--- /dev/null
+/**
+ * Copyright (c) 2016 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { Disposable } from 'common/Lifecycle';
+import { addDisposableDomListener } from 'browser/Lifecycle';
+import { IColorSet, IViewport } from 'browser/Types';
+import { ICharSizeService, IRenderService } from 'browser/services/Services';
+import { IBufferService, IOptionsService } from 'common/services/Services';
+
+const FALLBACK_SCROLL_BAR_WIDTH = 15;
+
+/**
+ * Represents the viewport of a terminal, the visible area within the larger buffer of output.
+ * Logic for the virtual scroll bar is included in this object.
+ */
+export class Viewport extends Disposable implements IViewport {
+ public scrollBarWidth: number = 0;
+ private _currentRowHeight: number = 0;
+ private _lastRecordedBufferLength: number = 0;
+ private _lastRecordedViewportHeight: number = 0;
+ private _lastRecordedBufferHeight: number = 0;
+ private _lastTouchY: number = 0;
+ private _lastScrollTop: number = 0;
+
+ // Stores a partial line amount when scrolling, this is used to keep track of how much of a line
+ // is scrolled so we can "scroll" over partial lines and feel natural on touchpads. This is a
+ // quick fix and could have a more robust solution in place that reset the value when needed.
+ private _wheelPartialScroll: number = 0;
+
+ private _refreshAnimationFrame: number | null = null;
+ private _ignoreNextScrollEvent: boolean = false;
+
+ constructor(
+ private readonly _scrollLines: (amount: number, suppressEvent: boolean) => void,
+ private readonly _viewportElement: HTMLElement,
+ private readonly _scrollArea: HTMLElement,
+ @IBufferService private readonly _bufferService: IBufferService,
+ @IOptionsService private readonly _optionsService: IOptionsService,
+ @ICharSizeService private readonly _charSizeService: ICharSizeService,
+ @IRenderService private readonly _renderService: IRenderService
+ ) {
+ super();
+
+ // Measure the width of the scrollbar. If it is 0 we can assume it's an OSX overlay scrollbar.
+ // Unfortunately the overlay scrollbar would be hidden underneath the screen element in that case,
+ // therefore we account for a standard amount to make it visible
+ this.scrollBarWidth = (this._viewportElement.offsetWidth - this._scrollArea.offsetWidth) || FALLBACK_SCROLL_BAR_WIDTH;
+ this.register(addDisposableDomListener(this._viewportElement, 'scroll', this._onScroll.bind(this)));
+
+ // Perform this async to ensure the ICharSizeService is ready.
+ setTimeout(() => this.syncScrollArea(), 0);
+ }
+
+ public onThemeChange(colors: IColorSet): void {
+ this._viewportElement.style.backgroundColor = colors.background.css;
+ }
+
+ /**
+ * Refreshes row height, setting line-height, viewport height and scroll area height if
+ * necessary.
+ */
+ private _refresh(immediate: boolean): void {
+ if (immediate) {
+ this._innerRefresh();
+ if (this._refreshAnimationFrame !== null) {
+ cancelAnimationFrame(this._refreshAnimationFrame);
+ }
+ return;
+ }
+ if (this._refreshAnimationFrame === null) {
+ this._refreshAnimationFrame = requestAnimationFrame(() => this._innerRefresh());
+ }
+ }
+
+ private _innerRefresh(): void {
+ if (this._charSizeService.height > 0) {
+ this._currentRowHeight = this._renderService.dimensions.scaledCellHeight / window.devicePixelRatio;
+ this._lastRecordedViewportHeight = this._viewportElement.offsetHeight;
+ const newBufferHeight = Math.round(this._currentRowHeight * this._lastRecordedBufferLength) + (this._lastRecordedViewportHeight - this._renderService.dimensions.canvasHeight);
+ if (this._lastRecordedBufferHeight !== newBufferHeight) {
+ this._lastRecordedBufferHeight = newBufferHeight;
+ this._scrollArea.style.height = this._lastRecordedBufferHeight + 'px';
+ }
+ }
+
+ // Sync scrollTop
+ const scrollTop = this._bufferService.buffer.ydisp * this._currentRowHeight;
+ if (this._viewportElement.scrollTop !== scrollTop) {
+ // Ignore the next scroll event which will be triggered by setting the scrollTop as we do not
+ // want this event to scroll the terminal
+ this._ignoreNextScrollEvent = true;
+ this._viewportElement.scrollTop = scrollTop;
+ }
+
+ this._refreshAnimationFrame = null;
+ }
+ /**
+ * Updates dimensions and synchronizes the scroll area if necessary.
+ */
+ public syncScrollArea(immediate: boolean = false): void {
+ // If buffer height changed
+ if (this._lastRecordedBufferLength !== this._bufferService.buffer.lines.length) {
+ this._lastRecordedBufferLength = this._bufferService.buffer.lines.length;
+ this._refresh(immediate);
+ return;
+ }
+
+ // If viewport height changed
+ if (this._lastRecordedViewportHeight !== this._renderService.dimensions.canvasHeight) {
+ this._refresh(immediate);
+ return;
+ }
+
+ // If the buffer position doesn't match last scroll top
+ const newScrollTop = this._bufferService.buffer.ydisp * this._currentRowHeight;
+ if (this._lastScrollTop !== newScrollTop) {
+ this._refresh(immediate);
+ return;
+ }
+
+ // If element's scroll top changed, this can happen when hiding the element
+ if (this._lastScrollTop !== this._viewportElement.scrollTop) {
+ this._refresh(immediate);
+ return;
+ }
+
+ // If row height changed
+ if (this._renderService.dimensions.scaledCellHeight / window.devicePixelRatio !== this._currentRowHeight) {
+ this._refresh(immediate);
+ return;
+ }
+ }
+
+ /**
+ * Handles scroll events on the viewport, calculating the new viewport and requesting the
+ * terminal to scroll to it.
