viewImpl.ts

/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/
'use strict';

import { onUnexpectedError } from 'vs/base/common/errors';
import { IDisposable } from 'vs/base/common/lifecycle';
import * as browser from 'vs/base/browser/browser';
import * as dom from 'vs/base/browser/dom';
import { FastDomNode, createFastDomNode } from 'vs/base/browser/fastDomNode';
import { ICommandService } from 'vs/platform/commands/common/commands';
import { Range } from 'vs/editor/common/core/range';
import * as editorCommon from 'vs/editor/common/editorCommon';
import { ViewEventHandler } from 'vs/editor/common/viewModel/viewEventHandler';
import { Configuration } from 'vs/editor/browser/config/configuration';
import { TextAreaHandler, ITextAreaHandlerHelper } from 'vs/editor/browser/controller/textAreaHandler';
import { PointerHandler } from 'vs/editor/browser/controller/pointerHandler';
import * as editorBrowser from 'vs/editor/browser/editorBrowser';
import { ViewController, ExecCoreEditorCommandFunc } from 'vs/editor/browser/view/viewController';
import { ViewEventDispatcher } from 'vs/editor/common/view/viewEventDispatcher';
import { ContentViewOverlays, MarginViewOverlays } from 'vs/editor/browser/view/viewOverlays';
import { ViewLayout } from 'vs/editor/common/viewLayout/viewLayout';
import { ViewContentWidgets } from 'vs/editor/browser/viewParts/contentWidgets/contentWidgets';
import { CurrentLineHighlightOverlay } from 'vs/editor/browser/viewParts/currentLineHighlight/currentLineHighlight';
import { CurrentLineMarginHighlightOverlay } from 'vs/editor/browser/viewParts/currentLineMarginHighlight/currentLineMarginHighlight';
import { DecorationsOverlay } from 'vs/editor/browser/viewParts/decorations/decorations';
import { GlyphMarginOverlay } from 'vs/editor/browser/viewParts/glyphMargin/glyphMargin';
import { LineNumbersOverlay } from 'vs/editor/browser/viewParts/lineNumbers/lineNumbers';
import { IndentGuidesOverlay } from 'vs/editor/browser/viewParts/indentGuides/indentGuides';
import { ViewLines } from 'vs/editor/browser/viewParts/lines/viewLines';
import { Margin } from 'vs/editor/browser/viewParts/margin/margin';
import { LinesDecorationsOverlay } from 'vs/editor/browser/viewParts/linesDecorations/linesDecorations';
import { MarginViewLineDecorationsOverlay } from 'vs/editor/browser/viewParts/marginDecorations/marginDecorations';
import { ViewOverlayWidgets } from 'vs/editor/browser/viewParts/overlayWidgets/overlayWidgets';
import { DecorationsOverviewRuler } from 'vs/editor/browser/viewParts/overviewRuler/decorationsOverviewRuler';
import { OverviewRuler } from 'vs/editor/browser/viewParts/overviewRuler/overviewRuler';
import { Rulers } from 'vs/editor/browser/viewParts/rulers/rulers';
import { ScrollDecorationViewPart } from 'vs/editor/browser/viewParts/scrollDecoration/scrollDecoration';
import { SelectionsOverlay } from 'vs/editor/browser/viewParts/selections/selections';
import { ViewCursors } from 'vs/editor/browser/viewParts/viewCursors/viewCursors';
import { ViewZones } from 'vs/editor/browser/viewParts/viewZones/viewZones';
import { ViewPart, PartFingerprint, PartFingerprints } from 'vs/editor/browser/view/viewPart';
import { ViewContext } from 'vs/editor/common/view/viewContext';
import { IViewModel } from 'vs/editor/common/viewModel/viewModel';
import { RenderingContext } from 'vs/editor/common/view/renderingContext';
import { IPointerHandlerHelper } from 'vs/editor/browser/controller/mouseHandler';
import { ViewOutgoingEvents } from 'vs/editor/browser/view/viewOutgoingEvents';
import { ViewportData } from 'vs/editor/common/viewLayout/viewLinesViewportData';
import { EditorScrollbar } from 'vs/editor/browser/viewParts/editorScrollbar/editorScrollbar';
import { Minimap } from 'vs/editor/browser/viewParts/minimap/minimap';
import * as viewEvents from 'vs/editor/common/view/viewEvents';
import { IEditorWhitespace } from 'vs/editor/common/viewLayout/whitespaceComputer';

