Move all impl to scrollable/

src/browser/scrollable/scrollbarVisibilityController.ts

@@ -0,0 +1,113 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { FastDomNode } from './fastDomNode';
+import { TimeoutTimer } from './async';
+import { Disposable } from './lifecycle';
+import { ScrollbarVisibility } from './scrollable';
+
+export class ScrollbarVisibilityController extends Disposable {
+	private _visibility: ScrollbarVisibility;
+	private _visibleClassName: string;
+	private _invisibleClassName: string;
+	private _domNode: FastDomNode<HTMLElement> | null;
+	private _rawShouldBeVisible: boolean;
+	private _shouldBeVisible: boolean;
+	private _isNeeded: boolean;
+	private _isVisible: boolean;
+	private _revealTimer: TimeoutTimer;
+
+	constructor(visibility: ScrollbarVisibility, visibleClassName: string, invisibleClassName: string) {
+		super();
+		this._visibility = visibility;
+		this._visibleClassName = visibleClassName;
+		this._invisibleClassName = invisibleClassName;
+		this._domNode = null;
+		this._isVisible = false;
+		this._isNeeded = false;
+		this._rawShouldBeVisible = false;
+		this._shouldBeVisible = false;
+		this._revealTimer = this._register(new TimeoutTimer());
+	}
+
+	public setVisibility(visibility: ScrollbarVisibility): void {
+		if (this._visibility !== visibility) {
+			this._visibility = visibility;
+			this._updateShouldBeVisible();
+		}
+	}
+
+	public setShouldBeVisible(rawShouldBeVisible: boolean): void {
+		this._rawShouldBeVisible = rawShouldBeVisible;
+		this._updateShouldBeVisible();
+	}
+
+	private _applyVisibilitySetting(): boolean {
+		if (this._visibility === ScrollbarVisibility.Hidden) {
+			return false;
+		}
+		if (this._visibility === ScrollbarVisibility.Visible) {
+			return true;
+		}
+		return this._rawShouldBeVisible;
+	}
+
+	private _updateShouldBeVisible(): void {
+		const shouldBeVisible = this._applyVisibilitySetting();
+
+		if (this._shouldBeVisible !== shouldBeVisible) {
+			this._shouldBeVisible = shouldBeVisible;
+			this.ensureVisibility();
+		}
+	}
+
+	public setIsNeeded(isNeeded: boolean): void {
+		if (this._isNeeded !== isNeeded) {
+			this._isNeeded = isNeeded;
+			this.ensureVisibility();
+		}
+	}
+
+	public setDomNode(domNode: FastDomNode<HTMLElement>): void {
+		this._domNode = domNode;
+		this._domNode.setClassName(this._invisibleClassName);
+
+		this.setShouldBeVisible(false);
+	}
+
+	public ensureVisibility(): void {
+
+		if (!this._isNeeded) {
+			this._hide(false);
+			return;
+		}
+
+		if (this._shouldBeVisible) {
+			this._reveal();
+		} else {
+			this._hide(true);
+		}
+	}
+
+	private _reveal(): void {
+		if (this._isVisible) {
+			return;
+		}
+		this._isVisible = true;
+
+		this._revealTimer.setIfNotSet(() => {
+			this._domNode?.setClassName(this._visibleClassName);
+		}, 0);
+	}
+
+	private _hide(withFadeAway: boolean): void {
+		this._revealTimer.cancel();
+		if (!this._isVisible) {
+			return;
+		}
+		this._isVisible = false;
+		this._domNode?.setClassName(this._invisibleClassName + (withFadeAway ? ' fade' : ''));
+	}
+}