FreeTimeCalculator.FindFreeTimeInterval(TimeInterval, TimeSpan, Boolean) Method

Performs a search for the nearest available time slot with the specified duration within the specified interval.

Namespace: DevExpress.XtraScheduler.Tools

Assembly: DevExpress.XtraScheduler.v24.1.Core.Desktop.dll

NuGet Package: DevExpress.Scheduler.CoreDesktop

Declaration

C#

public TimeInterval FindFreeTimeInterval(
    TimeInterval interval,
    TimeSpan duration,
    bool forward
)

VB.NET

Public Function FindFreeTimeInterval(
    interval As TimeInterval,
    duration As TimeSpan,
    forward As Boolean
) As TimeInterval

Parameters

Name	Type	Description
interval	TimeInterval	A TimeInterval object, representing the time period in which the search is performed.
duration	TimeSpan	A TimeSpan structure, which represents the duration of a time slot to find.
forward	Boolean	If true, the search starts at the interval.Start and continues forward in time. If false, it starts at interval.End, and continues backwards.

Returns

Type	Description
TimeInterval	A TimeInterval object, representing the interval which meets the conditions, or the TimeInterval.Empty value, if an interval is not found.

Remarks

The FindFreeTimeInterval method searches for the nearest free interval with a specified minimum duration within the specified period. Note that FindFreeTimeInterval method requires the time interval converted to server time zone, i.e. you should use the TimeZoneHelper.FromClientTime method to adjust the time interval passed as a parameter.

The following code sample illustrates the implementation of the method used to find a free time slot which has a specified duration, or is longer than that, before the end of the current work week.

The following code sample illustrates the implementation of the method used to find a free time slot which has a specified duration, or is longer than that, before the end of the current work week.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/winforms-scheduler-find-free-time-intervals

Form1.cs

using DevExpress.XtraScheduler;
using DevExpress.XtraScheduler.Tools;
using System;
using System.Windows.Forms;

namespace FreeTimeIntervals
{
    public partial class Form1 : Form {
        TimeZoneHelper timeZoneHelper;
        // Specify non-working time interval.
        TimeOfDayInterval nonWorkingTime = new TimeOfDayInterval(TimeSpan.FromHours(18), TimeSpan.FromDays(1) + TimeSpan.FromHours(9));

        internal TimeZoneHelper TimeZoneHelper { get { return timeZoneHelper; } }
        internal TimeOfDayInterval NonWorkingTime { get { return nonWorkingTime; } set { nonWorkingTime = value; } }

        public Form1() {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e) {
            // TODO: This line of code loads data into the 'xtraSchedulingDataSet1.Resources' table. You can move, or remove it, as needed.
            this.resourcesTableAdapter.Fill(this.xtraSchedulingDataSet1.Resources);
            // TODO: This line of code loads data into the 'xtraSchedulingDataSet.Appointments' table. You can move, or remove it, as needed.
            this.appointmentsTableAdapter.Fill(this.xtraSchedulingDataSet.Appointments);

            timeZoneHelper = new TimeZoneHelper(this.schedulerControl1.OptionsBehavior.ClientTimeZoneId);
        }

        private void button1_Click(object sender, EventArgs e) {
            TimeSpan duration = ((DateTime)slotDuration.EditValue).TimeOfDay;
            DateTime start = schedulerControl1.ActiveView.SelectedInterval.End;
            DateTime startOfWeek = DevExpress.XtraScheduler.Native.DateTimeHelper.GetStartOfWeek(start);
            TimeInterval interval = new TimeInterval(start, startOfWeek.AddDays(7));
            TimeInterval freeTime = FindInterval(interval, duration);
            string text;
            if (TimeInterval.Equals(freeTime, TimeInterval.Empty))
                text = "Not found";
            else {
                TimeInterval clientFreeInterval = TimeZoneHelper.ToClientTime(freeTime);
                text = "Free time interval with duration " + clientFreeInterval.Duration.ToString() +
                    " is found! \n\r It starts on " + clientFreeInterval.Start.Date.ToShortDateString() +
                    " at " + clientFreeInterval.Start.TimeOfDay.ToString() + ".";
                schedulerControl1.ActiveView.SetSelection(clientFreeInterval, ResourceEmpty.Resource);
            }
            MessageBox.Show(text, "Search Result", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
        private TimeInterval FindInterval(TimeInterval clientInterval, TimeSpan duration) {
            FreeTimeCalculator calculator = new FreeTimeCalculator(schedulerControl1.Storage);
            // Set a handler for the IntervalFound event.
            calculator.IntervalFound += new IntervalFoundEventHandler(OnIntervalFound);
            TimeInterval interval = TimeZoneHelper.FromClientTime(clientInterval);
            // Call the method which raises the event.
            return calculator.FindFreeTimeInterval(interval, duration, true);
        }
        private void OnIntervalFound(object sender, IntervalFoundEventArgs args) {
            TimeIntervalCollectionEx freeIntervals = args.FreeIntervals;
            DateTime start = freeIntervals.Start.Date.AddDays(-1);
            DateTime end = freeIntervals.End;
            while (start < end) {
                RemoveNonWorkingTime(freeIntervals, start);
                RemoveNonWorkingDay(freeIntervals, start);
                start += TimeSpan.FromDays(1);
            }
        }
        private void RemoveNonWorkingTime(TimeIntervalCollectionEx freeIntervals, DateTime date) {
            DateTime clientDate = TimeZoneHelper.ToClientTime(date).Date;        

