get expected indentation from above lines

src/vs/editor/common/controller/cursorTypeOperations.ts

@@ -103,16 +103,16 @@ export class TypeOperations {
 	}
 
 	private static _goodIndentForLine(config: CursorConfiguration, model: ITokenizedModel, lineNumber: number): string {
-		let inheritIndentAction = LanguageConfigurationRegistry.getInheritedIndentActionForCurrentLine(model, lineNumber);
+		let expectedIndentAction = LanguageConfigurationRegistry.getExpectedIndentActionAtPosition(model, lineNumber);
 
-		if (inheritIndentAction && inheritIndentAction.action) {
-			let indentation = inheritIndentAction.indentation;
+		if (expectedIndentAction && expectedIndentAction.action) {
+			let indentation = expectedIndentAction.indentation;
 
-			if (inheritIndentAction.action === IndentAction.Indent) {
+			if (expectedIndentAction.action === IndentAction.Indent) {
 				indentation = TypeOperations.shiftIndent(config, indentation);
 			}
 
-			if (inheritIndentAction.action === IndentAction.Outdent) {
+			if (expectedIndentAction.action === IndentAction.Outdent) {
 				indentation = TypeOperations.unshiftIndent(config, indentation);
 			}
 
@@ -213,37 +213,32 @@ export class TypeOperations {
 		}
 
 		let enterAction = LanguageConfigurationRegistry.getEnterActionAtPosition(model, range.startLineNumber, range.startColumn);
-		let beforeText = '';
-
-		let inheritedIntentationAction = LanguageConfigurationRegistry.getInheritedIndentActionForCurrentLine(model, range.startLineNumber);
-		let currentLineIndentationRule = LanguageConfigurationRegistry.getIndentationRuleForCurrentLine(model, range.startLineNumber, range.startColumn);
+		let expectedIndentAction = LanguageConfigurationRegistry.getExpectedIndentActionAtPosition(model, range.startLineNumber);
+		let expectedIndentationBeforeEnter = indentation;
 
-		if (inheritedIntentationAction || currentLineIndentationRule) {
-			// The indentation of current line may be adjusted
-			let expectedIndentation = indentation;
+		if (expectedIndentAction && expectedIndentAction.action) {
+			expectedIndentationBeforeEnter = expectedIndentAction.indentation;
 
-			if (inheritedIntentationAction && inheritedIntentationAction.action) {
-				if (inheritedIntentationAction.action === IndentAction.Indent) {
-					expectedIndentation = TypeOperations.shiftIndent(config, inheritedIntentationAction.indentation);
-				}
-
-				if (inheritedIntentationAction.action === IndentAction.Outdent) {
-					expectedIndentation = TypeOperations.unshiftIndent(config, inheritedIntentationAction.indentation);
-				}
+			if (expectedIndentAction.action === IndentAction.Indent) {
+				expectedIndentationBeforeEnter = TypeOperations.shiftIndent(config, expectedIndentationBeforeEnter);
 			}
 
-			if (currentLineIndentationRule && currentLineIndentationRule === IndentAction.Outdent) {
-				expectedIndentation = TypeOperations.unshiftIndent(config, expectedIndentation);
+			if (expectedIndentAction.action === IndentAction.Outdent) {
+				expectedIndentationBeforeEnter = TypeOperations.unshiftIndent(config, expectedIndentationBeforeEnter);
 			}
+		}
 
-			expectedIndentation = config.normalizeIndentation(expectedIndentation);
+		if (enterAction.outdentCurrentLine) {
+			expectedIndentationBeforeEnter = TypeOperations.unshiftIndent(config, expectedIndentationBeforeEnter);
+		}
 
-			if (expectedIndentation !== indentation) {
-				// adjust indentation of current line.
-				beforeText = expectedIndentation + lineText.substring(indentation.length, range.startColumn - 1);
-				indentation = expectedIndentation;
-				range = new Range(range.startLineNumber, 1, range.endLineNumber, range.endColumn);
-			}
+		expectedIndentationBeforeEnter = config.normalizeIndentation(expectedIndentationBeforeEnter);
+
+		let beforeText = '';
+		if (expectedIndentationBeforeEnter !== indentation) {
+			beforeText = expectedIndentationBeforeEnter + lineText.substring(indentation.length, range.startColumn - 1);
+			indentation = expectedIndentationBeforeEnter;
+			range = new Range(range.startLineNumber, 1, range.endLineNumber, range.endColumn);
 		}
 
 		// compute indentation of following lines

src/vs/editor/common/modes/languageConfiguration.ts

@@ -174,6 +174,10 @@ export interface EnterAction {
 	 * Describe what to do with the indentation.
 	 */
 	indentAction: IndentAction;
+	/**
+	 * Describe whether to outdent current line.
+	 */
+	outdentCurrentLine?: boolean;
 	/**
 	 * Describes text to be appended after the new line and after the indentation.
 	 */

src/vs/editor/common/modes/languageConfigurationRegistry.ts

@@ -279,16 +279,28 @@ export class LanguageConfigurationRegistryImpl {
 		return result;
 	}
 
