GWT : print button - gwt

Question

I am trying to create a button that prints the current browser window.
This is my current code, that uses (or at least it tries to use) JSNI:
private Button print = new Button(constants.print(), new ClickHandler() {
#Override
public void onClick(final ClickEvent event) {
/*-{
if ($wnd.print) {
$wnd.print();
return true;
} else {
return false;
}
}-*/
}
});
But when I click the button, nothing happens. It is my first GWT application, so I am not sure about how to implement it.

Answer 1

new Button(constants.print(), new ClickHandler() {
#Override
public void onClick(final ClickEvent event) {
print();
}
private native boolean print( ) /*-{
if ($wnd.print) {
$wnd.print();
return true;
} else {
return false;
}
}-*/; });
Should work! Always place JSNI within a native method.

Answer 2

Since GWT version 1.5, there's a built-in print function:
import com.google.gwt.user.client.Window
public class PrintHandler implements ClickHandler {
public void onClick (ClickEvent event) {
Window.print()
}
}

Answer 3

Here is my 2 cents:
Create a re-usable class:
public class PrintHandler implements ClickHandler {
public void onClick (ClickEvent event) {
print();
}
private native boolean print ()
/*-{
if ($wnd.print) {
$wnd.print();
return true;
} else {
return false;
}
}-*/;
}
And use it anywhere you like:
new Button( constants.print(), new PrintHandler() )