from '../../components';
+import { EuiCode, EuiDelayHide } from '../../../../src/components';
+import { renderToHtml } from '../../services';
+
+const delayHideSource = require('!!raw-loader!./delay_hide');
+const delayHideHtml = renderToHtml(DelayHide);
+
+export const DelayHideExample = {
+  title: 'DelayHide',
+  sections: [
+    {
+      title: 'DelayHide',
+      source: [
+        {
+          type: GuideSectionTypes.JS,
+          code: delayHideSource
+        },
+        {
+          type: GuideSectionTypes.HTML,
+          code: delayHideHtml
+        }
+      ],
+      text: (
+        <p>
+          <EuiCode>EuiDelayHide</EuiCode> is a component for conditionally toggling
+          the visibility of a child component. It will ensure that the child is
+          visible for at least 1000ms (default). This avoids UI glitches that
+          are common with loading spinners and other elements that are rendered
+          conditionally and potentially for a short amount of time.
+        </p>
+      ),
+      props: { EuiDelayHide },
+      demo: <DelayHide />
+    }
+  ]
+};

src/components/delay_hide/delay_hide.js

@@ -0,0 +1,63 @@
+import { Component } from 'react';
+import PropTypes from 'prop-types';
+
+export class EuiDelayHide extends Component {
+  static propTypes = {
+    hide: PropTypes.bool,
+    minimumDuration: PropTypes.number,
+    render: PropTypes.func.isRequired
+  };
+
+  static defaultProps = {
+    hide: false,
+    minimumDuration: 1000
+  };
+
+  constructor(props) {
+    super(props);
+
+    this.state = {
+      hide: this.props.hide
+    };
+
+    this.lastRenderedTime = this.props.hide ? 0 : Date.now();
+  }
+
+  getTimeRemaining(minimumDuration) {
+    const visibleDuration = Date.now() - this.lastRenderedTime;
+    return minimumDuration - visibleDuration;
+  }
+
+  componentWillReceiveProps(nextProps) {
+    clearTimeout(this.timeout);
+    const timeRemaining = this.getTimeRemaining(nextProps.minimumDuration);
+
+    if (nextProps.hide && timeRemaining > 0) {
+      this.setStateDelayed(timeRemaining);
+    } else {
+      if (this.state.hide && !nextProps.hide) {
+        this.lastRenderedTime = Date.now();
+      }
+
+      this.setState({ hide: nextProps.hide });
+    }
+  }
+
+  setStateDelayed = timeRemaining => {
+    this.timeout = setTimeout(() => {
+      this.setState({ hide: true });
+    }, timeRemaining);
+  };
+
+  componentWillUnmount() {
+    clearTimeout(this.timeout);
+  }
+
+  render() {
+    if (this.state.hide) {
+      return null;
+    }
+
+    return this.props.render();
+  }
+}

src/components/delay_hide/delay_hide.test.js

@@ -0,0 +1,109 @@
+import React from 'react';
+import { mount } from 'enzyme';
+import { EuiDelayHide } from './index';
+
+describe('when EuiDelayHide is visible initially', () => {
+  let wrapper;
+  beforeEach(() => {
+    jest.useFakeTimers();
+    wrapper = mount(
+      <EuiDelayHide
+        hide={false}
+        render={() => <div>Hello World</div>}
+      />
+    );
+  });
+
+  test('it should be visible initially', async () => {
+    wrapper.setProps({ hide: true });
+    expect(wrapper.html()).toEqual('<div>Hello World</div>');
+  });
+
+  test('it should be visible after 900ms', () => {
+    wrapper.setProps({ hide: true });
+    jest.advanceTimersByTime(900);
+    expect(wrapper.html()).toEqual('<div>Hello World</div>');
+  });
+
+  test('it should be hidden after 1100ms', () => {
+    wrapper.setProps({ hide: true });
+    jest.advanceTimersByTime(1100);
+    expect(wrapper.html()).toEqual(null);
+  });
+
+  test('it should be visible after 1100ms regardless of prop changes in-between', () => {
+    wrapper.setProps({ hide: true });
+    wrapper.setProps({ hide: false });
+    jest.advanceTimersByTime(1100);
+    expect(wrapper.html()).toEqual('<div>Hello World</div>');
+  });
+
+  test('it should hide immediately after prop change, if it has been displayed for 1100ms', () => {
+    const currentTime = Date.now();
+    jest.advanceTimersByTime(1100);
+    jest.spyOn(Date, 'now').mockReturnValue(currentTime + 1100);
+    expect(wrapper.html()).toEqual('<div>Hello World</div>');
+
+    wrapper.setProps({ hide: true });
+    expect(wrapper.html()).toEqual(null);
+  });
+});
+
+describe('when EuiDelayHide is hidden initially', () => {
+  let wrapper;
+  beforeEach(() => {
+    jest.useFakeTimers();
+    wrapper = mount(
+      <EuiDelayHide hide={true} render={() => <div>Hello World</div>} />
+    );
+  });
+
+  test('it should be hidden initially', async () => {
+    expect(wrapper.html()).toEqual(null);
+  });
+
+  test('it should become visible immediately after prop change', async () => {
+    wrapper.setProps({ hide: false });
+    expect(wrapper.html()).toEqual('<div>Hello World</div>');
+  });
+
+  test('it should be visible for at least 1100ms before hiding', async () => {
+    wrapper.setProps({ hide: false });
+    wrapper.setProps({ hide: true });
+    jest.advanceTimersByTime(900);
+
+    expect(wrapper.html()).toEqual('<div>Hello World</div>');
+
+    jest.advanceTimersByTime(200);
+    expect(wrapper.html()).toEqual(null);
+  });
+});
+
+describe('when EuiDelayHide is visible initially and has a minimumDuration of 2000ms ', () => {
+  let wrapper;
+  beforeEach(() => {
+    jest.useFakeTimers();
+    wrapper = mount(
+      <EuiDelayHide
+        hide={false}
+        minimumDuration={2000}
+        render={() => <div>Hello World</div>}
+      />
+    );
+    wrapper.setProps({ hide: true });
+  });
+
+  test('it should be visible initially', async () => {
+    expect(wrapper.html()).toEqual('<div>Hello World</div>');
+  });
+
+  test('it should be visible after 1900ms', () => {
+    jest.advanceTimersByTime(1900);
+    expect(wrapper.html()).toEqual('<div>Hello World</div>');
+  });
+
+  test('it should be hidden after 2100ms', () => {
+    jest.advanceTimersByTime(2100);
+    expect(wrapper.html()).toEqual(null);
+  });
+});

src/components/delay_hide/index.js

@@ -0,0 +1 @@
+export { EuiDelayHide } from './delay_hide';

src/components/index.js

@@ -53,6 +53,10 @@ export {
   EuiContextMenuItem,
 } from './context_menu';
 
+export {
+  EuiDelayHide
+} from './delay_hide';
+
 export {
   EuiDescriptionList,
   EuiDescriptionListTitle,