In computer science, a circular buffer, circular queue, cyclic buffer or ring buffer is a data structure that uses a single, fixed-size buffer as if it were connected end-to-end. This structure lends itself easily to buffering data streams.
In mathematics, modular arithmetic is a system of arithmetic for integers, where numbers "wrap around" when reaching a certain value, called the modulus.
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Shos.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
namespace Shos.UndoRedoList.Tests
{
[TestClass]
public class SampleTest
{
[TestMethod]
public void UndoRedoTest()
{
// list which support undo/redo.
var target = new UndoRedoList<int, List<int>>();
Assert.IsFalse(target.CanUndo);
Assert.IsFalse(target.CanRedo);
// Modify target
target.Add(100);
Assert.AreEqual(1, target.Count);
Assert.AreEqual(100, target[0]);
Assert.IsTrue (target.CanUndo);
Assert.IsFalse(target.CanRedo);
// Undo
Assert.IsTrue(target.Undo());
Assert.AreEqual(0, target.Count);
Assert.IsFalse(target.CanUndo);
Assert.IsTrue (target.CanRedo);
// Redo
Assert.IsTrue(target.Redo());
Assert.AreEqual(1, target.Count);
Assert.AreEqual(100, target[0]);
Assert.IsTrue (target.CanUndo);
Assert.IsFalse(target.CanRedo);
}
[TestMethod]
public void ActionScopeTest()
{
// list which support undo/redo.
var target = new UndoRedoList<int, List<int>>();
Assert.IsFalse(target.CanUndo);
Assert.IsFalse(target.CanRedo);
// ActionScope
using (var scope = new UndoRedoList<int, List<int>>.ActionScope(target)) {
// Modify target in ActionScope
target.Add(100);
target.Add(200);
target.Add(300);
}
Assert.AreEqual(3, target.Count);
Assert.AreEqual(100, target[0]);
Assert.AreEqual(200, target[1]);
Assert.AreEqual(300, target[2]);
Assert.IsTrue(target.CanUndo);
// Undo
Assert.IsTrue(target.Undo());
// The 3 actions in ActionScope can undo in one time.
Assert.AreEqual(0, target.Count);
Assert.IsFalse(target.CanUndo);
}
[TestMethod]
public void DisabledUndoScopeTest()
{
// list which support undo/redo.
var target = new UndoRedoList<int, List<int>>();
Assert.IsFalse(target.CanUndo);
Assert.IsFalse(target.CanRedo);
// DisabledUndoScope
using (var scope = new UndoRedoList<int, List<int>>.DisabledUndoScope(target)) {
// Modify target in DisabledUndoScope
target.Add(100);
}
// You can't undo actions in DisabledUndoScope.
Assert.IsFalse(target.CanUndo);
Assert.IsFalse(target.CanRedo);
}
[TestMethod]
public void UndoRedoListTest()
{
// List which support undo/redo.
var target = new UndoRedoList<int>();
target.Add(100);
// You can undo/redo also.
Assert.IsTrue (target.CanUndo);
Assert.IsFalse(target.CanRedo);
Assert.IsTrue(target.Undo());
Assert.IsTrue(target.Redo());
}
[TestMethod]
public void UndoRedoObservableCollectionTest()
{
// ObservableCollection which support undo/redo.
var target = new UndoRedoObservableCollection<int>();
target.CollectionChanged += ObservableCollection_CollectionChanged;
target.Add(100);
// You can undo/redo also.
Assert.IsTrue (target.CanUndo);
Assert.IsFalse(target.CanRedo);
Assert.IsTrue(target.Undo());
Assert.IsTrue(target.Redo());
// event handler
static void ObservableCollection_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{ /* do domething */ }
}
}
}
