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SHAPE ="RECT" HREF ="/reference/author.html" COORDS ="361,0,440,29"><AREA SHAPE ="RECT" HREF ="/reference/basic.html" COORDS ="254,0,360,29"><AREA SHAPE ="RECT" HREF ="/reference/help.html" COORDS ="183,0,251,29"><AREA SHAPE ="RECT" HREF ="/reference/cool.html" COORDS ="100,0,181,29"><AREA SHAPE ="RECT" HREF ="/reference/mybook.html" COORDS ="0,0,100,29"></MAP><MAP NAME ="header_r1.gif.map"><AREA SHAPE ="RECT" HREF ="/reference/personalize.html" COORDS ="339,0,439,29"></MAP><p><font face="Arial,Helvetica" size="-1" color="#006666"><A HREF="/reference/r_library.html"><B>All Categories</A> :</B><b><A HREF="/reference/r_java.html">Java</A></b></font><p><META><H1><FONT SIZE=6 COLOR=#Ff0000>Chapter 17</FONT></H1><H1><FONT SIZE=6 COLOR=#Ff0000>Graphical Text</FONT></H1><HR><P><CENTER><B><FONT SIZE=5><A NAME="CONTENTS">CONTENTS</A></FONT></B></CENTER><UL><LI><A HREF="#DealingwithGraphicalText">Dealing with Graphical Text</A><UL><LI><A HREF="#GettingFontAttributes">Getting Font Attributes</A><LI><A HREF="#ExampleDisplayingFontInformation">Example: Displaying Font Information</A><LI><A HREF="#GettingFontMetrics">Getting Font Metrics</A><LI><A HREF="#ExampleDisplayingFontMetrics">Example: Displaying Font Metrics</A></UL><LI><A HREF="#CreatingFonts">Creating Fonts</A><UL><LI><A HREF="#ExampleCreatingaFontwithMultipleStyles">Example: Creating a Font with Multiple Styles</A><LI><A HREF="#UsingtheFont">Using the Font</A><LI><A HREF="#ExampleDisplayingDifferentSizedFonts">Example: Displaying Different Sized Fonts</A></UL><LI><A HREF="#Summary">Summary</A><LI><A HREF="#ReviewQuestions">Review Questions</A><LI><A HREF="#ReviewExercises">Review Exercises</A></UL><HR><P>Now that you know how to draw all kinds of shapes in your applets,it's time to see how to use text and text fonts, as well. By combininggraphical text with other drawing methods, you can create attractiveapplets for your Web pages. In this chapter, you'll review howto display text, as well as how to create fonts and retrieve informationabout those fonts.<H2><A NAME="DealingwithGraphicalText"><FONT SIZE=5 COLOR=#Ff0000>Dealing with Graphical Text</FONT></A></H2><P>Earlier in this book, I said that because Windows is a device-independentgraphical environment, you can't assume much about how the user'ssystem is set up. At the time, I was talking about fonts and howdifferent fonts take up different amounts of space in the display.After giving you this good advice, I then proceeded to ignoreit. All the programs so far in this book display text stringswithout considering the font being used. Hopefully, you didn'trun into any troubles. If you did, you'll be delighted to knowthat in this section, you'll learn how to solve such problems.<H3><A NAME="GettingFontAttributes">Getting Font Attributes</A></H3><P>Every font that you can use with your Java applets is associatedwith a group of attributes that determines the size and appearanceof the font. The most important of these attributes is the font'sname, which determines the font's basic style. As shown in Figure17.1, there is a big difference between the Arial and Times Romanfonts as far as how they look. When you're setting up a font foruse, the name of the font is usually the first thing with whichyou're concerned.<P><A HREF="f17-1.gif"><B> Figure 17.1 : </B><I>The appearance of text is determined mostly by the font you choose.</I></A><P><P>You can easily get information about the currently active font.Start by calling the <TT>Graphics</TT> object's <TT>getFont()</TT>method, like this:<BLOCKQUOTE><PRE>Font font = g.getFont();</PRE></BLOCKQUOTE><P>The <TT>getFont()</TT> method returns a <TT>Font</TT> object forthe current font. Once you have the <TT>Font</TT> object, youcan use the <TT>Font</TT> class's various methods to obtain informationabout the font. Table 17.1 shows the most commonly used publicmethods of the <TT>Font</TT> class and what they do.<BR><P><CENTER><B>Table 17.1 The </B><I>Font</I><B> Class'sMost Commonly Used Public Methods.</B></CENTER><P><CENTER><TABLE BORDER=1 WIDTH=80%><TR VALIGN=TOP><TD WIDTH=128><I><B>Methods</B></I></TD><TD WIDTH=462><I><B>Description</B></I></TD></TR><TR VALIGN=TOP><TD WIDTH=128><TT>getFamily()</TT></TD><TD WIDTH=462>Returns the family name of the font.</TD></TR><TR VALIGN=TOP><TD WIDTH=128><TT>getName()</TT></TD><TD WIDTH=462>Returns the name of the font.</TD></TR><TR VALIGN=TOP><TD WIDTH=128><TT>getSize()</TT></TD><TD WIDTH=462>Returns the size of the font.</TD></TR><TR VALIGN=TOP><TD WIDTH=128><TT>getStyle()</TT></TD><TD WIDTH=462>Returns the style of the font, where 0 is plain, 1 is bold, 2 is italic, and 3 is bold italic.</TD></TR><TR VALIGN=TOP><TD WIDTH=128><TT>isBold()</TT></TD><TD WIDTH=462>Returns a <TT>boolean</TT> value indicating whether the font is bold.</TD></TR><TR VALIGN=TOP><TD WIDTH=128><TT>isItalic()</TT></TD><TD WIDTH=462>Returns a <TT>boolean</TT> value indicating whether the font is italic.</TD></TR><TR VALIGN=TOP><TD WIDTH=128><TT>isPlain()</TT></TD><TD WIDTH=462>Returns a <TT>boolean</TT> value indicating whether the font is plain.</TD></TR><TR VALIGN=TOP><TD WIDTH=128><TT>toString()</TT></TD><TD WIDTH=462>Returns a string of information about the font.</TD></TR></TABLE></CENTER><P><H3><A NAME="ExampleDisplayingFontInformation">Example: Displaying Font Information</A></H3><P>As always, the best way to see how something works is to try itout yourself. With that end in mind, Listing 17.1 is an appletthat displays information about the currently active font usingmany of the methods described in Table 17.1. Listing 17.2 is theHTML document used to run the applet, and Figure 17.2 shows theapplet running under Appletviewer.<P><A HREF="f17-2.gif"><B> Figure 17.2 : </B><I>This is FontApplet running under Appletviewer.</I></A><P><HR><BLOCKQUOTE><B>Listing 17.1 FontApplet.java: Getting InformationAbout a Font.<BR></B></BLOCKQUOTE><BLOCKQUOTE><PRE>import java.awt.*;import java.applet.*;public class FontApplet extends Applet{ public void paint(Graphics g) { Font font = getFont(); String name = font.getName(); String family = font.getFamily(); int n = font.getStyle(); String style; if (n == 0) style = "Plain"; else if (n == 1) style = "Bold"; else if (n == 2) style = "Italic"; else style = "Bold Italic"; n = font.getSize(); String size = String.valueOf(n); String info = font.toString(); String s = "Name: " + name; g.drawString(s, 50, 50); s = "Family: " + family; g.drawString(s, 50, 65); s = "Style: " + style; g.drawString(s, 50, 80); s = "Size: " + size; g.drawString(s, 50, 95);⌨️ 快捷键说明
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