export interface IContentWidgetData {
	widget: editorBrowser.IContentWidget;
	position: editorBrowser.IContentWidgetPosition;
}

export interface IOverlayWidgetData {
	widget: editorBrowser.IOverlayWidget;
	position: editorBrowser.IOverlayWidgetPosition;
}

export class View extends ViewEventHandler {

	private eventDispatcher: ViewEventDispatcher;

	private layoutProvider: ViewLayout;
	private _scrollbar: EditorScrollbar;
	private _context: ViewContext;

	// The view lines
	private viewLines: ViewLines;

	// These are parts, but we must do some API related calls on them, so we keep a reference
	private viewZones: ViewZones;
	private contentWidgets: ViewContentWidgets;
	private overlayWidgets: ViewOverlayWidgets;
	private viewCursors: ViewCursors;
	private viewParts: ViewPart[];

	private readonly _textAreaHandler: TextAreaHandler;
	private readonly pointerHandler: PointerHandler;

	private readonly outgoingEvents: ViewOutgoingEvents;

	// Dom nodes
	private linesContent: FastDomNode<HTMLElement>;
	public domNode: FastDomNode<HTMLElement>;
	private overflowGuardContainer: FastDomNode<HTMLElement>;

	// Actual mutable state
	private _isDisposed: boolean;

	private _renderAnimationFrame: IDisposable;

	constructor(
		commandService: ICommandService,
		configuration: Configuration,
		model: IViewModel,
		execCoreEditorCommandFunc: ExecCoreEditorCommandFunc
	) {
		super();
		this._isDisposed = false;
		this._renderAnimationFrame = null;
		this.outgoingEvents = new ViewOutgoingEvents(model);

		let viewController = new ViewController(model, execCoreEditorCommandFunc, this.outgoingEvents, commandService);

		// The event dispatcher will always go through _renderOnce before dispatching any events
		this.eventDispatcher = new ViewEventDispatcher((callback: () => void) => this._renderOnce(callback));

		// Ensure the view is the first event handler in order to update the layout
		this.eventDispatcher.addEventHandler(this);

		// The layout provider has such responsibilities as:
		// - scrolling (i.e. viewport / full size) & co.
		// - whitespaces (a.k.a. view zones) management & co.
		// - line heights updating & co.
		this.layoutProvider = new ViewLayout(configuration, model.getLineCount(), this.eventDispatcher);

		// The view context is passed on to most classes (basically to reduce param. counts in ctors)
		this._context = new ViewContext(configuration, model, this.eventDispatcher);

		this.viewParts = [];

		// Keyboard handler
		this._textAreaHandler = new TextAreaHandler(this._context, viewController, this.createTextAreaHandlerHelper());
		this.viewParts.push(this._textAreaHandler);

		this.createViewParts();
		this._setLayout();

		// Pointer handler
		this.pointerHandler = new PointerHandler(this._context, viewController, this.createPointerHandlerHelper());

		this._register(model.addEventListener((events: viewEvents.ViewEvent[]) => {
			this.eventDispatcher.emitMany(events);
		}));
	}

	private createViewParts(): void {
		// These two dom nodes must be constructed up front, since references are needed in the layout provider (scrolling & co.)
		this.linesContent = createFastDomNode(document.createElement('div'));
		this.linesContent.setClassName('lines-content' + ' monaco-editor-background');
		this.linesContent.setPosition('absolute');

		this.domNode = createFastDomNode(document.createElement('div'));
		this.domNode.setClassName(this._context.configuration.editor.viewInfo.editorClassName);

		this.overflowGuardContainer = createFastDomNode(document.createElement('div'));
		PartFingerprints.write(this.overflowGuardContainer, PartFingerprint.OverflowGuard);
		this.overflowGuardContainer.setClassName('overflow-guard');

		this._scrollbar = new EditorScrollbar(this._context, this.layoutProvider.getScrollable(), this.linesContent, this.domNode, this.overflowGuardContainer);
		this.viewParts.push(this._scrollbar);

