/tiwulfx/src/main/java/eu/schudt/javafx/controls/calendar/DatePicker.java

package eu.schudt.javafx.controls.calendar;



import javafx.application.Platform;

import javafx.beans.InvalidationListener;

import javafx.beans.Observable;

import javafx.beans.binding.StringBinding;

import javafx.beans.property.*;

import javafx.beans.value.ChangeListener;

import javafx.beans.value.ObservableValue;

import javafx.event.ActionEvent;

import javafx.event.EventHandler;

import javafx.geometry.Bounds;

import javafx.scene.control.Button;

import javafx.scene.control.TextField;

import javafx.scene.effect.DropShadow;

import javafx.scene.input.KeyCode;

import javafx.scene.input.KeyEvent;

import javafx.scene.input.MouseEvent;

import javafx.scene.layout.HBox;

import javafx.stage.Popup;



import java.text.DateFormat;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.Locale;

import java.util.Timer;

import java.util.TimerTask;



/**

 * This is the class DateControl is based on. I change the modifier to default

 * (package visibility) so it won't be visible by TiwulFX developer. I didn't delete

 * it just for future reference

 * @author Christian Schudt

 * http://myjavafx.blogspot.com/2012/01/javafx-calendar-control.html

 */

class DatePicker extends HBox {





    private static final String CSS_DATE_PICKER_VALID = "datepicker-valid";

    private static final String CSS_DATE_PICKER_INVALID = "datepicker-invalid";





    /**

     * Initializes the date picker with the default locale.

     */

    public DatePicker() {

        this(Locale.getDefault());

    }



    private Timer timer;



    /**

     * Initializes the date picker with the given locale.

     *

     * @param locale The locale.

     */

    public DatePicker(Locale locale) {

        calendarView = new CalendarView(locale);



        textField = new TextField();

        this.locale.set(locale);



        calendarView.setEffect(new DropShadow());



        // Use the same locale.

        calendarView.localeProperty().bind(localeProperty());



        // Bind the current date of the calendar view with the selected date, so that the calendar shows up with the same month as in the text field.

        calendarView.currentDateProperty().bind(selectedDateProperty());



        // When the user selects a date in the calendar view, hide it.

        calendarView.selectedDateProperty().addListener(new InvalidationListener() {

            @Override

            public void invalidated(Observable observable) {

                selectedDate.set(calendarView.selectedDateProperty().get());

                hidePopup();

            }

        });



        // Let the prompt text property listen to locale or date format changes.

        textField.promptTextProperty().bind(new StringBinding() {

            {

                super.bind(localeProperty(), promptTextProperty(), dateFormatProperty());

            }



            @Override

            protected String computeValue() {

                // First check, if there is a custom prompt text.

                if (promptTextProperty().get() != null) {

                    return promptTextProperty().get();

                }



                // If not, use the the date format's pattern.

                DateFormat dateFormat = getActualDateFormat();

                if (dateFormat instanceof SimpleDateFormat) {

                    return ((SimpleDateFormat) dateFormat).toPattern();

                }



                return "";

            }

        });





        // Change the CSS styles, when this control becomes invalid.

        invalid.addListener(new InvalidationListener() {

            @Override

            public void invalidated(Observable observable) {

                if (invalid.get()) {

                    textField.getStyleClass().add(CSS_DATE_PICKER_INVALID);

                    textField.getStyleClass().remove(CSS_DATE_PICKER_VALID);

                } else {

                    textField.getStyleClass().remove(CSS_DATE_PICKER_INVALID);

                    textField.getStyleClass().add(CSS_DATE_PICKER_VALID);

                }

            }

        });



        // When the text field no longer has the focus, try to parse the date.

        textField.addEventHandler(MouseEvent.MOUSE_PRESSED, new EventHandler<MouseEvent>() {

            @Override

            public void handle(MouseEvent event) {

                if (!textField.focusedProperty().get()) {

                    if (!textField.getText().equals("")) {

                        tryParse(true);

                    }

                } else {

                    showPopup();

                }

            }

        });



        // Listen to user input.

        textField.textProperty().addListener(new ChangeListener<String>() {

            @Override

            public void changed(ObservableValue<? extends String> observableValue, String s, String s1) {

                // Only evaluate the input, it it wasn't set programmatically.

                if (textSetProgrammatically) {

                    return;

                }



                if (timer != null) {

                    timer.cancel();

                }



                // If the user clears the text field, set the date to null and the field to valid.

                if (s1.equals("")) {

                    selectedDate.set(null);

                    invalid.set(false);

                } else {

                    // Start a timer, so that the user input is not evaluated immediately, but after a second.

                    // This way, input like 01/01/1 is not immediately parsed as 01/01/01.

                    // The user gets one second time, to complete his date, maybe his intention was to enter 01/01/12.

                    timer = new Timer();

                    timer.schedule(new TimerTask() {

                        @Override

                        public void run() {

                            Platform.runLater(new Runnable() {

                                @Override

                                public void run() {

                                    tryParse(false);

                                }

                            });

                        }

                    }, 1000);

                }

            }

        });



        selectedDateProperty().addListener(new InvalidationListener() {

            @Override

            public void invalidated(Observable observable) {

                updateTextField();

                invalid.set(false);

            }

        });



        localeProperty().addListener(new InvalidationListener() {

            @Override

            public void invalidated(Observable observable) {

                updateTextField();

            }

        });



        textField.addEventHandler(KeyEvent.KEY_PRESSED, new EventHandler<KeyEvent>() {

            @Override

            public void handle(KeyEvent keyEvent) {

                if (keyEvent.getCode() == KeyCode.DOWN) {

                    showPopup();

                }

            }

        });



        Button button = new Button(">");

        button.setFocusTraversable(false);

        button.setOnAction(new EventHandler<ActionEvent>() {

            @Override

            public void handle(ActionEvent actionEvent) {



                showPopup();



            }

        });

        getChildren().add(textField);

        //getChildren().add(button);

    }



    private void hidePopup() {

        if (popup != null) {

            popup.hide();

        }

    }



    /**

     * Tries to parse the text field for a valid date.

