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Avoid exposing internal classes from the cassowary library

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This commit is contained in:
Chinmay Garde 2015-06-24 18:18:58 -07:00
parent 891085b74b
commit 7dcd8115c3
10 changed files with 125 additions and 125 deletions
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6
packages/cassowary/lib/cassowary.dart
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@ -1,7 +1,7 @@
// Copyright (c) 2015, <your name>. All rights reserved. Use of this source code
// is governed by a BSD-style license that can be found in the LICENSE file.
// Copyright (c) 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/// The cassowary library.
library cassowary;
part 'constraint.dart';

2
packages/cassowary/lib/constant_member.dart
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@ -4,7 +4,7 @@
part of cassowary;
class ConstantMember extends EquationMember {
class ConstantMember extends _EquationMember {
double value = 0.0;
bool get isConstant => true;

16
packages/cassowary/lib/equation_member.dart
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@ -4,26 +4,26 @@
part of cassowary;
abstract class EquationMember {
abstract class _EquationMember {
Expression asExpression();
bool get isConstant;
double get value;
Constraint operator >=(EquationMember m) => asExpression() >= m;
Constraint operator >=(_EquationMember m) => asExpression() >= m;
Constraint operator <=(EquationMember m) => asExpression() <= m;
Constraint operator <=(_EquationMember m) => asExpression() <= m;
/* Constraint */ operator ==(EquationMember m) => asExpression() == m;
/* Constraint */ operator ==(_EquationMember m) => asExpression() == m;
Expression operator +(EquationMember m) => asExpression() + m;
Expression operator +(_EquationMember m) => asExpression() + m;
Expression operator -(EquationMember m) => asExpression() - m;
Expression operator -(_EquationMember m) => asExpression() - m;
Expression operator *(EquationMember m) => asExpression() * m;
Expression operator *(_EquationMember m) => asExpression() * m;
Expression operator /(EquationMember m) => asExpression() / m;
Expression operator /(_EquationMember m) => asExpression() / m;
int get hashCode =>
throw "An equation member is not comparable and cannot be added to collections";

22
packages/cassowary/lib/expression.dart
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@ -4,7 +4,7 @@
part of cassowary;
class Expression extends EquationMember {
class Expression extends _EquationMember {
final List<Term> terms;
final double constant;
@ -21,7 +21,7 @@ class Expression extends EquationMember {
Expression asExpression() => this;
Constraint _createConstraint(
EquationMember /* rhs */ value, Relation relation) {
_EquationMember /* rhs */ value, Relation relation) {
if (value is ConstantMember) {
return new Constraint(
new Expression(new List.from(terms), constant - value.value),
@ -51,16 +51,16 @@ class Expression extends EquationMember {
return null;
}
Constraint operator >=(EquationMember value) =>
Constraint operator >=(_EquationMember value) =>
_createConstraint(value, Relation.greaterThanOrEqualTo);
Constraint operator <=(EquationMember value) =>
Constraint operator <=(_EquationMember value) =>
_createConstraint(value, Relation.lessThanOrEqualTo);
operator ==(EquationMember value) =>
operator ==(_EquationMember value) =>
_createConstraint(value, Relation.equalTo);
Expression operator +(EquationMember m) {
Expression operator +(_EquationMember m) {
if (m is ConstantMember) {
return new Expression(new List.from(terms), constant + m.value);
}
@ -83,7 +83,7 @@ class Expression extends EquationMember {
return null;
}
Expression operator -(EquationMember m) {
Expression operator -(_EquationMember m) {
if (m is ConstantMember) {
return new Expression(new List.from(terms), constant - m.value);
}
@ -109,13 +109,13 @@ class Expression extends EquationMember {
return null;
}
EquationMember _applyMultiplicand(double m) {
_EquationMember _applyMultiplicand(double m) {
var newTerms = terms.fold(new List<Term>(), (list, term) => list
..add(new Term(term.variable, term.coefficient * m)));
return new Expression(newTerms, constant * m);
}
_Pair<Expression, double> _findMulitplierAndMultiplicand(EquationMember m) {
_Pair<Expression, double> _findMulitplierAndMultiplicand(_EquationMember m) {
// At least on of the the two members must be constant for the resulting
// expression to be linear
@ -135,7 +135,7 @@ class Expression extends EquationMember {
return null;
}
EquationMember operator *(EquationMember m) {
_EquationMember operator *(_EquationMember m) {
_Pair<Expression, double> args = _findMulitplierAndMultiplicand(m);
if (args == null) {
@ -147,7 +147,7 @@ class Expression extends EquationMember {
return args.first._applyMultiplicand(args.second);
}
EquationMember operator /(EquationMember m) {
_EquationMember operator /(_EquationMember m) {
if (!m.isConstant) {
throw new ParserException(
"The divisor was not a constant expression", [this, m]);

