#26948 Remember the view collapsible state and size

src/vs/base/browser/ui/splitview/splitview.ts

@@ -548,6 +548,11 @@ export class SplitView implements
 			throw new Error('Initial weight must be a positive number.');
 		}
 
+		/**
+		 * Reset size to null. This will layout newly added viees to initial weights.
+		 */
+		this.size = null;
+
 		let viewCount = this.views.length;
 
 		// Create view container

src/vs/workbench/browser/viewlet.ts

@@ -290,6 +290,7 @@ export class CollapseAction extends Action {
 }
 
 export interface IViewletView extends IView, IThemable {
+	id?: string;
 	create(): TPromise<void>;
 	setVisible(visible: boolean): TPromise<void>;
 	getActions(): IAction[];
@@ -449,10 +450,11 @@ export abstract class CollapsibleViewletView extends CollapsibleView implements
 		protected messageService: IMessageService,
 		protected keybindingService: IKeybindingService,
 		protected contextMenuService: IContextMenuService,
-		headerSize?: number
+		headerSize?: number,
+		minimumSize?: number
 	) {
 		super({
-			minimumSize: 5 * 22,
+			minimumSize: minimumSize === void 0 ? 5 * 22 : minimumSize,
 			initialState: collapsed ? CollapsibleState.COLLAPSED : CollapsibleState.EXPANDED,
 			ariaHeaderLabel: viewName,
 			headerSize

src/vs/workbench/parts/files/browser/explorerViewlet.ts

@@ -19,7 +19,7 @@ import { ActionRunner, FileViewletState } from 'vs/workbench/parts/files/browser
 import { ExplorerView } from 'vs/workbench/parts/files/browser/views/explorerView';
 import { EmptyView } from 'vs/workbench/parts/files/browser/views/emptyView';
 import { OpenEditorsView } from 'vs/workbench/parts/files/browser/views/openEditorsView';
-import { IStorageService } from 'vs/platform/storage/common/storage';
+import { IStorageService, StorageScope } from 'vs/platform/storage/common/storage';
 import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
 import { IWorkspaceContextService } from 'vs/platform/workspace/common/workspace';
 import { ITelemetryService } from 'vs/platform/telemetry/common/telemetry';
@@ -34,7 +34,15 @@ import { IThemeService } from 'vs/platform/theme/common/themeService';
 import { attachHeaderViewStyler } from 'vs/platform/theme/common/styler';
 import { ViewsRegistry, ViewLocation, IViewDescriptor } from 'vs/workbench/parts/views/browser/views';
 
+interface IViewState {
+	collapsed: boolean;
+	size: number;
+}
+
 export class ExplorerViewlet extends Viewlet {
+
+	private static EXPLORER_VIEWS_STATE = 'workbench.explorer.views.state';
+
 	private viewletContainer: Builder;
 	private splitView: SplitView;
 	private views: IViewletView[];
@@ -119,21 +127,24 @@ export class ExplorerViewlet extends Viewlet {
 			this.views.push(this.openEditorsView);
 		}
 
+		const viewsState = JSON.parse(this.storageService.get(ExplorerViewlet.EXPLORER_VIEWS_STATE, this.contextService.hasWorkspace() ? StorageScope.WORKSPACE : StorageScope.GLOBAL, '{}'));
+
 		// Explorer view
-		this.views.push(this.createExplorerOrEmptyView());
+		this.views.push(this.createExplorerOrEmptyView(viewsState));
 
 		// custom views
 		for (const view of customViews) {
 			this.views.push(this.instantiationService.createInstance(view.ctor, view.id, {
 				name: view.name,
 				actionRunner: this.getActionRunner(),
+				collapsed: viewsState[view.id] ? (<IViewState>viewsState[view.id]).collapsed : true
 			}));
 		}
 
 		for (let i = 0; i < this.views.length; i++) {
 			const view = this.views[i];
 			attachHeaderViewStyler(view, this.themeService, { noContrastBorder: i === 0 });
-			this.splitView.addView(view);
+			this.splitView.addView(view, viewsState[view.id] ? (<IViewState>viewsState[view.id]).size : void 0);
 		}
 
 		this.lastFocusedView = this.explorerView;
@@ -195,15 +206,17 @@ export class ExplorerViewlet extends Viewlet {
 		}
 		const views = [];
 
+		const viewsState = JSON.parse(this.storageService.get(ExplorerViewlet.EXPLORER_VIEWS_STATE, this.contextService.hasWorkspace() ? StorageScope.WORKSPACE : StorageScope.GLOBAL, '{}'));
 		for (const viewDescrirptor of viewDescriptors) {
 			const view = this.instantiationService.createInstance(viewDescrirptor.ctor, viewDescrirptor.id, {
 				name: viewDescrirptor.name,
 				actionRunner: this.getActionRunner(),
+				collapsed: viewsState[viewDescrirptor.id] ? (<IViewState>viewsState[viewDescrirptor.id]).collapsed : true
 			});
 			views.push(view);
 			this.views.push(view);
 			attachHeaderViewStyler(view, this.themeService);
-			this.splitView.addView(view);
+			this.splitView.addView(view, viewsState[view.id] ? (<IViewState>viewsState[view.id]).size : void 0);
 		}
 
