package org.geogebra.desktop.gui.layout;

/**
 * The state of the drag'n'drop procedure.
 * 
 * @author Florian Sonner
 */
public class DnDState {
	/**
	 * The panel will be placed in the top area of the target panel.
	 */
	public static final int TOP = 1;

	/**
	 * The panel will be placed in the right area of the target panel.
	 */
	public static final int RIGHT = 2;

	/**
	 * The panel will be placed at the bottom of the target panel.
	 */
	public static final int BOTTOM = 4;

	/**
	 * The panel will be placed in the left area of the target panel.
	 */
	public static final int LEFT = 8;

	/**
	 * The panel will be placed above the split pane (just for horizontal split
	 * panes).
	 */
	public static final int TOP_OUT = 16;

	/**
	 * The panel will be placed on the right side of the split pane (just for
	 * vertical split panes).
	 */
	public static final int RIGHT_OUT = 32;

	/**
	 * The panel will be placed at the bottom of the split pane (just for
	 * horizontal split panes).
	 */
	public static final int BOTTOM_OUT = 64;

	/**
	 * The panel will be placed on the left side of the split pane (just for
	 * vertical split panes).
	 */
	public static final int LEFT_OUT = 128;

	/**
	 * The panel which was dragged by the user. Can't be changed from the
	 * outside as a new source should create a new DockState.
	 */
	private DockPanelD source;

	/**
	 * The panel the mouse is above at the moment.
	 */
	private DockPanelD target;

	/**
	 * The exact region the mouse is above at the moment, see the constants of
	 * this class.
	 */
	private int region = TOP;

	public DnDState(DockPanelD source) {
		this.source = source;
	}

	public DockPanelD getSource() {
		return source;
	}

	public void setTarget(DockPanelD target) {
		this.target = target;
	}

	public DockPanelD getTarget() {
		return target;
	}

	public void setRegion(int region) {
		if (region < 0 || region > LEFT_OUT) {
			throw new IllegalArgumentException();
		}

		this.region = region;
	}

	public int getRegion() {
		return region;
	}

	public boolean isRegionOut() {
		return region >= TOP_OUT;
	}
}