Implements a web browser 2
//Send questions, comments, bug reports, etc. to the authors:
//Rob Warner (rwarner@interspatial.com)
//Robert Harris (rbrt_harris@yahoo.com)
import org.eclipse.swt.SWT;
import org.eclipse.swt.browser.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
/**
* This class implements a web browser
*/
public class AdvancedBrowser {
// The "at rest" text of the throbber
private static final String AT_REST = "Ready";
/**
* Runs the application
*
* @param location the initial location to display
*/
public void run(String location) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setText("Advanced Browser");
createContents(shell, location);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
/**
* Creates the main window's contents
*
* @param shell the main window
* @param location the initial location
*/
public void createContents(Shell shell, String location) {
shell.setLayout(new FormLayout());
// Create the composite to hold the buttons and text field
Composite controls = new Composite(shell, SWT.NONE);
FormData data = new FormData();
data.top = new FormAttachment(0, 0);
data.left = new FormAttachment(0, 0);
data.right = new FormAttachment(100, 0);
controls.setLayoutData(data);
// Create the status bar
Label status = new Label(shell, SWT.NONE);
data = new FormData();
data.left = new FormAttachment(0, 0);
data.right = new FormAttachment(100, 0);
data.bottom = new FormAttachment(100, 0);
status.setLayoutData(data);
// Create the web browser
final Browser browser = new Browser(shell, SWT.BORDER);
data = new FormData();
data.top = new FormAttachment(controls);
data.bottom = new FormAttachment(status);
data.left = new FormAttachment(0, 0);
data.right = new FormAttachment(100, 0);
browser.setLayoutData(data);
// Create the controls and wire them to the browser
controls.setLayout(new GridLayout(7, false));
// Create the back button
Button button = new Button(controls, SWT.PUSH);
button.setText("Back");
button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent event) {
browser.back();
}
});
// Create the forward button
button = new Button(controls, SWT.PUSH);
button.setText("Forward");
button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent event) {
browser.forward();
}
});
// Create the refresh button
button = new Button(controls, SWT.PUSH);
button.setText("Refresh");
button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent event) {
browser.refresh();
}
});
// Create the stop button
button = new Button(controls, SWT.PUSH);
button.setText("Stop");
button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent event) {
browser.stop();
}
});
// Create the address entry field and set focus to it
final Text url = new Text(controls, SWT.BORDER);
url.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
url.setFocus();
// Create the go button
button = new Button(controls, SWT.PUSH);
button.setText("Go");
button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent event) {
browser.setUrl(url.getText());
}
});
// Create the animated "throbber"
Label throbber = new Label(controls, SWT.NONE);
throbber.setText(AT_REST);
// Allow users to hit enter to go to the typed URL
shell.setDefaultButton(button);
// Add event handlers
browser.addCloseWindowListener(new AdvancedCloseWindowListener());
browser.addLocationListener(new AdvancedLocationListener(url));
browser.addProgressListener(new AdvancedProgressListener(throbber));
browser.addStatusTextListener(new AdvancedStatusTextListener(status));
// Go to the initial URL
if (location != null) {
browser.setUrl(location);
}
}
/**
* This class implements a CloseWindowListener for AdvancedBrowser
*/
class AdvancedCloseWindowListener implements CloseWindowListener {
/**
* Called when the parent window should be closed
*/
public void close(WindowEvent event) {
// Close the parent window
((Browser) event.widget).getShell().close();
}
}
/**
* This class implements a LocationListener for AdvancedBrowser
*/
class AdvancedLocationListener implements LocationListener {
// The address text box to update
private Text location;
/**
* Constructs an AdvancedLocationListener
*
* @param text the address text box to update
*/
public AdvancedLocationListener(Text text) {
// Store the address box for updates
location = text;
}
/**
* Called before the location changes
*
* @param event the event
*/
public void changing(LocationEvent event) {
// Show the location that's loading
location.setText("Loading " + event.location + "...");
}
/**
* Called after the location changes
*
* @param event the event
*/
public void changed(LocationEvent event) {
// Show the loaded location
location.setText(event.location);
}
}
/**
* This class implements a ProgressListener for AdvancedBrowser
*/
class AdvancedProgressListener implements ProgressListener {
// The label on which to report progress
private Label progress;
/**
* Constructs an AdvancedProgressListener
*
* @param label the label on which to report progress
*/
public AdvancedProgressListener(Label label) {
// Store the label on which to report updates
progress = label;
}
/**
* Called when progress is made
*
* @param event the event
*/
public void changed(ProgressEvent event) {
// Avoid divide-by-zero
if (event.total != 0) {
// Calculate a percentage and display it
int percent = (int) (event.current / event.total);
progress.setText(percent + "%");
} else {
// Since we can't calculate a percent, show confusion :-)
progress.setText("???");
}
}
/**
* Called when load is complete
*
* @param event the event
*/
public void completed(ProgressEvent event) {
// Reset to the "at rest" message
progress.setText(AT_REST);
}
}
/**
* This class implements a StatusTextListener for AdvancedBrowser
*/
class AdvancedStatusTextListener implements StatusTextListener {
// The label on which to report status
private Label status;
/**
* Constructs an AdvancedStatusTextListener
*
* @param label the label on which to report status
*/
public AdvancedStatusTextListener(Label label) {
// Store the label on which to report status
status = label;
}
/**
* Called when the status changes
*
* @param event the event
*/
public void changed(StatusTextEvent event) {
// Report the status
status.setText(event.text);
}
}
/**
* The application entry point
*
* @param args the command line arguments
*/
public static void main(String[] args) {
new AdvancedBrowser().run(args.length == 0 ? null : args[0]);
}
}
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