Zoombar.java

package nl.tudelft.lifetiles.graph.controller;

import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.geometry.Orientation;
import javafx.scene.control.Button;
import javafx.scene.control.Slider;
import javafx.scene.control.ToolBar;

/**
 * Creates a new Toolbar with two buttons and a slider.
 * The buttons will adjust the slider and you can get the value of the slider.
 *
 * @author AC Langerak
 *
 */
public class Zoombar {

    /**
     * The javafx toolbar.
     */
    private final ToolBar toolbar;

    /**
     * Integer which holds the current selected zoomlevel.
     * Can be listened to.
     */
    private final IntegerProperty zoomLevel;

    /**
     * The maximal amount of zooming.
     */
    private final int maxzoom;

    /**
     * The slider on the zoombar.
     */
    private Slider slider;

    /**
     * Create a new Toolbar.
     *
     * @param currentZoom
     *            the current starting zoom level.
     * @param maxZoom
     *            the maximal value of the zoom.
     */
    public Zoombar(final int currentZoom, final int maxZoom) {
        maxzoom = maxZoom;
        zoomLevel = new SimpleIntegerProperty();

        zoomLevel.set(currentZoom);
        slider = createSlider();

        slider.getStyleClass().add("slider");
        slider.valueProperty().addListener(
                (obserVal, oldVal, newVal) -> {
                    if (oldVal.intValue() != newVal.intValue()
                            && newVal.intValue() <= maxzoom) {
                        zoomLevel.set(newVal.intValue());
                    }
                });

        Button plus = new Button("+");
        plus.getStyleClass().add("plusButton");
        plus.setOnMouseClicked((event) -> {
            slider.setValue(slider.getValue() - slider.getMajorTickUnit());
        });

        Button minus = new Button("-");
        minus.getStyleClass().add("minusButton");
        minus.setOnMouseClicked((event) -> {
            slider.setValue(slider.getValue() + slider.getMajorTickUnit());
        });

        toolbar = new ToolBar();
        toolbar.getStyleClass().add("toolbar");

        toolbar.getItems().addAll(minus, slider, plus);
        toolbar.setOrientation(Orientation.VERTICAL);
    }

    /**
     *
     * @return javafx toolbar that is constructed
     */
    public ToolBar getToolBar() {
        return toolbar;
    }

    /**
     * Increment the zoom level by 1.
     */
    public final void incrementZoom() {
        int zoom = zoomLevel.get();
        if (zoom > 0) {
            zoomLevel.set(zoom + 1);
            slider.setValue(slider.getValue() - slider.getMajorTickUnit());
        }
    }

    /**
     * Decrease the zoom level by 1.
     */
    public final void decrementZoom() {
        int zoom = zoomLevel.get();
        if (zoom < maxzoom) {
            zoomLevel.set(zoom - 1);
            slider.setValue(slider.getValue() + slider.getMajorTickUnit());
        }
    }

    /**
     * @return the zoomlevel property
     */
    public IntegerProperty getZoomlevel() {
        return zoomLevel;
    }

    /**
     * Create a new Slider which runs from 0 to MAXZOOM.
     * The labeling will be in the opposite direction so MAXZOOM to 0
     *
     * @return the new slider
     */
    private Slider createSlider() {
        final CustomLabelSlider slider = new CustomLabelSlider(value -> Math
                .abs(value - maxzoom));

        slider.setOrientation(Orientation.VERTICAL);
        slider.setMin(0);
        slider.setValue(zoomLevel.intValue());
        slider.setMax(maxzoom);
        slider.setMajorTickUnit(1);
        slider.setMinorTickCount(0);
        slider.setShowTickMarks(true);
        slider.setShowTickLabels(true);
        slider.setSnapToTicks(true);
        slider.setMinHeight(Slider.USE_PREF_SIZE);

        slider.valueChangingProperty().addListener(
                observable -> slider.setValue(Math.round(slider.getValue())));

        return slider;
    }

}