vscode/src/vs/workbench/api/common/extHostEditorTabs.ts

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

import * as vscode from 'vscode';
import * as typeConverters from 'vs/workbench/api/common/extHostTypeConverters';
import { IEditorTabDto, IEditorTabGroupDto, IExtHostEditorTabsShape, MainContext, MainThreadEditorTabsShape, TabInputKind } from 'vs/workbench/api/common/extHost.protocol';
import { URI } from 'vs/base/common/uri';
import { Emitter } from 'vs/base/common/event';
import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
import { CustomEditorTabInput, NotebookDiffEditorTabInput, NotebookEditorTabInput, TerminalEditorTabInput, TextDiffTabInput, TextTabInput, ViewColumn, WebviewEditorTabInput } from 'vs/workbench/api/common/extHostTypes';
import { IExtHostRpcService } from 'vs/workbench/api/common/extHostRpcService';
import { assertIsDefined } from 'vs/base/common/types';

export interface IExtHostEditorTabs extends IExtHostEditorTabsShape {
	readonly _serviceBrand: undefined;
	tabGroups: vscode.TabGroups;
}

export const IExtHostEditorTabs = createDecorator<IExtHostEditorTabs>('IExtHostEditorTabs');

type AnyTabInput = TextTabInput | TextDiffTabInput | CustomEditorTabInput | NotebookEditorTabInput | NotebookDiffEditorTabInput | WebviewEditorTabInput | TerminalEditorTabInput;

class ExtHostEditorTab {
	private _apiObject: vscode.Tab | undefined;
	private _dto!: IEditorTabDto;
	private _input: AnyTabInput | undefined;
	private _parentGroup: ExtHostEditorTabGroup;
	private readonly _activeTabIdGetter: () => string;

	constructor(dto: IEditorTabDto, parentGroup: ExtHostEditorTabGroup, activeTabIdGetter: () => string) {
		this._activeTabIdGetter = activeTabIdGetter;
		this._parentGroup = parentGroup;
		this.acceptDtoUpdate(dto);
	}

	get apiObject(): vscode.Tab {
		// Don't want to lose reference to parent `this` in the getters
		const that = this;
		if (!this._apiObject) {
			const obj: vscode.Tab = {
				get isActive() {
					// We use a getter function here to always ensure at most 1 active tab per group and prevent iteration for being required
					return that._dto.id === that._activeTabIdGetter();
				},
				get label() {
					return that._dto.label;
				},
				get kind() {
					return that._input;
				},
				get isDirty() {
					return that._dto.isDirty;
				},
				get isPinned() {
					return that._dto.isPinned;
				},
				get isPreview() {
					return that._dto.isPreview;
				},
				get group() {
					return that._parentGroup.apiObject;
				}
			};
			this._apiObject = Object.freeze<vscode.Tab>(obj);
		}
		return this._apiObject;
	}

	get tabId(): string {
		return this._dto.id;
	}

	acceptDtoUpdate(dto: IEditorTabDto) {
		this._dto = dto;
		this._input = this._initInput();
	}

	private _initInput() {
		switch (this._dto.input.kind) {
			case TabInputKind.TextInput:
				return new TextTabInput(URI.revive(this._dto.input.uri));
			case TabInputKind.TextDiffInput:
				return new TextDiffTabInput(URI.revive(this._dto.input.original), URI.revive(this._dto.input.modified));
			case TabInputKind.CustomEditorInput:
				return new CustomEditorTabInput(URI.revive(this._dto.input.uri), this._dto.input.viewType);
			case TabInputKind.WebviewEditorInput:
				return new WebviewEditorTabInput(this._dto.input.viewType);
			case TabInputKind.NotebookInput:
				return new NotebookEditorTabInput(URI.revive(this._dto.input.uri), this._dto.input.notebookType);
			case TabInputKind.NotebookDiffInput:
				return new NotebookDiffEditorTabInput(URI.revive(this._dto.input.original), URI.revive(this._dto.input.modified), this._dto.input.notebookType);
			case TabInputKind.TerminalEditorInput:
				return new TerminalEditorTabInput();
			default:
				return undefined;
		}
	}
}