     *

     * @param setDateToNullOnException True, if the date should be set to null, when a {@link ParseException} occurs.

     *                                 This is the case, when the text field loses focus.

     */

    private void tryParse(boolean setDateToNullOnException) {

        if (timer != null) {

            timer.cancel();

        }

        try {

            // Double parse the date here, since e.g. 01.01.1 is parsed as year 1, and then formatted as 01.01.01 and then parsed as year 2001.

            // This might lead to an undesired date.

            DateFormat dateFormat = getActualDateFormat();

            Date parsedDate = dateFormat.parse(textField.getText());

            parsedDate = dateFormat.parse(dateFormat.format(parsedDate));

            if (selectedDate.get() == null || selectedDate.get() != null && parsedDate.getTime() != selectedDate.get().getTime()) {

                selectedDate.set(parsedDate);

            }

            invalid.set(false);

            updateTextField();

        } catch (ParseException e) {

            invalid.set(true);

            if (setDateToNullOnException) {

                selectedDate.set(null);

            }

        }



    }



    private boolean textSetProgrammatically;



    /**

     * Updates the text field.

     */

    public void updateTextField() {

        // Mark the we update the text field (and not the user), so that it can be ignored, by textField.textProperty()

        textSetProgrammatically = true;

        if (selectedDateProperty().get() != null) {

            String date = getActualDateFormat().format(selectedDateProperty().get());

            if (!textField.getText().equals(date)) {

                textField.setText(date);

            }

        } else {

            textField.setText("");

        }

        textSetProgrammatically = false;

    }



    /**

     * Gets the actual date format. If {@link #dateFormatProperty()} is set, take it, otherwise get a default format for the current locale.

     *

     * @return The date format.

     */

    private DateFormat getActualDateFormat() {

        if (dateFormat.get() != null) {

            return dateFormat.get();

        }



        DateFormat format = DateFormat.getDateInstance(DateFormat.SHORT, locale.get());

        format.setCalendar(calendarView.getCalendar());

        format.setLenient(false);



        return format;

    }



    private CalendarView calendarView;



    /**

     * Use this to set further properties of the calendar.

     *

     * @return The calendar view.

     */

    public CalendarView getCalendarView() {

        return calendarView;

    }



    private TextField textField;





    private BooleanProperty invalid = new SimpleBooleanProperty();



    /**

     * States whether the user input is invalid (is no valid date).

     *

     * @return The property.

     */

    public ReadOnlyBooleanProperty invalidProperty() {

        return invalid;

    }





    /**

     * The locale.

     *

     * @return The property.

     */

    public ObjectProperty<Locale> localeProperty() {

        return locale;

    }



    private ObjectProperty<Locale> locale = new SimpleObjectProperty<Locale>();



    public void setLocale(Locale locale) {

        this.locale.set(locale);

    }



    public Locale getLocale() {

        return locale.get();

    }





    /**

     * The selected date.

     *

     * @return The property.

     */

    public ObjectProperty<Date> selectedDateProperty() {

        return selectedDate;

    }



    private ObjectProperty<Date> selectedDate = new SimpleObjectProperty<Date>();



    public void setSelectedDate(Date date) {

        this.selectedDate.set(date);

    }



    public Date getSelectedDate() {

        return selectedDate.get();

    }



    /**

     * Gets the date format.

     *

     * @return The date format.

     */

    public ObjectProperty<DateFormat> dateFormatProperty() {

        return dateFormat;

    }



    private ObjectProperty<DateFormat> dateFormat = new SimpleObjectProperty<DateFormat>();



    public void setDateFormat(DateFormat dateFormat) {

        this.dateFormat.set(dateFormat);

    }



    public DateFormat getDateFormat() {

        return dateFormat.get();

    }



    private StringProperty promptText = new SimpleStringProperty();



    /**

     * The prompt text for the text field.

     * By default, the prompt text is taken from the date format pattern.

     *

     * @return The property.

     */

    public StringProperty promptTextProperty() {

        return promptText;

    }





    public void setPromptText(String promptText) {

        this.promptText.set(promptText);

    }



    public String getPromptText() {

        return promptText.get();

    }



    private Popup popup;



    /**

     * Shows the pop up.

     */

    private void showPopup() {



        if (popup == null) {

            popup = new Popup();

            popup.setAutoHide(true);

            popup.setHideOnEscape(true);

            popup.setAutoFix(true);

            popup.getContent().add(calendarView);

        }



        Bounds calendarBounds = calendarView.getBoundsInLocal();

        Bounds bounds = localToScene(getBoundsInLocal());



        double posX = calendarBounds.getMinX() + bounds.getMinX() + getScene().getX() + getScene().getWindow().getX();

        double posY = calendarBounds.getMinY() + bounds.getHeight() + bounds.getMinY() + getScene().getY() + getScene().getWindow().getY();



        popup.show(this, posX, posY);



    }



    @Override

    public void requestFocus() {

        textField.requestFocus();

    }

    

}