McBasic™Get McBasic™ ↗Left
Horizontal position in device-independent points, relative to the parent container.
Range: -100000 to 100000.
ImageCombo
Offer compact image-backed choices using a shared ImageList.
Use it in a Form#
The ImageList is nonvisual: it supplies images to visible controls. Keep image keys and item identities stable. SelectionChanged, ItemClick, ItemDoubleClick and ColumnClick represent different actions, so wire each explicitly instead of routing every interaction through one guessed Click event.
Add ImageCombo to its intended parent and name it icbActions for this example:
| Property | Example value |
|---|---|
Items | "Open=Open|open\nSave=Save|save\nClose=Close|close" |
ImageList | "imgImages" |
DropDownStyle | "DropDownList" |
ImageSize | 18 |
MaxDropDownItems | 6 |
Sorted | False |
SelectedIndex | 0 |
A complete handler from Forms/frmMain.bas. The linked lesson includes its surrounding controls, declarations and helpers.
Forms/frmMain.bas
Private Sub icbActions_Change()
lblStatus.Caption = "Action: " + icbActions.Text
End SubProperties#
Contract defaults are shown below. Where a new control has a different Designer starting value, that value is listed separately.
Top
Vertical position in device-independent points, relative to the parent container.
Range: -100000 to 100000.
Width
Control width in device-independent points.
Range: 0 to 100000.
Height
Control height in device-independent points.
Range: 0 to 100000.
MinWidth
Minimum control width in device-independent points; 0 lets the parent layout choose.
Range: 0 to 100000.
MinHeight
Minimum control height in device-independent points; 0 lets the parent layout choose.
Range: 0 to 100000.
MaxWidth
Maximum control width in device-independent points.
Range: 0 to 100000.
MaxHeight
Maximum control height in device-independent points.
Range: 0 to 100000.
TabIndex
Keyboard navigation order within the parent container; lower values come first.
Range: 0 to 100000.
TabStop
Whether the ComboBox participates in keyboard focus traversal.
ZIndex
Stacking order among sibling controls; larger values appear in front. Equal values preserve document order.
Range: -100000 to 100000.
Anchor
Edges kept at their authored distance when the parent resizes. Use a comma-separated combination of Left, Top, Right and Bottom; Dock overrides the effective anchor without deleting it.
Dock
Automatic placement within the parent: None, Left, Top, Right, Bottom or Fill. Dock overrides effective Anchor layout without deleting the stored anchors.
Margin
External spacing as one non-negative DIP value or Left,Top,Right,Bottom.
Cursor
Pointer shown over the control: Default, Arrow, Hand, IBeam, Cross, Wait, Help, SizeAll, SizeNS, SizeWE, SizeNWSE, SizeNESW or NotAllowed.
Opacity
Visual opacity from 0 (transparent) to 1 (opaque).
Range: 0 to 1.
DesignLocked
Prevents movement and resizing in the Designer without changing runtime interaction.
Visible
Whether the control is shown in the running application.
Enabled
Whether the control accepts user interaction in the running application.
HitTestVisible
Whether the running control participates in pointer hit testing. The control remains selectable in the Designer.
AllowDrop
Whether this running control accepts application drag-and-drop operations; Designer movement is separate.
DragMode
VB control drag: 0 Manual (code starts a drag with the Drag method) or 1 Automatic (a left-button press starts a drag, and the control raises no Click, MouseDown or MouseUp for that press).
Range: 0 to 1.
DragIcon
Case-insensitive name of a declared project image resource shown under the pointer while this control is dragged; empty shows a grey outline of the control.
Font
Font as Family|Size or Family|Size|Regular/Bold|Normal/Italic, size 6–96 DIP. Empty uses the theme font; System uses the theme family.
ForeColor
Text color as #RRGGBB. Empty uses the current macOS theme color.
BackColor
Background color as #RRGGBB. Empty uses the current macOS theme color.
Padding
Internal spacing around the ComboBox content as one non-negative DIP value or Left,Top,Right,Bottom.
AccessibleName
Name announced by assistive technology. Empty uses the stable control Name.
AccessibleDescription
Additional help text announced by assistive technology.
AutomationId
Stable automation identifier; empty uses the component Name.
AccessibleRole
Accessibility role override. Auto preserves the native semantic role; explicit values use the corresponding platform automation role.
ToolTipText
Help text shown when the pointer rests over the running control; empty disables the tooltip.
