PresentationWindowSwitcher.ThisAddin.vb

gistfile1.vb

Imports System.Diagnostics
Imports System.Runtime.InteropServices

Public Class ThisAddIn

    Private Sub ThisAddIn_Startup() Handles Me.Startup
        If System.Windows.Forms.Screen.AllScreens.Length > 1 Then
            If System.Windows.Forms.Screen.AllScreens.Any(Function(x) x.Bounds.X > 0 OrElse x.Bounds.Y > 0) Then
                isExtendedBefore = True
            End If
        End If
        timer.Interval = TimeSpan.FromMilliseconds(300)
        AddHandler Application.SlideShowBegin, Sub(Wn As PowerPoint.SlideShowWindow)
                                                   If Wn.Presentation.SlideShowSettings.ShowPresenterView = Microsoft.Office.Core.MsoTriState.msoTrue Then
                                                       Dim pid = Process.GetCurrentProcess.MainWindowHandle
                                                       hwndList.Clear()
                                                       EnumChildWindows(pid, Function(hw, lp)
                                                                                 hwndList.Add(hw)
                                                                                 Return True
                                                                             End Function, New IntPtr(0))
                                                       If Not hwndList.Contains(pid) Then
                                                           hwndList.Add(pid)
                                                       End If
                                                       isExtendCanceling = True
                                                       timer.Start()

                                                   End If
                                               End Sub
        AddHandler Application.SlideShowEnd, Sub(Pr As PowerPoint.Presentation)
                                                 If isExtendCanceling Then
                                                     timer.Stop()
                                                     isExtendCanceling = False
                                                     'RemoveHandler Application.WindowDeactivate, AddressOf Application_WindowDeactive
                                                 End If
                                             End Sub

        ps.CreateNoWindow = True
        ps.WindowStyle = ProcessWindowStyle.Hidden
        ps.FileName = "DisplaySwitch.exe"
        ps.Arguments = "/clone"
        p.StartInfo = ps

        ps2.CreateNoWindow = True
        ps2.WindowStyle = ProcessWindowStyle.Hidden
        ps2.FileName = "DisplaySwitch.exe"
        ps2.Arguments = "/extend"
        p2.StartInfo = ps2
    End Sub

    Private Sub Application_WindowDeactive(Pres As PowerPoint.Presentation, Wn As PowerPoint.DocumentWindow)
        
    End Sub

    Private p = New Process
    Private ps = New ProcessStartInfo

    Private p2 = New Process
    Private ps2 = New ProcessStartInfo

    Private WithEvents timer As New System.Windows.Threading.DispatcherTimer
    'Private Property activePtr As IntPtr = Nothing
    Private hwndList As New List(Of IntPtr)

    Private Property isExtendedBefore As Boolean = False
    Private Property isExtendCanceling As Boolean = False

    Private Sub ThisAddIn_Shutdown() Handles Me.Shutdown
        If timer.IsEnabled Then
            timer.Stop()
        End If
    End Sub

    <DllImport("user32.dll")> _
    Private Shared Function GetForegroundWindow() As IntPtr
    End Function

    <DllImport("user32.dll")>
    Public Shared Function EnumChildWindows(hWndParent As IntPtr, lpEnumFunc As EnumChildDelegate, lParam As IntPtr) As Boolean
    End Function

    Public Delegate Function EnumChildDelegate(hwnd As IntPtr, lParam As IntPtr) As Boolean

    Private isChanged As Boolean = False

    Private Sub timer_Tick(sender As Object, e As EventArgs) Handles timer.Tick
        Dim ip = GetForegroundWindow()
        If Not hwndList.Contains(ip) Then
            If Not isChanged Then
                isChanged = True
                If Not isExtendedBefore Then
                    p.Start()
                End If
            End If
        Else
            If isChanged Then
                isChanged = False
                If Not isExtendedBefore Then
                    p2.Start()
                End If
            End If
        End If
    End Sub
End Class