McBasic™ 0.7.881 · Build 881 · 13 min read

Hands-on tutorial · Input & events

Build a menu-driven, dynamic Classic workbench

Rebuild a Classic application with Menu Editor actions, runtime control arrays, control dragging, Type value copies, class initialization and Sub Main.

1 Form / control designs4 complete BASIC filesOriginal web lesson

Download complete project Complete event code

Create the layout below first. In Design → Menu Editor, add Actions as a title; indent Show details and Clear status underneath it. Name them mnuActions, mnuDetails and mnuClear; set Show details Checked True and Shortcut Ctrl+D. Parent values in the JSON are item IDs, not BASIC names. Give txtCell Index 0 and Dock None: it is the design-time template. DragMode 1 on lblToken is the automatic control-drag source; pnlDrop uses the Source As Control overload, not DragData. Project Settings selects Classic; Startup Object selects Sub Main. Add modStart, SessionCounter and WorkbenchTests before replacing their full source files below. The Boolean mLoaded prevents duplicate Load and missing Unload. Only the newly loaded member is removed; the original template remains. The record test distinguishes copied values (79) from shared identity, while two class instances keep separate counters.

Step 1Prepare a safe practice project#

Extract the archive into a new writable folder, separate from your own application. Open ModernWorkbench.mcproj in McBasic™. Keep every declared source, layout, resource and migration file together.

To reconstruct it yourself, create a DesktopApp project and add the files declared below. In the complete project, follow these steps as a guided rebuild: replace each named source file once and Check after all its procedures are present.

Exact project configuration

ModernWorkbench.mcproj

{
  "schemaVersion": 1,
  "projectId": "mcbasic-web-modern-workbench",
  "name": "ModernWorkbench",
  "kind": "DesktopApp",
  "language": {
    "dialect": "McBasic1",
    "requireExplicit": true,
    "compare": "Binary",
    "defaultArrayBase": 0
  },
  "application": {
    "bundleIdentifier": "com.mcbasic.web.modernworkbench",
    "version": "1.0.0",
    "buildNumber": "1",
    "startupObject": "SubMain",
    "shutdownMode": "OnLastFormClosed",
    "appearance": "Classic",
    "company": "Learning project",
    "copyright": "Tutorial example"
  },
  "forms": [
    {
      "id": "main",
      "typeName": "frmMain",
      "layout": "frmMain.form.json",
      "code": "frmMain.bas"
    }
  ],
  "modules": [
    {
      "name": "modStart",
      "path": "modStart.bas"
    }
  ],
  "classes": [
    {
      "name": "SessionCounter",
      "path": "SessionCounter.cls"
    }
  ],
  "tests": [
    {
      "name": "WorkbenchTests",
      "path": "WorkbenchTests.bas",
      "kind": "unit"
    }
  ],
  "references": [],
  "resources": [],
  "targets": [
    "osx-arm64"
  ],
  "capabilities": []
}

Step 2Build the Form and set its properties#

frmMain

Select the Form first and set its properties. Add containers before their children. These are initial Designer values, not statements to paste into a procedure.

Form property	Value
`Caption`	`"Modern Workbench"`
`Width`	`640`
`Height`	`420`
`BackColor`	`"ButtonFace"`

Type	Name	Parent
TextBox	`txtCell`	Form
CommandButton	`cmdAdd`	Form
CommandButton	`cmdRemove`	Form
CommandButton	`cmdValue`	Form
CommandButton	`cmdPopup`	Form
Label	`lblToken`	Form
Panel	`pnlDrop`	Form
Label	`lblStatus`	Form
MenuItem	`mnuActions`	Component tray
MenuItem	`mnuDetails`	Component tray
MenuItem	`mnuClear`	Component tray

txtCell · exact Inspector values

Property	Value
`Index`	`0`
`Left`	`24`
`Top`	`24`
`Width`	`160`
`Height`	`28`
`Text`	`"Template"`
`Dock`	`"None"`

cmdAdd · exact Inspector values

Property	Value
`Left`	`24`
`Top`	`110`
`Width`	`130`
`Height`	`32`
`Caption`	`"Load cell 1"`

cmdRemove · exact Inspector values

Property	Value
`Left`	`164`
`Top`	`110`
`Width`	`130`
`Height`	`32`
`Caption`	`"Unload cell 1"`