Tag
Application-defined text associated with this control; McBasic™ does not interpret it.
Text
Editable text or the selected display text.
Items
One item per line as Text|ImageKey. An optional case-insensitive collection key may prefix the line as Key=Text|ImageKey.
ImageList
Name of a nonvisual ImageList component on this Form. Empty disables item images.
Sorted
Sorts items by their display text using deterministic case-insensitive ordinal order.
DropDownStyle
DropDown permits free text; DropDownList requires an existing item.
MaxDropDownItems
Preferred maximum visible rows before the popup scrolls.
Range: 1 to 1000.
ImageSize
Rendered square image size in device-independent points (8–128).
Range: 8 to 128.
SelectedIndex
Zero-based selected item index, or -1 when no item is selected.
Range: -1 to 100000.
Index
Position of this control in its control array, 0 to 32767. Several controls share one name only when every one of them has an Index. Absent from the layout, and -1 in code, when the control is not in an array.
Designer values: 0 to 32767. Clear the dedicated Index row for a non-array control; BASIC then reads -1.
Events and parameters#
Replace control with the object’s Name when creating a handler. ByRef arguments may be changed by your handler; ByVal arguments report an input value.
Change
Occurs after the component value changes according to its McBasic™ change policy.
Signature — see the complete lesson for an implementation
Private Sub control_Change()No parameters.
DropDown
Occurs after the native choice list opens; opening alone does not raise Change.
Signature — see the complete lesson for an implementation
Private Sub control_DropDown()No parameters.
DropDownClosed
Occurs after the native choice list closes; closing alone does not raise Change.
Signature — see the complete lesson for an implementation
Private Sub control_DropDownClosed()No parameters.
DragEnter
Occurs when runtime drag data enters this control; set Effect to Copy, Move, Link or None.
Signature — see the complete lesson for an implementation
Private Sub control_DragEnter(ByVal Data As DragData, ByRef Effect As DragEffect, ByVal X As Double, ByVal Y As Double)| Parameter | Type | Direction |
|---|---|---|
Data | DragData | ByVal |
Effect | DragEffect | ByRef |
X | Double | ByVal |
Y | Double | ByVal |
DragOver
Occurs while runtime drag data moves over this control; Effect may be updated for the current position.
Signature — see the complete lesson for an implementation
Private Sub control_DragOver(ByVal Data As DragData, ByRef Effect As DragEffect, ByVal X As Double, ByVal Y As Double)| Parameter | Type | Direction |
|---|---|---|
Data | DragData | ByVal |
Effect | DragEffect | ByRef |
X | Double | ByVal |
Y | Double | ByVal |
DragOver
Occurs while a control dragged inside the app (DragMode or the Drag method) moves over this control: State is 0 when it enters, 2 while it moves over and 1 when it leaves; Source is the dragged control and X, Y are local DIP coordinates.
Signature — see the complete lesson for an implementation
Private Sub control_DragOver(ByVal Source As Control, ByVal X As Single, ByVal Y As Single, ByVal State As Integer)| Parameter | Type | Direction |
|---|---|---|
Source | Control | ByVal |
X | Single | ByVal |
Y | Single | ByVal |
State | Integer | ByVal |
DragLeave
Occurs when runtime drag data leaves this control without a drop.
Signature — see the complete lesson for an implementation
Private Sub control_DragLeave()No parameters.
Drop
Occurs when runtime drag data is dropped on this control with a stable McBasic™ effect and local DIP coordinates.
Signature — see the complete lesson for an implementation
Private Sub control_Drop(ByVal Data As DragData, ByVal Effect As DragEffect, ByVal X As Double, ByVal Y As Double)| Parameter | Type | Direction |
|---|---|---|
Data | DragData | ByVal |
Effect | DragEffect | ByVal |
X | Double | ByVal |
Y | Double | ByVal |
DragDrop
Occurs when a control dragged inside the app (DragMode or the Drag method) is released over this control; Source is the dragged control and X, Y are local DIP coordinates.
Signature — see the complete lesson for an implementation
Private Sub control_DragDrop(ByVal Source As Control, ByVal X As Single, ByVal Y As Single)| Parameter | Type | Direction |
|---|---|---|
Source | Control | ByVal |
X | Single | ByVal |
Y | Single | ByVal |
MouseDown
Occurs when a pointing-device button is pressed over this control; Button is stable McBasic™ identity and X/Y are control-local DIP coordinates.
