bugfix: onDateChange not called on tapped (#240)

android/src/main/java/com/henninghall/date_picker/pickers/AndroidNative.java

@@ -20,6 +20,7 @@ public class AndroidNative extends NumberPicker implements Picker {
 
     private Picker.OnValueChangeListener onValueChangedListener;
     private int state = SCROLL_STATE_IDLE;
+    private OnValueChangeListenerInScrolling listenerInScrolling;
 
     public AndroidNative(Context context) {
         super(context);
@@ -158,13 +159,7 @@ public class AndroidNative extends NumberPicker implements Picker {
             public void run() {
                 changeValueByOne(self, increment);
                 if (isLast) {
-                    new Handler().postDelayed(new Runnable() {
-                        @Override
-                        public void run() {
-                            onValueChangedListener.onValueChange();
-                        }
-                        // the delay make sure the wheel has stopped before sending the value change event
-                    }, 500);
+                    sendEventIn500ms();
                 }
             }
         }, ms);
@@ -172,34 +167,53 @@ public class AndroidNative extends NumberPicker implements Picker {
 
     @Override
     public void setOnValueChangeListenerInScrolling(final OnValueChangeListenerInScrolling listener) {
+        listenerInScrolling = listener;
+    }
+
+    @Override
+    public void setOnValueChangedListener(final Picker.OnValueChangeListener listener) {
+        this.onValueChangedListener = listener;
         final Picker self = this;
+
         super.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() {
             @Override
-            public void onValueChange(NumberPicker numberPicker, int from, int to) {
-                listener.onValueChangeInScrolling(self, from, to);
+            public void onValueChange(NumberPicker numberPicker, int oldVal, int newVal) {
+                if(listenerInScrolling != null) {
+                    listenerInScrolling.onValueChangeInScrolling(self, oldVal, newVal);
+                }
+                // onValueChange is triggered also during scrolling. Since we don't want
+                // to send event during scrolling we make sure wheel is still. This particular
+                // case happens when wheel is tapped, not scrolled.
+                if(state == SCROLL_STATE_IDLE) {
+                  sendEventIn500ms();
+                }
             }
         });
-    }
 
-    @Override
-    public void setOnValueChangedListener(final Picker.OnValueChangeListener listener) {
-        this.onValueChangedListener = listener;
         super.setOnScrollListener(new OnScrollListener() {
             @Override
             public void onScrollStateChange(NumberPicker numberPicker, int nextState) {
-                boolean stoppedScrolling = state != SCROLL_STATE_IDLE && nextState == SCROLL_STATE_IDLE;
-                if (stoppedScrolling) {
-                    new Handler().postDelayed(new Runnable() {
-                        @Override
-                        public void run() {
-                            listener.onValueChange();
-                        }
-                        // the delay make sure the wheel has stopped before sending the value change event
-                    }, 500);
-                }
-                state = nextState;
+               sendEventIfStopped(nextState);
+               state = nextState;
             }
         });
     }
 
+    private void sendEventIfStopped(int nextState){
+        boolean stoppedScrolling = state != SCROLL_STATE_IDLE && nextState == SCROLL_STATE_IDLE;
+        if (stoppedScrolling) {
+            sendEventIn500ms();
+        }
+    }
+
+    private void sendEventIn500ms(){
+        new Handler().postDelayed(new Runnable() {
+            @Override
+            public void run() {
+                onValueChangedListener.onValueChange();
+            }
+            // the delay make sure the wheel has stopped before sending the value change event
+        }, 500);
+    }
+
 }