Example usage for com.google.gwt.user.client IncrementalCommand execute

Introduction

In this page you can find the example usage for com.google.gwt.user.client IncrementalCommand execute.

Prototype

boolean execute();

Source Link

Document

Causes the IncrementalCommand to execute its encapsulated behavior.

Usage

From source file:gov.lbl.glamm.client.experiment.util.DelayConfigCommandExecutor.java

License:Apache License

/**
 * This method will dispatch commands from the command queue. It will dispatch
 * commands until one of the following conditions is <code>true</code>:
 * <ul>//from ww w. j  a v  a  2  s  . c  om
 * <li>It consumed its dispatching time slice
 * {@value #DEFAULT_TIME_SLICE_MILLIS}</li>
 * <li>It encounters a <code>null</code> in the command queue</li>
 * <li>All commands which were present at the start of the dispatching have
 * been removed from the command queue</li>
 * <li>The command that it was processing was canceled due to a false
 * cancellation -- in this case we exit without updating any state</li>
 * </ul>
 * 
 * @param startTimeMillis the time when this method started
 */
protected void doExecuteCommands(double startTimeMillis) {
    assert (!isExecutionTimerPending());

    boolean wasCanceled = false;
    try {
        setExecuting(true);

        iterator.setEnd(commands.size());

        cancellationTimer.schedule(DEFAULT_CANCELLATION_TIMEOUT_MILLIS);

        while (iterator.hasNext()) {
            Object element = iterator.next();

            boolean removeCommand = true;
            try {
                if (element == null) {
                    // null forces a yield or pause in execution
                    return;
                }

                if (element instanceof Command) {
                    Command command = (Command) element;
                    command.execute();
                } else if (element instanceof IncrementalCommand) {
                    IncrementalCommand incrementalCommand = (IncrementalCommand) element;
                    removeCommand = !incrementalCommand.execute();
                }

            } finally {
                wasCanceled = iterator.wasRemoved();
                if (wasCanceled) {
                    /*
                     * The iterator may have already had its remove method called, if it
                     * has, then we need to exit without updating any state
                     */
                    return;
                }

                if (removeCommand) {
                    iterator.remove();
                }
            }

            if (hasTimeSliceExpired(Duration.currentTimeMillis(), startTimeMillis)) {
                // the time slice has expired
                return;
            }
        }
    } finally {
        if (!wasCanceled) {
            cancellationTimer.cancel();

            setExecuting(false);

            maybeStartExecutionTimer();
        }
    }
}

---