InkOverlay class

Článek
01/07/2021

Represents an object that is useful for annotation scenarios where users are not concerned with performing recognition on ink but instead are interested in the size, shape, color, and position of the ink.

Creating the InkOverlay control behind a transparent control (such as a GroupBox with the WS_EX_TRANSPARENT property set) will prevent InkOverlay from collecting ink.

InkOverlay has these types of members:

Events
Interfaces
Methods
Properties

Events

The InkOverlay class has these events.

Event	Description
CursorButtonDown	Occurs when the InkOverlay detects a cursor button that is down.
CursorButtonUp	Occurs when the InkOverlay detects a cursor button that is up.
CursorDown	Occurs when the cursor tip contacts the digitizing tablet surface.
CursorInRange	Occurs when a cursor enters the physical detection range (proximity) of the tablet context.
CursorOutOfRange	Occurs when the cursor leaves the physical detection range (proximity) of the tablet context.
DoubleClick	Occurs when the InkOverlay object is double-clicked.
Gesture	Occurs when an application-specific gesture is recognized.
MouseDown	Occurs when the mouse pointer is over the InkOverlay object and a mouse button is pressed.
MouseMove	Occurs when the mouse pointer is moved over the InkOverlay object.
MouseUp	Occurs when the mouse pointer is over the InkOverlay object and a mouse button is released.
MouseWheel	Occurs when the mouse wheel moves while the InkOverlay object has focus.
NewInAirPackets	Occurs when an in-air packet is seen, which happens when a user moves a pen near the tablet and the cursor is within the InkOverlay object's window or the user moves a mouse within the InkOverlay object object's associated window.
NewPackets	Occurs when the InkOverlay object receives packets.
Painted	Occurs when the InkOverlay object has completed redrawing itself.
Painting	Occurs before the InkOverlay object redraws itself.
SelectionChanged	Occurs when the selection of ink within the control has changed, such as through alterations to the user interface, cut-and-paste procedures, or the Selection property.
SelectionChanging	Occurs when the selection of ink within the control is about to change, such as through alterations to the user interface, cut-and-paste procedures, or the Selection property.
SelectionMoved	Occurs when the position of the current selection has changed, such as through alterations to the user interface, cut-and-paste procedures, or the Selection property.
SelectionMoving	Occurs when the position of the current selection is about to change, such as through alterations to the user interface, cut-and-paste procedures, or the Selection property.
SelectionResized	Occurs when the size of the current selection has changed, such as through alterations to the user interface, cut-and-paste procedures, or the Selection property.
SelectionResizing	Occurs when the size of the current selection is about to change, such as through alterations to the user interface, cut-and-paste procedures, or the Selection property.
Stroke	Occurs when the user finishes drawing a new stroke on any tablet.
StrokesDeleted	Occurs after strokes have been deleted from the Ink property.
StrokesDeleting	Occurs before strokes are deleted from the Ink property.
SystemGesture	Occurs when a system gesture is recognized.
TabletAdded	Occurs when an IInkTablet is added to the system.
TabletRemoved	Occurs when a Tablet is removed from the system.

Interfaces

The InkOverlay class defines these interfaces.

Interface	Description
IInkOverlay	This object implements the IInkOverlay COM interface.

Methods

The InkOverlay class has these methods.

Method	Description
Draw	Sets a rectangle in which to redraw the ink within the InkOverlay object.
GetEventInterest	Returns the current state of a particular InkOverlay object event, that is, whether the event is being listened for or used.
GetGestureStatus	Returns whether the InkOverlay object is interested in a particular gesture.
GetWindowInputRectangle	Retrieves the window rectangle, in pixels, within which ink is drawn.
HitTestSelection	Determines what portion of the selection was hit during a hit test.
SetAllTabletsMode	This mode allows the InkOverlay object to collect ink from any tablet attached to the Tablet PC.
SetEventInterest	Sets whether a specific event should be listened for or used.
SetGestureStatus	Sets the interest of the InkOverlay object in a known gesture.
SetSingleTabletIntegratedMode	This mode allows the InkOverlay object to collect ink from only one tablet. Ink from other tablets is ignored by the InkOverlay object.
SetWindowInputRectangle	Sets the window rectangle, in pixels, to use to map drawn ink to the window.

Properties

The InkOverlay class has these properties.