2
packages/cassowary/lib/param.dart
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@ -4,7 +4,7 @@
part of cassowary;
class Param extends EquationMember {
class Param extends _EquationMember {
final Variable variable;
Param.withVariable(this.variable);

2
packages/cassowary/lib/parser_exception.dart
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@ -6,7 +6,7 @@ part of cassowary;
class ParserException implements Exception {
final String message;
List<EquationMember> members;
List<_EquationMember> members;
ParserException(this.message, this.members);
String toString() {

24
packages/cassowary/lib/row.dart
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@ -4,18 +4,18 @@
part of cassowary;
class Row {
final Map<Symbol, double> cells;
class _Row {
final Map<_Symbol, double> cells;
double constant = 0.0;
Row(this.constant) : this.cells = new Map<Symbol, double>();
Row.fromRow(Row row)
: this.cells = new Map<Symbol, double>.from(row.cells),
_Row(this.constant) : this.cells = new Map<_Symbol, double>();
_Row.fromRow(_Row row)
: this.cells = new Map<_Symbol, double>.from(row.cells),
this.constant = row.constant;
double add(double value) => constant += value;
void insertSymbol(Symbol symbol, [double coefficient = 1.0]) {
void insertSymbol(_Symbol symbol, [double coefficient = 1.0]) {
double val = _elvis(cells[symbol], 0.0) + coefficient;
if (_nearZero(val)) {
@ -25,18 +25,18 @@ class Row {
}
}
void insertRow(Row other, [double coefficient = 1.0]) {
void insertRow(_Row other, [double coefficient = 1.0]) {
constant += other.constant * coefficient;
other.cells.forEach((s, v) => insertSymbol(s, v * coefficient));
}
void removeSymbol(Symbol symbol) {
void removeSymbol(_Symbol symbol) {
cells.remove(symbol);
}
void reverseSign() => cells.forEach((s, v) => cells[s] = -v);
void solveForSymbol(Symbol symbol) {
void solveForSymbol(_Symbol symbol) {
assert(cells.containsKey(symbol));
double coefficient = -1.0 / cells[symbol];
cells.remove(symbol);
@ -44,14 +44,14 @@ class Row {
cells.forEach((s, v) => cells[s] = v * coefficient);
}
void solveForSymbols(Symbol lhs, Symbol rhs) {
void solveForSymbols(_Symbol lhs, _Symbol rhs) {
insertSymbol(lhs, -1.0);
solveForSymbol(rhs);
}
double coefficientForSymbol(Symbol symbol) => _elvis(cells[symbol], 0.0);
double coefficientForSymbol(_Symbol symbol) => _elvis(cells[symbol], 0.0);
void substitute(Symbol symbol, Row row) {
void substitute(_Symbol symbol, _Row row) {
double coefficient = cells[symbol];
if (coefficient == null) {