cmdValue · exact Inspector values

Property	Value
`Left`	`304`
`Top`	`110`
`Width`	`130`
`Height`	`32`
`Caption`	`"Test value copy"`

cmdPopup · exact Inspector values

Property	Value
`Left`	`444`
`Top`	`110`
`Width`	`160`
`Height`	`32`
`Caption`	`"Open action menu"`

lblToken · exact Inspector values

Property	Value
`Left`	`24`
`Top`	`180`
`Width`	`160`
`Height`	`40`
`Caption`	`"Drag this label"`
`DragMode`	`1`

pnlDrop · exact Inspector values

Property	Value
`Left`	`220`
`Top`	`170`
`Width`	`380`
`Height`	`90`
`BackColor`	`"WindowBackground"`

lblStatus · exact Inspector values

Property	Value
`Left`	`24`
`Top`	`290`
`Width`	`580`
`Height`	`70`
`Caption`	`"Ready"`
`WordWrap`	`True`

mnuActions · exact Inspector values

Property	Value
`Caption`	`"&Actions"`
`Order`	`0`

mnuDetails · exact Inspector values

Property	Value
`Caption`	`"&Show details"`
`Parent`	`"actions"`
`Order`	`0`
`Shortcut`	`"Ctrl+D"`
`Checked`	`True`

mnuClear · exact Inspector values

Property	Value
`Caption`	`"&Clear status"`
`Parent`	`"actions"`
`Order`	`1`

Step 3Connect the events explicitly#

frmMain

Object	Event	Procedure	Parameters
`txtCell`	`Change`	`txtCell_Change`	`Change(ByVal Index As Integer)`
`cmdAdd`	`Click`	`cmdAdd_Click`	`Click()`
`cmdRemove`	`Click`	`cmdRemove_Click`	`Click()`
`cmdValue`	`Click`	`cmdValue_Click`	`Click()`
`cmdPopup`	`Click`	`cmdPopup_Click`	`Click()`
`pnlDrop`	`DragOver`	`pnlDrop_DragOver`	`DragOver(ByVal Source As Control, ByVal X As Single, ByVal Y As Single, ByVal State As Integer)`
`pnlDrop`	`DragDrop`	`pnlDrop_DragDrop`	`DragDrop(ByVal Source As Control, ByVal X As Single, ByVal Y As Single)`
`mnuDetails`	`Click`	`mnuDetails_Click`	`Click()`
`mnuClear`	`Click`	`mnuClear_Click`	`Click()`
Form	`Load`	`Form_Load`	`()`

Step 4Enter the complete behavior#

Open the named source file. Enter declarations first, then every procedure. Expand a procedure for its full body, or copy the complete file. Helpers are required: do not stop after entering the first Click handler.

`frmMain.bas`

Enter these declarations at file scope, before the procedures.

frmMain.bas · declarations

Option Explicit
Private mLoaded As Boolean
Private mSession As SessionCounter

Private Sub Form_Load()

Initialize state before enabling dependent actions. Keep the shared declarations and startup dependencies with this procedure.

frmMain.bas · Form_Load

Private Sub Form_Load()
    Set mSession = New SessionCounter
    mLoaded = False
    cmdRemove.Enabled = False
    lblStatus.Caption = "Ready; " & txtCell.Count & " cell. " & App.CompanyName
End Sub

Private Sub cmdAdd_Click()

Enter the complete action, including its input checks and calls to helper procedures.

frmMain.bas · cmdAdd_Click

Private Sub cmdAdd_Click()
    If mLoaded Then Exit Sub
    Load txtCell(1)
    mLoaded = True
    txtCell(1).Top = 64
    txtCell(1).Text = "New member"
    txtCell(1).Visible = True
    cmdAdd.Enabled = False
    cmdRemove.Enabled = True
    lblStatus.Caption = "Loaded; " & txtCell.Count & " cells."
End Sub

Private Sub cmdRemove_Click()

Enter the complete action, including its input checks and calls to helper procedures.

