*/
public class TApplication {
+ /**
+ * If true, emit thread stuff to System.err.
+ */
+ private static final boolean debugThreads = false;
+
+ /**
+ * If true, emit events being processed to System.err.
+ */
+ private static final boolean debugEvents = false;
+
/**
* WidgetEventHandler is the main event consumer loop. There are at most
* two such threads in existence: the primary for normal case and a
}
event = application.drainEventQueue.remove(0);
}
+ // Wait for drawAll() or doIdle() to be done, then handle
+ // the event.
+ boolean oldLock = lockHandleEvent();
+ assert (oldLock == false);
if (primary) {
primaryHandleEvent(event);
} else {
if ((!primary)
&& (application.secondaryEventReceiver == null)
) {
- // Secondary thread, time to exit
+ // Secondary thread, time to exit.
+
+ // DO NOT UNLOCK. Primary thread just came back from
+ // primaryHandleEvent() and will unlock in the else
+ // block below.
return;
+ } else {
+ // Unlock. Either I am primary thread, or I am
+ // secondary thread and still running.
+ oldLock = unlockHandleEvent();
+ assert (oldLock == true);
}
}
} // while (true) (main runnable loop)
*/
private TWidget secondaryEventReceiver;
+ /**
+ * Spinlock for the primary and secondary event handlers.
+ * WidgetEventHandler.run() is responsible for setting this value.
+ */
+ private volatile boolean insideHandleEvent = false;
+
+ /**
+ * Set the insideHandleEvent flag to true. lockoutEventHandlers() will
+ * spin indefinitely until unlockHandleEvent() is called.
+ *
+ * @return the old value of insideHandleEvent
+ */
+ private boolean lockHandleEvent() {
+ if (debugThreads) {
+ System.err.printf(" >> lockHandleEvent(): oldValue %s",
+ insideHandleEvent);
+ }
+ boolean oldValue = true;
+
+ synchronized (this) {
+ // Wait for TApplication.run() to finish using the global state
+ // before allowing further event processing.
+ while (lockoutHandleEvent == true);
+
+ oldValue = insideHandleEvent;
+ insideHandleEvent = true;
+ }
+
+ if (debugThreads) {
+ System.err.printf(" ***\n");
+ }
+ return oldValue;
+ }
+
+ /**
+ * Set the insideHandleEvent flag to false. lockoutEventHandlers() will
+ * spin indefinitely until unlockHandleEvent() is called.
+ *
+ * @return the old value of insideHandleEvent
+ */
+ private boolean unlockHandleEvent() {
+ if (debugThreads) {
+ System.err.printf(" << unlockHandleEvent(): oldValue %s\n",
+ insideHandleEvent);
+ }
+ synchronized (this) {
+ boolean oldValue = insideHandleEvent;
+ insideHandleEvent = false;
+ return oldValue;
+ }
+ }
+
+ /**
+ * Spinlock for the primary and secondary event handlers. When true, the
+ * event handlers will spinlock wait before calling handleEvent().
+ */
+ private volatile boolean lockoutHandleEvent = false;
+
+ /**
+ * TApplication.run() needs to be able rely on the global data structures
+ * being intact when calling doIdle() and drawAll(). Tell the event
+ * handlers to wait for an unlock before handling their events.
+ */
+ private void stopEventHandlers() {
+ if (debugThreads) {
+ System.err.printf(">> stopEventHandlers()");
+ }
+
+ lockoutHandleEvent = true;
+ // Wait for the last event to finish processing before returning
+ // control to TApplication.run().
+ while (insideHandleEvent == true);
+
+ if (debugThreads) {
+ System.err.printf(" XXX\n");
+ }
+ }
+
+ /**
+ * TApplication.run() needs to be able rely on the global data structures
+ * being intact when calling doIdle() and drawAll(). Tell the event
+ * handlers that it is now OK to handle their events.
+ */
+ private void startEventHandlers() {
+ if (debugThreads) {
+ System.err.printf("<< startEventHandlers()\n");
+ }
+ lockoutHandleEvent = false;
+ }
+
/**
* Access to the physical screen, keyboard, and mouse.
*/
* Draw everything.
*/
public final void drawAll() {
+ if (debugThreads) {
+ System.err.printf("drawAll() enter\n");
+ }
+
if ((flush) && (!repaint)) {
backend.flushScreen();
flush = false;
return;
}
+ if (debugThreads) {
+ System.err.printf("drawAll() REDRAW\n");
+ }
+
// If true, the cursor is not visible
boolean cursor = false;
metaHandleEvent(event);
}
+ // Prevent stepping on the primary or secondary event handler.