 		TPromise.join(views.map(view => view.create())).then(() => void 0).then(() => {
@@ -227,7 +240,7 @@ export class ExplorerViewlet extends Viewlet {
 		}
 	}
 
-	private createExplorerOrEmptyView(): IViewletView {
+	private createExplorerOrEmptyView(viewsState: any): IViewletView {
 		let explorerOrEmptyView: ExplorerView | EmptyView;
 
 		// With a Workspace
@@ -264,12 +277,18 @@ export class ExplorerViewlet extends Viewlet {
 			});
 
 			const explorerInstantiator = this.instantiationService.createChild(new ServiceCollection([IWorkbenchEditorService, delegatingEditorService]));
-			this.explorerView = explorerOrEmptyView = explorerInstantiator.createInstance(ExplorerView, this.viewletState, this.getActionRunner(), this.viewletSettings, void 0);
+			this.explorerView = explorerOrEmptyView = explorerInstantiator.createInstance(ExplorerView, this.viewletState, {
+				collapsed: viewsState[ExplorerView.ID] ? (<IViewState>viewsState[ExplorerView.ID]).collapsed : false,
+				actionRunner: this.getActionRunner()
+			}, this.viewletSettings, void 0);
 		}
 
 		// No workspace
 		else {
-			this.emptyView = explorerOrEmptyView = this.instantiationService.createInstance(EmptyView, this.getActionRunner());
+			this.emptyView = explorerOrEmptyView = this.instantiationService.createInstance(EmptyView, {
+				collapsed: viewsState[EmptyView.ID] ? (<IViewState>viewsState[EmptyView.ID]).collapsed : false,
+				actionRunner: this.getActionRunner()
+			});
 		}
 
 		return explorerOrEmptyView;
@@ -376,11 +395,24 @@ export class ExplorerViewlet extends Viewlet {
 	}
 
 	public shutdown(): void {
+		const viewletState = this.views.reduce((result, view) => {
+			result[view.id] = this.getViewState(view);
+			return result;
+		}, {});
+		this.storageService.store(ExplorerViewlet.EXPLORER_VIEWS_STATE, JSON.stringify(viewletState), this.contextService.hasWorkspace() ? StorageScope.WORKSPACE : StorageScope.GLOBAL);
+
 		this.views.forEach((view) => view.shutdown());
 
 		super.shutdown();
 	}
 
+	private getViewState(view: IViewletView): IViewState {
+		return {
+			collapsed: !view.isExpanded(),
+			size: view.size > 0 ? view.size : void 0
+		};
+	}
+
 	public dispose(): void {
 
 		for (const view of this.views) {

src/vs/workbench/parts/files/browser/views/emptyView.ts

@@ -13,24 +13,32 @@ import { IActionRunner, IAction } from 'vs/base/common/actions';
 import { Button } from 'vs/base/browser/ui/button/button';
 import { $ } from 'vs/base/browser/builder';
 import { IActionItem } from 'vs/base/browser/ui/actionbar/actionbar';
-import { CollapsibleView } from 'vs/base/browser/ui/splitview/splitview';
+import { CollapsibleView, CollapsibleState } from 'vs/base/browser/ui/splitview/splitview';
 import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
 import { OpenFolderAction, OpenFileFolderAction } from 'vs/workbench/browser/actions/fileActions';
 import { attachButtonStyler } from 'vs/platform/theme/common/styler';
 import { IThemeService } from 'vs/platform/theme/common/themeService';
+import { IViewOptions } from 'vs/workbench/parts/views/browser/views';
 
 export class EmptyView extends CollapsibleView {
-	private openFolderButton: Button;
 
+	public static ID: string = 'workbench.explorer.emptyView';
+
+	public readonly id: string = EmptyView.ID;
+
+	private openFolderButton: Button;
+	private actionRunner: IActionRunner;
 	constructor(
-		private actionRunner: IActionRunner,
+		options: IViewOptions,
 		@IThemeService private themeService: IThemeService,
 		@IInstantiationService private instantiationService: IInstantiationService
 	) {
 		super({
-			minimumSize: 2 * 22,
-			ariaHeaderLabel: nls.localize('explorerSection', "Files Explorer Section")
+			minimumSize: 5 * 22,
+			ariaHeaderLabel: nls.localize('explorerSection', "Files Explorer Section"),
+			initialState: options.collapsed ? CollapsibleState.COLLAPSED : CollapsibleState.EXPANDED
 		});
+		this.actionRunner = options.actionRunner;
 	}
 
