81 lines
2.7 KiB
JavaScript
81 lines
2.7 KiB
JavaScript
/*
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Copyright 2018 New Vector Ltd
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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import React from "react";
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import AutoHideScrollbar from "./AutoHideScrollbar";
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export default class IndicatorScrollbar extends React.Component {
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constructor(props) {
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super(props);
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this._collectScroller = this._collectScroller.bind(this);
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this._collectScrollerComponent = this._collectScrollerComponent.bind(this);
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this.checkOverflow = this.checkOverflow.bind(this);
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this._scrollElement = null;
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this._autoHideScrollbar = null;
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}
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_collectScroller(scroller) {
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if (scroller && !this._scrollElement) {
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this._scrollElement = scroller;
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this._scrollElement.addEventListener("scroll", this.checkOverflow);
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this.checkOverflow();
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}
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}
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_collectScrollerComponent(autoHideScrollbar) {
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this._autoHideScrollbar = autoHideScrollbar;
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}
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checkOverflow() {
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const hasTopOverflow = this._scrollElement.scrollTop > 0;
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const hasBottomOverflow = this._scrollElement.scrollHeight >
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(this._scrollElement.scrollTop + this._scrollElement.clientHeight);
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if (hasTopOverflow) {
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this._scrollElement.classList.add("mx_IndicatorScrollbar_topOverflow");
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} else {
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this._scrollElement.classList.remove("mx_IndicatorScrollbar_topOverflow");
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}
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if (hasBottomOverflow) {
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this._scrollElement.classList.add("mx_IndicatorScrollbar_bottomOverflow");
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} else {
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this._scrollElement.classList.remove("mx_IndicatorScrollbar_bottomOverflow");
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}
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if (this._autoHideScrollbar) {
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this._autoHideScrollbar.checkOverflow();
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}
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}
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getScrollTop() {
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return this._autoHideScrollbar.getScrollTop();
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}
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componentWillUnmount() {
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if (this._scrollElement) {
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this._scrollElement.removeEventListener("scroll", this.checkOverflow);
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}
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}
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render() {
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return (<AutoHideScrollbar
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ref={this._collectScrollerComponent}
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wrappedRef={this._collectScroller}
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{... this.props}
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>
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{ this.props.children }
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</AutoHideScrollbar>);
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}
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}
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