Property	Access type	Description
AttachMode	Read/write	Gets or sets the value that specifies whether the InkOverlay object is attached behind or in front of the known window.
AutoRedraw	Read/write	Gets or sets a value that specifies whether the InkOverlay repaints the ink when the window is invalidated.
CollectingInk	Read-only	Gets a value that specifies whether ink is currently being drawn on an InkOverlay object.
CollectionMode	Read/write	Gets or sets the collection mode that determines whether ink, gestures, or both are recognized as the user writes.
Cursors	Read-only	Gets the Cursors collection that is available for use in the inking region.
DefaultDrawingAttributes	Read/write	Gets or sets the default InkDrawingAttributes object, which specifies the drawing attributes that are used when drawing and displaying ink.
DesiredPacketDescription	Read/write	Gets or sets interest in aspects of the packet associated with ink drawn on the InkOverlay object.
DynamicRendering	Read/write	Gets or sets a value that indicates whether ink is rendered as it is drawn.
EditingMode	Read/write	Gets or sets a value that indicates whether the InkOverlay is in ink mode, deletion mode, or selecting/editing mode.
Enabled	Read/write	Gets or sets a value that specifies whether the InkOverlay object collects pen input.
EraserMode	Read/write	Gets or sets a value that indicates whether ink is erased by stroke or by point.
EraserWidth	Read/write	Gets or sets a value that specifies the width of the eraser pen tip.
Handle	Read/write	Gets or sets the handle of the window to which the InkOverlay object is attached.
Ink	Read/write	Gets or sets the InkDisp object that is associated with the InkOverlay object.
MarginX	Read/write	Gets or sets the margins along the x-axis, in pixels.
MarginY	Read/write	Gets or sets the margins along the y-axis, in pixels.
MouseIcon	Read/write	Gets or sets the current custom mouse icon.
MousePointer	Read/write	Gets or sets a value that indicates the type of mouse pointer that appears when the mouse is over a particular part of the object.
Renderer	Read/write	Gets or sets the InkRenderer object that is used to draw ink.
Selection	Read/write	Gets or sets the InkStrokes collection that is currently selected inside the InkOverlay control.
SupportHighContrastInk	Read/write	Gets or sets a value that specifies whether ink is rendered as just one color when the system is in High Contrast mode.
SupportHighContrastSelectionUI	Read/write	Gets or sets a value that specifies whether all selection UI is drawn in high contrast when the system is in High Contrast mode.
Tablet	Read-only	Gets the tablet device that the InkOverlay object is currently using to collect input.

MFC Implementation Notes

If you attached the InkOverlay object to a CView object, release the InkOverlay object in response to the WM_DESTROY message as shown in the following example:

BOOL CRecognitionAlternatesSampleCppView::OnWndMsg(UINT msg, WPARAM wp, PARAM lp, LRESULT *pLR)
{
    if(WM_DESTROY == msg)
        m_spInkOverlay.Release();
    return CView::OnWndMsg(msg, wp, lp, pLR);
}

Remarks

This object can be instantiated by calling the CoCreateInstance method in C++.

The InkOverlay object is well suited for note taking and basic scribbling. The primary intended use of this object is to display ink as ink.

In general, the run-time user interface for this object is a transparent window with opaque ink.

The MouseDown, MouseMove, MouseUp, and MouseWheel events return x-coordinates and y-coordinates in pixels, and not the HIMETRIC units that are associated with the ink space. This is because these events replace the mouse events of pen-unaware applications and these applications understand only pixels.

Caution

If you are setting the InkOverlay object's AttachMode property to InFront then create the InkOverlay object in the thread in which the form is running. Your application may stop responding if the InkOverlay object is created in a different thread and its AttachMode property is set to InFront.

Note

The InkOverlay object cannot be safely released on a non-UI thread.

To improve your application's performance, dispose your InkOverlay object when it is no longer needed.

If you attached the InkOverlay object to a CView object, release the InkOverlay object in response to the WM_DESTROY message as shown in the following example:

BOOL CRecognitionAlternatesSampleCppView::OnWndMsg(UINT msg, WPARAM wp, PARAM lp, LRESULT *pLR)
{
    if(WM_DESTROY == msg)
        m_spInkOverlay.Release();
    return CView::OnWndMsg(msg, wp, lp, pLR);
}

Requirements

Requirement	Value
Minimum supported client	Windows XP Tablet PC Edition [desktop apps only]
Minimum supported server	None supported
Header	Msinkaut.h (also requires Msinkaut_i.c)
Library	InkObj.dll

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