 	public renderHeader(container: HTMLElement): void {

src/vs/workbench/parts/files/browser/views/explorerView.ts

@@ -12,7 +12,7 @@ import { ThrottledDelayer } from 'vs/base/common/async';
 import errors = require('vs/base/common/errors');
 import labels = require('vs/base/common/labels');
 import paths = require('vs/base/common/paths');
-import { Action, IActionRunner, IAction } from 'vs/base/common/actions';
+import { Action, IAction } from 'vs/base/common/actions';
 import { prepareActions } from 'vs/workbench/browser/actionBarRegistry';
 import { ITree } from 'vs/base/parts/tree/browser/tree';
 import { Tree } from 'vs/base/parts/tree/browser/treeImpl';
@@ -43,9 +43,11 @@ import { IWorkbenchThemeService, IFileIconTheme } from 'vs/workbench/services/th
 import { isLinux } from 'vs/base/common/platform';
 import { IEnvironmentService } from 'vs/platform/environment/common/environment';
 import { attachListStyler } from 'vs/platform/theme/common/styler';
+import { IViewOptions } from 'vs/workbench/parts/views/browser/views';
 
 export class ExplorerView extends CollapsibleViewletView {
 
+	public static ID: string = 'workbench.explorer.fileView';
 	private static EXPLORER_FILE_CHANGES_REACT_DELAY = 500; // delay in ms to react to file changes to give our internal events a chance to react first
 	private static EXPLORER_FILE_CHANGES_REFRESH_DELAY = 100; // delay in ms to refresh the explorer from disk file changes
 	private static EXPLORER_IMPORT_REFRESH_DELAY = 300; // delay in ms to refresh the explorer from imports
@@ -55,6 +57,8 @@ export class ExplorerView extends CollapsibleViewletView {
 
 	private static COMMON_SCM_FOLDERS = ['.git', '.svn', '.hg'];
 
+	public readonly id: string = ExplorerView.ID;
+
 	private explorerViewer: ITree;
 	private filter: FileFilter;
 	private viewletState: FileViewletState;
@@ -76,7 +80,7 @@ export class ExplorerView extends CollapsibleViewletView {
 
 	constructor(
 		viewletState: FileViewletState,
-		actionRunner: IActionRunner,
+		options: IViewOptions,
 		settings: any,
 		headerSize: number,
 		@IMessageService messageService: IMessageService,
@@ -95,11 +99,11 @@ export class ExplorerView extends CollapsibleViewletView {
 		@IWorkbenchThemeService private themeService: IWorkbenchThemeService,
 		@IEnvironmentService private environmentService: IEnvironmentService
 	) {
-		super(actionRunner, false, nls.localize('explorerSection', "Files Explorer Section"), messageService, keybindingService, contextMenuService, headerSize);
+		super(options.actionRunner, options.collapsed, nls.localize('explorerSection', "Files Explorer Section"), messageService, keybindingService, contextMenuService, headerSize);
 
 		this.settings = settings;
 		this.viewletState = viewletState;
-		this.actionRunner = actionRunner;
+		this.actionRunner = options.actionRunner;
 		this.autoReveal = true;
 
 		this.explorerRefreshDelayer = new ThrottledDelayer<void>(ExplorerView.EXPLORER_FILE_CHANGES_REFRESH_DELAY);

src/vs/workbench/parts/files/browser/views/openEditorsView.ts

@@ -43,6 +43,8 @@ export class OpenEditorsView extends AdaptiveCollapsibleViewletView {
 	private static DEFAULT_VISIBLE_OPEN_EDITORS = 9;
 	private static DEFAULT_DYNAMIC_HEIGHT = true;
 
+	readonly id: string = 'workbench.explorer.openEditorsView';
+
 	private settings: any;
 	private visibleOpenEditors: number;
 	private dynamicHeight: boolean;

src/vs/workbench/parts/views/browser/treeView.ts

@@ -55,11 +55,14 @@ export class TreeView extends CollapsibleViewletView {
 		@IExtensionService private extensionService: IExtensionService,
 		@ICommandService private commandService: ICommandService
 	) {
-		super(options.actionRunner, true, options.name, messageService, keybindingService, contextMenuService);
+		super(options.actionRunner, options.collapsed, options.name, messageService, keybindingService, contextMenuService);
 		this.menus = this.instantiationService.createInstance(Menus, this.id);
 		this.viewFocusContext = this.contextKeyService.createKey<boolean>(this.id, void 0);
 		this.menus.onDidChangeTitle(() => this.updateActions(), this, this.disposables);
 		this.themeService.onThemeChange(() => this.tree.refresh() /* soft refresh */, this, this.disposables);
+		if (!options.collapsed) {
+			this.triggerActivation();
+		}
 	}
 
 	public renderHeader(container: HTMLElement): void {

src/vs/workbench/parts/views/browser/views.ts

@@ -28,6 +28,7 @@ export enum TreeItemCollapsibleState {
 export interface IViewOptions {
 	name: string;
 	actionRunner: IActionRunner;
+	collapsed: boolean;
 }
 
 export interface IViewConstructorSignature {