fix #774 Implement a date range picker component

domino-ui/src/main/java/org/dominokit/domino/ui/datepicker/CalendarDay.java

@@ -114,12 +114,37 @@ public Element getClickableElement() {
    * @return true if the day is today's date, false otherwise.
    */
   public boolean isTodayDate() {
-    Date date = new Date();
+    return isSameDayAs(new Date());
+  }
+
+  /**
+   * Checks if the day represents the specified date.
+   *
+   * @return true if the day is same year, month, and day, false otherwise.
+   */
+  public boolean isSameDayAs(Date date) {
     return date.getYear() == this.date.getYear()
         && date.getMonth() == this.date.getMonth()
         && date.getDate() == this.date.getDate();
   }
 
+  public boolean isInRange(Date dateFrom, Date dateTo) {
+    Date fromNoTime = removeTime(dateFrom);
+    Date toNoTime = removeTime(dateTo);
+    Date thisDayNoTime = removeTime(date);
+    return thisDayNoTime.getTime() >= fromNoTime.getTime()
+        && thisDayNoTime.getTime() <= toNoTime.getTime();
+  }
+
+  public static Date removeTime(Date date) {
+    date.setHours(0);
+    date.setMinutes(0);
+    date.setSeconds(0);
+
+    date.setTime(date.getTime() / 1000 * 1000); // Set milliseconds to zero
+    return date;
+  }
+
   /**
    * Checks if the day represents the currently selected date in the calendar.
    *

domino-ui/src/main/java/org/dominokit/domino/ui/datepicker/CalendarMonth.java

@@ -20,7 +20,9 @@
 import static org.dominokit.domino.ui.utils.Domino.*;
 
 import elemental2.dom.HTMLDivElement;
+import java.util.Arrays;
 import java.util.Date;
+import java.util.List;
 import org.dominokit.domino.ui.elements.DivElement;
 import org.dominokit.domino.ui.utils.BaseDominoElement;
 
@@ -178,6 +180,10 @@ private void updateView() {
     }
   }
 
+  public List<CalendarDay> getMonthViewDays() {
+    return Arrays.asList(monthDays);
+  }
+
   /**
    * {@inheritDoc}
    *

domino-ui/src/main/java/org/dominokit/domino/ui/datepicker/CalendarStyles.java

@@ -96,4 +96,6 @@ public interface CalendarStyles {
   CssClass dui_selected_year = () -> "dui-selected-year";
 
   CssClass dui_selected_month = () -> "dui-selected-month";
+
+  CssClass dui_date_in_range = () -> "dui-date-in-range";
 }

domino-ui/src/main/java/org/dominokit/domino/ui/forms/DateRange.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright © 2019 Dominokit
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.dominokit.domino.ui.forms;
+
+import java.util.Date;
+import java.util.Objects;
+
+public class DateRange {
+
+  private final Date from;
+  private final Date to;
+
+  public DateRange() {
+    this(new Date(), new Date());
+  }
+
+  public DateRange(Date from, Date to) {
+    Objects.requireNonNull(from);
+    Objects.requireNonNull(to);
+    this.from = from;
+    this.to = to;
+  }
+
+  public Date getFrom() {
+    return from;
+  }
+
+  public Date getTo() {
+    return to;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    DateRange dateRange = (DateRange) o;
+    return Objects.equals(from, dateRange.from) && Objects.equals(to, dateRange.to);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(from, to);
+  }
+}