AnnAutoHilightPen property (ILEADRasterAnnotation)

Syntax	OLE_COLOR AnnAutoHilightPen
Overview	Refer to Implementing Annotations.

Remarks

(Document/Medical only) Gets or sets the color of the pen that is used for highlighting. The default value is 0xFFFFFF (white).

Use the AnnAutoHilightPen property to change the color of the pen that is used for highlighting and selecting. More specifically, this pen is used in the following situations:

$image\sqrblit.gif$ In automated annotation design mode, after selecting ANY tool and clicking and dragging the mouse to draw an outline. The outline is displayed using the highlight pen.

$image\sqrblit.gif$ In automated annotation design mode, after choosing the Select tool and clicking on an existing annotation object. When the mouse is down, the selected object is displayed using the highlight pen.

The highlighting is implemented by taking the "exclusive-or" (XOR) of the highlight pen color and the underlying image.

The default highlight pen has an RGB value of 0xFFFFFF(white). This color works well for most images. However, images that have many mid-range gray colors will not effectively show a highlight. To understand why this is so, consider an image that contains only the color gray 0x808080. The highlight color will be determined by

Highlight Color = (0xFFFFFF) XOR (0x808080)

= 0x7F7F7F

The highlight color (0x7F7F7F) (gray) and the underlying image color (0x808080) (gray) are almost the same color, and nearly indistinguishable to the naked eye. In cases like this, the highlight will not be visible.

To avoid this, choose a different highlight pen color so that the XOR with the underlying color will give a result that is visibly different from the underlying color. A good choice is (silver). Using this color the highlight color will be determined as follows:

Highlight Color = (0xC0C0C0) XOR (0x808080)

= 0x404040

The resulting highlight color (0x404040) is another gray, but is more visible and stands out much more clearly against the underlying image color (0x808080), allowing for easy differentiation between the two.

Note that several of the automated mode annotation cursors are displayed using an XOR operation. For images with many mid-range grays, these cursors will not be visible. To avoid this, define new cursors and use the AnnAutoCursor property.

See Also

Elements:	AnnAlpha property, AnnAutoSnapCursor property, AnnCalibrateRuler method, AnnFillMode property, AnnGetFillModeExt method, AnnGetOptions method, AnnGetRotateOptions method, AnnGetTextOptions method, AnnSetFillModeExt method, AnnSetOptions method, AnnSetRotateOptions method, AnnSetTextOptions method, AnnShowBorder property, AnnShowRotateHandles property, AnnShowText property, AnnTextColor property, AnnTextEdit method, AnnSetAutoBackColor method, AnnGetBackColor method, AnnSetBackColor method, AnnAutoCursor property, AnnGetContainer method, AnnAutoDialogFontSize property, AnnAutoDrawEnable property, AnnAutoMenuEnable property, AnnGetAutoMenuItemEnable method, AnnAutoMenuItemEnable property, AnnGetAutoText method, AnnSetAutoDefaults method, AnnSetAutoText method, AnnUndoEnable property
Topics:	Annotations (Document/Medical only): Object Manipulation
	Annotations (Document/Medical only): Automation
	Obtaining Annotation Object Information
	Annotations (Document/Medical only): Getting and Setting Color Properties