@21epub/epub-thirdparty
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epub-thirdparty
205 lines (204 loc) • 9.03 kB
JavaScript
/*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
import * as dom from '../../dom.js';
import { createFastDomNode } from '../../fastDomNode.js';
import { GlobalMouseMoveMonitor, standardMouseMoveMerger } from '../../globalMouseMoveMonitor.js';
import { ScrollbarArrow } from './scrollbarArrow.js';
import { ScrollbarVisibilityController } from './scrollbarVisibilityController.js';
import { Widget } from '../widget.js';
import * as platform from '../../../common/platform.js';
/**
* The orthogonal distance to the slider at which dragging "resets". This implements "snapping"
*/
const MOUSE_DRAG_RESET_DISTANCE = 140;
export class AbstractScrollbar extends Widget {
constructor(opts) {
super();
this._lazyRender = opts.lazyRender;
this._host = opts.host;
this._scrollable = opts.scrollable;
this._scrollByPage = opts.scrollByPage;
this._scrollbarState = opts.scrollbarState;
this._visibilityController = this._register(new ScrollbarVisibilityController(opts.visibility, 'visible scrollbar ' + opts.extraScrollbarClassName, 'invisible scrollbar ' + opts.extraScrollbarClassName));
this._visibilityController.setIsNeeded(this._scrollbarState.isNeeded());
this._mouseMoveMonitor = this._register(new GlobalMouseMoveMonitor());
this._shouldRender = true;
this.domNode = createFastDomNode(document.createElement('div'));
this.domNode.setAttribute('role', 'presentation');
this.domNode.setAttribute('aria-hidden', 'true');
this._visibilityController.setDomNode(this.domNode);
this.domNode.setPosition('absolute');
this.onmousedown(this.domNode.domNode, (e) => this._domNodeMouseDown(e));
}
// ----------------- creation
/**
* Creates the dom node for an arrow & adds it to the container
*/
_createArrow(opts) {
const arrow = this._register(new ScrollbarArrow(opts));
this.domNode.domNode.appendChild(arrow.bgDomNode);
this.domNode.domNode.appendChild(arrow.domNode);
}
/**
* Creates the slider dom node, adds it to the container & hooks up the events
*/
_createSlider(top, left, width, height) {
this.slider = createFastDomNode(document.createElement('div'));
this.slider.setClassName('slider');
this.slider.setPosition('absolute');
this.slider.setTop(top);
this.slider.setLeft(left);
if (typeof width === 'number') {
this.slider.setWidth(width);
}
if (typeof height === 'number') {
this.slider.setHeight(height);
}
this.slider.setLayerHinting(true);
this.slider.setContain('strict');
this.domNode.domNode.appendChild(this.slider.domNode);
this.onmousedown(this.slider.domNode, (e) => {
if (e.leftButton) {
e.preventDefault();
this._sliderMouseDown(e, () => { });
}
});
this.onclick(this.slider.domNode, e => {
if (e.leftButton) {
e.stopPropagation();
}
});
}
// ----------------- Update state
_onElementSize(visibleSize) {
if (this._scrollbarState.setVisibleSize(visibleSize)) {
this._visibilityController.setIsNeeded(this._scrollbarState.isNeeded());
this._shouldRender = true;
if (!this._lazyRender) {
this.render();
}
}
return this._shouldRender;
}
_onElementScrollSize(elementScrollSize) {
if (this._scrollbarState.setScrollSize(elementScrollSize)) {
this._visibilityController.setIsNeeded(this._scrollbarState.isNeeded());
this._shouldRender = true;
if (!this._lazyRender) {
this.render();
}
}
return this._shouldRender;
}
_onElementScrollPosition(elementScrollPosition) {
if (this._scrollbarState.setScrollPosition(elementScrollPosition)) {
this._visibilityController.setIsNeeded(this._scrollbarState.isNeeded());
this._shouldRender = true;
if (!this._lazyRender) {
this.render();
}
}
