Wait for a modal result

{
  "schemaVersion": 1,
  "projectId": "4a5bc501-3496-4e8d-bbd6-5446cde70811",
  "name": "ModalDialog",
  "kind": "DesktopApp",
  "language": {
    "dialect": "McBasic1",
    "requireExplicit": true,
    "compare": "Binary",
    "defaultArrayBase": 0
  },
  "application": {
    "bundleIdentifier": "com.mcbasic.samples.modaldialog",
    "version": "0.1.0",
    "buildNumber": "1",
    "startupFormId": "modal-main",
    "shutdownMode": "OnStartupFormClosed"
  },
  "forms": [
    {
      "id": "modal-main",
      "typeName": "frmMain",
      "layout": "Forms/frmMain.form.json",
      "code": "Forms/frmMain.bas"
    },
    {
      "id": "modal-details",
      "typeName": "frmDetails",
      "layout": "Forms/frmDetails.form.json",
      "code": "Forms/frmDetails.bas"
    }
  ],
  "modules": [],
  "classes": [],
  "tests": [],
  "references": [],
  "resources": [],
  "targets": [
    "osx-arm64"
  ],
  "capabilities": []
}

Private Async Sub cmdOpen_Click()
    Set details = New frmDetails
    lblStatus.Caption = "Opening modal"
    Await details.ShowDialogAsync(Me)
    If details.Accepted Then
        lblStatus.Caption = "Modal closed: " & details.ResultText
    Else
        lblStatus.Caption = "Modal closed"
    End If
End Sub

Option Explicit

' The last dialog stays referenced after it unloads.
Private details As frmDetails

Private Async Sub cmdOpen_Click()
    Set details = New frmDetails
    lblStatus.Caption = "Opening modal"
    Await details.ShowDialogAsync(Me)
    If details.Accepted Then
        lblStatus.Caption = "Modal closed: " & details.ResultText
    Else
        lblStatus.Caption = "Modal closed"
    End If
End Sub

Private Sub Form_Initialize()
    CancelNextClose = True
End Sub

Public Function Describe() As String
    Describe = lblState.Caption
End Function

Private Sub Form_QueryUnload(ByRef Cancel As Integer, ByVal UnloadMode As Integer)
    If CancelNextClose Then
        Cancel = 1
        CancelNextClose = False
        lblState.Caption = "Close cancelled"
    End If
End Sub

Private Sub cmdClose_Click()
    Accepted = True
    ResultText = "details saved"
    Unload Me
End Sub

Option Explicit

' Public variables keep their values after the dialog unloads, so the
' owner can read them once Await ShowDialogAsync returns.
Public Accepted As Boolean
Public ResultText As String

Private CancelNextClose As Boolean

Private Sub Form_Initialize()
    CancelNextClose = True
End Sub

' A Public procedure may use controls, so it needs a loaded dialog.
Public Function Describe() As String
    Describe = lblState.Caption
End Function

Private Sub Form_QueryUnload(ByRef Cancel As Integer, ByVal UnloadMode As Integer)
    If CancelNextClose Then
        Cancel = 1
        CancelNextClose = False
        lblState.Caption = "Close cancelled"
    End If
End Sub

Private Sub cmdClose_Click()
    Accepted = True
    ResultText = "details saved"
    Unload Me
End Sub