		// View Lines
		this.viewLines = new ViewLines(this._context, this.linesContent, this.layoutProvider);

		// View Zones
		this.viewZones = new ViewZones(this._context, this.layoutProvider);
		this.viewParts.push(this.viewZones);

		// Decorations overview ruler
		let decorationsOverviewRuler = new DecorationsOverviewRuler(
			this._context, this.layoutProvider.getScrollHeight(),
			(lineNumber: number) => this.layoutProvider.getVerticalOffsetForLineNumber(lineNumber)
		);
		this.viewParts.push(decorationsOverviewRuler);


		let scrollDecoration = new ScrollDecorationViewPart(this._context);
		this.viewParts.push(scrollDecoration);

		let contentViewOverlays = new ContentViewOverlays(this._context);
		this.viewParts.push(contentViewOverlays);
		contentViewOverlays.addDynamicOverlay(new CurrentLineHighlightOverlay(this._context));
		contentViewOverlays.addDynamicOverlay(new SelectionsOverlay(this._context));
		contentViewOverlays.addDynamicOverlay(new DecorationsOverlay(this._context));
		contentViewOverlays.addDynamicOverlay(new IndentGuidesOverlay(this._context));

		let marginViewOverlays = new MarginViewOverlays(this._context);
		this.viewParts.push(marginViewOverlays);
		marginViewOverlays.addDynamicOverlay(new CurrentLineMarginHighlightOverlay(this._context));
		marginViewOverlays.addDynamicOverlay(new GlyphMarginOverlay(this._context));
		marginViewOverlays.addDynamicOverlay(new MarginViewLineDecorationsOverlay(this._context));
		marginViewOverlays.addDynamicOverlay(new LinesDecorationsOverlay(this._context));
		marginViewOverlays.addDynamicOverlay(new LineNumbersOverlay(this._context));

		let margin = new Margin(this._context);
		margin.getDomNode().appendChild(this.viewZones.marginDomNode);
		margin.getDomNode().appendChild(marginViewOverlays.getDomNode());
		this.viewParts.push(margin);

		// Content widgets
		this.contentWidgets = new ViewContentWidgets(this._context, this.domNode);
		this.viewParts.push(this.contentWidgets);

		this.viewCursors = new ViewCursors(this._context);
		this.viewParts.push(this.viewCursors);

		// Overlay widgets
		this.overlayWidgets = new ViewOverlayWidgets(this._context);
		this.viewParts.push(this.overlayWidgets);

		let rulers = new Rulers(this._context);
		this.viewParts.push(rulers);

		let minimap = new Minimap(this._context, this.layoutProvider, this._scrollbar);
		this.viewParts.push(minimap);

		// -------------- Wire dom nodes up

		if (decorationsOverviewRuler) {
			let overviewRulerData = this._scrollbar.getOverviewRulerLayoutInfo();
			overviewRulerData.parent.insertBefore(decorationsOverviewRuler.getDomNode(), overviewRulerData.insertBefore);
		}

		this.linesContent.appendChild(contentViewOverlays.getDomNode());
		this.linesContent.appendChild(rulers.domNode);
		this.linesContent.appendChild(this.viewZones.domNode);
		this.linesContent.appendChild(this.viewLines.getDomNode());
		this.linesContent.appendChild(this.contentWidgets.domNode);
		this.linesContent.appendChild(this.viewCursors.getDomNode());
		this.overflowGuardContainer.appendChild(margin.getDomNode());
		this.overflowGuardContainer.appendChild(this._scrollbar.getDomNode());
		this.overflowGuardContainer.appendChild(scrollDecoration.getDomNode());
		this.overflowGuardContainer.appendChild(this.overlayWidgets.getDomNode());
		this.overflowGuardContainer.appendChild(this._textAreaHandler.textArea);
		this.overflowGuardContainer.appendChild(this._textAreaHandler.textAreaCover);
		this.overflowGuardContainer.appendChild(minimap.getDomNode());
		this.domNode.appendChild(this.overflowGuardContainer);
		this.domNode.appendChild(this.contentWidgets.overflowingContentWidgetsDomNode);
	}