return this._shouldRender;
}
// ----------------- rendering
beginReveal() {
this._visibilityController.setShouldBeVisible(true);
}
beginHide() {
this._visibilityController.setShouldBeVisible(false);
}
render() {
if (!this._shouldRender) {
return;
}
this._shouldRender = false;
this._renderDomNode(this._scrollbarState.getRectangleLargeSize(), this._scrollbarState.getRectangleSmallSize());
this._updateSlider(this._scrollbarState.getSliderSize(), this._scrollbarState.getArrowSize() + this._scrollbarState.getSliderPosition());
}
// ----------------- DOM events
_domNodeMouseDown(e) {
if (e.target !== this.domNode.domNode) {
return;
}
this._onMouseDown(e);
}
delegateMouseDown(e) {
const domTop = this.domNode.domNode.getClientRects()[0].top;
const sliderStart = domTop + this._scrollbarState.getSliderPosition();
const sliderStop = domTop + this._scrollbarState.getSliderPosition() + this._scrollbarState.getSliderSize();
const mousePos = this._sliderMousePosition(e);
if (sliderStart <= mousePos && mousePos <= sliderStop) {
// Act as if it was a mouse down on the slider
if (e.leftButton) {
e.preventDefault();
this._sliderMouseDown(e, () => { });
}
}
else {
// Act as if it was a mouse down on the scrollbar
this._onMouseDown(e);
}
}
_onMouseDown(e) {
let offsetX;
let offsetY;
if (e.target === this.domNode.domNode && typeof e.browserEvent.offsetX === 'number' && typeof e.browserEvent.offsetY === 'number') {
offsetX = e.browserEvent.offsetX;
offsetY = e.browserEvent.offsetY;
}
else {
const domNodePosition = dom.getDomNodePagePosition(this.domNode.domNode);
offsetX = e.posx - domNodePosition.left;
offsetY = e.posy - domNodePosition.top;
}
const offset = this._mouseDownRelativePosition(offsetX, offsetY);
this._setDesiredScrollPositionNow(this._scrollByPage
? this._scrollbarState.getDesiredScrollPositionFromOffsetPaged(offset)
: this._scrollbarState.getDesiredScrollPositionFromOffset(offset));
if (e.leftButton) {
e.preventDefault();
this._sliderMouseDown(e, () => { });
}
}
_sliderMouseDown(e, onDragFinished) {
const initialMousePosition = this._sliderMousePosition(e);
const initialMouseOrthogonalPosition = this._sliderOrthogonalMousePosition(e);
const initialScrollbarState = this._scrollbarState.clone();
this.slider.toggleClassName('active', true);
this._mouseMoveMonitor.startMonitoring(e.target, e.buttons, standardMouseMoveMerger, (mouseMoveData) => {
const mouseOrthogonalPosition = this._sliderOrthogonalMousePosition(mouseMoveData);
const mouseOrthogonalDelta = Math.abs(mouseOrthogonalPosition - initialMouseOrthogonalPosition);
if (platform.isWindows && mouseOrthogonalDelta > MOUSE_DRAG_RESET_DISTANCE) {
// The mouse has wondered away from the scrollbar => reset dragging
this._setDesiredScrollPositionNow(initialScrollbarState.getScrollPosition());
return;
}
const mousePosition = this._sliderMousePosition(mouseMoveData);
const mouseDelta = mousePosition - initialMousePosition;
this._setDesiredScrollPositionNow(initialScrollbarState.getDesiredScrollPositionFromDelta(mouseDelta));
}, () => {
this.slider.toggleClassName('active', false);
this._host.onDragEnd();
onDragFinished();
});
this._host.onDragStart();
}
_setDesiredScrollPositionNow(_desiredScrollPosition) {
const desiredScrollPosition = {};
this.writeScrollPosition(desiredScrollPosition, _desiredScrollPosition);
this._scrollable.setScrollPositionNow(desiredScrollPosition);
}
updateScrollbarSize(scrollbarSize) {
this._updateScrollbarSize(scrollbarSize);
this._scrollbarState.setScrollbarSize(scrollbarSize);
this._shouldRender = true;
if (!this._lazyRender) {
this.render();
}
}
isNeeded() {
return this._scrollbarState.isNeeded();
}
}