HitTest(Rectangle, Single) Method [InkDisp Class]
HitTest(Rectangle, Single) Method [InkDisp Class] |
Retrieves the strokes that are contained within a specified rectangle.
Declaration
[C++]
HRESULT HitTestWithRectangle (
[in] IInkRectangle* selectionRectangle,
[in] float percentIntersect,
[out, retval] IInkStrokes **Strokes
);
[Microsoft® Visual Basic® 6.0]
Public Function HitTestWithRectangle( _
selectionRectangle As InkRectangle, _
percentIntersect As Single _
) As InkStrokes
Parameters
selectionRectangle
[in] The selection rectangle, of type InkRectangle, in ink space coordinates.
percentIntersect
[in] The float or single percentage value that determines which strokes are included in the collection. Strokes that intersect the rectangle are included in the collection if the percentage of points in those strokes contained within the rectangle is greater than or equal to the percentIntersect percentage.
Strokes
[out] Returns the collection of strokes that makes up the ink.
Return Value
| HRESULT value | Description |
|---|---|
| S_OK | Success. |
| E_POINTER | A parameter contained an invalid pointer. |
| E_INK_EXCEPTION | An exception occurred inside the method. |
| E_INVALIDARG | Invalid display handle. |
Remarks
To determine which points of a known stroke intersect the test area, call the GetRectangleIntersections method of the IInkStrokeDisp object, which retrieves the points where a stroke intersects a known rectangle.
Example
[Visual Basic 6.0]
This Visual Basic 6.0 example shows how to call HitTest(Rectangle, Single) using an InkRectangle, theHitRect, to select an InkStrokes collection from InkDisp, theInkCollector.Ink. The percentIntersect parameter is set to 50.0, so a stroke must have at least 50 percent of its points contained within the rectangle to be included in the collection. The example begins with a Standard EXE application, to which a reference to the Microsoft Tablet PC Type Library has been added. A check box, CheckHitTestMode, is added to the form, with a caption of Hit Test Mode. When the check box is cleared, strokes may be inked in the form. When the check box is set, the cursor will have a rectangle surrounding it, which will turn red if it contains more than 50% of a stroke, and the affected stroke will be drawn in blue.
Option Explicit
Dim mouseX As Long
Dim mouseY As Long
Dim inkX As Long
Dim inkY As Long
Dim inkRadius As Long
Dim theInkCollector As InkCollector
Private Sub CheckHitTestMode_Click()
'Toggle the ink collection mode
theInkCollector.Enabled = Not theInkCollector.Enabled
theInkCollector.AutoRedraw = Not theInkCollector.AutoRedraw
Refresh
End Sub
Private Sub Form_Load()
'Set ScaleMode to pixels to make calculating easier
Me.ScaleMode = vbPixels
'Set up the InkCollector
Set theInkCollector = New InkCollector
theInkCollector.hWnd = Me.hWnd
theInkCollector.Enabled = True
'Preload the inkRadius to the inkspace equivalent of
'20 pixels
inkRadius = 20
theInkCollector.Renderer.PixelToInkSpace Me.hDC, inkRadius, 0
'Start with the hit test mode turned off
CheckHitTestMode.Value = 0
End Sub
Private Sub Form_MouseMove( _
Button As Integer, Shift As Integer, X As Single, Y As Single)
If CheckHitTestMode.Value = 1 Then
mouseX = X
mouseY = Y
inkX = X
inkY = Y
theInkCollector.Renderer.PixelToInkSpace Me.hDC, inkX, inkY
Refresh
End If
End Sub
Private Sub Form_Paint()
If CheckHitTestMode.Value = 1 Then
'Create the hit test rectangle
Dim theHitRect As New InkRectangle
theHitRect.SetRectangle inkY - inkRadius, inkX - inkRadius, _
inkY + inkRadius, inkX + inkRadius
'Set the standard ink drawing attributes to black
Dim theDrawingAttributes As New InkDrawingAttributes
theDrawingAttributes.Color = vbBlack
theInkCollector.Ink.Strokes.ModifyDrawingAttributes theDrawingAttributes
'Get the collection of strokes which have at
'least 50% of their points within the hit test rectangle
Dim hitStrokes As InkStrokes
Set hitStrokes = _ theInkCollector.Ink.HitTestWithRectangle(theHitRect, 50!)
If hitStrokes.Count > 0 Then
'Draw the hit test circle in red
Me.ForeColor = vbRed
'Draw the hit strokes in blue
theDrawingAttributes.Color = vbBlue
hitStrokes.ModifyDrawingAttributes theDrawingAttributes
Else
'Draw the hit test circle in black
Me.ForeColor = vbBlack
End If
'Draw the strokes, and the hit test rectangle
theInkCollector.Renderer.Draw Me.hDC, theInkCollector.Ink.Strokes
Line (mouseX - 20, mouseY - 20)-Step(40, 40), , B
End If
End Sub