package jcgp.gui.dragresize;

import javafx.event.EventHandler;
import javafx.scene.Cursor;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Region;
import jcgp.gui.GUI;

/**
 * 
 * http://andrewtill.blogspot.co.uk/2012/12/dragging-to-resize-javafx-region.html
 * 
 *
 */
public class VerticalDragResize {
	
	private boolean dragging = false;
	private final Region region;
	
	private VerticalDragResize(Region region) {
		this.region = region;
	}
	
	public static void makeDragResizable(final Region region) {
		final VerticalDragResize dr = new VerticalDragResize(region);

		region.setOnMousePressed(new EventHandler<MouseEvent>() {
			@Override
			public void handle(MouseEvent event) {
		        dr.mousePressed(event);
			}
		});
		region.setOnMouseDragged(new EventHandler<MouseEvent>() {
			@Override
			public void handle(MouseEvent event) {
				dr.mouseDragged(event);
			}
		});
		region.setOnMouseMoved(new EventHandler<MouseEvent>() {
			@Override
			public void handle(MouseEvent event) {
				dr.mouseMoved(event);
			}
		});
		region.setOnMouseReleased(new EventHandler<MouseEvent>() {
			@Override
			public void handle(MouseEvent event) {
				dr.mouseReleased();
			}
		});
		
	}
	
	private void mousePressed(MouseEvent event) {
		if(isInDraggableZone(event)) {
	        dragging = true;
        }
	}

	private void mouseDragged(MouseEvent event) {
		if(dragging) {
			double newHeight = region.getHeight() - event.getY();
			if (newHeight >= region.getMinHeight()) {
				region.setPrefHeight(newHeight);
			} else {
				region.setPrefHeight(region.getMinHeight());
			}
		}
	}
	
	private void mouseMoved(MouseEvent event) {
		if(isInDraggableZone(event) || dragging) {
			region.setCursor(Cursor.V_RESIZE);
        }
        else {
        	region.setCursor(Cursor.DEFAULT);
        }
	}

	private void mouseReleased() {
		dragging = false;
		region.setCursor(Cursor.DEFAULT);
	}

	private boolean isInDraggableZone(MouseEvent event) {
		return event.getY() < (GUI.RESIZE_MARGIN);
	}

}