basic support for nested snippets, #24855

src/vs/editor/contrib/snippet/browser/snippetController2.ts

@@ -13,6 +13,62 @@ import { SnippetSession } from './snippetSession';
 import { EditorContextKeys } from 'vs/editor/common/editorContextKeys';
 import { KeyCode, KeyMod } from 'vs/base/common/keyCodes';
 
+class SnippetSessions {
+
+	private _stack: SnippetSession[] = [];
+
+	add(session: SnippetSession): number {
+		return this._stack.push(session);
+	}
+
+	clear(): void {
+		dispose(this._stack);
+		this._stack.length = 0;
+	}
+
+	get empty(): boolean {
+		return this._stack.length === 0;
+	}
+
+	get hasPlaceholder(): boolean {
+		return this._stack.some(s => s.hasPlaceholder);
+	}
+
+	get isAtFirstPlaceholder(): boolean {
+		// return !this.empty && this._stack[0].isAtFirstPlaceholder;
+		return this._stack.every(s => s.isAtFirstPlaceholder);
+	}
+
+	get isAtFinalPlaceholder(): boolean {
+		// return !this.empty && this._stack[0].isAtFinalPlaceholder;
+		return this._stack.every(s => s.isAtFinalPlaceholder);
+	}
+
+	get isSelectionWithinPlaceholders(): boolean {
+		return this._stack.some(s => s.isSelectionWithinPlaceholders());
+	}
+
+	prev(): void {
+		for (let i = this._stack.length - 1; i >= 0; i--) {
+			const snippet = this._stack[i];
+			if (!snippet.isAtFirstPlaceholder) {
+				snippet.prev();
+				break;
+			}
+		}
+	}
+
+	next(): void {
+		for (let i = this._stack.length - 1; i >= 0; i--) {
+			const snippet = this._stack[i];
+			if (!snippet.isAtFinalPlaceholder) {
+				snippet.next();
+				break;
+			}
+		}
+	}
+}
+
 @commonEditorContribution
 export class SnippetController2 {
 
@@ -28,7 +84,8 @@ export class SnippetController2 {
 	private readonly _hasNextTabstop: IContextKey<boolean>;
 	private readonly _hasPrevTabstop: IContextKey<boolean>;
 
-	private _snippet: SnippetSession;
+	// private _snippet: SnippetSession;
+	private _sessions = new SnippetSessions();
 	private _snippetListener: IDisposable[] = [];
 
 	constructor(
@@ -44,7 +101,7 @@ export class SnippetController2 {
 		this._inSnippet.reset();
 		this._hasPrevTabstop.reset();
 		this._hasNextTabstop.reset();
-		dispose(this._snippet);
+		this._sessions.clear();
 	}
 
 	getId(): string {
@@ -56,47 +113,49 @@ export class SnippetController2 {
 		overwriteBefore: number = 0, overwriteAfter: number = 0,
 		undoStopBefore: boolean = true, undoStopAfter: boolean = true
 	): void {
+
+		// don't listen while inserting the snippet
+		// as that is the inflight state causing cancelation
+		this._snippetListener = dispose(this._snippetListener);
+
 		if (undoStopBefore) {
 			this._editor.getModel().pushStackElement();
 		}
-		if (!this._snippet) {
-			// create a new session
-			this._snippet = new SnippetSession(this._editor);
-			this._snippet.insert(template, overwriteBefore, overwriteAfter);
-			this._snippetListener = [
-				this._editor.onDidChangeModel(() => this.cancel()),
-				this._editor.onDidChangeCursorSelection(() => this._updateState())
-			];
-		} else {
-			// only insert the snippet when a session
-			// is already active
-			this._snippet.insert(template, overwriteBefore, overwriteAfter);
-		}
+
+		const snippet = new SnippetSession(this._editor);
+		snippet.insert(template, overwriteBefore, overwriteAfter);
+		this._sessions.add(snippet);
+
 		if (undoStopAfter) {
 			this._editor.getModel().pushStackElement();
 		}
+
+		this._snippetListener = [
+			this._editor.onDidChangeModel(() => this.cancel()),
+			this._editor.onDidChangeCursorSelection(() => this._updateState())
+		];
 		this._updateState();
 	}
 
 	private _updateState(): void {
-		if (!this._snippet) {
+		if (this._sessions.empty) {
 			// canceled in the meanwhile
 			return;
 		}
 
-		if (!this._snippet.hasPlaceholder) {
+		if (!this._sessions.hasPlaceholder) {
 			// don't listen for selection changes and don't
 			// update context keys when the snippet is plain text
 			return this.cancel();
 		}
 
