better decoration management, more tests, finish at final tab stop

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

@@ -6,7 +6,7 @@
 'use strict';
 
 import { getLeadingWhitespace } from 'vs/base/common/strings';
-import { ICommonCodeEditor, IModel, TrackedRangeStickiness, IIdentifiedSingleEditOperation } from 'vs/editor/common/editorCommon';
+import { ICommonCodeEditor, IModel, IModelDecorationOptions, TrackedRangeStickiness, IIdentifiedSingleEditOperation } from 'vs/editor/common/editorCommon';
 import { EditOperation } from 'vs/editor/common/core/editOperation';
 import { TextmateSnippet, Placeholder, SnippetParser } from '../common/snippetParser';
 import { Selection } from 'vs/editor/common/core/selection';
@@ -24,6 +24,9 @@ class OneSnippet {
 	private _placeholderGroups: Placeholder[][];
 	private _placeholderGroupsIdx: number;
 
+	private static readonly _growingDecoration: IModelDecorationOptions = { stickiness: TrackedRangeStickiness.AlwaysGrowsWhenTypingAtEdges };
+	private static readonly _fixedDecoration: IModelDecorationOptions = { stickiness: TrackedRangeStickiness.NeverGrowsWhenTypingAtEdges };
+
 	constructor(editor: ICommonCodeEditor, snippet: TextmateSnippet, offset: number) {
 		this._editor = editor;
 		this._snippet = snippet;
@@ -58,16 +61,7 @@ class OneSnippet {
 				const end = model.getPositionAt(this._offset + placeholderOffset + placeholderLen);
 				const range = new Range(start.lineNumber, start.column, end.lineNumber, end.column);
 
-				let stickiness: TrackedRangeStickiness;
-				if (placeholder.isFinalTabstop) {
-					stickiness = TrackedRangeStickiness.NeverGrowsWhenTypingAtEdges;
-				} else if (lastRange && lastRange.getEndPosition().equals(range.getStartPosition())) {
-					stickiness = TrackedRangeStickiness.GrowsOnlyWhenTypingAfter;
-				} else {
-					stickiness = TrackedRangeStickiness.AlwaysGrowsWhenTypingAtEdges;
-				}
-
-				const handle = accessor.addDecoration(range, { stickiness });
+				const handle = accessor.addDecoration(range, OneSnippet._fixedDecoration);
 				this._placeholderDecorations.set(placeholder, handle);
 
 				lastRange = range;
@@ -91,27 +85,50 @@ class OneSnippet {
 
 		this._init();
 
+		const prevGroupsIdx = this._placeholderGroupsIdx;
+
 		if (fwd && this._placeholderGroupsIdx < this._placeholderGroups.length - 1) {
 			this._placeholderGroupsIdx += 1;
-			return this._getCurrentPlaceholderSelections();
 
 		} else if (!fwd && this._placeholderGroupsIdx > 0) {
 			this._placeholderGroupsIdx -= 1;
-			return this._getCurrentPlaceholderSelections();
 
 		} else {
-			return undefined;
+			return [];
 		}
+
+		return this._editor.getModel().changeDecorations(accessor => {
+
+			// change stickness to never grow when typing at its edges
+			// so that in-active tabstops never grow
+			if (prevGroupsIdx !== -1) {
+				for (const placeholder of this._placeholderGroups[prevGroupsIdx]) {
+					const id = this._placeholderDecorations.get(placeholder);
+					accessor.changeDecorationOptions(id, OneSnippet._fixedDecoration);
+				}
+			}
+
+			// change stickiness to always grow when typing at its edges
+			// because these decorations represent the currently active
+			// tabstop. Special case: reaching the final tab stop
+			const selections: Selection[] = [];
+			for (const placeholder of this._placeholderGroups[this._placeholderGroupsIdx]) {
+				const id = this._placeholderDecorations.get(placeholder);
+				const range = this._editor.getModel().getDecorationRange(id);
+				selections.push(new Selection(range.startLineNumber, range.startColumn, range.endLineNumber, range.endColumn));
+
+				accessor.changeDecorationOptions(id, placeholder.isFinalTabstop ? OneSnippet._fixedDecoration : OneSnippet._growingDecoration);
+			}
+			return selections;
+		});
 	}
 
-	private _getCurrentPlaceholderSelections(): Selection[] {
-		const selections: Selection[] = [];
-		for (const placeholder of this._placeholderGroups[this._placeholderGroupsIdx]) {
-			const handle = this._placeholderDecorations.get(placeholder);
-			const range = this._editor.getModel().getDecorationRange(handle);
-			selections.push(new Selection(range.startLineNumber, range.startColumn, range.endLineNumber, range.endColumn));
+	get isAtFinalPlaceholder() {
+		if (this._placeholderGroupsIdx < 0) {
+			return false;
+		} else {
+			return this._placeholderGroups[this._placeholderGroupsIdx][0].isFinalTabstop;
 		}
-		return selections;
 	}
 }
 
@@ -161,32 +178,34 @@ export class SnippetSession {
 		this._editor.setSelections(newSelections);
 	}
 