Signature — see the complete lesson for an implementation
Private Sub control_MouseDown(ByVal Button As MouseButton, ByVal Shift As KeyModifiers, ByVal X As Double, ByVal Y As Double)| Parameter | Type | Direction |
|---|---|---|
Button | MouseButton | ByVal |
Shift | KeyModifiers | ByVal |
X | Double | ByVal |
Y | Double | ByVal |
MouseUp
Occurs when a pointing-device button is released for this control; Button is stable McBasic™ identity and X/Y are control-local DIP coordinates.
Signature — see the complete lesson for an implementation
Private Sub control_MouseUp(ByVal Button As MouseButton, ByVal Shift As KeyModifiers, ByVal X As Double, ByVal Y As Double)| Parameter | Type | Direction |
|---|---|---|
Button | MouseButton | ByVal |
Shift | KeyModifiers | ByVal |
X | Double | ByVal |
Y | Double | ByVal |
MouseMove
Occurs when the pointer moves over the logical McBasic™ control; Button contains the currently held buttons and X/Y are local DIP coordinates.
Signature — see the complete lesson for an implementation
Private Sub control_MouseMove(ByVal Button As MouseButtons, ByVal Shift As KeyModifiers, ByVal X As Double, ByVal Y As Double)| Parameter | Type | Direction |
|---|---|---|
Button | MouseButtons | ByVal |
Shift | KeyModifiers | ByVal |
X | Double | ByVal |
Y | Double | ByVal |
MouseEnter
Occurs once when the pointer enters the effective bounds of the logical McBasic™ control.
Signature — see the complete lesson for an implementation
Private Sub control_MouseEnter()No parameters.
MouseLeave
Occurs once when the pointer leaves the effective bounds of the logical McBasic™ control.
Signature — see the complete lesson for an implementation
Private Sub control_MouseLeave()No parameters.
MouseWheel
Occurs for normalized pointer-wheel input; Delta is portable, and X/Y are local DIP coordinates.
Signature — see the complete lesson for an implementation
Private Sub control_MouseWheel(ByVal Delta As Double, ByVal Shift As KeyModifiers, ByVal X As Double, ByVal Y As Double)| Parameter | Type | Direction |
|---|---|---|
Delta | Double | ByVal |
Shift | KeyModifiers | ByVal |
X | Double | ByVal |
Y | Double | ByVal |
DoubleClick
Occurs when native system timing recognizes a primary-button double activation on the same logical McBasic™ control.
Signature — see the complete lesson for an implementation
Private Sub control_DoubleClick()No parameters.
GotFocus
Occurs once when the ComboBox receives effective keyboard focus.
Signature — see the complete lesson for an implementation
Private Sub control_GotFocus()No parameters.
LostFocus
Occurs once when the ComboBox loses effective keyboard focus.
Signature — see the complete lesson for an implementation
Private Sub control_LostFocus()No parameters.
KeyDown
Occurs when a physical key is pressed while this control owns effective keyboard focus; setting Handled suppresses normal processing.
Signature — see the complete lesson for an implementation
Private Sub control_KeyDown(ByVal KeyCode As KeyCode, ByVal Shift As KeyModifiers, ByRef Handled As Boolean)| Parameter | Type | Direction |
|---|---|---|
KeyCode | KeyCode | ByVal |
Shift | KeyModifiers | ByVal |
Handled | Boolean | ByRef |
KeyPress
Occurs for committed Unicode text input; set Handled to suppress the control default.
Signature — see the complete lesson for an implementation
Private Sub control_KeyPress(ByVal Character As String, ByRef Handled As Boolean)| Parameter | Type | Direction |
|---|---|---|
Character | String | ByVal |
Handled | Boolean | ByRef |
KeyUp
Occurs when a physical key is released while this control owns effective keyboard focus; setting Handled suppresses normal processing.
Signature — see the complete lesson for an implementation
Private Sub control_KeyUp(ByVal KeyCode As KeyCode, ByVal Shift As KeyModifiers, ByRef Handled As Boolean)| Parameter | Type | Direction |
|---|---|---|
KeyCode | KeyCode | ByVal |
Shift | KeyModifiers | ByVal |
Handled | Boolean | ByRef |
Methods#
SetFocus
Method contract
Sub SetFocus()Call on your instance: icbActions.SetFocus.
Source baseline
20f4bfed6b · Build manifest