Chapter 1

The second case will cause problems even when the phone supplies fonts with a wide range
of sizes. If this situation is not dealt with properly, then the width of text at low zoom factors
does not scale in proportion to the height. As can be seen in the following diagram, this can
cause the text to be too wide for the surrounding box:
Figure 15.6
When getting a CFont from a TFontSpec you are converting from a twips size to a pixel
size and, as you would expect, the height and width of a font will scale proportionately. But a
character cannot be displayed in a width smaller than that of a pixel so, if the width scales to
less than this, the excess will accumulate, character by character, along the length of the
text.
One sensible solution at such low zoom factors is to calculate the width of the whole string in
twips, convert the result to pixels and simply draw a horizontal line of the appropriate length.
You might want to support these low zoom factors in order to display the shape of words,
sentences and paragraphs even when the font is too small to read, so eventually you can
just make out where the capital letters are and, with even lower zoom states, just where the
paragraphs are. This requirement applies to a print preview, for example. The Symbian OS
rich text view, unlike our example application, can properly handle and display fonts even
smaller than a pixel, using techniques such as that described above. Not all smartphone
views will have to support this, so for many phones it is not actually an issue.
Drawing the text
We are now back to the hello view class's DrawInRect() function, in which we will see
how our allocated font is used.
void CExampleHelloView:: DrawInRect(const MGraphicsDeviceMap& aMap,
CGraphicsContext& aGc, const TRect& aDeviceRect, CFont* aFont)
{
//Draw some text
if (iFullRedraw)
{
aGc.SetBrushStyle(CGraphicsContext::ESolidBrush);
aGc.SetBrushColor(KRgbWhite);
}
else aGc.SetBrushStyle(CGraphicsContext::ENullBrush);
aGc.SetPenStyle(CGraphicsContext::ESolidPen);
aGc.SetPenColor(KRgbBlack);
aGc.UseFont(aFont);