+ stopEventHandlers();
+
// Process timers and call doIdle()'s
doIdle();
// Update the screen
- drawAll();
+ synchronized (getScreen()) {
+ drawAll();
+ }
+
+ // Let the event handlers run again.
+ startEventHandlers();
}
// Shutdown the consumer threads
*/
private void metaHandleEvent(final TInputEvent event) {
- /*
- System.err.printf(String.format("metaHandleEvents event: %s\n",
- event)); System.err.flush();
- */
+ if (debugEvents) {
+ System.err.printf(String.format("metaHandleEvents event: %s\n",
+ event)); System.err.flush();
+ }
if (quit) {
// Do no more processing if the application is already trying
*/
private void primaryHandleEvent(final TInputEvent event) {
- // System.err.printf("Handle event: %s\n", event);
+ if (debugEvents) {
+ System.err.printf("Handle event: %s\n", event);
+ }
// Special application-wide events -----------------------------------
mouse.setX(mouse.getX() - window.getX());
mouse.setY(mouse.getY() - window.getY());
}
- // System.err("TApplication dispatch event: %s\n", event);
+ if (debugEvents) {
+ System.err.printf("TApplication dispatch event: %s\n",
+ event);
+ }
window.handleEvent(event);
break;
}
*/
public final void yield() {
assert (secondaryEventReceiver != null);
+ // This is where we handoff the event handler lock from the primary
+ // to secondary thread. We unlock here, and in a future loop the
+ // secondary thread locks again. When it gives up, we have the
+ // single lock back.
+ boolean oldLock = unlockHandleEvent();
+ assert (oldLock == true);
+
while (secondaryEventReceiver != null) {
synchronized (this) {
try {
* Do stuff when there is no user input.
*/
private void doIdle() {
+ if (debugThreads) {
+ System.err.printf("doIdle()\n");
+ }
+
// Now run any timers that have timed out
Date now = new Date();
List<TTimer> keepTimers = new LinkedList<TTimer>();
return true;
}
- /*
- TODO
if (command.equals(cmShell)) {
- openTerminal(0, 0, TWindow.Flag.RESIZABLE);
+ openTerminal(0, 0, TWindow.RESIZABLE);
repaint = true;
return true;
}
- */
if (command.equals(cmTile)) {
tileWindows();
return true;
}
- /*
- TODO
- if (menu.id == TMenu.MID_SHELL) {
- openTerminal(0, 0, TWindow.Flag.RESIZABLE);
+ if (menu.getId() == TMenu.MID_SHELL) {
+ openTerminal(0, 0, TWindow.RESIZABLE);
repaint = true;
return true;
}
- */
if (menu.getId() == TMenu.MID_TILE) {
tileWindows();
* @param title menu title
* @return the new menu
*/
- public final TMenu addMenu(String title) {
+ public final TMenu addMenu(final String title) {
int x = 0;
int y = 0;
TMenu menu = new TMenu(this, x, y, title);
int newWidth = (getScreen().getWidth() / a);
int newHeight1 = ((getScreen().getHeight() - 1) / b);
int newHeight2 = ((getScreen().getHeight() - 1) / (b + c));
- // System.err.printf("Z %s a %s b %s c %s newWidth %s newHeight1 %s newHeight2 %s",
- // z, a, b, c, newWidth, newHeight1, newHeight2);
List<TWindow> sorted = new LinkedList<TWindow>(windows);
Collections.sort(sorted);
return new TInputBox(this, title, caption, text);
}
+ /**
+ * Convenience function to open a terminal window.
+ *
+ * @param x column relative to parent
+ * @param y row relative to parent
+ * @return the terminal new window
+ */
+ public final TTerminalWindow openTerminal(final int x, final int y) {
+ return openTerminal(x, y, TWindow.RESIZABLE);
+ }
+
+ /**
+ * Convenience function to open a terminal window.
+ *
+ * @param x column relative to parent
+ * @param y row relative to parent
+ * @param flags mask of CENTERED, MODAL, or RESIZABLE
+ * @return the terminal new window
+ */
+ public final TTerminalWindow openTerminal(final int x, final int y,
+ final int flags) {
+
+ return new TTerminalWindow(this, x, y, flags);
+ }
+
}
git://git.nikiroo.be / nikiroo-utils.git / blobdiff