Fix - Range selection ordering (#818)

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

@@ -15,6 +15,7 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import org.threeten.bp.LocalDate;
 
 /**
  * Pager adapter backing the calendar view
@@ -294,6 +295,13 @@ public void clearSelections() {
         invalidateSelectedDates();
     }
 
+    /**
+     * Select or un-select a day.
+     *
+     * @param day Day to select or un-select
+     * @param selected Whether to select or un-select the day from the list.
+     * @see CalendarPagerAdapter#selectRange(CalendarDay, CalendarDay)
+     */
     public void setDateSelected(CalendarDay day, boolean selected) {
         if (selected) {
             if (!selectedDates.contains(day)) {
@@ -308,6 +316,31 @@ public void setDateSelected(CalendarDay day, boolean selected) {
         }
     }
 
+    /**
+     * Clear the previous selection, select the range of days from first to last, and finally
+     * invalidate. First day should be before last day, otherwise the selection won't happen.
+     *
+     * @param first The first day of the range.
+     * @param last The last day in the range.
+     * @see CalendarPagerAdapter#setDateSelected(CalendarDay, boolean)
+     */
+    public void selectRange(final CalendarDay first, final CalendarDay last) {
+        selectedDates.clear();
+
+        // Copy to start from the first day and increment
+        LocalDate temp = LocalDate.of(first.getYear(), first.getMonth(), first.getDay());
+
+        // for comparison
+        final LocalDate end = last.getDate();
+
+        while (temp.isBefore(end) || temp.equals(end)) {
+            selectedDates.add(CalendarDay.from(temp));
+            temp = temp.plusDays(1);
+        }
+
+        invalidateSelectedDates();
+    }
+
     private void invalidateSelectedDates() {
         validateSelectedDates();
         for (V pagerView : currentViews) {

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

@@ -15,7 +15,6 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
-import java.util.Locale;
 import org.threeten.bp.DayOfWeek;
 import org.threeten.bp.LocalDate;
 import org.threeten.bp.temporal.TemporalField;

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

@@ -780,10 +780,19 @@ public void setWeekDayTextAppearance(int resourceId) {
     }
 
     /**
-     * @return the selected day, or null if no selection. If in multiple selection mode, this
-     * will return the last selected date
+     * Get the currently selected date, or null if no selection. Depending on the selection mode,
+     * you might get different results.
+     *
+     * <p>For {@link #SELECTION_MODE_SINGLE}, returns the selected date.</p>
+     * <p>For {@link #SELECTION_MODE_MULTIPLE}, returns the last date selected.</p>
+     * <p>For {@link #SELECTION_MODE_RANGE}, returns the last date of the range. In most cases, you should probably be using {@link #getSelectedDates()}.</p>
+     * <p>For {@link #SELECTION_MODE_NONE}, returns null.</p>
+     *
+     * @return The selected day, or null if no selection. If in multiple selection mode, this
+     * will return the last date of the list of selected dates.
+     * @see MaterialCalendarView#getSelectedDates()
      */
-    public CalendarDay getSelectedDate() {
+    @Nullable public CalendarDay getSelectedDate() {
         List<CalendarDay> dates = adapter.getSelectedDates();
         if (dates.isEmpty()) {
             return null;
@@ -793,10 +802,16 @@ public CalendarDay getSelectedDate() {
     }
 
     /**
-     * @return all of the currently selected dates
+     * Return the list of currently selected dates. Mostly useful for {@link #SELECTION_MODE_MULTIPLE}
+     * and {@link #SELECTION_MODE_RANGE}. For the other modes, check {@link #getSelectedDate()}.
+     *
+     * <p>For {@link #SELECTION_MODE_MULTIPLE}, returns the list in the order of selection.</p>
+     * <p>For {@link #SELECTION_MODE_RANGE}, returns the range of dates ordered chronologically.</p>
+     *
+     * @return All of the currently selected dates.
+     * @see MaterialCalendarView#getSelectedDate()
      */
-    @NonNull
-    public List<CalendarDay> getSelectedDates() {
+    @NonNull public List<CalendarDay> getSelectedDates() {
         return adapter.getSelectedDates();
     }
 
@@ -1395,30 +1410,13 @@ protected void dispatchOnDateSelected(final CalendarDay day, final boolean selec
     }
 
