Roll Observatory packages and add a roll script

csslib/lib/src/polyfill.dart

-// Copyright (c) 2013, 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.
-
-part of csslib.parser;
-
-/**
- * CSS polyfill emits CSS to be understood by older parsers that which do not
- * understand (var, calc, etc.).
- */
-class PolyFill {
-  final Messages _messages;
-  final bool _warningsAsErrors;
-  Map<String, VarDefinition> _allVarDefinitions =
-      new Map<String, VarDefinition>();
-
-  Set<StyleSheet> allStyleSheets = new Set<StyleSheet>();
-
-  /**
-   * [_pseudoElements] list of known pseudo attributes found in HTML, any
-   * CSS pseudo-elements 'name::custom-element' is mapped to the manged name
-   * associated with the pseudo-element key.
-   */
-  PolyFill(this._messages, this._warningsAsErrors);
-
-  /**
-   * Run the analyzer on every file that is a style sheet or any component that
-   * has a style tag.
-   */
-  void process(StyleSheet styleSheet, {List<StyleSheet> includes: null}) {
-    if (includes != null) {
-      processVarDefinitions(includes);
-    }
-    processVars(styleSheet);
-
-    // Remove all var definitions for this style sheet.
-    new _RemoveVarDefinitions().visitTree(styleSheet);
-  }
-
-  /** Process all includes looking for var definitions. */
-  void processVarDefinitions(List<StyleSheet> includes) {
-    for (var include in includes) {
-      _allVarDefinitions = (new _VarDefinitionsIncludes(_allVarDefinitions)
-        ..visitTree(include)).varDefs;
-    }
-  }
-
-  void processVars(StyleSheet styleSheet) {
-    // Build list of all var definitions.
-    var mainStyleSheetVarDefs = (new _VarDefAndUsage(
-        this._messages, _allVarDefinitions)..visitTree(styleSheet)).varDefs;
-
-    // Resolve all definitions to a non-VarUsage (terminal expression).
-    mainStyleSheetVarDefs.forEach((key, value) {
-      for (var _ in (value.expression as Expressions).expressions) {
-        mainStyleSheetVarDefs[key] =
-            _findTerminalVarDefinition(_allVarDefinitions, value);
-      }
-    });
-  }
-}
-
-/** Build list of all var definitions in all includes. */
-class _VarDefinitionsIncludes extends Visitor {
-  final Map<String, VarDefinition> varDefs;
-
-  _VarDefinitionsIncludes(this.varDefs);
-
-  void visitTree(StyleSheet tree) {
-    visitStyleSheet(tree);
-  }
-
-  visitVarDefinition(VarDefinition node) {
-    // Replace with latest variable definition.
-    varDefs[node.definedName] = node;
-    super.visitVarDefinition(node);
-  }
-
-  void visitVarDefinitionDirective(VarDefinitionDirective node) {
-    visitVarDefinition(node.def);
-  }
-}
-
-/**
- * Find var- definitions in a style sheet.
- * [found] list of known definitions.
- */
-class _VarDefAndUsage extends Visitor {
-  final Messages _messages;
-  final Map<String, VarDefinition> _knownVarDefs;
-  final Map<String, VarDefinition> varDefs = new Map<String, VarDefinition>();
-
-  VarDefinition currVarDefinition;
-  List<Expression> currentExpressions;
-
-  _VarDefAndUsage(this._messages, this._knownVarDefs);
-
-  void visitTree(StyleSheet tree) {
-    visitStyleSheet(tree);
-  }
-
-  visitVarDefinition(VarDefinition node) {
-    // Replace with latest variable definition.
-    currVarDefinition = node;
-
-    _knownVarDefs[node.definedName] = node;
-    varDefs[node.definedName] = node;
-
-    super.visitVarDefinition(node);
-
-    currVarDefinition = null;
-  }
-
-  void visitVarDefinitionDirective(VarDefinitionDirective node) {
-    visitVarDefinition(node.def);
-  }
-
-  void visitExpressions(Expressions node) {
-    currentExpressions = node.expressions;
-    super.visitExpressions(node);
-    currentExpressions = null;
-  }
-
-  void visitVarUsage(VarUsage node) {
-    if (currVarDefinition != null && currVarDefinition.badUsage) return;
-
-    // Don't process other var() inside of a varUsage.  That implies that the
-    // default is a var() too.  Also, don't process any var() inside of a
-    // varDefinition (they're just place holders until we've resolved all real
-    // usages.
