X-Git-Url: https://git.argeo.org/?p=gpl%2Fargeo-suite.git;a=blobdiff_plain;f=org.argeo.app.ui%2Fsrc%2Forg%2Fargeo%2Fapp%2Fui%2Fwidgets%2FDelayedText.java;fp=org.argeo.app.ui%2Fsrc%2Forg%2Fargeo%2Fapp%2Fui%2Fwidgets%2FDelayedText.java;h=ecf66396868364ba893c187a5dbf0014babe04bd;hp=0000000000000000000000000000000000000000;hb=6e56ffa34cb02ab04d028423aea342e3dfed4358;hpb=c285180bece610b2c2921d44fe14b6dde2123efa

diff --git a/org.argeo.app.ui/src/org/argeo/app/ui/widgets/DelayedText.java b/org.argeo.app.ui/src/org/argeo/app/ui/widgets/DelayedText.java
new file mode 100644
index 0000000..ecf6639
--- /dev/null
+++ b/org.argeo.app.ui/src/org/argeo/app/ui/widgets/DelayedText.java
@@ -0,0 +1,91 @@
+package org.argeo.app.ui.widgets;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Consumer;
+
+import org.eclipse.rap.rwt.service.ServerPushSession;
+import org.eclipse.swt.events.ModifyEvent;
+import org.eclipse.swt.events.ModifyListener;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Text;
+
+/**
+ * A text input which notifies changes after a delay, typically in order to
+ * apply a filter.
+ */
+public class DelayedText {
+	private final static ScheduledExecutorService scheduler;
+	static {
+		// create only one scheduler, in order not to exhaust threads
+		scheduler = Executors.newScheduledThreadPool(0, (r) -> {
+			Thread thread = new Thread(r, "Delayed text scheduler");
+			// we mark threads as deamons so that the shutdown hook is triggered
+			thread.setDaemon(true);
+			return thread;
+		});
+		Runtime.getRuntime().addShutdownHook(new Thread(() -> {
+			scheduler.shutdown();
+		}, "Shutdown delayed text scheduler"));
+	}
+	private final static int DEFAULT_DELAY = 800;
+
+	private final long delay;
+	private final InternalModifyListener modifyListener;
+	private final Text text;
+	protected List<Consumer<String>> toDos = new ArrayList<>();
+	private ServerPushSession pushSession;
+
+	private ScheduledFuture<String> lastTask;
+
+	public DelayedText(Composite parent, int style) {
+		this(parent, style, DEFAULT_DELAY);
+	}
+
+	public DelayedText(Composite parent, int style, long delayInMs) {
+		this.delay = delayInMs;
+		this.modifyListener = new InternalModifyListener();
+		pushSession = new ServerPushSession();
+		pushSession.start();
+		text = new Text(parent, style);
+		text.addModifyListener(modifyListener);
+	}
+
+	protected void notifyText(String txt) {
+		// text.getDisplay().syncExec(()-> pushSession.start());
+		for (Consumer<String> toDo : toDos) {
+			text.getDisplay().syncExec(() -> toDo.accept(txt));
+		}
+		// text.getDisplay().syncExec(()->pushSession.stop());
+	}
+
+	public Text getText() {
+		return text;
+	}
+
+	public void addListener(Consumer<String> toDo) {
+		toDos.add(toDo);
+	}
+
+	private class InternalModifyListener implements ModifyListener {
+		private static final long serialVersionUID = -6178431173400385005L;
+
+		public void modifyText(ModifyEvent e) {
+			String txt = text.getText();
+			ScheduledFuture<String> task = scheduler.schedule(() -> {
+				notifyText(txt);
+				return txt;
+			}, delay, TimeUnit.MILLISECONDS);
+			// cancel previous task
+			if (lastTask != null && !lastTask.isDone()) {
+				lastTask.cancel(false);
+			}
+			lastTask = task;
+		}
+	};
+
+}