-		if (this._snippet.isAtFinalPlaceholder || !this._snippet.isSelectionWithinPlaceholders()) {
+		if (this._sessions.isAtFinalPlaceholder || !this._sessions.isSelectionWithinPlaceholders) {
 			return this.cancel();
 		}
 
 		this._inSnippet.set(true);
-		this._hasPrevTabstop.set(!this._snippet.isAtFirstPlaceholder);
-		this._hasNextTabstop.set(!this._snippet.isAtFinalPlaceholder);
+		this._hasPrevTabstop.set(!this._sessions.isAtFirstPlaceholder);
+		this._hasNextTabstop.set(!this._sessions.isAtFinalPlaceholder);
 	}
 
 	finish(): void {
@@ -106,28 +165,21 @@ export class SnippetController2 {
 	}
 
 	cancel(): void {
-		if (this._snippet) {
-			this._inSnippet.reset();
-			this._hasPrevTabstop.reset();
-			this._hasNextTabstop.reset();
-			dispose(this._snippetListener);
-			dispose(this._snippet);
-			this._snippet = undefined;
-		}
+		this._inSnippet.reset();
+		this._hasPrevTabstop.reset();
+		this._hasNextTabstop.reset();
+		this._sessions.clear();
+		dispose(this._snippetListener);
 	}
 
 	prev(): void {
-		if (this._snippet) {
-			this._snippet.prev();
-			this._updateState();
-		}
+		this._sessions.prev();
+		this._updateState();
 	}
 
 	next(): void {
-		if (this._snippet) {
-			this._snippet.next();
-			this._updateState();
-		}
+		this._sessions.next();
+		this._updateState();
 	}
 }
 

src/vs/editor/contrib/snippet/browser/snippetSession.ts

@@ -130,11 +130,13 @@ export class OneSnippet {
 	}
 
 	get isAtFirstPlaceholder() {
-		return this._placeholderGroupsIdx === 0;
+		return this._placeholderGroupsIdx === 0 || this._placeholderGroups.length === 0;
 	}
 
 	get isAtFinalPlaceholder() {
-		if (this._placeholderGroupsIdx < 0) {
+		if (this._placeholderGroups.length === 0) {
+			return true;
+		} else if (this._placeholderGroupsIdx < 0) {
 			return false;
 		} else {
 			return this._placeholderGroups[this._placeholderGroupsIdx][0].isFinalTabstop;
@@ -196,24 +198,35 @@ export class SnippetSession {
 		return selection;
 	}
 
-	static makeInsertEditsAndSnippets(editor: ICommonCodeEditor, template: string, overwriteBefore: number = 0, overwriteAfter: number = 0): { edits: IIdentifiedSingleEditOperation[], snippets: OneSnippet[] } {
+	private readonly _editor: ICommonCodeEditor;
+	private _snippets: OneSnippet[] = [];
+
+	constructor(editor: ICommonCodeEditor) {
+		this._editor = editor;
+	}
+
+	dispose(): void {
+		dispose(this._snippets);
+	}
+
+	insert(template: string, overwriteBefore: number = 0, overwriteAfter: number = 0): void {
+
+		const model = this._editor.getModel();
+		const edits: IIdentifiedSingleEditOperation[] = [];
 
 		let delta = 0;
-		let edits: IIdentifiedSingleEditOperation[] = [];
-		let snippets: OneSnippet[] = [];
-		let model = editor.getModel();
 
 		// know what text the overwrite[Before|After] extensions
 		// of the primary curser have selected because only when
 		// secondary selections extend to the same text we can grow them
-		let firstBeforeText = model.getValueInRange(SnippetSession.adjustSelection(model, editor.getSelection(), overwriteBefore, 0));
-		let firstAfterText = model.getValueInRange(SnippetSession.adjustSelection(model, editor.getSelection(), 0, overwriteAfter));
+		let firstBeforeText = model.getValueInRange(SnippetSession.adjustSelection(model, this._editor.getSelection(), overwriteBefore, 0));
+		let firstAfterText = model.getValueInRange(SnippetSession.adjustSelection(model, this._editor.getSelection(), 0, overwriteAfter));
 
 		// sort selections by their start position but remeber
 		// the original index. that allows you to create correct
 		// offset-based selection logic without changing the
 		// primary selection
-		const indexedSelection = editor.getSelections()
+		const indexedSelection = this._editor.getSelections()
 			.map((selection, idx) => ({ selection, idx }))
 			.sort((a, b) => Range.compareRangesUsingStarts(a.selection, b.selection));
 