170
packages/cassowary/lib/solver.dart
View File

@ -5,13 +5,13 @@
part of cassowary;
class Solver {
final Map<Constraint, Tag> _constraints = new Map<Constraint, Tag>();
final Map<Symbol, Row> _rows = new Map<Symbol, Row>();
final Map<Variable, Symbol> _vars = new Map<Variable, Symbol>();
final Map<Variable, EditInfo> _edits = new Map<Variable, EditInfo>();
final List<Symbol> _infeasibleRows = new List<Symbol>();
final Row _objective = new Row(0.0);
Row _artificial = new Row(0.0);
final Map<Constraint, _Tag> _constraints = new Map<Constraint, _Tag>();
final Map<_Symbol, _Row> _rows = new Map<_Symbol, _Row>();
final Map<Variable, _Symbol> _vars = new Map<Variable, _Symbol>();
final Map<Variable, _EditInfo> _edits = new Map<Variable, _EditInfo>();
final List<_Symbol> _infeasibleRows = new List<_Symbol>();
final _Row _objective = new _Row(0.0);
_Row _artificial = new _Row(0.0);
int tick = 0;
Result addConstraint(Constraint constraint) {
@ -19,12 +19,12 @@ class Solver {
return Result.duplicateConstraint;
}
Tag tag = new Tag(
new Symbol(SymbolType.invalid, 0), new Symbol(SymbolType.invalid, 0));
_Tag tag = new _Tag(
new _Symbol(SymbolType.invalid, 0), new _Symbol(SymbolType.invalid, 0));
Row row = _createRow(constraint, tag);
_Row row = _createRow(constraint, tag);
Symbol subject = _chooseSubjectForRow(row, tag);
_Symbol subject = _chooseSubjectForRow(row, tag);
if (subject.type == SymbolType.invalid && _allDummiesInRow(row)) {
if (!_nearZero(row.constant)) {
@ -50,28 +50,28 @@ class Solver {
}
Result removeConstraint(Constraint constraint) {
Tag tag = _constraints[constraint];
_Tag tag = _constraints[constraint];
if (tag == null) {
return Result.unknownConstraint;
}
tag = new Tag.fromTag(tag);
tag = new _Tag.fromTag(tag);
_constraints.remove(constraint);
_removeConstraintEffects(constraint, tag);
Row row = _rows[tag.marker];
_Row row = _rows[tag.marker];
if (row != null) {
_rows.remove(tag.marker);
} else {
_Pair<Symbol, Row> rowPair =
_Pair<_Symbol, _Row> rowPair =
_getLeavingRowPairForMarkerSymbol(tag.marker);
if (rowPair == null) {
return Result.internalSolverError;
}
Symbol leaving = rowPair.first;
_Symbol leaving = rowPair.first;
row = rowPair.second;
var removed = _rows.remove(rowPair.first);
assert(removed != null);
@ -102,7 +102,7 @@ class Solver {
return Result.internalSolverError;
}
EditInfo info = new EditInfo();
_EditInfo info = new _EditInfo();
info.tag = _constraints[constraint];
info.constraint = constraint;
info.constant = 0.0;
@ -113,7 +113,7 @@ class Solver {
}
Result removeEditVariable(Variable variable) {
EditInfo info = _edits[variable];
_EditInfo info = _edits[variable];
if (info == null) {
return Result.unknownEditVariable;
}
@ -142,8 +142,8 @@ class Solver {
void updateVariable() {
for (Variable variable in _vars.keys) {
Symbol symbol = _vars[variable];
Row row = _rows[symbol];
_Symbol symbol = _vars[variable];
_Row row = _rows[symbol];
if (row == null) {
variable.value = 0.0;
} else {
@ -154,28 +154,28 @@ class Solver {
Solver operator <<(Constraint c) => this..addConstraint(c);
Symbol _getSymbolForVariable(Variable variable) {
Symbol symbol = _vars[variable];
_Symbol _getSymbolForVariable(Variable variable) {
