Java Reference
In-Depth Information
CENA
. . .
with many more font names in the list.
How It Works
You first get a
Toolkit
object by calling the
static
method
getDefaultToolkit()
— this is the key
to the other information. The
getScreenResolution()
method returns the number of pixels per inch as
a value of type
int
. The
getScreenSize()
method returns a
Dimension
object that specifies the width
and height of the screen in pixels.
You use the
getAvailableFontFamilyNames()
method to get a
String
array containing the names of
the fonts, which you output to the console.
Font Metrics
Every component has a
getFontMetrics()
method that you can use to retrieve
font metrics
— a wealth of
dimensional data about a font. You pass a
Font
object as an argument to the method, and it returns an object
of type
FontMetrics
that you can use to obtain data relating to the particular font. For example, if
aWindow
is a
Frame
object and
myFont
is a
Font
object, you could obtain a
FontMetrics
object corresponding to the
font with the following statement:
FontMetrics metrics = aWindow.getFontMetrics(myFont);
You could use the
getFont()
method for a component to explore the characteristics of the font that the
component contains. For example:
FontMetrics metrics = aWindow.getFontMetrics(aWindow.getFont());
You can now call any of the following
FontMetrics
methods for the object to get at the basic dimensions
of the font:
•
int getAscent()
: Returns the
ascent
of the font, which is the distance from the baseline to the
top of the majority of the characters in the font. The
baseline
is the line on which the characters
rest. Depending on the font, some characters can extend beyond the ascent.
•
int getMaxAscent()
: Returns the maximum ascent for the font. No character exceeds this ascent.
•
int getDescent()
: Returns the
descent
of the font, which is the distance from the baseline to the
bottom of most of the font characters that extend below the baseline. Depending on the font, some
characters may extend beyond the descent for the font.
•
int getMaxDescent()
: Returns the maximum descent of the characters in the font. No character
exceeds this descent.
•
int getLeading()
: Returns the
leading
for the font, which is the line spacing for the font — that
is the spacing between the bottom of one line of text and the top of the next. The term originated
when type was actually made of lead, and there was a strip of lead between one line of type and
the next when a page was typeset.
•
int getHeight()
: Returns the height of the font, which is defined as the sum of the ascent, the
descent, and the leading.