+	dispose(): void {
+		dispose(this._snippets);
+	}
+
 	next(): void {
 		const newSelections = this._move(true);
-		this._editor.setSelections(newSelections);
+		if (newSelections.length > 0) {
+			this._editor.setSelections(newSelections);
+		}
 	}
 
 	prev(): void {
 		const newSelections = this._move(false);
-		this._editor.setSelections(newSelections);
+		if (newSelections.length > 0) {
+			this._editor.setSelections(newSelections);
+		}
 	}
 
 	private _move(fwd: boolean): Selection[] {
 		const selections: Selection[] = [];
 		for (const snippet of this._snippets) {
 			const oneSelection = snippet.move(fwd);
-			if (!oneSelection) {
-				if (fwd) {
-					this.stop();
-				}
-				return this._editor.getSelections();
-			}
 			selections.push(...oneSelection);
 		}
 		return selections;
 	}
 
-	stop(): void {
-		dispose(this._snippets);
+	get isAtFinalPlaceholder() {
+		return this._snippets[0].isAtFinalPlaceholder;
 	}
 }

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

@@ -59,6 +59,19 @@ suite('SnippetInsertion', function () {
 		assertSelections(editor, new Selection(1, 10, 1, 10), new Selection(2, 14, 2, 14));
 	});
 
+	test('snippets, repeated tabstops', function () {
+		const session = new SnippetSession(editor, '${1:abc}foo${1:abc}$0');
+		assertSelections(editor,
+			new Selection(1, 1, 1, 4), new Selection(1, 7, 1, 10),
+			new Selection(2, 5, 2, 8), new Selection(2, 11, 2, 14),
+		);
+		session.next();
+		assertSelections(editor,
+			new Selection(1, 10, 1, 10),
+			new Selection(2, 14, 2, 14),
+		);
+	});
+
 	test('snippets, selections and new text with newlines', () => {
 
 		const session = new SnippetSession(editor, 'foo\n\t${1:bar}\n$0');
@@ -141,5 +154,76 @@ suite('SnippetInsertion', function () {
 		assertSelections(editor, new Selection(1, 15, 1, 15));
 	});
 
+	test('snippets, don\'t merge touching tabstops 1/2', function () {
+
+		const session = new SnippetSession(editor, '$1$2$3$0');
+		assertSelections(editor, new Selection(1, 1, 1, 1), new Selection(2, 5, 2, 5));
+
+		session.next();
+		assertSelections(editor, new Selection(1, 1, 1, 1), new Selection(2, 5, 2, 5));
+
+		session.next();
+		assertSelections(editor, new Selection(1, 1, 1, 1), new Selection(2, 5, 2, 5));
+
+		session.next();
+		assertSelections(editor, new Selection(1, 1, 1, 1), new Selection(2, 5, 2, 5));
+
+		session.prev();
+		session.prev();
+		session.prev();
+		assertSelections(editor, new Selection(1, 1, 1, 1), new Selection(2, 5, 2, 5));
+		editor.trigger('test', 'type', { text: '111' });
+
+		session.next();
+		editor.trigger('test', 'type', { text: '222' });
+
+		session.next();
+		editor.trigger('test', 'type', { text: '333' });
+
+		session.next();
+		assert.equal(model.getValue(), '111222333function foo() {\n    111222333console.log(a);\n}');
+		assertSelections(editor, new Selection(1, 10, 1, 10), new Selection(2, 14, 2, 14));
+
+		session.prev();
+		assertSelections(editor, new Selection(1, 7, 1, 7), new Selection(2, 11, 2, 11));
+		session.prev();
+		assertSelections(editor, new Selection(1, 4, 1, 4), new Selection(2, 8, 2, 8));
+		session.prev();
+		assertSelections(editor, new Selection(1, 1, 1, 4), new Selection(2, 5, 2, 8));
+	});
+	test('snippets, don\'t merge touching tabstops 2/2', function () {
+
+		const session = new SnippetSession(editor, '$1$2$3$0');
+		assertSelections(editor, new Selection(1, 1, 1, 1), new Selection(2, 5, 2, 5));
+
+		editor.trigger('test', 'type', { text: '111' });
+
+		session.next();
+		assertSelections(editor, new Selection(1, 4, 1, 4), new Selection(2, 8, 2, 8));
+		editor.trigger('test', 'type', { text: '222' });
+
+		session.next();
+		assertSelections(editor, new Selection(1, 7, 1, 7), new Selection(2, 11, 2, 11));
+		editor.trigger('test', 'type', { text: '333' });
+
+		session.next();
+		assert.equal(session.isAtFinalPlaceholder, true);
+	});
+
+	test('snippets, gracefully move over final tabstop', function () {
+		const session = new SnippetSession(editor, '${1}bar$0');
+
+		assert.equal(session.isAtFinalPlaceholder, false);
+		assertSelections(editor, new Selection(1, 1, 1, 1), new Selection(2, 5, 2, 5));
+
+		session.next();
+		assert.equal(session.isAtFinalPlaceholder, true);
+		assertSelections(editor, new Selection(1, 4, 1, 4), new Selection(2, 8, 2, 8));
+
+		session.next();
+		assert.equal(session.isAtFinalPlaceholder, true);
+		assertSelections(editor, new Selection(1, 4, 1, 4), new Selection(2, 8, 2, 8));
+	});
+
 });