[Tabs] Reduce the bundle size

.size-limit.js

@@ -22,7 +22,7 @@ module.exports = [
  name: 'The size of the @material-ui/core modules',
  webpack: true,
  path: 'packages/material-ui/build/index.js',
- limit: '95 KB',
+ limit: '94.9 KB',
  },
  {
  name: 'The size of the @material-ui/styles modules',
@@ -35,7 +35,7 @@ module.exports = [
  name: 'The size of the @material-ui/core/Popper component',
  webpack: true,
  path: 'packages/material-ui/build/Popper/index.js',
- limit: '10.0 KB',
+ limit: '9.9 KB',
  },
  {
  name: 'The main docs bundle',

packages/material-ui/src/Tabs/ScrollbarSize.js

@@ -4,11 +4,12 @@ import EventListener from 'react-event-listener';
 import debounce from 'debounce'; // < 1kb payload overhead when lodash/debounce is > 3kb.
 
 const styles = {
- width: 100,
- height: 100,
+ width: 90,
+ height: 90,
  position: 'absolute',
- top: -10000,
+ top: -9000,
  overflow: 'scroll',
+ // Support IE 11
  msOverflowStyle: 'scrollbar',
 };
 
@@ -23,30 +24,29 @@ class ScrollbarSize extends React.Component {
 
  if (typeof window !== 'undefined') {
  this.handleResize = debounce(() => {
- const { onChange } = this.props;
-
  const prevHeight = this.scrollbarHeight;
- const prevWidth = this.scrollbarWidth;
  this.setMeasurements();
- if (prevHeight !== this.scrollbarHeight || prevWidth !== this.scrollbarWidth) {
- onChange({ scrollbarHeight: this.scrollbarHeight, scrollbarWidth: this.scrollbarWidth });
+
+ if (prevHeight !== this.scrollbarHeight) {
+ this.props.onChange(this.scrollbarHeight);
  }
  }, 166); // Corresponds to 10 frames at 60 Hz.
  }
  }
 
  componentDidMount() {
  this.setMeasurements();
- this.props.onLoad({
- scrollbarHeight: this.scrollbarHeight,
- scrollbarWidth: this.scrollbarWidth,
- });
+ this.props.onChange(this.scrollbarHeight);
  }
 
  componentWillUnmount() {
  this.handleResize.clear();
  }
 
+ handleRef = ref => {
+ this.nodeRef = ref;
+ };
+
  setMeasurements = () => {
  const nodeRef = this.nodeRef;
 
@@ -55,29 +55,20 @@ class ScrollbarSize extends React.Component {
  }
 
  this.scrollbarHeight = nodeRef.offsetHeight - nodeRef.clientHeight;
- this.scrollbarWidth = nodeRef.offsetWidth - nodeRef.clientWidth;
  };
 
  render() {
- const { onChange } = this.props;
-
  return (
- <div>
- {onChange ? <EventListener target="window" onResize={this.handleResize} /> : null}
- <div
- style={styles}
- ref={ref => {
- this.nodeRef = ref;
- }}
- />
- </div>
+ <React.Fragment>
+ <EventListener target="window" onResize={this.handleResize} />
+ <div style={styles} ref={this.handleRef} />
+ </React.Fragment>
  );
  }
 }
 
 ScrollbarSize.propTypes = {
  onChange: PropTypes.func.isRequired,
- onLoad: PropTypes.func.isRequired,
 };
 
 export default ScrollbarSize;

packages/material-ui/src/Tabs/ScrollbarSize.test.js

@@ -7,7 +7,6 @@ import ScrollbarSize from './ScrollbarSize';
 
 describe('<ScrollbarSize />', () => {
  const defaultProps = {
- onLoad: () => {},
  onChange: () => {},
  };
  let clock;
@@ -20,28 +19,24 @@ describe('<ScrollbarSize />', () => {
  clock.restore();
  });
 
- describe('prop: onLoad', () => {
+ describe('mount', () => {
  let wrapper;
 
  afterEach(() => {
  wrapper.unmount();
  });
 
  it('should not call on initial load', () => {
- const onLoad = spy();
+ const onChange = spy();
  wrapper = mount(<ScrollbarSize {...defaultProps} />);
- assert.strictEqual(onLoad.callCount, 0, 'should not have been called');
+ assert.strictEqual(onChange.callCount, 0);
  });
 
  it('should call on initial load', () => {
- const onLoad = spy();
- wrapper = mount(<ScrollbarSize {...defaultProps} onLoad={onLoad} />);
- assert.strictEqual(onLoad.callCount, 1, 'should have been called once');
- assert.strictEqual(
- onLoad.calledWith({ scrollbarHeight: 0, scrollbarWidth: 0 }),
- true,
- 'should have been called with expected sizes',
- );
+ const onChange = spy();
+ wrapper = mount(<ScrollbarSize {...defaultProps} onChange={onChange} />);
+ assert.strictEqual(onChange.callCount, 1);
+ assert.strictEqual(onChange.calledWith(0), true);
  });
  });
 
@@ -56,26 +51,22 @@ describe('<ScrollbarSize />', () => {
  instance.nodeRef = {
  offsetHeight: 17,
  clientHeight: 0,
- offsetWidth: 17,
- clientWidth: 0,
  };
  });
 
  it('should call on first resize event', () => {
+ assert.strictEqual(onChange.callCount, 1);
  wrapper.find(EventListener).simulate('resize');
  clock.tick(166);
- assert.strictEqual(onChange.callCount, 1, 'should have been called once');
- assert.strictEqual(
- onChange.calledWith({ scrollbarHeight: 17, scrollbarWidth: 17 }),
- true,
- 'should have been called with expected sizes',
- );
+ assert.strictEqual(onChange.callCount, 2);
+ assert.strictEqual(onChange.calledWith(17), true);
  });
 
  it('should not call on second resize event', () => {
+ assert.strictEqual(onChange.callCount, 1);
  wrapper.find(EventListener).simulate('resize');
  clock.tick(166);
- assert.strictEqual(onChange.callCount, 1, 'should only have been called once');
+ assert.strictEqual(onChange.callCount, 2);
  });
  });
 });

packages/material-ui/src/Tabs/Tabs.js

@@ -114,10 +114,7 @@ class Tabs extends React.Component {
  const { classes, scrollable, ScrollButtonComponent, scrollButtons, theme } = this.props;
  const conditionalElements = {};
  conditionalElements.scrollbarSizeListener = scrollable ? (
- <ScrollbarSize
- onLoad={this.handleScrollbarSizeChange}
- onChange={this.handleScrollbarSizeChange}
- />
+ <ScrollbarSize onChange={this.handleScrollbarSizeChange} />
  ) : null;
 
  const showScrollButtons = scrollable && (scrollButtons === 'auto' || scrollButtons === 'on');
@@ -194,7 +191,7 @@ class Tabs extends React.Component {
  this.moveTabsScroll(this.tabsRef.clientWidth);
  };
 
- handleScrollbarSizeChange = ({ scrollbarHeight }) => {
+ handleScrollbarSizeChange = scrollbarHeight => {
  this.setState({
  scrollerStyle: {
  marginBottom: -scrollbarHeight,