@@ -248,46 +261,18 @@ export class SnippetSession {
 			// that ensures the primiary cursor stays primary despite not being
 			// the one with lowest start position
 			edits[idx] = EditOperation.replaceMove(snippetSelection, snippet.text);
-			snippets[idx] = new OneSnippet(editor, snippet, offset);
-		}
-
-		return { edits, snippets };
-	}
-
-	private readonly _editor: ICommonCodeEditor;
-	private _snippets: OneSnippet[];
-
-	constructor(editor: ICommonCodeEditor) {
-		this._editor = editor;
-	}
-
-	dispose(): void {
-		dispose(this._snippets);
-	}
-
-	insert(template: string, overwriteBefore: number = 0, overwriteAfter: number = 0): void {
-
-		const model = this._editor.getModel();
-		const { edits, snippets } = SnippetSession.makeInsertEditsAndSnippets(
-			this._editor, template, overwriteBefore, overwriteAfter
-		);
-
-		let isNestedInsert = true;
-		if (!this._snippets) {
-			// keep snippets around
-			this._snippets = snippets;
-			isNestedInsert = false;
+			this._snippets[idx] = new OneSnippet(this._editor, snippet, offset);
 		}
 
 		// make insert edit and start with first selections
-		const newSelections = model.pushEditOperations(this._editor.getSelections(), edits, undoEdits => {
-			if (!isNestedInsert && this._snippets[0].hasPlaceholder) {
+
+		this._editor.setSelections(model.pushEditOperations(this._editor.getSelections(), edits, undoEdits => {
+			if (this._snippets[0].hasPlaceholder) {
 				return this._move(true);
 			} else {
 				return undoEdits.map(edit => Selection.fromPositions(edit.range.getEndPosition()));
 			}
-		});
-		this._editor.setSelections(newSelections);
+		}));
 	}
 
 	next(): void {
@@ -322,6 +307,11 @@ export class SnippetSession {
 	}
 
 	isSelectionWithinPlaceholders(): boolean {
+
+		if (!this.hasPlaceholder) {
+			return false;
+		}
+
 		const selections = this._editor.getSelections();
 		if (selections.length < this._snippets.length) {
 			// this means we started snippet mode with N

src/vs/editor/contrib/snippet/test/browser/snippetController2.test.ts

@@ -148,17 +148,37 @@ suite('SnippetController2', function () {
 		// assertContextKeys(contextKeys, false, false, false);
 	});
 
-	test('insert, insert nested', function () {
+	test('insert, nested snippet', function () {
 		const ctrl = new SnippetController2(editor, contextKeys);
 		ctrl.insert('${1:foobar}$0');
 		assertContextKeys(contextKeys, true, false, true);
 		assertSelections(editor, new Selection(1, 1, 1, 7), new Selection(2, 5, 2, 11));
 
-		ctrl.insert('farboo');
+		ctrl.insert('farboo$1$0');
+		assertSelections(editor, new Selection(1, 7, 1, 7), new Selection(2, 11, 2, 11));
+		assertContextKeys(contextKeys, true, false, true);
+
+		ctrl.next();
+		assertSelections(editor, new Selection(1, 7, 1, 7), new Selection(2, 11, 2, 11));
+		assertContextKeys(contextKeys, true, true, true);
+
+		ctrl.next();
+		assertSelections(editor, new Selection(1, 7, 1, 7), new Selection(2, 11, 2, 11));
+		assertContextKeys(contextKeys, false, false, false);
+	});
+
+	test('insert, nested plain text', function () {
+		const ctrl = new SnippetController2(editor, contextKeys);
+		ctrl.insert('${1:foobar}$0');
 		assertContextKeys(contextKeys, true, false, true);
+		assertSelections(editor, new Selection(1, 1, 1, 7), new Selection(2, 5, 2, 11));
+
+		ctrl.insert('farboo');
 		assertSelections(editor, new Selection(1, 7, 1, 7), new Selection(2, 11, 2, 11));
+		assertContextKeys(contextKeys, true, false, true);
 
 		ctrl.next();
+		assertSelections(editor, new Selection(1, 7, 1, 7), new Selection(2, 11, 2, 11));
 		assertContextKeys(contextKeys, false, false, false);
 	});
 });

src/vs/editor/contrib/snippet/test/browser/snippetSession.test.ts

@@ -403,20 +403,5 @@ suite('SnippetSession', function () {
 		assert.equal(model.getValue(), '@line=1function foo() {\n    @line=2console.log(a);\n}');
 		assertSelections(editor, new Selection(1, 8, 1, 8), new Selection(2, 12, 2, 12));
 	});
-
-	test('snippet, insert-nested', function () {
-		const session = new SnippetSession(editor);
-		session.insert('foo$1foo$0');
-
-		assertSelections(editor, new Selection(1, 4, 1, 4), new Selection(2, 8, 2, 8));
-		session.insert('bar');
-		assert.ok(session.isSelectionWithinPlaceholders());
-		assertSelections(editor, new Selection(1, 7, 1, 7), new Selection(2, 11, 2, 11));
-
-		session.next();
-		assertSelections(editor, new Selection(1, 10, 1, 10), new Selection(2, 14, 2, 14));
-		assert.ok(session.isAtFinalPlaceholder);
-	});
-
 });