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minor fixes/rewording

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git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@4276 626c5289-ae23-0410-ae9c-e8d60b6d4f22
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William S Fulton 2003-02-09 00:17:33 +00:00
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SWIG/Doc/Manual/Java.html
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@ -2805,8 +2805,9 @@ int c = example.count('e',"Hello World");
<a name="n52"></a><H3>15.7.4 Typemaps for mapping C/C++ types to Java types</H3>
The typemaps available to the Java module include the common typemaps listed in the main typemaps section. There are a number of additional typemaps which can be used with Java.
The most important of these implement the mapping of C/C++ types to Java types. There are three of them:
The typemaps available to the Java module include the common typemaps listed in the main typemaps section.
There are a number of additional typemaps which are necessary for using SWIG with Java.
The most important of these implement the mapping of C/C++ types to Java types:
<br>&nbsp;
<table BORDER>
@ -2848,6 +2849,18 @@ The most important of these implement the mapping of C/C++ types to Java types.
</tr>
</table>
<p>
If you are writing your own typemaps to handle a particular type, you will normally have to write a collection of them.
The default typemaps are in <tt>java.swg</tt> and so might be a good place for finding typemaps to base any new ones on.</li>
<p>
The "jni", "jtype" and "jstype" typemaps are usually defined together to handle the Java to C/C++ type mapping.
An "in" typemap should be accompanied by a "javain" typemap and likewise an "out" typemap by a "javaout" typemap.
If an "in" typemap is written, a "freearg" and "argout" typemap may also need to be written
as some types have a default "freearg" and/or "argout" typemap which may need overriding.
The "freearg" typemap sometimes releases memory allocated by the "in" typemap.
The "argout" typemap sometimes sets values in function parameters which are passed by reference in Java.
<p>The default code generated by SWIG for the Java module comes from the typemaps in the <tt>java.swg</tt> library file which implements the
<a href="#n49">Default primitive type mappings</a>
covered earlier.
@ -2967,17 +2980,6 @@ is released afterwards</td>
</tr>
</table>
<p>
If you are writing your own typemaps to handle a particular type, you will normally have to write a collection of them.
Take a look at the default typemaps in <tt>java.swg</tt>.</li>
<p>
The "jni", "jtype" and "jstype" typemaps are usually defined together to handle the Java to C/C++ type mapping.
An "in" typemap is usually accompanied by a "javain" typemap and likewise an "out" typemap with a "javaout" typemap.
If an "in" typemap is written, a "freearg" and "argout" typemap may also need to be written.
as some types have a default "freearg" and/or "argout" typemap which may need overriding.
The "freearg" typemap sometimes releases memory allocated by the "in" typemap.
The "argout" typemap sometimes sets values in function parameters which are passed by reference in Java.
<a name="n53"></a><H3>15.7.5 Java special variables</H3>
@ -3553,6 +3555,10 @@ public:
}
...
};
Vehicle *vehicle_factory() {
return new Ambulance("Very loud");
}
</pre></blockquote>
If we execute the following Java code:
@ -3575,8 +3581,8 @@ java.lang.ClassCastException
Even though we know from examination of the C++ code that <tt>vehicle_factory</tt> returns an object of type <tt>Ambulance</tt>,
we are not able to use this knowledge to perform the downcast in Java.
This occurs because the runtime type information is not completely passed from C++ to Java when returning the type from <tt>vehicle_factory</tt>.
Usually this is not a problem as virtual functions, as in the case of <tt>start</tt> work.
This occurs because the runtime type information is not completely passed from C++ to Java when returning the type from <tt>vehicle_factory()</tt>.
Usually this is not a problem as virtual functions do work by default, such as in the case of <tt>start()</tt>.
There are a few solutions to getting downcasts to work.
<p>