Index: lib/src/nesting_level.dart |
diff --git a/lib/src/nesting_level.dart b/lib/src/nesting_level.dart |
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+// Copyright (c) 2015, the Dart project authors. Please see the AUTHORS file |
+// for details. All rights reserved. Use of this source code is governed by a |
+// BSD-style license that can be found in the LICENSE file. |
+ |
+library dart_style.src.nesting_level; |
+ |
+import 'fast_hash.dart'; |
+ |
+/// A single level of expression nesting. |
+/// |
+/// When a line is split in the middle of an expression, this tracks the |
+/// context of where in the expression that split occurs. It ensures that the |
+/// [LineSplitter] obeys the expression nesting when deciding what column to |
+/// start lines at when split inside an expression. |
+/// |
+/// Each instance of this represents a single level of expression nesting. If we |
+/// split at to chunks with different levels of nesting, the splitter ensures |
+/// they each get assigned to different columns. |
+/// |
+/// In addition, each level has an indent. This is the number of spaces it is |
+/// indented relative to the outer expression. It's almost always |
+/// [Indent.expression], but cascades are special magic snowflakes and use |
+/// [Indent.cascade]. |
+class NestingLevel extends FastHash { |
+ /// The nesting level surrounding this one, or `null` if this is represents |
+ /// top level code in a block. |
+ NestingLevel get parent => _parent; |
+ NestingLevel _parent; |
+ |
+ /// The number of characters that this nesting level is indented relative to |
+ /// the containing level. |
+ /// |
+ /// Normally, this is [Indent.expression], but cascades use [Indent.cascade]. |
+ final int indent; |
+ |
+ /// The total number of characters of indentation from this level and all of |
+ /// its parents, after determining which nesting levels are actually used. |
+ /// |
+ /// This is only valid during line splitting. |
+ int get totalUsedIndent => _totalUsedIndent; |
+ int _totalUsedIndent; |
+ |
+ bool get isNested => _parent != null; |
+ |
+ NestingLevel() : indent = 0; |
+ |
+ NestingLevel._(this._parent, this.indent); |
+ |
+ /// Creates a new deeper level of nesting indented [spaces] more characters |
+ /// that the outer level. |
+ NestingLevel nest(int spaces) => new NestingLevel._(this, spaces); |
+ |
+ /// Clears the previously calculated total indent of this nesting level. |
+ void clearTotalUsedIndent() { |
+ _totalUsedIndent = null; |
+ if (_parent != null) _parent.clearTotalUsedIndent(); |
+ } |
+ |
+ /// Calculates the total amount of indentation from this nesting level and |
+ /// all of its parents assuming only [usedNesting] levels are in use. |
+ void refreshTotalUsedIndent(Set<NestingLevel> usedNesting) { |
+ if (_totalUsedIndent != null) return; |
+ |
+ _totalUsedIndent = 0; |
+ |
+ if (_parent != null) { |
+ _parent.refreshTotalUsedIndent(usedNesting); |
+ _totalUsedIndent += _parent.totalUsedIndent; |
+ } |
+ |
+ if (usedNesting.contains(this)) _totalUsedIndent += indent; |
+ } |
+ |
+ String toString() { |
+ if (_parent == null) return indent.toString(); |
+ return "$parent:$indent"; |
+ } |
+} |