From 6b44352839d1ba21db4c31fd753aedfd8d376f75 Mon Sep 17 00:00:00 2001
From: Peli de Halleux <pelikhan@users.noreply.github.com>
Date: Thu, 26 Oct 2017 20:38:17 -0700
Subject: [PATCH] event for ultrasonic module

---
 libs/core/_locales/core-jsdoc-strings.json |  3 ++
 libs/core/_locales/core-strings.json       |  1 +
 libs/core/ultrasonic.ts                    | 42 +++++++++++++++++++++-
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/libs/core/_locales/core-jsdoc-strings.json b/libs/core/_locales/core-jsdoc-strings.json
index 7c2a88f8..79da497f 100644
--- a/libs/core/_locales/core-jsdoc-strings.json
+++ b/libs/core/_locales/core-jsdoc-strings.json
@@ -38,6 +38,9 @@
   "input.TouchSensor.onEvent": "Do something when a touch sensor is touched...",
   "input.TouchSensor.onEvent|param|body": "code to run when the event is raised",
   "input.UltraSonicSensor.distance": "Gets the distance from the sonar in millimeters",
+  "input.UltraSonicSensor.onObject": "Registers code to run when the given color is close",
+  "input.UltraSonicSensor.onObject|param|distance": "the distance in centimeters when an object is close, eg: 10",
+  "input.UltraSonicSensor.onObject|param|handler": "the code to run when detected",
   "input.buttonDown": "Down button on the EV3 Brick.",
   "input.buttonEnter": "Enter button on the EV3 Brick.",
   "input.buttonLeft": "Left button on the EV3 Brick.",
diff --git a/libs/core/_locales/core-strings.json b/libs/core/_locales/core-strings.json
index c6c420c7..15244f77 100644
--- a/libs/core/_locales/core-strings.json
+++ b/libs/core/_locales/core-strings.json
@@ -44,6 +44,7 @@
   "input.TouchSensor.isTouched|block": "%sensor|is touched",
   "input.TouchSensor.onEvent|block": "on %sensor|%event",
   "input.UltraSonicSensor.distance|block": "%sensor|distance",
+  "input.UltraSonicSensor.onObject|block": "on %sensor|object within %distance|cm",
   "input.buttonDown|block": "brick button down",
   "input.buttonEnter|block": "brick button enter",
   "input.buttonLeft|block": "brick button left",
diff --git a/libs/core/ultrasonic.ts b/libs/core/ultrasonic.ts
index 79b63a0f..8cdc6981 100644
--- a/libs/core/ultrasonic.ts
+++ b/libs/core/ultrasonic.ts
@@ -1,15 +1,55 @@
+enum UltrasonicEvent {
+    ObjectClose = 1,
+    ObjectDetected = 2
+}
+
 namespace input {
 
     //% fixedInstances
     export class UltraSonicSensor extends internal.UartSensor {
+        private threshold: number;
+
         constructor(port: number) {
             super(port)
+            this.threshold = 10;
         }
 
         _deviceType() {
             return DAL.DEVICE_TYPE_ULTRASONIC
         }
 
+        _query(): number {
+            const d = this.getNumber(NumberFormat.UInt16LE, 0) & 0x0fff;            
+            return d < this.threshold ? UltrasonicEvent.ObjectClose
+                : d > this.threshold + 5 ? UltrasonicEvent.ObjectDetected
+                : 0;
+        }
+
+        _update(prev: number, curr: number) {
+            if (curr) 
+                control.raiseEvent(this._id, curr);
+        }
+
+        /**
+         * Registers code to run when the given color is close
+         * @param distance the distance in centimeters when an object is close, eg: 10
+         * @param handler the code to run when detected
+         */
+        //% help=input/ultrasonic/on-object
+        //% block="on %sensor|object within %distance|cm"
+        //% blockId=ultrasonicOnObjectClose
+        //% parts="ultrasonicsensor"
+        //% blockNamespace=input
+        //% weight=100 blockGap=8
+        //% group="Ultrasonic Sensor"
+        onObject(distance: number, handler: () => void) {
+            this.threshold = Math.max(1, Math.min(95, distance));
+            control.onEvent(this._id, UltrasonicEvent.ObjectClose, handler);
+            this._setMode(0)
+            if (this._query() == UltrasonicEvent.ObjectClose)
+                control.runInBackground(handler);
+        }
+
         /**
          * Gets the distance from the sonar in millimeters
          * @param sensor the ultrasonic sensor port
@@ -24,7 +64,7 @@ namespace input {
         distance() {
             // it supposedly also has an inch mode, but we stick to mm
             this._setMode(0)
-            return this.getNumber(NumberFormat.UInt16LE, 0) & 0x0fff
+            return this.getNumber(NumberFormat.UInt16LE, 0) & 0x0fff;
         }
     }