How to: Hide Certain Columns in the Timeline View

• Nov 13, 2018
• 4 minutes to read

This example illustrates how to hide columns for certain (non-working) hours in the Timeline View.

To accomplish this task, you can implement a custom time scale. It enables you to hide unneeded time periods.

A custom time scale class is inherited from the TimeScale class, overriding methods used for date and time handling and formatting.

The following properties and methods can be overridden to create a custom time scale:

• SortingWeight - used to compare time scales;
• TimeScale.Floor - specifies column boundaries;
• HasNextDate - checks whether moving to the next date is allowed;
• GetNextDate - navigates to the next date;
• DefaultDisplayFormat - specifies the format for the column header caption;
• DefaultMenuCaption - specifies the caption for the context menu item which enables this time scale;
• TimeScale.FormatCaption - returns a string to be displayed as a column header caption.

To ensure proper alignment of an upper (Day) scale, create a descendant of the TimeScaleDay class that overrides the TimeScaleDay.Floor method. Add this descendant to the TimelineView.Scales collection in place of the default TimeScaleDay scale.

The resulting Timeline View is demonstrated in the following picture.

Note

Actually, non-working hours are not hidden. They are packed within the last time cell of each day because the time line has to be continuous.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-hide-certain-columns-in-the-timeline-view-implement-a-custom-scale-e531

Form1.cs

TimeScaleCollection scales = schedulerControl1.TimelineView.Scales;

scales.BeginUpdate();
try {
    scales.Clear();
    scales.Add(new CustomTimeScaleDay());
    scales.Add(new CustomTimeScaleHour());
} finally {
    scales.EndUpdate();
}

CustomTimeScale.cs

public class CustomTimeScaleDay : TimeScaleDay {
    public override DateTime Floor(DateTime date) {
        if (date == DateTime.MinValue)
            return date.AddHours(8);

        DateTime start = base.Floor(date);
        if (date.Hour < 8)
            start = start.AddDays(-1);

        return start.AddHours(8);
    }
}
public class CustomTimeScaleHour : TimeScale {
    private const int StartHour = 8;
    private const int FinishHour = 19;

    protected override string DefaultDisplayFormat { get { return "HH:mm"; } }
    protected override string DefaultMenuCaption { get { return "8:00-19:00"; } }

    protected override TimeSpan SortingWeight {
        get { return TimeSpan.FromHours(FinishHour - StartHour + 1); }
    }
    public override DateTime Floor(DateTime date) {
        if (date == DateTime.MinValue || date == DateTime.MaxValue)
            return RoundToHour(date, date.Hour);

        if (date.Hour < StartHour)
            // Round down to the end of the previous working day.
            return RoundToHour(date.AddDays(-1), FinishHour); 

        if (date.Hour > FinishHour)
            // Round down to the end of the current working day.
            return RoundToHour(date, FinishHour);

        return RoundToHour(date, date.Hour);
    }
    protected DateTime RoundToHour(DateTime date, int hour) {
        return new DateTime(date.Year, date.Month, date.Day, hour, 0, 0);
    }
    protected override bool HasNextDate(DateTime date) {
        return date <= RoundToHour(DateTime.MaxValue, FinishHour);
    }
    public override DateTime GetNextDate(DateTime date) {
        return (date.Hour > FinishHour - 1) ? RoundToHour(date.AddDays(1), StartHour) : date.AddHours(1);
    }
}

CustomTimeScale.vb

Public Class CustomTimeScaleDay
    Inherits TimeScaleDay

    Public Overrides Function Floor(ByVal [date] As Date) As Date
        If [date] = Date.MinValue Then
            Return [date].AddHours(8)
        End If

        Dim start As Date = MyBase.Floor([date])
        If [date].Hour < 8 Then
            start = start.AddDays(-1)
        End If

        Return start.AddHours(8)
    End Function
End Class
Public Class CustomTimeScaleHour
    Inherits TimeScale

    Private Const StartHour As Integer = 8
    Private Const FinishHour As Integer = 19

    Protected Overrides ReadOnly Property DefaultDisplayFormat() As String
        Get
            Return "HH:mm"
        End Get
    End Property
    Protected Overrides ReadOnly Property DefaultMenuCaption() As String
        Get
            Return "8:00-19:00"
        End Get
    End Property

    Protected Overrides ReadOnly Property SortingWeight() As TimeSpan
        Get
            Return TimeSpan.FromHours(FinishHour - StartHour + 1)
        End Get
    End Property
    Public Overrides Function Floor(ByVal [date] As Date) As Date
        If [date] = Date.MinValue OrElse [date] = Date.MaxValue Then
            Return RoundToHour([date], [date].Hour)
        End If

        If [date].Hour < StartHour Then
            ' Round down to the end of the previous working day.
            Return RoundToHour([date].AddDays(-1), FinishHour)
        End If

        If [date].Hour > FinishHour Then
            ' Round down to the end of the current working day.
            Return RoundToHour([date], FinishHour)
        End If

        Return RoundToHour([date], [date].Hour)
    End Function
    Protected Function RoundToHour(ByVal [date] As Date, ByVal hour As Integer) As Date
        Return New Date([date].Year, [date].Month, [date].Day, hour, 0, 0)
    End Function
    Protected Overrides Function HasNextDate(ByVal [date] As Date) As Boolean
        Return [date] <= RoundToHour(Date.MaxValue, FinishHour)
    End Function
    Public Overrides Function GetNextDate(ByVal [date] As Date) As Date
        Return If([date].Hour > FinishHour - 1, RoundToHour([date].AddDays(1), StartHour), [date].AddHours(1))
    End Function
End Class

Form1.vb

Dim scales As TimeScaleCollection = schedulerControl1.TimelineView.Scales

scales.BeginUpdate()
Try
    scales.Clear()
    scales.Add(New CustomTimeScaleDay())
    scales.Add(New CustomTimeScaleHour())
Finally
    scales.EndUpdate()
End Try