/* * 1.0 code. */ import java.applet.*; import java.awt.*; import java.util.Enumeration; public class Sender extends Applet { private String myName; private TextField nameField; private TextArea status; public void init() { GridBagLayout gridBag = new GridBagLayout(); GridBagConstraints c = new GridBagConstraints(); setLayout(gridBag); Label receiverLabel = new Label("Receiver name:", Label.RIGHT); gridBag.setConstraints(receiverLabel, c); add(receiverLabel); nameField = new TextField(getParameter("RECEIVERNAME"), 10); c.fill = GridBagConstraints.HORIZONTAL; gridBag.setConstraints(nameField, c); add(nameField); Button button = new Button("Send message"); c.gridwidth = GridBagConstraints.REMAINDER; //end row c.anchor = GridBagConstraints.WEST; //stick to the text field c.fill = GridBagConstraints.NONE; //keep the button small gridBag.setConstraints(button, c); add(button); status = new TextArea(5, 60); status.setEditable(false); c.anchor = GridBagConstraints.CENTER; //reset to the default c.fill = GridBagConstraints.BOTH; //make this big c.weightx = 1.0; c.weighty = 1.0; gridBag.setConstraints(status, c); add(status); myName = getParameter("NAME"); Label senderLabel = new Label("(My name is " + myName + ".)", Label.CENTER); c.weightx = 0.0; c.weighty = 0.0; gridBag.setConstraints(senderLabel, c); add(senderLabel); validate(); } public boolean action(Event event, Object o) { Applet receiver = null; String receiverName = nameField.getText(); //Get name to search for. receiver = getAppletContext().getApplet(receiverName); if (receiver != null) { //Use the instanceof operator to make sure the applet //we found is a Receiver object. if (!(receiver instanceof Receiver)) { status.appendText("Found applet named " + receiverName + ", " + "but it's not a Receiver object.\n"); } else { status.appendText("Found applet named " + receiverName + ".\n" + " Sending message to it.\n"); //Cast the receiver to be a Receiver object //(instead of just an Applet object) so that the //compiler will let us call a Receiver method. ((Receiver)receiver).processRequestFrom(myName); } } else { status.appendText("Couldn't find any applet named " + receiverName + ".\n"); } return false; } public Insets insets() { return new Insets(3,3,3,3); } public void paint(Graphics g) { g.drawRect(0, 0, size().width - 1, size().height - 1); } public String getAppletInfo() { return "Sender by Kathy Walrath"; } }
