/// <summary>
/// Gets the page offset for the specific paging information.
/// </summary>
/// <param name="pagingInfo">Presentation paging information.</param>
/// <returns>Page offset.</returns>
public int GetPageOffSet(PresentationPagingInfo pagingInfo)
{
double halfPage = Math.Round((double)(pagingInfo.MaxPageNumbersToShow / 2));
if (pagingInfo.PageNumber < halfPage)
{
return(0); // first half of page set, dont offset
}
int quarterPage = Convert.ToInt32(Math.Round(halfPage / 2, 0, MidpointRounding.AwayFromZero));
var offSet = Convert.ToInt32(pagingInfo.PageNumber - (quarterPage + 1));
// Handle if we are at the end of the set (we still want to show the full maxPageNumbersToShow of options)
while (offSet + pagingInfo.MaxPageNumbersToShow > pagingInfo.LastPageNumber + 1)
{
offSet--;
}
if (offSet < 0)
{
return(0); // offset should never be less than zero
}
return(offSet);
}
public void WhenTotalItemsCountAndPageSizeAreValid_ThenReturnTotalPageCount(int totalItemsCount, int pageSize, int expected)
{
var classUnderTest = new PresentationPagingInfo(totalItemsCount, pageSize, 0);
var result = classUnderTest.TotalPageCount;
Assert.That(result, Is.EqualTo(expected));
}
public void WhenPageNumerIsGiven_ThenOffSetIsReturned(int pageNumber, int expected)
{
var pagingInfo = new PresentationPagingInfo(TotalItems, PageSize, pageNumber);
var result = Act(pagingInfo);
Assert.That(result, Is.EqualTo(expected));
}
public void WhenTotalItems51_AndPageSize10_AndPageNumber1_AndMaxPagesToShow3_ThenReturnOffsetZero()
{
var pagingInfo = new PresentationPagingInfo(51, 10, 1, 3);
var result = Act(pagingInfo);
Assert.That(result, Is.EqualTo(0));
}
[TestCase(110, 10, 11)] // 110 / 10 = 11
public void WhenZeroOffSet_ThenCreateCorrectSizeOfList(int totalItemsCount, int pageSize, int expected)
{
var pagingInfo = new PresentationPagingInfo(totalItemsCount, pageSize, 0, 1000);
var classUnderTest = CreateClassUnderTest();
var pageNumbers = classUnderTest.Create(pagingInfo);
Assert.That(pageNumbers.Count, Is.EqualTo(expected));
}
private static PaginationPageViewModel CreatePaginationPageViewModel(int pageNumber)
{
var pagingInfo = new PresentationPagingInfo(TotalItemsCount, PageSize, pageNumber, MaxPageNumbersToShow);
return(new PaginationPageViewModel(TotalItemsCount, pageNumber, PageSize)
{
PageNavigationNumbers = new PageNumbersFactory(new MiddlePageOffSetStrategy()).Create(pagingInfo)
});
}
public void WhenZeroOffSet_AndTotalItemCountIsZero_ThenCreateEmptyCollection()
{
var pagingInfo = new PresentationPagingInfo(0, 2, 0);
var classUnderTest = CreateClassUnderTest();
var pageNumbers = classUnderTest.Create(pagingInfo);
Assert.That(pageNumbers.Count, Is.EqualTo(0));
}
public void WhenZeroOffSet_AndPageNumberCountIsGreaterThanMaxPageNumbersToShow_ThenCreateListOfSizeMaxPageNumbersToShow()
{
const int maxPageNumbersToShow = 11;
var pagingInfo = new PresentationPagingInfo(110, 10, 0, maxPageNumbersToShow);
var classUnderTest = CreateClassUnderTest();
var pageNumbers = classUnderTest.Create(pagingInfo); // 120 / 10 = 12
Assert.That(pageNumbers.Count, Is.EqualTo(maxPageNumbersToShow));
}
public void WhenZeroOffSet_ThenSetIsCurrentPageTo4thPage()
{
var pagingInfo = new PresentationPagingInfo(10, 3, 3);
var classUnderTest = CreateClassUnderTest();
var pageNumbers = classUnderTest.Create(pagingInfo);
Assert.That(pageNumbers[0].IsCurrentPage, Is.False);
Assert.That(pageNumbers[1].IsCurrentPage, Is.False);
Assert.That(pageNumbers[2].IsCurrentPage, Is.False);
Assert.That(pageNumbers[3].IsCurrentPage, Is.True);
}
public void WhenZeroOffSet_ThenSetDisplayTextCorrectly()
{
var pagingInfo = new PresentationPagingInfo(10, 2, 0);
var classUnderTest = CreateClassUnderTest();
var pageNumbers = classUnderTest.Create(pagingInfo);
Assert.That(pageNumbers[0].DisplayNumber, Is.EqualTo("1"));
Assert.That(pageNumbers[1].DisplayNumber, Is.EqualTo("2"));
Assert.That(pageNumbers[2].DisplayNumber, Is.EqualTo("3"));
Assert.That(pageNumbers[3].DisplayNumber, Is.EqualTo("4"));
Assert.That(pageNumbers[4].DisplayNumber, Is.EqualTo("5"));
}
public void WhenTotalItemsLessThanZero_ThenThrowException()
{
Assert.Throws <ArgumentOutOfRangeException>(() => _ = new PresentationPagingInfo(-1, 10, 0));
}
public void WhenPageNumberGreaterThanTotalPageCount_ThenSetPageNumberToLastPage()
{
var classUnderTest = new PresentationPagingInfo(100, 10, 10);
Assert.That(classUnderTest.PageNumber, Is.EqualTo(classUnderTest.LastPageNumber));
}
public void WhenPageSizeLessThanOne_ThenThrowException()
{
Assert.Throws <ArgumentOutOfRangeException>(() => _ = new PresentationPagingInfo(100, 0, 0));
}
public int GetPageOffSet(PresentationPagingInfo pagingInfo)
{
return(5);
}
public void WhenPageNumberIsLessThanZero_ThenThrowException()
{
Assert.Throws <ArgumentOutOfRangeException>(() => _ = new PresentationPagingInfo(100, 10, -1));
}
public void WhenTotalPageCountIsTwo_ThenReturnOne()
{
var classUnderTest = new PresentationPagingInfo(20, 10, 0);
Assert.That(classUnderTest.LastPageNumber, Is.EqualTo(1));
}
public void WhenMaxPageNumbersToShowIsLessThanOne_ThenThrowException()
{
Assert.Throws <ArgumentOutOfRangeException>(() => _ = new PresentationPagingInfo(100, 10, 0, 0));
}
public void WhenPageNumberLessThanOrEqualToTotalPageCount_ThenSetPageNumber()
{
var classUnderTest = new PresentationPagingInfo(100, 10, 9);
Assert.That(classUnderTest.PageNumber, Is.EqualTo(classUnderTest.LastPageNumber));
}
private int Act(PresentationPagingInfo pagingInfo)
{
return(_classUnderTest.GetPageOffSet(pagingInfo));
}
