protected void forward(int offset, ChronoUnit unit, boolean focusDayCell, boolean withAnimation) {
    if (withAnimation) {
        if (tempImageTransition == null || tempImageTransition.getStatus() == Status.STOPPED) {
            Pane monthContent = (Pane) calendarPlaceHolder.getChildren().get(0);
            this.getParent().setManaged(false);
            SnapshotParameters snapShotparams = new SnapshotParameters();
            snapShotparams.setFill(Color.TRANSPARENT);
            WritableImage temp = monthContent.snapshot(snapShotparams,
                new WritableImage((int) monthContent.getWidth(),
                    (int) monthContent.getHeight()));
            ImageView tempImage = new ImageView(temp);
            calendarPlaceHolder.getChildren().add(calendarPlaceHolder.getChildren().size() - 2, tempImage);
            TranslateTransition imageTransition = new TranslateTransition(Duration.millis(160), tempImage);
            imageTransition.setToX(-offset * calendarPlaceHolder.getWidth());
            imageTransition.setOnFinished((finish) -> calendarPlaceHolder.getChildren().remove(tempImage));
            monthContent.setTranslateX(offset * calendarPlaceHolder.getWidth());
            TranslateTransition contentTransition = new TranslateTransition(Duration.millis(160), monthContent);
            contentTransition.setToX(0);

            tempImageTransition = new ParallelTransition(imageTransition, contentTransition);
            tempImageTransition.setOnFinished((finish) -> {
                calendarPlaceHolder.getChildren().remove(tempImage);
                this.getParent().setManaged(true);
            });
            tempImageTransition.play();
        }
    }
    YearMonth yearMonth = selectedYearMonth.get();
    DateCell dateCell = currentFocusedDayCell;
    if (dateCell == null || !(dayCellDate(dateCell).getMonth() == yearMonth.getMonth())) {
        dateCell = findDayCellOfDate(yearMonth.atDay(1));
    }
    goToDayCell(dateCell, offset, unit, focusDayCell);
}
 

private DateCell findDayCellOfDate(LocalDate date) {
    for (int i = 0; i < dayCellDates.length; i++) {
        if (date.equals(dayCellDates[i])) {
            return dayCells.get(i);
        }
    }
    return dayCells.get(dayCells.size() / 2 + 1);
}
 

@FXML
void initialize() {
    LocalDate date = LocalDate.now();
    Callback<DatePicker, DateCell> callback = d -> new DateCell() {
        @Override
        public void updateItem(LocalDate item, boolean empty) {
            super.updateItem(item, empty);
            this.getStyleClass().remove("selected");
            this.getStyleClass().remove("contains");

            LocalDate from = UnitDialog.this.from.getValue();
            LocalDate to = UnitDialog.this.to.getValue();
            if (from != null && to != null) {
                if (item.equals(from) || item.equals(to)) {
                    this.getStyleClass().add("selected");
                } else if ((from.compareTo(to) < 0 && item.compareTo(from) > 0 && item.compareTo(to) < 0)
                        || (from.compareTo(to) > 0 && item.compareTo(from) < 0 && item.compareTo(to) > 0)) {
                    this.getStyleClass().add("contains");
                }
            }
        }
    };
    this.to.setValue(date);
    this.to.setDayCellFactory(callback);
    this.from.setValue(date.minusWeeks(2));
    this.from.setDayCellFactory(callback);
}
 

private void initUI() {
    VBox vbox = new VBox(20);
    vbox.setStyle("-fx-padding: 10;");
    Scene scene = new Scene(vbox, 400, 400);
    stage.setScene(scene);

    checkInDatePicker = new DatePicker();
    checkOutDatePicker = new DatePicker();
    checkInDatePicker.setValue(LocalDate.now());

    final Callback<DatePicker, DateCell> dayCellFactory = new Callback<DatePicker, DateCell>() {
        @Override
        public DateCell call(final DatePicker datePicker) {
            return new DateCell() {
                @Override
                public void updateItem(LocalDate item, boolean empty) {
                    super.updateItem(item, empty);

                    if (item.isBefore(checkInDatePicker.getValue().plusDays(1))) {
                        setDisable(true);
                        setStyle("-fx-background-color: #ffc0cb;");
                    }
                    long p = ChronoUnit.DAYS.between(checkInDatePicker.getValue(), item);
                    setTooltip(new Tooltip("You're about to stay for " + p + " days"));
                }
            };
        }
    };

    checkOutDatePicker.setDayCellFactory(dayCellFactory);
    checkOutDatePicker.setValue(checkInDatePicker.getValue().plusDays(1));
    checkInDatePicker.setChronology(ThaiBuddhistChronology.INSTANCE);
    checkOutDatePicker.setChronology(HijrahChronology.INSTANCE);

    GridPane gridPane = new GridPane();
    gridPane.setHgap(10);
    gridPane.setVgap(10);

    Label checkInlabel = new Label("Check-In Date:");
    gridPane.add(checkInlabel, 0, 0);
    GridPane.setHalignment(checkInlabel, HPos.LEFT);

    gridPane.add(checkInDatePicker, 0, 1);

    Label checkOutlabel = new Label("Check-Out Date:");
    gridPane.add(checkOutlabel, 0, 2);
    GridPane.setHalignment(checkOutlabel, HPos.LEFT);

    gridPane.add(checkOutDatePicker, 0, 3);

    vbox.getChildren().add(gridPane);

