Merge pull request #2223 from diamonddevgroup/master

Introduced monthChangedListener that fires only when a new month is selected

CodenameOne/src/com/codename1/ui/Calendar.java

@@ -85,6 +85,7 @@ public class Calendar extends Container {
     static final long WEEK = DAY * 7;
     private EventDispatcher dispatcher = new EventDispatcher();
     private EventDispatcher dataChangedListeners = new EventDispatcher();
+    private EventDispatcher monthChangedListeners = new EventDispatcher();
     private long[] dates = new long[42];
     private boolean changesSelectedDateEnabled = true;
     private TimeZone tmz;
@@ -124,7 +125,8 @@ public Calendar(long time, TimeZone tmz) {
     }
 
     /**
-     * Constructs a calendar with the current date and time with left and right images set
+     * Constructs a calendar with the current date and time with left and right
+     * images set
      *
      * @param leftArrowImage an image for calendar left arrow
      * @param rightArrowImage an image for calendar right arrow
@@ -437,6 +439,24 @@ public void removeActionListener(ActionListener l) {
         mv.removeActionListener(l);
     }
 
+    /**
+     * Fires when a new month is selected
+     *
+     * @param l listener to add
+     */
+    public void addMonthChangedListener(ActionListener l) {
+        mv.addMonthChangedListener(l);
+    }
+
+    /**
+     * Fires when a new month is selected
+     *
+     * @param l listener to remove
+     */
+    public void removeMonthChangedListener(ActionListener l) {
+        mv.removeMonthChangedListener(l);
+    }
+
     /**
      * Adds an ActionListener to the day buttons. This is different from
      * {@code Calendar.addActionListener} and will only fire when an active day
@@ -1128,6 +1148,7 @@ public void setSelectedDay(long selectedDay) {
         }
 
         private void setMonth(int year, int month) {
+            fireMonthChangedEvent();
             java.util.Calendar cal = java.util.Calendar.getInstance(tmz);
             cal.setTimeZone(TimeZone.getDefault());
             cal.set(java.util.Calendar.MONTH, month);
@@ -1171,6 +1192,14 @@ public void removeActionListener(ActionListener l) {
             dispatcher.removeListener(l);
         }
 
+        public void addMonthChangedListener(ActionListener l) {
+            monthChangedListeners.addListener(l);
+        }
+
+        public void removeMonthChangedListener(ActionListener l) {
+            monthChangedListeners.removeListener(l);
+        }
+
         public void addDayActionListener(ActionListener l) {
             dayListeners.add(l);
             for (Component cmp : components) {
@@ -1209,6 +1238,10 @@ protected void fireActionEvent() {
             dispatcher.fireActionEvent(new ActionEvent(Calendar.this, ActionEvent.Type.Calendar));
         }
 
+        protected void fireMonthChangedEvent() {
+            monthChangedListeners.fireActionEvent(new ActionEvent(Calendar.this, ActionEvent.Type.Calendar));
+        }
+
         public void actionPerformed(ActionEvent evt) {
             Object src = evt.getSource();
             if (src instanceof ComboBox) {