_Symbol symbol = _vars[variable];
if (symbol != null) {
return symbol;
}
symbol = new Symbol(SymbolType.external, tick++);
symbol = new _Symbol(SymbolType.external, tick++);
_vars[variable] = symbol;
return symbol;
}
Row _createRow(Constraint constraint, Tag tag) {
_Row _createRow(Constraint constraint, _Tag tag) {
Expression expr = new Expression.fromExpression(constraint.expression);
Row row = new Row(expr.constant);
_Row row = new _Row(expr.constant);
expr.terms.forEach((term) {
if (!_nearZero(term.coefficient)) {
Symbol symbol = _getSymbolForVariable(term.variable);
_Symbol symbol = _getSymbolForVariable(term.variable);
Row foundRow = _rows[symbol];
_Row foundRow = _rows[symbol];
if (foundRow != null) {
row.insertRow(foundRow, term.coefficient);
@ -192,12 +192,12 @@ class Solver {
double coefficient =
constraint.relation == Relation.lessThanOrEqualTo ? 1.0 : -1.0;
Symbol slack = new Symbol(SymbolType.slack, tick++);
_Symbol slack = new _Symbol(SymbolType.slack, tick++);
tag.marker = slack;
row.insertSymbol(slack, coefficient);
if (!constraint.required) {
Symbol error = new Symbol(SymbolType.error, tick++);
_Symbol error = new _Symbol(SymbolType.error, tick++);
tag.other = error;
row.insertSymbol(error, -coefficient);
_objective.insertSymbol(error, constraint.priority);
@ -206,8 +206,8 @@ class Solver {
break;
case Relation.equalTo:
if (!constraint.required) {
Symbol errPlus = new Symbol(SymbolType.error, tick++);
Symbol errMinus = new Symbol(SymbolType.error, tick++);
_Symbol errPlus = new _Symbol(SymbolType.error, tick++);
_Symbol errMinus = new _Symbol(SymbolType.error, tick++);
tag.marker = errPlus;
tag.other = errMinus;
row.insertSymbol(errPlus, -1.0);
@ -215,7 +215,7 @@ class Solver {
_objective.insertSymbol(errPlus, constraint.priority);
_objective.insertSymbol(errMinus, constraint.priority);
} else {
Symbol dummy = new Symbol(SymbolType.dummy, tick++);
_Symbol dummy = new _Symbol(SymbolType.dummy, tick++);
tag.marker = dummy;
row.insertSymbol(dummy);
}
@ -229,8 +229,8 @@ class Solver {
return row;
}
Symbol _chooseSubjectForRow(Row row, Tag tag) {
for (Symbol symbol in row.cells.keys) {
_Symbol _chooseSubjectForRow(_Row row, _Tag tag) {
for (_Symbol symbol in row.cells.keys) {
if (symbol.type == SymbolType.external) {
return symbol;
}
@ -250,11 +250,11 @@ class Solver {
}
}
return new Symbol(SymbolType.invalid, 0);
return new _Symbol(SymbolType.invalid, 0);
}
bool _allDummiesInRow(Row row) {
for (Symbol symbol in row.cells.keys) {
bool _allDummiesInRow(_Row row) {
for (_Symbol symbol in row.cells.keys) {
if (symbol.type != SymbolType.dummy) {
return false;
}
@ -262,10 +262,10 @@ class Solver {
return true;
}
bool _addWithArtificialVariableOnRow(Row row) {
Symbol artificial = new Symbol(SymbolType.slack, tick++);
_rows[artificial] = new Row.fromRow(row);
_artificial = new Row.fromRow(row);
bool _addWithArtificialVariableOnRow(_Row row) {
_Symbol artificial = new _Symbol(SymbolType.slack, tick++);
_rows[artificial] = new _Row.fromRow(row);
_artificial = new _Row.fromRow(row);
Result result = _optimizeObjectiveRow(_artificial);
@ -275,16 +275,16 @@ class Solver {
}
bool success = _nearZero(_artificial.constant);