+ * @param ev The scroll event.
+ */
+ private _onScroll(ev: Event): void {
+ // Record current scroll top position
+ this._lastScrollTop = this._viewportElement.scrollTop;
+
+ // Don't attempt to scroll if the element is not visible, otherwise scrollTop will be corrupt
+ // which causes the terminal to scroll the buffer to the top
+ if (!this._viewportElement.offsetParent) {
+ return;
+ }
+
+ // Ignore the event if it was flagged to ignore (when the source of the event is from Viewport)
+ if (this._ignoreNextScrollEvent) {
+ this._ignoreNextScrollEvent = false;
+ return;
+ }
+
+ const newRow = Math.round(this._lastScrollTop / this._currentRowHeight);
+ const diff = newRow - this._bufferService.buffer.ydisp;
+ this._scrollLines(diff, true);
+ }
+
+ /**
+ * Handles bubbling of scroll event in case the viewport has reached top or bottom
+ * @param ev The scroll event.
+ * @param amount The amount scrolled
+ */
+ private _bubbleScroll(ev: Event, amount: number): boolean {
+ const scrollPosFromTop = this._viewportElement.scrollTop + this._lastRecordedViewportHeight;
+ if ((amount < 0 && this._viewportElement.scrollTop !== 0) ||
+ (amount > 0 && scrollPosFromTop < this._lastRecordedBufferHeight)) {
+ if (ev.cancelable) {
+ ev.preventDefault();
+ }
+ return false;
+ }
+ return true;
+ }
+
+ /**
+ * Handles mouse wheel events by adjusting the viewport's scrollTop and delegating the actual
+ * scrolling to `onScroll`, this event needs to be attached manually by the consumer of
+ * `Viewport`.
+ * @param ev The mouse wheel event.
+ */
+ public onWheel(ev: WheelEvent): boolean {
+ const amount = this._getPixelsScrolled(ev);
+ if (amount === 0) {
+ return false;
+ }
+ this._viewportElement.scrollTop += amount;
+ return this._bubbleScroll(ev, amount);
+ }
+
+ private _getPixelsScrolled(ev: WheelEvent): number {
+ // Do nothing if it's not a vertical scroll event
+ if (ev.deltaY === 0) {
+ return 0;
+ }
+
+ // Fallback to WheelEvent.DOM_DELTA_PIXEL
+ let amount = this._applyScrollModifier(ev.deltaY, ev);
+ if (ev.deltaMode === WheelEvent.DOM_DELTA_LINE) {
+ amount *= this._currentRowHeight;
+ } else if (ev.deltaMode === WheelEvent.DOM_DELTA_PAGE) {
+ amount *= this._currentRowHeight * this._bufferService.rows;
+ }
+ return amount;
+ }
+
+ /**
+ * Gets the number of pixels scrolled by the mouse event taking into account what type of delta
+ * is being used.
+ * @param ev The mouse wheel event.
+ */
+ public getLinesScrolled(ev: WheelEvent): number {
+ // Do nothing if it's not a vertical scroll event
+ if (ev.deltaY === 0) {
+ return 0;
+ }
+
+ // Fallback to WheelEvent.DOM_DELTA_LINE
+ let amount = this._applyScrollModifier(ev.deltaY, ev);
+ if (ev.deltaMode === WheelEvent.DOM_DELTA_PIXEL) {
+ amount /= this._currentRowHeight + 0.0; // Prevent integer division
+ this._wheelPartialScroll += amount;
+ amount = Math.floor(Math.abs(this._wheelPartialScroll)) * (this._wheelPartialScroll > 0 ? 1 : -1);
+ this._wheelPartialScroll %= 1;
+ } else if (ev.deltaMode === WheelEvent.DOM_DELTA_PAGE) {
+ amount *= this._bufferService.rows;
+ }
+ return amount;
+ }
+
+ private _applyScrollModifier(amount: number, ev: WheelEvent): number {
+ const modifier = this._optionsService.options.fastScrollModifier;
+ // Multiply the scroll speed when the modifier is down
+ if ((modifier === 'alt' && ev.altKey) ||
+ (modifier === 'ctrl' && ev.ctrlKey) ||
+ (modifier === 'shift' && ev.shiftKey)) {
+ return amount * this._optionsService.options.fastScrollSensitivity * this._optionsService.options.scrollSensitivity;
+ }
+
+ return amount * this._optionsService.options.scrollSensitivity;
+ }
+
+ /**
+ * Handles the touchstart event, recording the touch occurred.
+ * @param ev The touch event.
+ */
+ public onTouchStart(ev: TouchEvent): void {
+ this._lastTouchY = ev.touches[0].pageY;
+ }
+
+ /**
+ * Handles the touchmove event, scrolling the viewport if the position shifted.
+ * @param ev The touch event.
+ */
+ public onTouchMove(ev: TouchEvent): boolean {
+ const deltaY = this._lastTouchY - ev.touches[0].pageY;
+ this._lastTouchY = ev.touches[0].pageY;
+ if (deltaY === 0) {
+ return false;
+ }
+ this._viewportElement.scrollTop += deltaY;
+ return this._bubbleScroll(ev, deltaY);
+ }
+}
projects / VSoRC / .git / blobdiff