CustomControlContext class

The callback object handed to a custom control’s Initialize. Holds the connection back into the framework — used to deserialize designer-set property values, request repaints, create timers, and move the keyboard focus between elements the control has drawn.

Custom controls store the CustomControlContext in a private field (typically called ControlContext) so that they can call back into the framework at any point after Initialize has returned. The form-class counterpart CustomFormContext extends this surface with Show and Close.

Private Sub OnInitialize(ByVal Ctx As CustomControls.CustomControlContext) _
        Implements CustomControls.ICustomControl.Initialize

    ' Load any serialized property values
    If Not Ctx.GetSerializer.RuntimeUISrzDeserialize(Me, False) Then
        InitializeDefaultValues
    End If

    ' Remember the context for later
    Set Me.ControlContext = Ctx
End Sub

Methods

ChangeFocusedElement

Asks the framework to move the keyboard focus to a particular ElementTabIndex value, as if the user had pressed TAB until it landed there. Used by WaynesGrid when a cell is selected programmatically — the grid changes its SelectedCellX / SelectedCellY and then calls this method so that the form-level focus tracking matches.

Syntax: object.ChangeFocusedElement ElementTabIndex

ElementTabIndex

required A Long matching the ElementTabIndex of an element that was added to the canvas in the most recent paint pass.

CreateTimer

Returns a new CustomControlTimer bound to this control’s lifetime. The timer is Disabled on creation; the caller sets Interval, subscribes to the timer’s OnTimer event, and sets Enabled to True to start it.

Syntax: object.CreateTimer ( ) As stdole.IUnknown

The framework returns the timer typed as stdole.IUnknown; cast with CType(Of CustomControlTimer)(…) to get a strongly-typed reference. WaynesTimer and WaynesSlider both use this pattern.

GetSerializer

Returns the SerializeInfo handle for this control instance. The serializer surfaces the deserialization entry point and the run-time / design-time mode flags.

Syntax: object.GetSerializer ( ) As SerializeInfo

Repaint

Tells the framework that the control’s appearance has changed and that the canvas should be repainted at the next opportunity. The framework eventually calls back into ICustomControl.Paint; calling Repaint multiple times in quick succession produces at most one paint.

Syntax: object.Repaint ( )

Every concrete Waynes… control hooks the OnChanged events on its state and style sub-objects, and calls Repaint from the handler — so a runtime assignment like btn.NormalState.BackgroundFill.ColorPoints.SetSolidColor vbBlue triggers an automatic redraw.