frmMain.bas · cmdRemove_Click

Private Sub cmdRemove_Click()
    If Not mLoaded Then Exit Sub
    Unload txtCell(1)
    mLoaded = False
    cmdAdd.Enabled = True
    cmdRemove.Enabled = False
    lblStatus.Caption = "Removed; " & txtCell.Count & " cell remains."
End Sub

Private Sub txtCell_Change(ByVal Index As Integer)

Read the current value or selection and update its dependent interface. The binding above determines which object calls this handler.

frmMain.bas · txtCell_Change

Private Sub txtCell_Change(ByVal Index As Integer)
    lblStatus.Caption = "Cell " & Index & ": " & txtCell(Index).Text
End Sub

Private Sub cmdValue_Click()

Enter the complete action, including its input checks and calls to helper procedures.

frmMain.bas · cmdValue_Click

Private Sub cmdValue_Click()
    mSession.Increment
    lblStatus.Caption = "Copy proof: " & CopyProof() & "; clicks: " & mSession.Count
End Sub

Private Sub cmdPopup_Click()

Enter the complete action, including its input checks and calls to helper procedures.

frmMain.bas · cmdPopup_Click

Private Sub cmdPopup_Click()
    PopupMenu mnuActions
End Sub

Private Sub mnuDetails_Click()

Enter the complete action, including its input checks and calls to helper procedures.

frmMain.bas · mnuDetails_Click

Private Sub mnuDetails_Click()
    mnuDetails.Checked = Not mnuDetails.Checked
    lblStatus.Visible = mnuDetails.Checked
End Sub

Private Sub mnuClear_Click()

Enter the complete action, including its input checks and calls to helper procedures.

frmMain.bas · mnuClear_Click

Private Sub mnuClear_Click()
    lblStatus.Caption = "Ready"
End Sub

Private Sub pnlDrop_DragOver(ByVal Source As Control, ByVal X As Single, ByVal Y As Single, ByVal State As Integer)

Enter this helper in the named source file, outside every other procedure. Its callers are included in the same project.

frmMain.bas · pnlDrop_DragOver

Private Sub pnlDrop_DragOver(ByVal Source As Control, ByVal X As Single, ByVal Y As Single, ByVal State As Integer)
    If State = vbEnter Then lblStatus.Caption = "Release to identify " & Source.Name
End Sub

Private Sub pnlDrop_DragDrop(ByVal Source As Control, ByVal X As Single, ByVal Y As Single)

Enter this helper in the named source file, outside every other procedure. Its callers are included in the same project.

frmMain.bas · pnlDrop_DragDrop

Private Sub pnlDrop_DragDrop(ByVal Source As Control, ByVal X As Single, ByVal Y As Single)
    lblStatus.Caption = "Dropped " & Source.Name & " at " & X & ", " & Y
End Sub

Copy the complete frmMain.bas file

Replace the file once; do not append duplicate procedures.

frmMain.bas

Option Explicit
Private mLoaded As Boolean
Private mSession As SessionCounter

Private Sub Form_Load()
    Set mSession = New SessionCounter
    mLoaded = False
    cmdRemove.Enabled = False
    lblStatus.Caption = "Ready; " & txtCell.Count & " cell. " & App.CompanyName
End Sub

Private Sub cmdAdd_Click()
    If mLoaded Then Exit Sub
    Load txtCell(1)
    mLoaded = True
    txtCell(1).Top = 64
    txtCell(1).Text = "New member"
    txtCell(1).Visible = True
    cmdAdd.Enabled = False
    cmdRemove.Enabled = True
    lblStatus.Caption = "Loaded; " & txtCell.Count & " cells."
End Sub

Private Sub cmdRemove_Click()
    If Not mLoaded Then Exit Sub
    Unload txtCell(1)
    mLoaded = False
    cmdAdd.Enabled = True
    cmdRemove.Enabled = False
    lblStatus.Caption = "Removed; " & txtCell.Count & " cell remains."
End Sub

Private Sub txtCell_Change(ByVal Index As Integer)
    lblStatus.Caption = "Cell " & Index & ": " & txtCell(Index).Text
End Sub

Private Sub cmdValue_Click()
    mSession.Increment
    lblStatus.Caption = "Copy proof: " & CopyProof() & "; clicks: " & mSession.Count
End Sub

