- Store all current composites with pinned state

- Retain the composites states
- Compute pinned composites from loaded composite states and  current composites
- Store on shutdown
- Parameter in add api to activate the added composite
- Pin the added composite at currect location

src/vs/workbench/browser/parts/activitybar/activitybarPart.ts

@@ -242,6 +242,11 @@ export class ActivitybarPart extends Part {
 		return sizes;
 	}
 
+	public shutdown(): void {
+		this.compositeBar.shutdown();
+		super.shutdown();
+	}
+
 	public dispose(): void {
 		if (this.compositeBar) {
 			this.compositeBar.dispose();

src/vs/workbench/browser/parts/compositebar/compositeBar.ts

@@ -34,6 +34,11 @@ export interface ICompositeBarOptions {
 	hidePart: () => TPromise<any>;
 }
 
+interface CompositeState {
+	id: string;
+	pinned: boolean;
+}
+
 export class CompositeBar implements ICompositeBar {
 
 	private readonly _onDidContextMenu: Emitter<MouseEvent>;
@@ -50,6 +55,7 @@ export class CompositeBar implements ICompositeBar {
 	private compositeIdToActivityStack: { [compositeId: string]: ICompositeActivity[]; };
 	private compositeSizeInBar: Map<string, number>;
 
+	private initialCompositesStates: CompositeState[];
 	private pinnedComposites: string[];
 	private activeCompositeId: string;
 	private activeUnpinnedCompositeId: string;
@@ -66,31 +72,35 @@ export class CompositeBar implements ICompositeBar {
 		this.compositeSizeInBar = new Map<string, number>();
 
 		this._onDidContextMenu = new Emitter<MouseEvent>();
-
-		const pinnedComposites = JSON.parse(this.storageService.get(this.options.storageId, StorageScope.GLOBAL, null)) as string[];
-		if (pinnedComposites) {
-			const compositeIds = this.options.composites.map(c => c.id);
-			this.pinnedComposites = pinnedComposites.filter(pcid => compositeIds.indexOf(pcid) >= 0);
-		} else {
-			this.pinnedComposites = this.options.composites.map(c => c.id);
-		}
+		this.initialCompositesStates = this.loadCompositesStates();
+		this.pinnedComposites = this.initialCompositesStates
+			.filter(c => c.pinned)
+			.map(c => c.id)
+			.filter(id => this.options.composites.some(c => c.id === id));
 	}
 
 	public get onDidContextMenu(): Event<MouseEvent> {
 		return this._onDidContextMenu.event;
 	}
 
-	public addComposite(compositeData: { id: string; name: string, order: number }, pin: boolean): void {
+	public addComposite(compositeData: { id: string; name: string, order: number }, activate: boolean): void {
 		if (this.options.composites.filter(c => c.id === compositeData.id).length) {
 			return;
 		}
-		let i = 0;
-		while (i < this.options.composites.length && this.options.composites[i].order < compositeData.order) {
-			i++;
-		}
 		this.options.composites.push(compositeData);
-		if (pin) {
-			this.pin(compositeData.id, true, i);
+
+		const compositeState = this.initialCompositesStates.filter(c => c.id === compositeData.id)[0];
+		if (!compositeState /* new composites are pinned by default */ || compositeState.pinned) {
+			let index;
+			if (compositeState) {
+				index = this.initialCompositesStates.indexOf(compositeState);
+			} else {
+				index = 0;
+				while (index < this.options.composites.length && this.options.composites[index].order < compositeData.order) {
+					index++;
+				}
+			}
+			this.pin(compositeData.id, true, index, activate);
 		}
 	}
 
@@ -437,19 +447,20 @@ export class CompositeBar implements ICompositeBar {
 		});
 
 		// Persist
-		this.savePinnedComposites();
+		this.saveCompositesStates();
 	}
 
 	public isPinned(compositeId: string): boolean {
 		return this.pinnedComposites.indexOf(compositeId) >= 0;
 	}
 
-	public pin(compositeId: string, update = true, index = this.pinnedComposites.length): void {
+	public pin(compositeId: string, update = true, index = this.pinnedComposites.length, activate: boolean = true): void {
 		if (this.isPinned(compositeId)) {
 			return;
 		}
 
-		this.options.openComposite(compositeId).then(() => {
+		const activatePromise = activate ? this.options.openComposite(compositeId) : TPromise.as(null);
+		activatePromise.then(() => {
 			this.pinnedComposites.splice(index, 0, compositeId);
 			this.pinnedComposites = arrays.distinct(this.pinnedComposites);
 
@@ -458,7 +469,7 @@ export class CompositeBar implements ICompositeBar {
 			}
 
 			// Persist
-			this.savePinnedComposites();
+			this.saveCompositesStates();
 		});
 	}
 
@@ -490,7 +501,7 @@ export class CompositeBar implements ICompositeBar {
 		}, 0);
 
 		// Persist
-		this.savePinnedComposites();
+		this.saveCompositesStates();
 	}
 
 	public layout(dimension: Dimension): void {
@@ -514,8 +525,30 @@ export class CompositeBar implements ICompositeBar {
 		this.updateCompositeSwitcher();
 	}
 
-	private savePinnedComposites(): void {
-		this.storageService.store(this.options.storageId, JSON.stringify(this.pinnedComposites), StorageScope.GLOBAL);
+	private loadCompositesStates(): CompositeState[] {
+		const storedStates = <Array<string | CompositeState>>JSON.parse(this.storageService.get(this.options.storageId, StorageScope.GLOBAL, '[]'));
+		const compositeStates = <CompositeState[]>storedStates.map(c =>
+			typeof c === 'string' /* migration from pinned states to composites states */ ? { id: c, pinned: true } : c);
+
+		const newComposites = this.options.composites.filter(c => compositeStates.every(s => s.id !== c.id));
+		newComposites.sort((c1, c2) => c1.order < c2.order ? -1 : 1);
+		newComposites.forEach(c => compositeStates.push({ id: c.id, pinned: true /* new composites are pinned by default */ }));
+
+		return compositeStates;
+	}
+
+	private saveCompositesStates(): void {
+		const toSave = this.pinnedComposites.map(id => (<CompositeState>{ id, pinned: true }));
+		for (const composite of this.options.composites) {
+			if (this.pinnedComposites.indexOf(composite.id) === -1) { // Unpinned composites
+				toSave.push({ id: composite.id, pinned: false });
+			}
+		}
+		this.storageService.store(this.options.storageId, JSON.stringify(toSave), StorageScope.GLOBAL);
+	}
+
+	public shutdown(): void {
+		this.saveCompositesStates();
 	}
 
 	public dispose(): void {

src/vs/workbench/browser/parts/panel/panelPart.ts

@@ -243,6 +243,11 @@ export class PanelPart extends CompositePart<Panel> implements IPanelService {
 		return sizes;
 	}
 
+	public shutdown(): void {
+		this.compositeBar.shutdown();
+		super.shutdown();
+	}
+
 	private layoutCompositeBar(): void {
 		if (this.dimension) {
 			let availableWidth = this.dimension.width - 40; // take padding into account