-	public getInheritedIndentActionForCurrentLine(model: ITokenizedModel, lineNumber: number): { indentation: string, action: IndentAction } {
+
+	public getEnterActionAtPosition(model: ITokenizedModel, lineNumber: number, column: number): EnterAction {
+		let enterAction = this.getRawEnterActionAtPosition(model, lineNumber, column);
+		if (!enterAction) {
+			enterAction = {
+				indentAction: IndentAction.None,
+				appendText: '',
+			};
+		} else {
+			if (!enterAction.appendText) {
+				enterAction.appendText = '';
+			}
+		}
+
+		return enterAction;
+	}
+
+	public getExpectedIndentActionAtPosition(model: ITokenizedModel, lineNumber: number) {
 		/**
 		 * In order to get correct indentation for current line
-		 * we need to loop backwards all the lines from current line until
-		 * 	1. a line is not empty
-		 *  2. and the line doesn't match `unIndentedLinePattern` pattern
+		 * we need to loop backwards all the lines from current line until a line contains non whitespace characters.
 		 */
-
-		// TODO: how about a line filled with only spaces?
-
 		let lastLineNumber = lineNumber - 1;
 
 		for (lastLineNumber = lineNumber - 1; lastLineNumber >= 1; lastLineNumber--) {
@@ -313,18 +325,17 @@ export class LanguageConfigurationRegistryImpl {
 		}
 
 		let lineText = model.getLineContent(lastLineNumber);
-		let lineTextAbove: string;
+		let oneLineAboveText: string;
 		if (lastLineNumber > 1) {
-			lineTextAbove = model.getLineContent(lastLineNumber - 1);
+			oneLineAboveText = model.getLineContent(lastLineNumber - 1);
 		}
 
 		let indentation = strings.getLeadingWhitespace(lineText);
-
-		let inheritedIntentationRule = onEnterSupport.getInheritedIndentationRules(lineText, lineTextAbove);
+		let expectedIntentAction = onEnterSupport.getExpectedIndentActionAtPosition(lineText, oneLineAboveText);
 
 		return {
 			indentation: indentation,
-			action: inheritedIntentationRule
+			action: expectedIntentAction
 		};
 	}
 
@@ -342,22 +353,6 @@ export class LanguageConfigurationRegistryImpl {
 		return indentAction;
 	}
 
-	public getEnterActionAtPosition(model: ITokenizedModel, lineNumber: number, column: number): EnterAction {
-		let enterAction = this.getRawEnterActionAtPosition(model, lineNumber, column);
-		if (!enterAction) {
-			enterAction = {
-				indentAction: IndentAction.None,
-				appendText: '',
-			};
-		} else {
-			if (!enterAction.appendText) {
-				enterAction.appendText = '';
-			}
-		}
-
-		return enterAction;
-	}
-
 	// end onEnter
 
 	public getBracketsSupport(languageId: LanguageId): RichEditBrackets {

src/vs/editor/common/modes/supports/onEnter.ts

@@ -75,7 +75,6 @@ export class OnEnterSupport {
 		// (3): Indentation Support
 		if (this._indentationRules) {
 			let enterAction: EnterAction = null;
-
 			if (this._indentationRules.increaseIndentPattern && this._indentationRules.increaseIndentPattern.test(beforeEnterText)) {
 				enterAction = { indentAction: IndentAction.Indent };
 			}
@@ -90,6 +89,13 @@ export class OnEnterSupport {
 				if (this._indentationRules.indentNextLinePattern && this._indentationRules.indentNextLinePattern.test(oneLineAboveText)) {
 					enterAction = { indentAction: IndentAction.Outdent };
 				}
+				if (this._indentationRules.decreaseIndentPattern && this._indentationRules.decreaseIndentPattern.test(beforeEnterText)) {
+					if (enterAction === null) {
+						enterAction = { indentAction: IndentAction.None, outdentCurrentLine: true };
+					} else {
+						enterAction = { indentAction: enterAction.indentAction, outdentCurrentLine: true };
+					}
+				}
 			}
 
 			if (enterAction !== null) {
@@ -110,10 +116,10 @@ export class OnEnterSupport {
 		return null;
 	}
 
-	public getInheritedIndentationRules(text: string, textOneLineAbove?: string): IndentAction {
+	public getExpectedIndentActionAtPosition(text: string, oneLineAboveText?: string): IndentAction {
 		let offset = 0;
 		if (this._indentationRules) {
-			if (textOneLineAbove && this._indentationRules.indentNextLinePattern && this._indentationRules.indentNextLinePattern.test(textOneLineAbove)) {
+			if (oneLineAboveText && this._indentationRules.indentNextLinePattern && this._indentationRules.indentNextLinePattern.test(oneLineAboveText)) {
 				offset -= 1;
 			}
 
@@ -144,17 +150,6 @@ export class OnEnterSupport {
 		return null;
 	}
 
-	public getIndentActionForContent(text: string): IndentAction {
-		if (this._indentationRules && /^\s/.test(text)) {
-			// No reason to run regular expressions if there is nothing to outdent from
-			if (this._indentationRules.decreaseIndentPattern && this._indentationRules.decreaseIndentPattern.test(text)) {
-				return IndentAction.Outdent;
-			}
-		}
-
-		return null;
-	}
-
 	private static _createOpenBracketRegExp(bracket: string): RegExp {
 		var str = strings.escapeRegExpCharacters(bracket);
 		if (!/\B/.test(str.charAt(0))) {

src/vs/editor/test/common/controller/cursor.test.ts

@@ -1142,7 +1142,8 @@ class OnEnterMode extends MockMode {
 			onEnterRules: [{
 				beforeText: /.*/,
 				action: {
-					indentAction: indentAction
+					indentAction: indentAction,
+					outdentCurrentLine: outdentCurrentLine
 				}
 			}]
 		}));

src/vs/monaco.d.ts

@@ -4298,6 +4298,10 @@ declare module monaco.languages {
          * Describe what to do with the indentation.
          */
         indentAction: IndentAction;
+        /**
+         * Describe whether to outdent current line.
+         */
+        outdentCurrentLine?: boolean;
         /**
          * Describes text to be appended after the new line and after the indentation.
          */