     /**
-     * Dispatch a range of days to a listener, if set. First day must be before last Day.
+     * Dispatch a range of days to a range listener, if set, ordered chronologically.
      *
-     * @param firstDay first day enclosing a range
-     * @param lastDay  last day enclosing a range
+     * @param days Enclosing days ordered from first to last day.
      */
-    protected void dispatchOnRangeSelected(final CalendarDay firstDay, final CalendarDay lastDay) {
-        final OnRangeSelectedListener listener = rangeListener;
-        final List<CalendarDay> days = new ArrayList<>();
-
-        // Copy to start from the first day and increment
-        LocalDate temp = LocalDate.of(firstDay.getYear(), firstDay.getMonth(), firstDay.getDay());
-
-        // for comparison
-        final LocalDate end = lastDay.getDate();
-
-        while (temp.isBefore(end) || temp.equals(end)) {
-            final CalendarDay current = CalendarDay.from(temp);
-            adapter.setDateSelected(current, true);
-            days.add(current);
-            temp = temp.plusDays(1);
-        }
-
-        if (listener != null) {
-            listener.onRangeSelected(MaterialCalendarView.this, days);
+    protected void dispatchOnRangeSelected(@NonNull final List<CalendarDay> days) {
+        if (rangeListener != null) {
+            rangeListener.onRangeSelected(MaterialCalendarView.this, days);
         }
     }
 
@@ -1457,16 +1455,18 @@ protected void onDateClicked(@NonNull CalendarDay date, boolean nowSelected) {
                 } else if (currentSelection.size() == 1) {
                     // Selecting the second date of a range
                     final CalendarDay firstDaySelected = currentSelection.get(0);
-                    adapter.setDateSelected(date, nowSelected);
                     if (firstDaySelected.equals(date)) {
                         // Right now, we are not supporting a range of one day, so we are removing the day instead.
+                        adapter.setDateSelected(date, nowSelected);
                         dispatchOnDateSelected(date, nowSelected);
                     } else if (firstDaySelected.isAfter(date)) {
-                        // Selecting a range, dispatching...
-                        dispatchOnRangeSelected(date, firstDaySelected);
-                    } else {
                         // Selecting a range, dispatching in reverse order...
-                        dispatchOnRangeSelected(firstDaySelected, date);
+                        adapter.selectRange(date, firstDaySelected);
+                        dispatchOnRangeSelected(adapter.getSelectedDates());
+                    } else {
+                        // Selecting a range, dispatching in order...
+                        adapter.selectRange(firstDaySelected, date);
+                        dispatchOnRangeSelected(adapter.getSelectedDates());
                     }
                 } else {
                     // Clearing selection and making a selection of the new date.
@@ -1493,13 +1493,14 @@ protected void onDateClicked(@NonNull CalendarDay date, boolean nowSelected) {
      * @param lastDay  last day of the range to select
      */
     public void selectRange(final CalendarDay firstDay, final CalendarDay lastDay) {
-        clearSelection();
         if (firstDay == null || lastDay == null) {
             return;
         } else if (firstDay.isAfter(lastDay)) {
-            dispatchOnRangeSelected(lastDay, firstDay);
+            adapter.selectRange(lastDay, firstDay);
+            dispatchOnRangeSelected(adapter.getSelectedDates());
         } else {
-            dispatchOnRangeSelected(firstDay, lastDay);
+            adapter.selectRange(firstDay, lastDay);
+            dispatchOnRangeSelected(adapter.getSelectedDates());
         }
     }
 

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

@@ -4,21 +4,17 @@
 import android.content.Context;
 import android.content.DialogInterface;
 import android.graphics.Color;
-import android.icu.util.Calendar;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.v7.app.AlertDialog;
 import android.support.v7.app.AppCompatActivity;
-import android.util.Log;
 import android.view.View;
-import android.widget.DatePicker;
 import android.widget.LinearLayout;
 import android.widget.NumberPicker;
 import android.widget.Toast;
 import com.prolificinteractive.materialcalendarview.CalendarDay;
 import com.prolificinteractive.materialcalendarview.CalendarMode;
 import com.prolificinteractive.materialcalendarview.MaterialCalendarView;
-import java.sql.Date;
 import java.util.Random;
 import butterknife.BindView;
 import butterknife.ButterKnife;

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

@@ -3,6 +3,7 @@
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.v7.app.AppCompatActivity;
+import android.util.Log;
 import android.widget.Toast;
 import butterknife.BindView;
 import butterknife.ButterKnife;
@@ -13,6 +14,7 @@
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.List;
+import org.threeten.bp.format.DateTimeFormatter;
 
 /**
  * An activity that demonstrate the multiple selection mode that the calendar offers.
@@ -23,7 +25,7 @@
 public class SelectionModesActivity extends AppCompatActivity
     implements OnDateSelectedListener, OnRangeSelectedListener {
 
-  private static final DateFormat FORMATTER = SimpleDateFormat.getDateInstance();
+  private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("EEE, d MMM yyyy");
 
   @BindView(R.id.calendar_view_single) MaterialCalendarView single;
   @BindView(R.id.calendar_view_multi) MaterialCalendarView multi;
@@ -72,5 +74,4 @@ void onCalendarModeChanged(boolean checked) {
     range.state().edit().setCalendarDisplayMode(mode).commit();
     none.state().edit().setCalendarDisplayMode(mode).commit();
   }
-
 }