| // Copyright 2019 The Fuchsia Authors. 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 'inspect.dart'; |
| |
| /// A key-value pair with a [String] key and a typed value. |
| abstract class Property<T> { |
| /// The VMO index for this property. |
| /// @nodoc |
| @visibleForTesting |
| final int index; |
| |
| /// The writer for the underlying VMO. |
| /// |
| /// Will be set to null if the [Property] has been deleted or could not be |
| /// created in the VMO. |
| /// If so, all actions on this [Property] should be no-ops and not throw. |
| VmoWriter _writer; |
| |
| /// Creates a modifiable [Property]. |
| Property._(this.index, this._writer) { |
| if (index == invalidIndex) { |
| _writer = null; |
| } |
| } |
| |
| /// Creates a property that never does anything. |
| /// |
| /// These are returned when calling methods on a deleted Node, |
| /// or if there is no space for a newly created property in underlying storage. |
| Property.deleted() |
| : _writer = null, |
| index = invalidIndex; |
| |
| bool get _isDeleted => _writer == null; |
| |
| /// Sets the value of this property. |
| void setValue(T value); |
| |
| /// Deletes this property from underlying storage. |
| /// Calls on a deleted property have no effect and do not result in an error. |
| void delete() { |
| _writer?.deleteEntity(index); |
| _writer = null; |
| } |
| } |
| |
| /// Sets value on properties which store a byte-vector. |
| mixin BytesProperty<T> on Property<T> { |
| @override |
| void setValue(T value) { |
| _writer?.setProperty(index, value); |
| } |
| } |
| |
| /// Operations on "Metric" type properties - those which store a number. |
| mixin Arithmetic<T extends num> on Property<T> { |
| /// Adds [delta] to the value of this metric. |
| void add(T delta) { |
| _writer?.addMetric(index, delta); |
| } |
| |
| /// Subtracts [delta] from the value of this metric. |
| void subtract(T delta) { |
| _writer?.subMetric(index, delta); |
| } |
| |
| @override |
| void setValue(T value) { |
| _writer?.setMetric(index, value); |
| } |
| } |
| |
| /// A property holding an [int]. |
| /// |
| /// Only [Node.intProperty()] can create this object. |
| class IntProperty extends Property<int> with Arithmetic<int> { |
| IntProperty._(String name, int parentIndex, VmoWriter writer) |
| : super._(writer.createMetric(parentIndex, name, 0), writer); |
| |
| IntProperty._deleted() : super.deleted(); |
| } |
| |
| /// A property holding a [double]. |
| /// |
| /// Only [Node.doubleProperty()] can create this object. |
| class DoubleProperty extends Property<double> with Arithmetic<double> { |
| DoubleProperty._(String name, int parentIndex, VmoWriter writer) |
| : super._(writer.createMetric(parentIndex, name, 0.0), writer); |
| |
| DoubleProperty._deleted() : super.deleted(); |
| } |
| |
| /// A property holding a [String]. |
| /// |
| /// Only [Node.stringProperty()] can create this object. |
| class StringProperty extends Property<String> with BytesProperty<String> { |
| StringProperty._(String name, int parentIndex, VmoWriter writer) |
| : super._(writer.createProperty(parentIndex, name), writer); |
| |
| StringProperty._deleted() : super.deleted(); |
| } |
| |
| /// A property holding a [ByteData]. |
| /// |
| /// Only [Node.byteDataProperty()] can create this object. |
| class ByteDataProperty extends Property<ByteData> with BytesProperty<ByteData> { |
| ByteDataProperty._(String name, int parentIndex, VmoWriter writer) |
| : super._(writer.createProperty(parentIndex, name), writer); |
| |
| ByteDataProperty._deleted() : super.deleted(); |
| } |