_artificial = new Row(0.0);
_artificial = new _Row(0.0);
Row foundRow = _rows[artificial];
_Row foundRow = _rows[artificial];
if (foundRow != null) {
_rows.remove(artificial);
if (foundRow.cells.isEmpty) {
return success;
}
Symbol entering = _anyPivotableSymbol(foundRow);
_Symbol entering = _anyPivotableSymbol(foundRow);
if (entering.type == SymbolType.invalid) {
return false;
}
@ -294,29 +294,29 @@ class Solver {
_rows[entering] = foundRow;
}
for (Row row in _rows.values) {
for (_Row row in _rows.values) {
row.removeSymbol(artificial);
}
_objective.removeSymbol(artificial);
return success;
}
Result _optimizeObjectiveRow(Row objective) {
Result _optimizeObjectiveRow(_Row objective) {
while (true) {
Symbol entering = _getEnteringSymbolForObjectiveRow(objective);
_Symbol entering = _getEnteringSymbolForObjectiveRow(objective);
if (entering.type == SymbolType.invalid) {
return Result.success;
}
_Pair<Symbol, Row> leavingPair =
_Pair<_Symbol, _Row> leavingPair =
_getLeavingRowForEnteringSymbol(entering);
if (leavingPair == null) {
return Result.internalSolverError;
}
Symbol leaving = leavingPair.first;
Row row = leavingPair.second;
_Symbol leaving = leavingPair.first;
_Row row = leavingPair.second;
_rows.remove(leavingPair.first);
row.solveForSymbols(leaving, entering);
_substitute(entering, row);
@ -324,21 +324,21 @@ class Solver {
}
}
Symbol _getEnteringSymbolForObjectiveRow(Row objective) {
Map<Symbol, double> cells = objective.cells;
_Symbol _getEnteringSymbolForObjectiveRow(_Row objective) {
Map<_Symbol, double> cells = objective.cells;
for (Symbol symbol in cells.keys) {
for (_Symbol symbol in cells.keys) {
if (symbol.type != SymbolType.dummy && cells[symbol] < 0.0) {
return symbol;
}
}
return new Symbol(SymbolType.invalid, 0);
return new _Symbol(SymbolType.invalid, 0);
}
_Pair<Symbol, Row> _getLeavingRowForEnteringSymbol(Symbol entering) {
_Pair<_Symbol, _Row> _getLeavingRowForEnteringSymbol(_Symbol entering) {
double ratio = double.MAX_FINITE;
_Pair<Symbol, Row> result = new _Pair(null, null);
_Pair<_Symbol, _Row> result = new _Pair(null, null);
_rows.forEach((symbol, row) {
if (symbol.type != SymbolType.external) {
@ -363,7 +363,7 @@ class Solver {
return result;
}
void _substitute(Symbol symbol, Row row) {
void _substitute(_Symbol symbol, _Row row) {
_rows.forEach((first, second) {
second.substitute(symbol, row);
if (first.type != SymbolType.external && second.constant < 0.0) {
@ -377,16 +377,16 @@ class Solver {
}
}
Symbol _anyPivotableSymbol(Row row) {
for (Symbol symbol in row.cells.keys) {
_Symbol _anyPivotableSymbol(_Row row) {
for (_Symbol symbol in row.cells.keys) {
if (symbol.type == SymbolType.slack || symbol.type == SymbolType.error) {
return symbol;
}
}
return new Symbol(SymbolType.invalid, 0);
return new _Symbol(SymbolType.invalid, 0);
}
void _removeConstraintEffects(Constraint cn, Tag tag) {
void _removeConstraintEffects(Constraint cn, _Tag tag) {
if (tag.marker.type == SymbolType.error) {
_removeMarkerEffects(tag.marker, cn.priority);
}
@ -395,8 +395,8 @@ class Solver {
}
}
void _removeMarkerEffects(Symbol marker, double strength) {
Row row = _rows[marker];
