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300 Day 8
The Glyph Property
The Glyph property represents the bitmap on the button. The value of the Glyph property is
a picture, or glyph.
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A glyph is a picture that is typically in the form of a Windows bitmap file (BMP).
The glyph itself consists of one or more bitmaps that represent the four possible states a
button can be in: up, down, disabled, and stay down. If you are creating your own buttons,
you can probably get by with supplying just one glyph, which the BitBtn component will then
modify to represent the other three possible states. The bitmap will move down and to the
left when the button is clicked and will be grayed out when disabled. The glyph in the staydown
state will be the same as in the up state, although the button face will change to give
a pressed look.
If you provide more than one glyph, the glyphs must all be the same height and width and
must be contained in a bitmap strip. The bitmaps that ship with C++Builder provide two
glyphs. Figure 8.5 shows the bitmap for the print button that comes with C++Builder
(PRINT.BMP) in both its actual size and zoomed in to show detail. Note that the two glyphs
each occupy the same width in the bitmap.
Figure 8.5.
The PRINT.BMP
bitmap.
TIP
The pixel in the lower-left corner of the bitmap is the color that will be
used for the transparent color. Any pixels in the bitmap having that
color will be transparent when the glyph is displayed on the button.
You must keep this in mind when designing your bitmaps. If you are
not using transparency, you will need the pixel in the lower-left corner
to be a color not present anywhere else on the bitmap.