Merge pull request #294 from wassx/datePickerFix

Multiple MaterialDatePicker valuechangehandler firing #293

Author: kevzlou7979

gwt-material/src/main/java/gwt/material/design/client/ui/MaterialDatePicker.java

@@ -119,6 +119,12 @@ protected void onAttach() {
         setPlaceholder(this.placeholder);
     }
 
+    @Override
+    protected void onDetach() {
+        super.onDetach();
+        removeClickHandler(pickatizedDateInput, this);
+    }
+
     @Override
     public void clear() {
         if (initialized) {
@@ -147,6 +153,10 @@ public void setDateSelectionType(MaterialDatePickerType type) {
         }
     }
 
+    native void removeClickHandler(Element picker, MaterialDatePicker parent) /*-{
+        picker.pickadate('picker').off("close", "open", "set");
+    }-*/;
+
     native void initClickHandler(Element picker, MaterialDatePicker parent) /*-{
         picker.pickadate('picker').on({
             close: function () {
@@ -288,6 +298,15 @@ public static native JsDate getDatePickerValue(Element picker)/*-{
         return picker.pickadate('picker').get('select').obj;
     }-*/;
 
+    /**
+     * Clears the values of the picker field.
+     */
+    public void clearValues() {
+        if (pickatizedDateInput != null) {
+            clearValues(pickatizedDateInput);
+        }
+    }
+
     public native void clearValues(Element picker) /*-{
         picker.pickadate('picker').clear();
     }-*/;