-    var expressions = currentExpressions;
-    var index = expressions.indexOf(node);
-    assert(index >= 0);
-    var def = _knownVarDefs[node.name];
-    if (def != null) {
-      if (def.badUsage) {
-        // Remove any expressions pointing to a bad var definition.
-        expressions.removeAt(index);
-        return;
-      }
-      _resolveVarUsage(currentExpressions, index,
-          _findTerminalVarDefinition(_knownVarDefs, def));
-    } else if (node.defaultValues.any((e) => e is VarUsage)) {
-      // Don't have a VarDefinition need to use default values resolve all
-      // default values.
-      var terminalDefaults = <Expression>[];
-      for (var defaultValue in node.defaultValues) {
-        terminalDefaults.addAll(resolveUsageTerminal(defaultValue));
-      }
-      expressions.replaceRange(index, index + 1, terminalDefaults);
-    } else if (node.defaultValues.isNotEmpty) {
-      // No VarDefinition but default value is a terminal expression; use it.
-      expressions.replaceRange(index, index + 1, node.defaultValues);
-    } else {
-      if (currVarDefinition != null) {
-        currVarDefinition.badUsage = true;
-        var mainStyleSheetDef = varDefs[node.name];
-        if (mainStyleSheetDef != null) {
-          varDefs.remove(currVarDefinition.property);
-        }
-      }
-      // Remove var usage that points at an undefined definition.
-      expressions.removeAt(index);
-      _messages.warning("Variable is not defined.", node.span);
-    }
-
-    var oldExpressions = currentExpressions;
-    currentExpressions = node.defaultValues;
-    super.visitVarUsage(node);
-    currentExpressions = oldExpressions;
-  }
-
-  List<Expression> resolveUsageTerminal(VarUsage usage) {
-    var result = [];
-
-    var varDef = _knownVarDefs[usage.name];
-    var expressions;
-    if (varDef == null) {
-      // VarDefinition not found try the defaultValues.
-      expressions = usage.defaultValues;
-    } else {
-      // Use the VarDefinition found.
-      expressions = (varDef.expression as Expressions).expressions;
-    }
-
-    for (var expr in expressions) {
-      if (expr is VarUsage) {
-        // Get terminal value.
-        result.addAll(resolveUsageTerminal(expr));
-      }
-    }
-
-    // We're at a terminal just return the VarDefinition expression.
-    if (result.isEmpty && varDef != null) {
-      result = (varDef.expression as Expressions).expressions;
-    }
-
-    return result;
-  }
-
-  _resolveVarUsage(List<Expression> expressions, int index, VarDefinition def) {
-    var defExpressions = (def.expression as Expressions).expressions;
-    expressions.replaceRange(index, index + 1, defExpressions);
-  }
-}
-
-/** Remove all var definitions. */
-class _RemoveVarDefinitions extends Visitor {
-  void visitTree(StyleSheet tree) {
-    visitStyleSheet(tree);
-  }
-
-  void visitStyleSheet(StyleSheet ss) {
-    ss.topLevels.removeWhere((e) => e is VarDefinitionDirective);
-    super.visitStyleSheet(ss);
-  }
-
-  void visitDeclarationGroup(DeclarationGroup node) {
-    node.declarations.removeWhere((e) => e is VarDefinition);
-    super.visitDeclarationGroup(node);
-  }
-}
-
-/** Find terminal definition (non VarUsage implies real CSS value). */
-VarDefinition _findTerminalVarDefinition(
-    Map<String, VarDefinition> varDefs, VarDefinition varDef) {
-  var expressions = varDef.expression as Expressions;
-  for (var expr in expressions.expressions) {
-    if (expr is VarUsage) {
-      var usageName = (expr as VarUsage).name;
-      var foundDef = varDefs[usageName];
-
-      // If foundDef is unknown check if defaultValues; if it exist then resolve
-      // to terminal value.
-      if (foundDef == null) {
-        // We're either a VarUsage or terminal definition if in varDefs;
-        // either way replace VarUsage with it's default value because the
-        // VarDefinition isn't found.
-        var defaultValues = (expr as VarUsage).defaultValues;
-        var replaceExprs = expressions.expressions;
-        assert(replaceExprs.length == 1);
-        replaceExprs.replaceRange(0, 1, defaultValues);
-        return varDef;
-      }
-      if (foundDef is VarDefinition) {
-        return _findTerminalVarDefinition(varDefs, foundDef);
-      }
-    } else {
-      // Return real CSS property.
-      return varDef;
-    }
-  }
-
-  // Didn't point to a var definition that existed.
-  return varDef;
-}