	private _flushAccumulatedAndRenderNow(): void {
		this._renderNow();
	}

	private createPointerHandlerHelper(): IPointerHandlerHelper {
		return {
			viewDomNode: this.domNode.domNode,
			linesContentDomNode: this.linesContent.domNode,

			focusTextArea: () => {
				this.focus();
			},

			getScrollLeft: () => {
				return this.layoutProvider.getScrollLeft();
			},
			getScrollTop: () => {
				return this.layoutProvider.getScrollTop();
			},

			setScrollPosition: (position: editorCommon.INewScrollPosition) => {
				this.layoutProvider.setScrollPosition(position);
			},

			isAfterLines: (verticalOffset: number) => {
				return this.layoutProvider.isAfterLines(verticalOffset);
			},
			getLineNumberAtVerticalOffset: (verticalOffset: number) => {
				return this.layoutProvider.getLineNumberAtVerticalOffset(verticalOffset);
			},
			getVerticalOffsetForLineNumber: (lineNumber: number) => {
				return this.layoutProvider.getVerticalOffsetForLineNumber(lineNumber);
			},
			getWhitespaceAtVerticalOffset: (verticalOffset: number) => {
				return this.layoutProvider.getWhitespaceAtVerticalOffset(verticalOffset);
			},
			getLastViewCursorsRenderData: () => {
				return this.viewCursors.getLastRenderData() || [];
			},
			shouldSuppressMouseDownOnViewZone: (viewZoneId: number) => {
				return this.viewZones.shouldSuppressMouseDownOnViewZone(viewZoneId);
			},
			shouldSuppressMouseDownOnWidget: (widgetId: string) => {
				return this.contentWidgets.shouldSuppressMouseDownOnWidget(widgetId);
			},
			getPositionFromDOMInfo: (spanNode: HTMLElement, offset: number) => {
				this._flushAccumulatedAndRenderNow();
				return this.viewLines.getPositionFromDOMInfo(spanNode, offset);
			},

			visibleRangeForPosition2: (lineNumber: number, column: number) => {
				this._flushAccumulatedAndRenderNow();
				let visibleRanges = this.viewLines.visibleRangesForRange2(new Range(lineNumber, column, lineNumber, column));
				if (!visibleRanges) {
					return null;
				}
				return visibleRanges[0];
			},

			getLineWidth: (lineNumber: number) => {
				this._flushAccumulatedAndRenderNow();
				return this.viewLines.getLineWidth(lineNumber);
			}
		};
	}

	private createTextAreaHandlerHelper(): ITextAreaHandlerHelper {
		return {
			visibleRangeForPositionRelativeToEditor: (lineNumber: number, column: number) => {
				this._flushAccumulatedAndRenderNow();
				let visibleRanges = this.viewLines.visibleRangesForRange2(new Range(lineNumber, column, lineNumber, column));
				if (!visibleRanges) {
					return null;
				}
				return visibleRanges[0];
			},
			getVerticalOffsetForLineNumber: (lineNumber: number) => {
				return this.layoutProvider.getVerticalOffsetForLineNumber(lineNumber);
			}
		};
	}

	private _setLayout(): void {
		const layoutInfo = this._context.configuration.editor.layoutInfo;
		if (browser.isChrome) {
			/* tslint:disable:no-unused-variable */
			// Access overflowGuardContainer.clientWidth to prevent relayouting bug in Chrome
			// See Bug 19676: Editor misses a layout event
			let clientWidth = this.overflowGuardContainer.domNode.clientWidth + 'px';
			/* tslint:enable:no-unused-variable */
		}
		this.domNode.setWidth(layoutInfo.width);
		this.domNode.setHeight(layoutInfo.height);

		this.overflowGuardContainer.setWidth(layoutInfo.width);
		this.overflowGuardContainer.setHeight(layoutInfo.height);

		this.linesContent.setWidth(1000000);
		this.linesContent.setHeight(1000000);