class ExtHostEditorTabGroup {

	private _apiObject: vscode.TabGroup | undefined;
	private _dto: IEditorTabGroupDto;
	private _tabs: ExtHostEditorTab[] = [];
	private _activeTabId: string = '';
	private _activeGroupIdGetter: () => number | undefined;

	constructor(dto: IEditorTabGroupDto, proxy: MainThreadEditorTabsShape, activeGroupIdGetter: () => number | undefined) {
		this._dto = dto;
		this._activeGroupIdGetter = activeGroupIdGetter;
		// Construct all tabs from the given dto
		for (const tabDto of dto.tabs) {
			if (tabDto.isActive) {
				this._activeTabId = tabDto.id;
			}
			this._tabs.push(new ExtHostEditorTab(tabDto, this, () => this.activeTabId()));
		}
	}

	get apiObject(): vscode.TabGroup {
		// Don't want to lose reference to parent `this` in the getters
		const that = this;
		if (!this._apiObject) {
			const obj: vscode.TabGroup = {
				get isActive() {
					// We use a getter function here to always ensure at most 1 active group and prevent iteration for being required
					return that._dto.groupId === that._activeGroupIdGetter();
				},
				get viewColumn() {
					return typeConverters.ViewColumn.to(that._dto.viewColumn);
				},
				get activeTab() {
					return that._tabs.find(tab => tab.tabId === that._activeTabId)?.apiObject;
				},
				get tabs() {
					return Object.freeze(that._tabs.map(tab => tab.apiObject));
				}
			};
			this._apiObject = Object.freeze<vscode.TabGroup>(obj);
		}
		return this._apiObject;
	}

	get groupId(): number {
		return this._dto.groupId;
	}

	get tabs(): ExtHostEditorTab[] {
		return this._tabs;
	}

	acceptGroupDtoUpdate(dto: IEditorTabGroupDto) {
		this._dto = dto;
	}

	acceptTabDtoUpdate(dto: IEditorTabDto) {
		const tab = this._tabs.find(extHostTab => extHostTab.tabId === dto.id);
		if (!tab) {
			throw new Error('INVALID tab');
		}
		if (dto.isActive) {
			this._activeTabId = dto.id;
		} else if (this._activeTabId === dto.id && !dto.isActive) {
			// Events aren't guaranteed to be in order so if we receive a dto that matches the active tab id
			// but isn't active we mark the active tab id as empty. This prevent onDidActiveTabChange frorm
			// firing incorrectly
			this._activeTabId = '';
		}
		tab.acceptDtoUpdate(dto);
		return tab;
	}

	// Not a getter since it must be a function to be used as a callback for the tabs
	activeTabId(): string {
		return this._activeTabId;
	}
}

export class ExtHostEditorTabs implements IExtHostEditorTabs {
	readonly _serviceBrand: undefined;

	private readonly _proxy: MainThreadEditorTabsShape;
	private readonly _onDidChangeTabs = new Emitter<vscode.Tab[]>();
	private readonly _onDidChangeActiveTab = new Emitter<vscode.Tab>();
	private readonly _onDidChangeTabGroups = new Emitter<vscode.TabGroup[]>();
	private readonly _onDidChangeActiveTabGroup = new Emitter<vscode.TabGroup>();

	// Have to use ! because this gets initialized via an RPC proxy
	private _activeGroupId!: number;

	private _extHostTabGroups: ExtHostEditorTabGroup[] = [];

	private _apiObject: vscode.TabGroups | undefined;

	constructor(@IExtHostRpcService extHostRpc: IExtHostRpcService) {
		this._proxy = extHostRpc.getProxy(MainContext.MainThreadEditorTabs);
	}