Private Sub cmdPopup_Click()
    PopupMenu mnuActions
End Sub

Private Sub mnuDetails_Click()
    mnuDetails.Checked = Not mnuDetails.Checked
    lblStatus.Visible = mnuDetails.Checked
End Sub

Private Sub mnuClear_Click()
    lblStatus.Caption = "Ready"
End Sub

Private Sub pnlDrop_DragOver(ByVal Source As Control, ByVal X As Single, ByVal Y As Single, ByVal State As Integer)
    If State = vbEnter Then lblStatus.Caption = "Release to identify " & Source.Name
End Sub

Private Sub pnlDrop_DragDrop(ByVal Source As Control, ByVal X As Single, ByVal Y As Single)
    lblStatus.Caption = "Dropped " & Source.Name & " at " & X & ", " & Y
End Sub

`modStart.bas`

Enter these declarations at file scope, before the procedures.

modStart.bas · declarations

Option Explicit

Public Type Reading
    Name As String
    Value As Long
End Type

Public Sub Main()

Enter this helper in the named source file, outside every other procedure. Its callers are included in the same project.

modStart.bas · Main

Public Sub Main()
    frmMain.Show
End Sub

Public Function CopyProof() As Long

Enter this helper in the named source file, outside every other procedure. Its callers are included in the same project.

modStart.bas · CopyProof

Public Function CopyProof() As Long
    Dim original As Reading
    Dim edited As Reading
    original.Name = "Sample"
    original.Value = 7
    edited = original
    With edited
        .Value = 9
    End With
    CopyProof = original.Value * 10 + edited.Value
End Function

Copy the complete modStart.bas file

Replace the file once; do not append duplicate procedures.

modStart.bas

Option Explicit

Public Type Reading
    Name As String
    Value As Long
End Type

Public Sub Main()
    frmMain.Show
End Sub

Public Function CopyProof() As Long
    Dim original As Reading
    Dim edited As Reading
    original.Name = "Sample"
    original.Value = 7
    edited = original
    With edited
        .Value = 9
    End With
    CopyProof = original.Value * 10 + edited.Value
End Function

`SessionCounter.cls`

Enter these declarations at file scope, before the procedures.

SessionCounter.cls · declarations

Option Explicit
Private mCount As Long

Private Sub Class_Initialize()

Enter this helper in the named source file, outside every other procedure. Its callers are included in the same project.

SessionCounter.cls · Class_Initialize

Private Sub Class_Initialize()
    mCount = 0
End Sub

Public Sub Increment()

Enter this helper in the named source file, outside every other procedure. Its callers are included in the same project.

SessionCounter.cls · Increment

Public Sub Increment()
    mCount = mCount + 1
End Sub

Public Property Get Count() As Long

Keep this public property accessor with its complementary accessor and the fields or controls it uses.

SessionCounter.cls · Count

Public Property Get Count() As Long
    Count = mCount
End Property

Copy the complete SessionCounter.cls file

Replace the file once; do not append duplicate procedures.

SessionCounter.cls

Option Explicit
Private mCount As Long

Private Sub Class_Initialize()
    mCount = 0
End Sub

Public Sub Increment()
    mCount = mCount + 1
End Sub

Public Property Get Count() As Long
    Count = mCount
End Property

`WorkbenchTests.bas`

Enter these declarations at file scope, before the procedures.

WorkbenchTests.bas · declarations

Option Explicit

Public Sub Test_ValueCopy()

Enter this helper in the named source file, outside every other procedure. Its callers are included in the same project.

WorkbenchTests.bas · Test_ValueCopy

Public Sub Test_ValueCopy()
    Assert.AreEqual 79, CopyProof()
End Sub

Public Sub Test_IndependentClasses()

Enter this helper in the named source file, outside every other procedure. Its callers are included in the same project.

WorkbenchTests.bas · Test_IndependentClasses

Public Sub Test_IndependentClasses()
    Dim first As SessionCounter
    Dim second As SessionCounter
    Set first = New SessionCounter
    Set second = New SessionCounter
    first.Increment
    Assert.AreEqual 1, first.Count
    Assert.AreEqual 0, second.Count
End Sub

Copy the complete WorkbenchTests.bas file

Replace the file once; do not append duplicate procedures.