	}

	// --- begin event handlers

	public onConfigurationChanged(e: viewEvents.ViewConfigurationChangedEvent): boolean {
		if (e.viewInfo) {
			this.domNode.setClassName(this._context.configuration.editor.viewInfo.editorClassName);
		}
		if (e.layoutInfo) {
			this._setLayout();
		}
		this.layoutProvider.onConfigurationChanged(e);
		return false;
	}
	public onFlushed(e: viewEvents.ViewFlushedEvent): boolean {
		this.layoutProvider.onFlushed(this._context.model.getLineCount());
		return false;
	}
	public onFocusChanged(e: viewEvents.ViewFocusChangedEvent): boolean {
		this.domNode.toggleClassName('focused', e.isFocused);
		if (e.isFocused) {
			this.outgoingEvents.emitViewFocusGained();
		} else {
			this.outgoingEvents.emitViewFocusLost();
		}
		return false;
	}
	public onLinesDeleted(e: viewEvents.ViewLinesDeletedEvent): boolean {
		this.layoutProvider.onLinesDeleted(e);
		return false;
	}
	public onLinesInserted(e: viewEvents.ViewLinesInsertedEvent): boolean {
		this.layoutProvider.onLinesInserted(e);
		return false;
	}
	public onScrollChanged(e: viewEvents.ViewScrollChangedEvent): boolean {
		this.outgoingEvents.emitScrollChanged(e);
		return false;
	}
	public onScrollRequest(e: viewEvents.ViewScrollRequestEvent): boolean {
		this.layoutProvider.setScrollPosition({
			scrollTop: e.desiredScrollTop
		});
		return false;
	}

	// --- end event handlers

	public dispose(): void {
		this._isDisposed = true;
		if (this._renderAnimationFrame !== null) {
			this._renderAnimationFrame.dispose();
			this._renderAnimationFrame = null;
		}

		this.eventDispatcher.removeEventHandler(this);
		this.outgoingEvents.dispose();

		this.pointerHandler.dispose();

		this.viewLines.dispose();

		// Destroy view parts
		for (let i = 0, len = this.viewParts.length; i < len; i++) {
			this.viewParts[i].dispose();
		}
		this.viewParts = [];

		this.layoutProvider.dispose();

		super.dispose();
	}

	private _renderOnce(callback: () => any): any {
		let r = safeInvokeNoArg(callback);
		this._scheduleRender();
		return r;
	}

	private _scheduleRender(): void {
		if (this._renderAnimationFrame === null) {
			this._renderAnimationFrame = dom.runAtThisOrScheduleAtNextAnimationFrame(this._onRenderScheduled.bind(this), 100);
		}
	}

	private _onRenderScheduled(): void {
		this._renderAnimationFrame = null;
		this._flushAccumulatedAndRenderNow();
	}

	private _renderNow(): void {
		safeInvokeNoArg(() => this._actualRender());
	}

	private _getViewPartsToRender(): ViewPart[] {
		let result: ViewPart[] = [];
		for (let i = 0, len = this.viewParts.length; i < len; i++) {
			let viewPart = this.viewParts[i];
			if (viewPart.shouldRender()) {
				result.push(viewPart);
			}
		}
		return result;
	}

	private _actualRender(): void {
		if (!dom.isInDOM(this.domNode.domNode)) {
			return;
		}

		let viewPartsToRender = this._getViewPartsToRender();

		if (!this.viewLines.shouldRender() && viewPartsToRender.length === 0) {
			// Nothing to render
			this._textAreaHandler.writeToTextArea();
			return;
		}

		let partialViewportData = this.layoutProvider.getLinesViewportData();
		this._context.model.setViewport(partialViewportData.startLineNumber, partialViewportData.endLineNumber, partialViewportData.centeredLineNumber);

		let viewportData = new ViewportData(partialViewportData, this._context.model);

		if (this.viewLines.shouldRender()) {
			this.viewLines.renderText(viewportData, () => {
				this._textAreaHandler.writeToTextArea();
			});
			this.viewLines.onDidRender();