}
 

private void updateDayCells() {
    Locale locale = getLocale();
    Chronology chrono = getPrimaryChronology();
    // get the index of the first day of the month
    int firstDayOfWeek = WeekFields.of(getLocale()).getFirstDayOfWeek().getValue();
    int firstOfMonthIndex = selectedYearMonth.get().atDay(1).getDayOfWeek().getValue() - firstDayOfWeek;
    firstOfMonthIndex += firstOfMonthIndex < 0 ? daysPerWeek : 0;
    YearMonth currentYearMonth = selectedYearMonth.get();

    int daysInCurMonth = -1;

    for (int i = 0; i < 6 * daysPerWeek; i++) {
        DateCell dayCell = dayCells.get(i);
        dayCell.getStyleClass().setAll("cell", "date-cell", "day-cell");
        dayCell.setPrefSize(40, 42);
        dayCell.setDisable(false);
        dayCell.setStyle(null);
        dayCell.setGraphic(null);
        dayCell.setTooltip(null);
        dayCell.setTextFill(DEFAULT_COLOR);
        dayCell.setBackground(new Background(new BackgroundFill(Color.TRANSPARENT,
            CornerRadii.EMPTY,
            Insets.EMPTY)));

        try {
            if (daysInCurMonth == -1) {
                daysInCurMonth = currentYearMonth.lengthOfMonth();
            }

            int dayIndex = i - firstOfMonthIndex + 1;

            LocalDate date = currentYearMonth.atDay(dayIndex);
            dayCellDates[i] = date;

            // if it's today
            if (date.equals(LocalDate.now())) {
                dayCell.setTextFill(this.datePicker.getDefaultColor());
                dayCell.getStyleClass().add("today");
            }
            // if it's the current selected value
            if (date.equals(datePicker.getValue())) {
                dayCell.getStyleClass().add("selected");
                dayCell.setTextFill(Color.WHITE);
                dayCell.setBackground(
                    new Background(new BackgroundFill(this.datePicker.getDefaultColor(),
                        new CornerRadii(40),
                        Insets.EMPTY)));
            }

            ChronoLocalDate cDate = chrono.date(date);
            String cellText = dayCellFormatter.withLocale(locale)
                .withChronology(chrono)
                .withDecimalStyle(DecimalStyle.of(locale))
                .format(cDate);
            dayCell.setText(cellText);
            if (i < firstOfMonthIndex) {
                dayCell.getStyleClass().add("previous-month");
                dayCell.setText("");
            } else if (i >= firstOfMonthIndex + daysInCurMonth) {
                dayCell.getStyleClass().add("next-month");
                dayCell.setText("");
            }
            // update cell item
            dayCell.updateItem(date, false);
        } catch (DateTimeException ex) {
            // Disable day cell if its date is out of range
            dayCell.setText("");
            dayCell.setDisable(true);
        }
    }
}
 

protected LocalDate dayCellDate(DateCell dateCell) {
    assert dayCellDates != null;
    return dayCellDates[dayCells.indexOf(dateCell)];
}
 

private void goToDayCell(DateCell dateCell, int offset, ChronoUnit unit, boolean focusDayCell) {
    YearMonth yearMonth = selectedYearMonth.get().plus(offset, unit);
    goToDate(dayCellDate(dateCell).plus(offset, unit).withYear(yearMonth.getYear()), focusDayCell);
}
 

private void selectDayCell(DateCell dateCell) {
    datePicker.setValue(dayCellDate(dateCell));
    datePicker.hide();
}
 

protected void createDayCells() {
    for (int row = 0; row < 6; row++) {
        for (int col = 0; col < daysPerWeek; col++) {
            DateCell dayCell = createDayCell();
            dayCell.addEventHandler(MouseEvent.MOUSE_CLICKED, click -> {
                // allow date selection on mouse primary button click
                if (click.getButton() != MouseButton.PRIMARY) {
                    return;
                }
                DateCell selectedDayCell = (DateCell) click.getSource();
                selectDayCell(selectedDayCell);
                currentFocusedDayCell = selectedDayCell;
            });
            // add mouse hover listener
            dayCell.setOnMouseEntered((event) -> {
                if (!dayCell.getStyleClass().contains("selected")) {
                    dayCell.setBackground(new Background(new BackgroundFill(Color.valueOf("#EDEDED"),
                        new CornerRadii(40),
                        Insets.EMPTY)));
                }
            });
            dayCell.setOnMouseExited((event) -> {
                if (!dayCell.getStyleClass().contains("selected")) {
                    dayCell.setBackground(new Background(new BackgroundFill(Color.TRANSPARENT,
                        CornerRadii.EMPTY,
                        Insets.EMPTY)));
                }
            });
            dayCell.setAlignment(Pos.BASELINE_CENTER);
            dayCell.setBorder(
                new Border(new BorderStroke(Color.TRANSPARENT,
                    BorderStrokeStyle.SOLID,
                    CornerRadii.EMPTY,
                    new BorderWidths(5))));
            dayCell.setFont(Font.font(ROBOTO, FontWeight.BOLD, 12));
            dayCells.add(dayCell);
        }
    }
    dayCellDates = new LocalDate[6 * daysPerWeek];
    // position the cells into the grid
    updateContentGrid();
}