package org.latexlab.docs.client.content.menus;
import org.latexlab.docs.client.commands.SystemPasteCommand;
import org.latexlab.docs.client.content.latex.LatexCommand;
import org.latexlab.docs.client.content.latex.LatexCommandSet;
import org.latexlab.docs.client.content.latex.SetBigOperators;
import org.latexlab.docs.client.widgets.DynamicMenuBar;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.RunAsyncCallback;
import com.google.gwt.user.client.rpc.AsyncCallback;
/**
* Contains a LaTeX Big Operators menu with on-demand loading.
*/
public class DynamicLatexBigOperatorsMenu extends DynamicMenuBar {
protected static DynamicLatexBigOperatorsMenu instance;
/**
* Retrieves the single instance of this class.
*/
public static DynamicLatexBigOperatorsMenu get() {
if (instance == null) {
instance = new DynamicLatexBigOperatorsMenu();
}
return instance;
}
/**
* Constructs a latex big operators menu.
*/
protected DynamicLatexBigOperatorsMenu() {
super(true);
}
/**
* Asynchronously loads the MenuBar's sub items.
*
* @param callback the callback carrying the sub items
*/
@Override
protected void getSubMenu(final AsyncCallback<ExtendedMenuItem[]> callback) {
GWT.runAsync(new RunAsyncCallback() {
@Override
public void onFailure(Throwable reason) {
callback.onFailure(reason);
}
@Override
public void onSuccess() {
LatexCommandSet set = SetBigOperators.get();
LatexCommand[] cmds = set.getCommands();
ExtendedMenuItem[] items = new ExtendedMenuItem[cmds.length];
for (int i=0; i<cmds.length; i++) {
LatexCommand cmd = cmds[i];
items[i] = new ExtendedMenuItem(cmd.getIcon(), cmd.getTitle(), new SystemPasteCommand(cmd.getText()));
}
callback.onSuccess(items);
}
});
}
}