			// Rendering of viewLines might cause scroll events to occur, so collect view parts to render again
			viewPartsToRender = this._getViewPartsToRender();
		} else {
			this._textAreaHandler.writeToTextArea();
		}

		let renderingContext = new RenderingContext(this.layoutProvider, viewportData, this.viewLines);

		// Render the rest of the parts
		for (let i = 0, len = viewPartsToRender.length; i < len; i++) {
			let viewPart = viewPartsToRender[i];
			viewPart.prepareRender(renderingContext);
		}

		for (let i = 0, len = viewPartsToRender.length; i < len; i++) {
			let viewPart = viewPartsToRender[i];
			viewPart.render(renderingContext);
			viewPart.onDidRender();
		}
	}

	// --- BEGIN CodeEditor helpers

	public getScrollWidth(): number {
		return this.layoutProvider.getScrollWidth();
	}

	public getScrollLeft(): number {
		return this.layoutProvider.getScrollLeft();
	}

	public getScrollHeight(): number {
		return this.layoutProvider.getScrollHeight();
	}

	public getScrollTop(): number {
		return this.layoutProvider.getScrollTop();
	}

	public setScrollPosition(scrollPosition: editorCommon.INewScrollPosition): void {
		this.layoutProvider.setScrollPosition(scrollPosition);
	}

	public getVerticalOffsetForViewLineNumber(viewLineNumber: number): number {
		return this.layoutProvider.getVerticalOffsetForLineNumber(viewLineNumber);
	}

	public delegateVerticalScrollbarMouseDown(browserEvent: MouseEvent): void {
		this._scrollbar.delegateVerticalScrollbarMouseDown(browserEvent);
	}

	public getOffsetForColumn(modelLineNumber: number, modelColumn: number): number {
		let modelPosition = this._context.model.validateModelPosition({
			lineNumber: modelLineNumber,
			column: modelColumn
		});
		let viewPosition = this._context.model.coordinatesConverter.convertModelPositionToViewPosition(modelPosition);
		this._flushAccumulatedAndRenderNow();
		let visibleRanges = this.viewLines.visibleRangesForRange2(new Range(viewPosition.lineNumber, viewPosition.column, viewPosition.lineNumber, viewPosition.column));
		if (!visibleRanges) {
			return -1;
		}
		return visibleRanges[0].left;
	}

	public getTargetAtClientPoint(clientX: number, clientY: number): editorBrowser.IMouseTarget {
		return this.pointerHandler.getTargetAtClientPoint(clientX, clientY);
	}

	public getCompletelyVisibleViewRange(): Range {
		const partialData = this.layoutProvider.getLinesViewportData();
		const startViewLineNumber = partialData.completelyVisibleStartLineNumber;
		const endViewLineNumber = partialData.completelyVisibleEndLineNumber;

		return new Range(
			startViewLineNumber, this._context.model.getLineMinColumn(startViewLineNumber),
			endViewLineNumber, this._context.model.getLineMaxColumn(endViewLineNumber)
		);
	}

	public getCompletelyVisibleViewRangeAtScrollTop(scrollTop: number): Range {
		const partialData = this.layoutProvider.getLinesViewportDataAtScrollTop(scrollTop);
		const startViewLineNumber = partialData.completelyVisibleStartLineNumber;
		const endViewLineNumber = partialData.completelyVisibleEndLineNumber;

		return new Range(
			startViewLineNumber, this._context.model.getLineMinColumn(startViewLineNumber),
			endViewLineNumber, this._context.model.getLineMaxColumn(endViewLineNumber)
		);
	}

	public getInternalEventBus(): ViewOutgoingEvents {
		return this.outgoingEvents;
	}

	public createOverviewRuler(cssClassName: string, minimumHeight: number, maximumHeight: number): OverviewRuler {
		return new OverviewRuler(
			this._context, cssClassName, this.layoutProvider.getScrollHeight(), minimumHeight, maximumHeight,
			(lineNumber: number) => this.layoutProvider.getVerticalOffsetForLineNumber(lineNumber)
		);
	}

