from: fromMode to: toMode width: aPoint color: aMask
"Shan July 23, 1989"
^self new
from: fromMode
to: toMode
width: aPoint
color: aMask! !
Object subclass: #ToolGhost
instanceVariableNames: ''
classVariableNames: 'GhostBitBlt '
poolDictionaries: ''
category: 'NetworkMode-Shan'!
ToolGhost comment:
'ToolGhost draws a ghost line between two given points.
A ghost line is a line which is drawn by taking the reverse of each current pixel value on the straight line between the two given points.
This capability is implemented by drawing a line with a pixel size black form using a combination rule which specifies reversal of destination (the display screen) pixels affected. Thus, black lines on the screen will become white if drawn over with a ghost line, wheras ''white lines'' will become black when drawn over by a ghost line. This is especially useful in drawing links in the network mode: as the user is moving the mouse to select the endpoint node for the link, the link is successively drawn and erased --both with ToolGhost. Final lines use drawing package methods in lieu of ToolGhost.
The implementation is dependent upon the system class BitBlt.
Done:
-) checked over -- documentation added. "peb - 1 June 1987"