The Pen property of a canvas controls the way lines appear, including lines drawn as the outlines of shapes. Drawing a straight line is really just changing a group of pixels that lie between two points.
The pen itself has four properties you can change:
- The Color property changes the pen color.
- The Width property changes the pen width.
- The Style property changes the pen style.
- The Mode property changes the pen mode.
The values of these properties determine how the pen changes the pixels in the line. By default, every pen starts out black, with a width of 1 pixel, a solid style, and a mode called copy that overwrites anything already on the canvas.
You can use Vcl.Graphics.TPenRecall for quick saving off and restoring the properties of pens.