	public change(callback: (changeAccessor: editorBrowser.IViewZoneChangeAccessor) => any): boolean {
		let zonesHaveChanged = false;

		this._renderOnce(() => {
			let changeAccessor: editorBrowser.IViewZoneChangeAccessor = {
				addZone: (zone: editorBrowser.IViewZone): number => {
					zonesHaveChanged = true;
					return this.viewZones.addZone(zone);
				},
				removeZone: (id: number): void => {
					if (!id) {
						return;
					}
					zonesHaveChanged = this.viewZones.removeZone(id) || zonesHaveChanged;
				},
				layoutZone: (id: number): void => {
					if (!id) {
						return;
					}
					zonesHaveChanged = this.viewZones.layoutZone(id) || zonesHaveChanged;
				}
			};

			safeInvoke1Arg(callback, changeAccessor);

			// Invalidate changeAccessor
			changeAccessor.addZone = null;
			changeAccessor.removeZone = null;

			if (zonesHaveChanged) {
				this.layoutProvider.onHeightMaybeChanged();
				this._context.privateViewEventBus.emit(new viewEvents.ViewZonesChangedEvent());
			}
		});
		return zonesHaveChanged;
	}

	public getWhitespaces(): IEditorWhitespace[] {
		return this.layoutProvider.getWhitespaces();
	}

	public render(now: boolean, everything: boolean): void {
		if (everything) {
			// Force everything to render...
			this.viewLines.forceShouldRender();
			for (let i = 0, len = this.viewParts.length; i < len; i++) {
				let viewPart = this.viewParts[i];
				viewPart.forceShouldRender();
			}
		}
		if (now) {
			this._flushAccumulatedAndRenderNow();
		} else {
			this._scheduleRender();
		}
	}

	public setAriaActiveDescendant(id: string): void {
		this._textAreaHandler.setAriaActiveDescendant(id);
	}

	public saveState(): editorCommon.IViewState {
		return this.layoutProvider.saveState();
	}

	public restoreState(state: editorCommon.IViewState): void {
		return this.layoutProvider.restoreState(state);
	}

	public focus(): void {
		this._textAreaHandler.focusTextArea();
	}

	public isFocused(): boolean {
		return this._textAreaHandler.isFocused();
	}

	public addContentWidget(widgetData: IContentWidgetData): void {
		this.contentWidgets.addWidget(widgetData.widget);
		this.layoutContentWidget(widgetData);
		this._scheduleRender();
	}

	public layoutContentWidget(widgetData: IContentWidgetData): void {
		let newPosition = widgetData.position ? widgetData.position.position : null;
		let newPreference = widgetData.position ? widgetData.position.preference : null;
		this.contentWidgets.setWidgetPosition(widgetData.widget, newPosition, newPreference);
		this._scheduleRender();
	}

	public removeContentWidget(widgetData: IContentWidgetData): void {
		this.contentWidgets.removeWidget(widgetData.widget);
		this._scheduleRender();
	}

	public addOverlayWidget(widgetData: IOverlayWidgetData): void {
		this.overlayWidgets.addWidget(widgetData.widget);
		this.layoutOverlayWidget(widgetData);
		this._scheduleRender();
	}

	public layoutOverlayWidget(widgetData: IOverlayWidgetData): void {
		let newPreference = widgetData.position ? widgetData.position.preference : null;
		let shouldRender = this.overlayWidgets.setWidgetPosition(widgetData.widget, newPreference);
		if (shouldRender) {
			this._scheduleRender();
		}
	}

	public removeOverlayWidget(widgetData: IOverlayWidgetData): void {
		this.overlayWidgets.removeWidget(widgetData.widget);
		this._scheduleRender();
	}

	// --- END CodeEditor helpers

}

function safeInvokeNoArg(func: Function): any {
	try {
		return func();
	} catch (e) {
		onUnexpectedError(e);
	}
}

function safeInvoke1Arg(func: Function, arg1: any): any {
	try {
		return func(arg1);
	} catch (e) {
		onUnexpectedError(e);
	}
}