Class EventQueue

java.lang.Object

vaadinx.awt.EventQueue

public class EventQueue
extends Object

Emulator for EventQueue. Three EDT primitives — invokeLater(Runnable), invokeAndWait(Runnable), isDispatchThread() — delegate to SwingUtilities and bottom out in UI.getCurrent() != null (the Vaadin UI-thread proxy); getMostRecentEventTime() returns System.currentTimeMillis(). The remainder of the JDK surface (instance dispatch machinery, postEvent, peekEvent, getNextEvent, dispatchEvent, getCurrentEvent, push / pop, createSecondaryLoop) is present so migrated code compiles, but each method WARNs via EHelper.onUnimplemented(String, String, Object...) and returns a safe default — no AWT EventQueue dispatch thread exists server-side, so the dispatch contract can't be honoured. This matches R_match_swing_errors / D_never_fail_on_gaps: log the gap, never crash the host app.

Why ported despite not being Component-shaped. The JDK EventQueue bottoms out in an AWT EventQueue dispatch thread that doesn't exist server-side; EventQueue.invokeLater(...) against the JDK class would silently queue the runnable and never run it. The porting rule is "port what would silently fail server-side; leave what works unchanged on the JDK" — EventQueue's static EDT methods fall on the port side, and once the class is present the rest of its API surface is added as WARN-stubs to avoid compile errors on incidental references.

Constructor Summary

Constructors

Constructor	Description
EventQueue()

Method Summary

Modifier and Type	Method	Description
SecondaryLoop	createSecondaryLoop()
protected void	dispatchEvent(AWTEvent event)
static AWTEvent	getCurrentEvent()
static long	getMostRecentEventTime()	Approximation of "time of the most recently dispatched AWT event."
AWTEvent	getNextEvent()
static void	invokeAndWait(Runnable runnable)	Posts the runnable to the Vaadin UI thread and blocks the calling thread until it has run.
static void	invokeLater(Runnable runnable)	Posts the runnable to the Vaadin UI thread asynchronously.
static boolean	isDispatchThread()
AWTEvent	peekEvent()
AWTEvent	peekEvent(int id)
protected void	pop()	Real EventQueue.pop() throws EmptyStackException when called on a non-pushed queue.
void	postEvent(AWTEvent event)
void	push(EventQueue newEventQueue)

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

EventQueue

public EventQueue()

Method Details

isDispatchThread

public static boolean isDispatchThread()

Returns:

true when called from a Vaadin UI thread context.

See Also:

• SwingUtilities.isEventDispatchThread()

invokeLater

public static void invokeLater(Runnable runnable)

Posts the runnable to the Vaadin UI thread asynchronously. See SwingUtilities.invokeLater(Runnable) for the full dispatch contract, including the background-thread case.

Throws:

IllegalStateException - on a thread with neither a current UI nor an EmulatorContext.

invokeAndWait

public static void invokeAndWait(Runnable runnable)
                          throws InterruptedException,
InvocationTargetException

Posts the runnable to the Vaadin UI thread and blocks the calling thread until it has run. See SwingUtilities.invokeAndWait(Runnable) for the full dispatch contract; in particular, calling from the EDT throws IllegalStateException (D_gap_severity_triage case 2: the loom rescue trigger).

Throws:

IllegalStateException - when called from the EDT, or on a thread with no EmulatorContext.

InvocationTargetException - if the runnable throws.

InterruptedException - if the wait is interrupted.

BrowserSessionClosedError - if the session has no live UI to run the runnable on.

getMostRecentEventTime

public static long getMostRecentEventTime()

Approximation of "time of the most recently dispatched AWT event." We have no AWT event pump, so we return the current wall-clock time; migrated code that uses this for event-recency comparisons sees a monotonically advancing value, which is the closest faithful behaviour without a real event queue.

getCurrentEvent

public static AWTEvent getCurrentEvent()

postEvent

public void postEvent(AWTEvent event)

getNextEvent

public AWTEvent getNextEvent()
                      throws InterruptedException

Throws:

InterruptedException

peekEvent

public AWTEvent peekEvent()

peekEvent

public AWTEvent peekEvent(int id)

dispatchEvent

protected void dispatchEvent(AWTEvent event)

push

public void push(EventQueue newEventQueue)

pop

protected void pop()

Real EventQueue.pop() throws EmptyStackException when called on a non-pushed queue. Without an event-pump stack to interrogate, we WARN and return — pop is a paired operation with push(EventQueue), and push already WARNs.

createSecondaryLoop

public SecondaryLoop createSecondaryLoop()