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<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Now For Something Useful</title><meta name="generator" content="DocBook XSL Stylesheets V1.65.1"><link rel="home" href="index.html" title="jEdit 4.2 User's Guide"><link rel="up" href="macro-basics.html" title="Chapter 13. Macro Basics"><link rel="previous" href="dynamic-typing.html" title="BeanShell Dynamic Typing"><link rel="next" href="dialog-macro.html" title="Chapter 14. A Dialog-Based Macro"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Now For Something Useful</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="dynamic-typing.html">Prev</a> </td><th width="60%" align="center">Chapter 13. Macro Basics</th><td width="20%" align="right"> <a accesskey="n" href="dialog-macro.html">Next</a></td></tr></table><hr></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="something-useful"></a>Now For Something Useful</h2></div></div><div></div></div><p>
    Here is a macro that inserts the path of the current buffer in
    the text:
  </p><div class="informalexample"><table border="0" bgcolor="#E0E0E0"><tr><td><pre class="programlisting">String newText = buffer.getPath();
textArea.setSelectedText(newText);</pre></td></tr></table></div><p>
    Unlike in our first macro example, here we are calling class methods on
    particular objects. First, we call <tt class="function">getPath()</tt> on the
    current <a href="../api/org/gjt/sp/jedit/Buffer.html" target="_top">Buffer</a> object to get the full path of the
    text file currently being edited. Next, we call
    <tt class="function">setSelectedText()</tt> on the current text display
    component, specifying the text to be inserted as a parameter.
  </p><p>
    In precise terms, the <tt class="function">setSelectedText()</tt> method
    substitutes the contents of the <tt class="classname">String</tt>
    parameter for a range of selected text that includes the current caret
    position. If no text is selected at the caret position, the effect
    of this operation is simply to insert the new text at that position.
  </p><p>
    Here's a few alternatives to the full file path that you could
    use to insert various useful things:
  </p><div class="informalexample"><table border="0" bgcolor="#E0E0E0"><tr><td><pre class="programlisting">// the file name (without full path)
String newText = buffer.getName();

// today's date
import java.text.DateFormat;

String newText = DateFormat.getDateInstance()
    .format(new Date());

// a line count for the current buffer
String newText = "This file contains "
    + textArea.getLineCount() + " lines.";</pre></td></tr></table></div><p>
    Here are brief comments on each:
  </p><div class="itemizedlist"><ul type="disc"><li><p>
      In the first, the call to <tt class="function">getName()</tt> invokes
      another method of the <a href="../api/org/gjt/sp/jedit/Buffer.html" target="_top">Buffer</a> class.
    </p></li><li><p>
      The syntax of the second example chains the results of
      several methods. You could write it this way:
    </p><table border="0" bgcolor="#E0E0E0"><tr><td><pre class="programlisting">import java.text.DateFormat;
Date d = new Date();
DateFormat df = DateFormat.getDateInstance();
String result = df.format(d);
</pre></td></tr></table><p>
	  Taking the pieces in order:
   </p><div class="itemizedlist"><ul type="circle"><li><p>
         A Java <tt class="classname">Date</tt> object is created using the
         <tt class="function">new</tt> keyword. The empty parenthesis after
         <tt class="classname">Date</tt> signify a call on the <i class="glossterm">
         constructor method</i> of <tt class="classname">Date</tt> having no
         parameters; here, a <tt class="classname">Date</tt> is created representing
         the current date and time.
       </p></li><li><p>
         <tt class="function">DateFormat.getDateInstance()</tt> is a static method
         that creates and returns a <tt class="classname">DateFormat</tt> object. As
         the name implies, <tt class="classname">DateFormat</tt> is a Java class
         that takes <tt class="classname">Date</tt> objects and produces readable
         text. The method <tt class="function">getDateInstance()</tt> returns a
         <tt class="classname">DateFormat</tt> object that parses and formats dates.
         It will use the default <i class="glossterm">locale</i> or text format
         specified in the user's Java installation.
       </p></li><li><p>
        Finally, <tt class="classname">DateFormat.format()</tt> is called on the
        new <tt class="classname">DateFormat</tt> object using the
        <tt class="classname">Date</tt> object as a parameter. The result is a
        <tt class="classname">String</tt> containing the date in the default
        locale.
      </p></li><li><p>
        Note that the <tt class="classname">Date</tt> class is contained in
        the <tt class="literal">java.util</tt> package, so an explicit import
        statement is not required. However, <tt class="classname">DateFormat</tt>
        is part of the <tt class="literal">java.text</tt> package, which is
        not automatically imported, so an explicit
        <tt class="function">import</tt> statement must be used.
      </p></li></ul></div></li><li><p>
    The third example shows three items of note:
	 </p><div class="itemizedlist"><ul type="circle"><li><p>
       <tt class="function">getLineCount()</tt> is a method in jEdit's
       <a href="../api/org/gjt/sp/jedit/textarea/JEditTextArea.html" target="_top">JEditTextArea</a> class. It returns an
       <tt class="classname">int</tt> representing the number of lines in the
       current text buffer. We call it on <tt class="varname">textArea</tt>, the
       pre-defined, current <a href="../api/org/gjt/sp/jedit/textarea/JEditTextArea.html" target="_top">JEditTextArea</a> object.
      </p></li><li><p>
       The use of the <tt class="function">+</tt> operator (which can be chained,
       as here) appends objects and string
       literals to return a single, concatenated <tt class="classname">String</tt>.
       </p></li></ul></div><p>
   </p></li></ul></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="dynamic-typing.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="macro-basics.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="dialog-macro.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">BeanShell Dynamic Typing </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 14. A Dialog-Based Macro</td></tr></table></div></body></html>