            TimeInterval clientNonWorkingTime = new TimeInterval(clientDate + NonWorkingTime.Start, clientDate + NonWorkingTime.End);
            freeIntervals.Remove(TimeZoneHelper.FromClientTime(clientNonWorkingTime));
        }
        private void RemoveNonWorkingDay(TimeIntervalCollectionEx freeIntervals, DateTime date) {
            DateTime clientDate = TimeZoneHelper.ToClientTime(date).Date;
            bool isWorkDay = schedulerControl1.WorkDays.IsWorkDay(clientDate);
            if (!isWorkDay) {
                TimeInterval clientInterval = new TimeInterval(clientDate, TimeSpan.FromDays(1));
                freeIntervals.Remove(TimeZoneHelper.FromClientTime(clientInterval));
            }
        }
        private void OnApptChangedInsertedDeleted(object sender, PersistentObjectsEventArgs e) {
            appointmentsTableAdapter.Update(xtraSchedulingDataSet);
            xtraSchedulingDataSet.AcceptChanges();
        }
    }
}

Program.cs

using System;
using System.Collections.Generic;
using System.Windows.Forms;

namespace FreeTimeIntervals
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            DevExpress.Skins.SkinManager.EnableFormSkins();
            Application.Run(new Form1());
        }
    }
}

Form1.vb

Imports DevExpress.XtraScheduler
Imports DevExpress.XtraScheduler.Tools
Imports System
Imports System.Windows.Forms

Namespace FreeTimeIntervals
    Partial Public Class Form1
        Inherits Form


        Private timeZoneHelper_Renamed As TimeZoneHelper
        ' Specify non-working time interval.

        Private nonWorkingTime_Renamed As New TimeOfDayInterval(TimeSpan.FromHours(18), TimeSpan.FromDays(1).Add(TimeSpan.FromHours(9)))

        Friend ReadOnly Property TimeZoneHelper() As TimeZoneHelper
            Get
                Return timeZoneHelper_Renamed
            End Get
        End Property
        Friend Property NonWorkingTime() As TimeOfDayInterval
            Get
                Return nonWorkingTime_Renamed
            End Get
            Set(ByVal value As TimeOfDayInterval)
                nonWorkingTime_Renamed = value
            End Set
        End Property

        Public Sub New()
            InitializeComponent()
        End Sub
        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
            ' TODO: This line of code loads data into the 'xtraSchedulingDataSet1.Resources' table. You can move, or remove it, as needed.
            Me.resourcesTableAdapter.Fill(Me.xtraSchedulingDataSet1.Resources)
            ' TODO: This line of code loads data into the 'xtraSchedulingDataSet.Appointments' table. You can move, or remove it, as needed.
            Me.appointmentsTableAdapter.Fill(Me.xtraSchedulingDataSet.Appointments)

            timeZoneHelper_Renamed = New TimeZoneHelper(Me.schedulerControl1.OptionsBehavior.ClientTimeZoneId)
        End Sub

        Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
            Dim duration As TimeSpan = CDate(slotDuration.EditValue).TimeOfDay
            Dim start As Date = schedulerControl1.ActiveView.SelectedInterval.End
            Dim startOfWeek As Date = DevExpress.XtraScheduler.Native.DateTimeHelper.GetStartOfWeek(start)
            Dim interval As New TimeInterval(start, startOfWeek.AddDays(7))
            Dim freeTime As TimeInterval = FindInterval(interval, duration)