	get tabGroups(): vscode.TabGroups {
		if (!this._apiObject) {
			const that = this;
			const obj: vscode.TabGroups = {
				// never changes -> simple value
				onDidChangeTabGroups: that._onDidChangeTabGroups.event,
				onDidChangeActiveTabGroup: that._onDidChangeActiveTabGroup.event,
				onDidChangeTabs: that._onDidChangeTabs.event,
				onDidChangeActiveTab: that._onDidChangeActiveTab.event,
				// dynamic -> getters
				get groups() {
					return Object.freeze(that._extHostTabGroups.map(group => group.apiObject));
				},
				get activeTabGroup() {
					const activeTabGroupId = that._activeGroupId;
					const activeTabGroup = assertIsDefined(that._extHostTabGroups.find(candidate => candidate.groupId === activeTabGroupId)?.apiObject);
					return activeTabGroup;
				},
				close: async (tab: vscode.Tab | vscode.Tab[], preserveFocus?: boolean) => {
					const tabs = Array.isArray(tab) ? tab : [tab];
					const extHostTabIds: string[] = [];
					for (const tab of tabs) {
						const extHostTab = this._findExtHostTabFromApi(tab);
						if (!extHostTab) {
							throw new Error('Tab close: Invalid tab not found!');
						}
						extHostTabIds.push(extHostTab.tabId);
					}
					return this._proxy.$closeTab(extHostTabIds, preserveFocus);
				},
				move: async (tab: vscode.Tab, viewColumn: ViewColumn, index: number, preservceFocus?: boolean) => {
					const extHostTab = this._findExtHostTabFromApi(tab);
					if (!extHostTab) {
						throw new Error('Invalid tab');
					}
					this._proxy.$moveTab(extHostTab.tabId, index, typeConverters.ViewColumn.from(viewColumn), preservceFocus);
					return;
				}
			};
			this._apiObject = Object.freeze(obj);
		}
		return this._apiObject;
	}

	private _findExtHostTabFromApi(apiTab: vscode.Tab): ExtHostEditorTab | undefined {
		for (const group of this._extHostTabGroups) {
			for (const tab of group.tabs) {
				if (tab.apiObject === apiTab) {
					return tab;
				}
			}
		}
		return;
	}

	$acceptEditorTabModel(tabGroups: IEditorTabGroupDto[]): void {

		this._extHostTabGroups = tabGroups.map(tabGroup => {
			const group = new ExtHostEditorTabGroup(tabGroup, this._proxy, () => this._activeGroupId);
			return group;
		});

		// Set the active tab group id
		const activeTabGroupId = assertIsDefined(tabGroups.find(group => group.isActive === true)?.groupId);
		if (activeTabGroupId !== undefined && this._activeGroupId !== activeTabGroupId) {
			this._activeGroupId = activeTabGroupId;
			this._onDidChangeActiveTabGroup.fire(this.tabGroups.activeTabGroup);
		}
		this._onDidChangeTabGroups.fire(this._extHostTabGroups.map(g => g.apiObject));
	}

	$acceptTabGroupUpdate(groupDto: IEditorTabGroupDto) {
		const group = this._extHostTabGroups.find(group => group.groupId === groupDto.groupId);
		if (!group) {
			throw new Error('Update Group IPC call received before group creation.');
		}
		group.acceptGroupDtoUpdate(groupDto);
		if (groupDto.isActive) {
			const oldActiveGroupId = this._activeGroupId;
			this._activeGroupId = groupDto.groupId;
			if (oldActiveGroupId !== this._activeGroupId) {
				this._onDidChangeActiveTabGroup.fire(group.apiObject);
			}
		}
		this._onDidChangeTabGroups.fire([group.apiObject]);
	}

	$acceptTabUpdate(groupId: number, tabDto: IEditorTabDto) {
		const group = this._extHostTabGroups.find(group => group.groupId === groupId);
		if (!group) {
			throw new Error('Update Tabs IPC call received before group creation.');
		}
		const tab = group.acceptTabDtoUpdate(tabDto);
		this._onDidChangeTabs.fire([tab.apiObject]);
		if (tab.apiObject.isActive) {
			this._onDidChangeActiveTab.fire(tab.apiObject);
		}
	}
}