Chapter 1

Pen
The pen defines draw modes (color and style). These are used for drawing lines, the
outlines of filled shapes, and text.
Draw mode options include Boolean operations on pixel color values – probably the only
useful ones are solid (use the color specified), null (don't draw) and XOR with white (invert),
which can be useful for cursor selection, rubber banding, and so on.
Style options include solid, dotted, dashed, and also pen width. However, the BITGDI that
draws screen graphics (that you saw in Chapter 9)doesn't support combinations of style and
pen width – that is, it can't do thick dotted lines.
Use the SetPenColor(), SetPenStyle(), and SetPenSize()member functions to
control the pen. By default, the pen is black, solid, and one pixel thick.
The brush defines fill and background color or pattern.
Brush
The brush can be null, solid, a hatching pattern, or a bitmap. For hatching and bitmaps, you
can set an offset so that pattern fills on adjacent drawing primitives abut each other without
odd edge effects. Use SetBrushStyle(), SetBrushColor(), SetBrushOrigin(),
SetBrushPattern(), and DiscardBrushPattern() to control brush settings; defaults
are null brush, zero origin.
Font
The font defines the font to be used for drawing text.
You specify it by passing a CFont* to CGraphicsContext. We'll cover fonts properly in
Chapter 15, but for now you note that the CONE environment has one font (iCoeEnv-
>NormalFont()), while the Uikon environment contains several (iEikonEnv-
>TitleFont(), LegendFont(), SymbolFont(), AnnotationFont(), and Dense-
Font()). Use UseFont() to set a font, DiscardFont() to say you no longer wish to use
that font, and SetUnderlineStyle() and Set-StrikethroughStyle() to set
algorithmic enhancements to the font in use.
By default, no font and no algorithmic enhancements are in use – you'll get panicked if you
try to draw text without a font in use. You can find more information about the use of fonts in
Chapter 15.
Current position
Current position is set by MoveTo() and various DrawXxxTo() member functions, and
moved by MoveBy() and corresponding DrawXxxBy()functions. It is also affected by
DrawPolyLine(). The XxxBy() functions support relative moving and drawing. By
default, the current position is at (0, 0).
Origin
The origin defines the offset from the device origin that will be used for drawing and you can
use SetOrigin() to control it. By default, the origin is (0, 0).
Clipping region