            Dim text_Renamed As String
            If TimeInterval.Equals(freeTime, TimeInterval.Empty) Then
                text_Renamed = "Not found"
            Else
                Dim clientFreeInterval As TimeInterval = TimeZoneHelper.ToClientTime(freeTime)
                text_Renamed = "Free time interval with duration " & clientFreeInterval.Duration.ToString() & " is found! " & ControlChars.Lf & ControlChars.Cr & " It starts on " & clientFreeInterval.Start.Date.ToShortDateString() & " at " & clientFreeInterval.Start.TimeOfDay.ToString() & "."
                schedulerControl1.ActiveView.SetSelection(clientFreeInterval, ResourceEmpty.Resource)
            End If
            MessageBox.Show(text_Renamed, "Search Result", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End Sub
        Private Function FindInterval(ByVal clientInterval As TimeInterval, ByVal duration As TimeSpan) As TimeInterval
            Dim calculator As New FreeTimeCalculator(schedulerControl1.Storage)
            ' Set a handler for the IntervalFound event.
            AddHandler calculator.IntervalFound, AddressOf OnIntervalFound
            Dim interval As TimeInterval = TimeZoneHelper.FromClientTime(clientInterval)
            ' Call the method which raises the event.
            Return calculator.FindFreeTimeInterval(interval, duration, True)
        End Function
        Private Sub OnIntervalFound(ByVal sender As Object, ByVal args As IntervalFoundEventArgs)
            Dim freeIntervals As TimeIntervalCollectionEx = args.FreeIntervals
            Dim start As Date = freeIntervals.Start.Date.AddDays(-1)
            Dim [end] As Date = freeIntervals.End
            Do While start < [end]
                RemoveNonWorkingTime(freeIntervals, start)
                RemoveNonWorkingDay(freeIntervals, start)
                start = start.Add(TimeSpan.FromDays(1))
            Loop
        End Sub
        Private Sub RemoveNonWorkingTime(ByVal freeIntervals As TimeIntervalCollectionEx, ByVal [date] As Date)
            Dim clientDate As Date = TimeZoneHelper.ToClientTime([date]).Date

            Dim clientNonWorkingTime As New TimeInterval(clientDate + NonWorkingTime.Start, clientDate + NonWorkingTime.End)
            freeIntervals.Remove(TimeZoneHelper.FromClientTime(clientNonWorkingTime))
        End Sub
        Private Sub RemoveNonWorkingDay(ByVal freeIntervals As TimeIntervalCollectionEx, ByVal [date] As Date)
            Dim clientDate As Date = TimeZoneHelper.ToClientTime([date]).Date
            Dim isWorkDay As Boolean = schedulerControl1.WorkDays.IsWorkDay(clientDate)
            If Not isWorkDay Then
                Dim clientInterval As New TimeInterval(clientDate, TimeSpan.FromDays(1))
                freeIntervals.Remove(TimeZoneHelper.FromClientTime(clientInterval))
            End If
        End Sub
        Private Sub OnApptChangedInsertedDeleted(ByVal sender As Object, ByVal e As PersistentObjectsEventArgs) Handles schedulerStorage1.AppointmentsChanged, schedulerStorage1.AppointmentsInserted, schedulerStorage1.AppointmentsDeleted
            appointmentsTableAdapter.Update(xtraSchedulingDataSet)
            xtraSchedulingDataSet.AcceptChanges()
        End Sub
    End Class
End Namespace

Program.vb

Imports System
Imports System.Collections.Generic
Imports System.Windows.Forms

Namespace FreeTimeIntervals
    Friend NotInheritable Class Program

        Private Sub New()
        End Sub

        ''' <summary>
        ''' The main entry point for the application.
        ''' </summary>
        <STAThread> _
        Shared Sub Main()
            Application.EnableVisualStyles()
            Application.SetCompatibleTextRenderingDefault(False)
            DevExpress.Skins.SkinManager.EnableFormSkins()
            Application.Run(New Form1())
        End Sub
    End Class
End Namespace

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the FindFreeTimeInterval(TimeInterval, TimeSpan, Boolean) method.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

winforms-scheduler-find-free-time-intervals/CS/FreeTimeIntervals/Form1.cs#L52

    // Call the method which raises the event.
    return calculator.FindFreeTimeInterval(interval, duration, true);
}

VB.NET

winforms-scheduler-find-free-time-intervals/VB/FreeTimeIntervals/Form1.vb#L68

    ' Call the method which raises the event.
    Return calculator.FindFreeTimeInterval(interval, duration, True)
End Function