WorkbenchTests.bas

Option Explicit

Public Sub Test_ValueCopy()
    Assert.AreEqual 79, CopyProof()
End Sub

Public Sub Test_IndependentClasses()
    Dim first As SessionCounter
    Dim second As SessionCounter
    Set first = New SessionCounter
    Set second = New SessionCounter
    first.Increment
    Assert.AreEqual 1, first.Count
    Assert.AreEqual 0, second.Count
End Sub

Step 5Keep resources and storage reproducible#

No external resource or migration files are declared. Any inline migration, seed data or local JSON is present in the code above. Runtime application data and private preferences are not included in the archive.

Step 6Check, run and test the result#

Save all files and run Check. Resolve diagnostics before Run. Developer CLI users can work from the extracted folder:

Developer CLI

mcbasic check ModernWorkbench.mcproj
mcbasic run ModernWorkbench.mcproj
mcbasic test ModernWorkbench.mcproj

Acceptance checklist

Check the complete project, then run Test: both unit tests pass.
Run: the startup procedure opens one Classic window; the initial label reports one cell.
Load cell 1: a second field becomes visible below the template. Typing in it reports Cell 1. Add is disabled.
Unload cell 1: it disappears, Count returns to one, and Load becomes available again. Repeat twice.
Test value copy twice: the proof stays 79 and the class counter advances from 1 to 2.
Use Actions → Show details and its shortcut: the checkmark and label visibility agree. Restore visibility, then test the popup button and Clear status.
Drag the label onto the white panel: expect Dropped lblToken with coordinates. The label itself intentionally does not move.
Close the window: the Sub Main application ends. Change Appearance to macOS and repeat the interaction checks.

Step 7Make one change and repeat the tests#

Add another menu command that calls the existing copy-proof helper. Do not call an event handler directly; share the calculation and preserve the original two tests.

Save a working Git checkpoint first. Change one behavior, Check again and repeat the acceptance checklist. Compare with the downloaded solution if a regression appears.

Source baseline 20f4bfed6b · Build manifest

Sources & maintenance

Original web explanation, reviewed against these repository sources. API tables and example files follow the implementation.

tests/McBasic.Compiler.Tests/UserTypeChecks.cs
tests/McBasic.Compiler.Tests/Vb6ScreenClassChecks.cs
tests/McBasic.Compiler.Tests/SubMainChecks.cs
tests/McBasic.Compiler.Tests/ApplicationObjectChecks.cs
src/McBasic.Runtime/McApp.cs
src/McBasic.Compiler/Binder.cs
src/McBasic.Workspace/MenuRules.cs
src/McBasic.Workspace/MenuShortcuts.cs
macos/McBasicIDE/Sources/MenuEditorWindow.swift
tests/McBasic.Compiler.Tests/MenuCompilerChecks.cs
tests/McBasic.Compiler.Tests/PopupMenuChecks.cs
macos/McBasicIDE/Sources/ProjectSettingsSheet.swift
src/McBasic.Workspace/ProjectReader.cs
tests/McBasic.Compiler.Tests/ApplicationAppearanceChecks.cs
tests/McBasic.Compiler.Tests/AppIconChecks.cs
tests/McBasic.Compiler.Tests/VbControlDragChecks.cs
src/McBasic.Runtime/McSystemColors.cs
src/McBasic.Runtime.UI/McControlArray.cs
site/examples/ModernWorkbench/ModernWorkbench.mcproj
site/examples/ModernWorkbench/SessionCounter.cls
site/examples/ModernWorkbench/WorkbenchTests.bas
site/examples/ModernWorkbench/frmMain.bas
site/examples/ModernWorkbench/frmMain.form.json
site/examples/ModernWorkbench/modStart.bas

Build a menu-driven, dynamic Classic workbench

Step 1Prepare a safe practice project#

Step 2Build the Form and set its properties#

frmMain

Step 3Connect the events explicitly#

frmMain

Step 4Enter the complete behavior#

frmMain.bas

modStart.bas

SessionCounter.cls

WorkbenchTests.bas

Step 5Keep resources and storage reproducible#

Step 6Check, run and test the result#

Acceptance checklist

Step 7Make one change and repeat the tests#

Continue learning#

`frmMain.bas`

`modStart.bas`

`SessionCounter.cls`

`WorkbenchTests.bas`