swig/Examples/android/extend/src/org/swig/extendexample/SwigExtend.java
2013-09-25 17:29:33 +12:00

129 lines
4.8 KiB
Java

package org.swig.extendexample;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.ScrollView;
import android.text.method.ScrollingMovementMethod;
// CEO class, which overrides Employee::getPosition().
class CEO extends Manager {
public CEO(String name) {
super(name);
}
public String getPosition() {
return "CEO";
}
// Public method to stop the SWIG proxy base class from thinking it owns the underlying C++ memory.
public void disownMemory() {
swigCMemOwn = false;
}
}
public class SwigExtend extends Activity
{
TextView outputText = null;
ScrollView scroller = null;
/** Handles upcalls from C++ so that C++ code can display text on the TextView */
class TextViewStreamer extends Streamer {
public void display(String text) {
outputText.append(text);
}
}
TextViewStreamer textViewStreamer = new TextViewStreamer();
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
outputText = (TextView)findViewById(R.id.OutputText);
outputText.setText("Press 'Run' to start...\n");
outputText.setMovementMethod(new ScrollingMovementMethod());
scroller = (ScrollView)findViewById(R.id.Scroller);
example.setStreamer(textViewStreamer);
}
public void onRunButtonClick(View view)
{
outputText.append("Started...\n");
nativeCall();
outputText.append("Finished!\n");
// Ensure scroll to end of text
scroller.post(new Runnable() {
public void run() {
scroller.fullScroll(ScrollView.FOCUS_DOWN);
}
});
}
/** Calls into C/C++ code */
public void nativeCall()
{
// Create an instance of CEO, a class derived from the Java proxy of the
// underlying C++ class. The calls to getName() and getPosition() are standard,
// the call to getTitle() uses the director wrappers to call CEO.getPosition().
CEO e = new CEO("Alice");
outputText.append( e.getName() + " is a " + e.getPosition() + "\n");
outputText.append( "Just call her \"" + e.getTitle() + "\"\n" );
outputText.append( "----------------------\n" );
// Create a new EmployeeList instance. This class does not have a C++
// director wrapper, but can be used freely with other classes that do.
EmployeeList list = new EmployeeList();
// EmployeeList owns its items, so we must surrender ownership of objects we add.
e.disownMemory();
list.addEmployee(e);
outputText.append( "----------------------\n" );
// Now we access the first four items in list (three are C++ objects that
// EmployeeList's constructor adds, the last is our CEO). The virtual
// methods of all these instances are treated the same. For items 0, 1, and
// 2, all methods resolve in C++. For item 3, our CEO, getTitle calls
// getPosition which resolves in Java. The call to getPosition is
// slightly different, however, because of the overridden getPosition() call, since
// now the object reference has been "laundered" by passing through
// EmployeeList as an Employee*. Previously, Java resolved the call
// immediately in CEO, but now Java thinks the object is an instance of
// class Employee. So the call passes through the
// Employee proxy class and on to the C wrappers and C++ director,
// eventually ending up back at the Java CEO implementation of getPosition().
// The call to getTitle() for item 3 runs the C++ Employee::getTitle()
// method, which in turn calls getPosition(). This virtual method call
// passes down through the C++ director class to the Java implementation
// in CEO. All this routing takes place transparently.
outputText.append( "(position, title) for items 0-3:\n" );
outputText.append( " " + list.get_item(0).getPosition() + ", \"" + list.get_item(0).getTitle() + "\"\n" );
outputText.append( " " + list.get_item(1).getPosition() + ", \"" + list.get_item(1).getTitle() + "\"\n" );
outputText.append( " " + list.get_item(2).getPosition() + ", \"" + list.get_item(2).getTitle() + "\"\n" );
outputText.append( " " + list.get_item(3).getPosition() + ", \"" + list.get_item(3).getTitle() + "\"\n" );
outputText.append( "----------------------\n" );
// Time to delete the EmployeeList, which will delete all the Employee*
// items it contains. The last item is our CEO, which gets destroyed as well.
list.delete();
outputText.append( "----------------------\n" );
}
/** static constructor */
static {
System.loadLibrary("example");
}
}