Merge pull request #1 from jartu/develop

jabrena · web-flow · commit 27135b264de1 · 2017-07-12T20:24:22.000+01:00
Adding new Button example that demonstrates the new EV3Key implementation.
diff --git a/ev3dev-lang-java/src/main/java/ev3dev/sensors/ButtonListenersExample.java b/ev3dev-lang-java/src/main/java/ev3dev/sensors/ButtonListenersExample.java
@@ -0,0 +1,69 @@
+package ev3dev.sensors;
+
+import lejos.hardware.Key;
+import lejos.hardware.KeyListener;
+
+import java.time.LocalTime;
+import java.time.format.DateTimeFormatter;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class ButtonListenersExample {
+
+    private static final DateTimeFormatter TIMESTAMP_FORMAT = DateTimeFormatter.ofPattern(
+            "HH:mm:ss.SSS");
+
+    private static class MyKeyListener implements KeyListener {
+        private final Key registeredForKey;
+
+        public MyKeyListener(final Key registeredForKey) {
+            this.registeredForKey = registeredForKey;
+        }
+
+        @Override
+        public void keyPressed(final Key key) {
+            System.out.format("%s - [%s listener] %s pressed%n", LocalTime.now().format(TIMESTAMP_FORMAT),
+                    this.registeredForKey.getName(), key.getName());
+        }
+        @Override
+        public void keyReleased(final Key key) {
+            System.out.format("%s - [%s listener] %s released%n", LocalTime.now().format(TIMESTAMP_FORMAT),
+                    this.registeredForKey.getName(), key.getName());
+        }
+    }
+
+    private static final List<Key> BUTTONS_FOR_LISTENERS = Arrays.asList(new Key[] {
+            Button.UP,
+            Button.DOWN,
+            new EV3Key(EV3Key.BUTTON_ALL)   // a special key that stands for 'any' key
+    });
+
+    public static void main(final String[] args){
+
+        // registering the listeners
+        System.out.println("Registering key listeners...");
+        BUTTONS_FOR_LISTENERS.forEach((key) -> {
+            key.addKeyListener(new MyKeyListener(key));
+            System.out.format("Listener for %s key registered%n", key.getName());
+        });
+
+        // printing some on-screen help
+        final Key exitButton = Button.ESCAPE;
+        final Key anyButton = new EV3Key(EV3Key.BUTTON_ALL);
+        final List<String> registeredKeyNamesExceptAll = BUTTONS_FOR_LISTENERS.stream()
+                .filter((button) -> ! button.equals(anyButton))
+                .map(Key::getName).collect(Collectors.toList());
+        System.out.format("%nKeep pressing any buttons to see listeners getting key press/release events.%n");
+        System.out.format("Notice that if you press or release one of the %s buttons, you'll get two events:%n", registeredKeyNamesExceptAll);
+        System.out.format("  1) one for the listener registered on that specific key%n");
+        System.out.format("  2) another one for the listener registered on the special %s key%n", anyButton.getName());
+
+        // printing the key events (from the listeners) until the ESCAPE key is pressed (i.e. the call above blocks)
+        System.out.format("%nPress the %s key to terminate the program...%n", exitButton.getName());
+        exitButton.waitForPress();
+
+        // terminating
+        System.out.format("%n%s press detected, terminating the program.%n", exitButton.getName());
+    }
+}