void _removeMarkerEffects(_Symbol marker, double strength) {
_Row row = _rows[marker];
if (row != null) {
_objective.insertRow(row, -strength);
} else {
@ -404,11 +404,11 @@ class Solver {
}
}
_Pair<Symbol, Row> _getLeavingRowPairForMarkerSymbol(Symbol marker) {
_Pair<_Symbol, _Row> _getLeavingRowPairForMarkerSymbol(_Symbol marker) {
double r1 = double.MAX_FINITE;
double r2 = double.MAX_FINITE;
_Pair<Symbol, Row> first, second, third;
_Pair<_Symbol, _Row> first, second, third;
_rows.forEach((symbol, row) {
double c = row.coefficientForSymbol(marker);
@ -444,13 +444,13 @@ class Solver {
}
void _suggestValueForEditInfoWithoutDualOptimization(
EditInfo info, double value) {
_EditInfo info, double value) {
double delta = value - info.constant;
info.constant = value;
{
Symbol symbol = info.tag.marker;
Row row = _rows[info.tag.marker];
_Symbol symbol = info.tag.marker;
_Row row = _rows[info.tag.marker];
if (row != null) {
if (row.add(-delta) < 0.0) {
@ -470,8 +470,8 @@ class Solver {
}
}
for (Symbol symbol in _rows.keys) {
Row row = _rows[symbol];
for (_Symbol symbol in _rows.keys) {
_Row row = _rows[symbol];
double coeff = row.coefficientForSymbol(info.tag.marker);
if (coeff != 0.0 &&
row.add(delta * coeff) < 0.0 &&
@ -483,11 +483,11 @@ class Solver {
Result _dualOptimize() {
while (_infeasibleRows.length != 0) {
Symbol leaving = _infeasibleRows.removeLast();
Row row = _rows[leaving];
_Symbol leaving = _infeasibleRows.removeLast();
_Row row = _rows[leaving];
if (row != null && row.constant < 0.0) {
Symbol entering = _getDualEnteringSymbolForRow(row);
_Symbol entering = _getDualEnteringSymbolForRow(row);
if (entering.type == SymbolType.invalid) {
return Result.internalSolverError;
@ -503,14 +503,14 @@ class Solver {
return Result.success;
}
Symbol _getDualEnteringSymbolForRow(Row row) {
Symbol entering;
_Symbol _getDualEnteringSymbolForRow(_Row row) {
_Symbol entering;
double ratio = double.MAX_FINITE;
Map<Symbol, double> rowCells = row.cells;
Map<_Symbol, double> rowCells = row.cells;
for (Symbol symbol in rowCells.keys) {
for (_Symbol symbol in rowCells.keys) {
double value = rowCells[symbol];
if (value > 0.0 && symbol.type != SymbolType.dummy) {
@ -523,22 +523,22 @@ class Solver {
}
}
return _elvis(entering, new Symbol(SymbolType.invalid, 0));
return _elvis(entering, new _Symbol(SymbolType.invalid, 0));
}
}
class Tag {
Symbol marker;
Symbol other;
class _Tag {
_Symbol marker;
_Symbol other;
Tag(this.marker, this.other);
Tag.fromTag(Tag tag)
_Tag(this.marker, this.other);
_Tag.fromTag(_Tag tag)
: this.marker = tag.marker,
this.other = tag.other;
}
class EditInfo {
Tag tag;
class _EditInfo {
_Tag tag;
Constraint constraint;
double constant;
}

4
packages/cassowary/lib/symbol.dart
View File

@ -6,9 +6,9 @@ part of cassowary;
enum SymbolType { invalid, external, slack, error, dummy, }
class Symbol {
class _Symbol {
final SymbolType type;
int tick;
Symbol(this.type, this.tick);
_Symbol(this.type, this.tick);
}

2
packages/cassowary/lib/term.dart
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@ -4,7 +4,7 @@
part of cassowary;
class Term extends EquationMember {
class Term extends _EquationMember {
final Variable variable;
final double coefficient;