Added: OnWeekChangedListener

library/src/main/java/com/prolificinteractive/materialcalendarview/MaterialCalendarView.java

@@ -208,7 +208,12 @@ public void onPageSelected(int position) {
           currentMonth = adapter.getItem(position);
           updateUi();
 
-          dispatchOnMonthChanged(currentMonth);
+          if (adapter instanceof MonthPagerAdapter) {
+            dispatchOnMonthChanged(currentMonth);
+          }
+          if (adapter instanceof WeekPagerAdapter) {
+            dispatchOnWeekChanged(currentMonth);
+          }
         }
 
         @Override
@@ -226,6 +231,7 @@ public void onPageScrolled(int position, float positionOffset, int positionOffse
   private OnDateSelectedListener listener;
   private OnDateLongClickListener longClickListener;
   private OnMonthChangedListener monthListener;
+  private OnWeekChangedListener weekListener;
   private OnRangeSelectedListener rangeListener;
 
   CharSequence calendarContentDescription;
@@ -1328,6 +1334,15 @@ public void setOnMonthChangedListener(OnMonthChangedListener listener) {
     this.monthListener = listener;
   }
 
+  /**
+   * Sets the listener to be notified upon week changes.
+   *
+   * @param listener thing to be notified
+   */
+  public void setOnWeekChangedListener(OnWeekChangedListener listener) {
+    this.weekListener = listener;
+  }
+
   /**
    * Sets the listener to be notified upon a range has been selected.
    *
@@ -1380,6 +1395,17 @@ protected void dispatchOnMonthChanged(final CalendarDay day) {
     }
   }
 
+  /**
+   * Dispatch date change events to a listener, if set
+   *
+   * @param day first day of the new week
+   */
+  protected void dispatchOnWeekChanged(final CalendarDay day) {
+    if (weekListener != null) {
+      weekListener.onWeekChanged(MaterialCalendarView.this, day);
+    }
+  }
+
   /**
    * Call by {@link CalendarPagerView} to indicate that a day was clicked and we should handle it.
    * This method will always process the click to the selected date.

library/src/main/java/com/prolificinteractive/materialcalendarview/OnWeekChangedListener.java

@@ -0,0 +1,15 @@
+package com.prolificinteractive.materialcalendarview;
+
+/**
+ * The callback used to indicate the user changes the displayed week
+ */
+public interface OnWeekChangedListener {
+
+  /**
+   * Called upon change of the selected day
+   *
+   * @param widget the view associated with this listener
+   * @param date the week picked, as the first day of the week
+   */
+  void onWeekChanged(MaterialCalendarView widget, CalendarDay date);
+}

sample/src/main/java/com/prolificinteractive/materialcalendarview/sample/SwappableBasicActivityDecorated.java

@@ -3,24 +3,30 @@
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.v7.app.AppCompatActivity;
+import android.widget.Toast;
 import butterknife.BindView;
 import butterknife.ButterKnife;
 import butterknife.OnClick;
 import com.prolificinteractive.materialcalendarview.CalendarDay;
 import com.prolificinteractive.materialcalendarview.CalendarMode;
 import com.prolificinteractive.materialcalendarview.MaterialCalendarView;
 import com.prolificinteractive.materialcalendarview.OnDateSelectedListener;
+import com.prolificinteractive.materialcalendarview.OnMonthChangedListener;
+import com.prolificinteractive.materialcalendarview.OnWeekChangedListener;
 import com.prolificinteractive.materialcalendarview.sample.decorators.HighlightWeekendsDecorator;
 import com.prolificinteractive.materialcalendarview.sample.decorators.MySelectorDecorator;
 import com.prolificinteractive.materialcalendarview.sample.decorators.OneDayDecorator;
 import org.threeten.bp.LocalDate;
 import org.threeten.bp.Month;
+import org.threeten.bp.format.DateTimeFormatter;
 
 /**
  * Shows off the most basic usage
  */
 public class SwappableBasicActivityDecorated extends AppCompatActivity
-    implements OnDateSelectedListener {
+    implements OnDateSelectedListener, OnMonthChangedListener, OnWeekChangedListener {
+
+  private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("EEE, d MMM yyyy");
 
   private final OneDayDecorator oneDayDecorator = new OneDayDecorator();
 
@@ -31,6 +37,8 @@ public class SwappableBasicActivityDecorated extends AppCompatActivity
     setContentView(R.layout.activity_basic_modes);
     ButterKnife.bind(this);
 
+    widget.setOnMonthChangedListener(this);
+    widget.setOnWeekChangedListener(this);
     widget.setOnDateChangedListener(this);
     widget.setShowOtherDates(MaterialCalendarView.SHOW_ALL);
 
@@ -72,4 +80,17 @@ public void onSetMonthMode() {
         .setCalendarDisplayMode(CalendarMode.MONTHS)
         .commit();
   }
+
+  @Override
+  public void onMonthChanged(MaterialCalendarView widget, CalendarDay date) {
+    Toast.makeText(this, "First day of Month: " + FORMATTER.format(date.getDate()),
+            Toast.LENGTH_SHORT).show();
+  }
+
+  @Override
+  public void onWeekChanged(MaterialCalendarView widget, CalendarDay date) {
+    Toast.makeText(this, "First day of Week: " + FORMATTER.format(date.getDate()),
+            Toast.LENGTH_SHORT).show();
+  }
+
 }