/* 
 
Copyright 2006 Rene Grothmann, modified by Eric Hakenholz

This file is part of C.a.R. software.

    C.a.R. is a free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, version 3 of the License.

    C.a.R. is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 */
 
 
 package rene.zirkel.objects;

// file: LineObject.java

import rene.util.xml.XmlWriter;
import rene.gui.Global;
import rene.zirkel.ZirkelCanvas;
import rene.zirkel.construction.Construction;
import rene.zirkel.construction.Count;
import rene.zirkel.graphics.MyGraphics;
import rene.zirkel.graphics.MainGraphics;

public class LineObject extends TwoPointLineObject {
	static Count N = new Count();

	public LineObject(final Construction c, final PointObject p1,
			final PointObject p2) {
		super(c, p1, p2);
		validate();
		updateText();
	}

	@Override
	public String getTag() {
		return "Line";
	}

	@Override
	public void updateText() {
		setText(text2(Global.name("text.line"), P1.getName(), P2.getName()));
	}

	@Override
	public void validate() {
		if (!P1.valid() || !P2.valid()) {
			Valid = false;
			return;
		} else {
			Valid = true;
			X1 = P1.getX();
			Y1 = P1.getY();
			X2 = P2.getX();
			Y2 = P2.getY();
			// compute normalized vector in the direction of the line:
			DX = X2 - X1;
			DY = Y2 - Y1;
			R = Math.sqrt(DX * DX + DY * DY);
			if (R < 1e-10) {
				Valid = false;
				return;
			}
			DX /= R;
			DY /= R;
		}
	}

	@Override
	public void paint(final MyGraphics g, final ZirkelCanvas zc) {
		if (!Valid || mustHide(zc))
			return;
		if (!Partial || zc.showHidden()) {
			super.paint(g, zc);
			return;
		}
		// compute middle of the screen:
		final double xm = (zc.minX() + zc.maxX()) / 2, ym = (zc.minY() + zc
				.maxY()) / 2;
		// compute distance from middle to line:
		final double d = (xm - X1) * DY - (ym - Y1) * DX;
		// compute point with minimal distance
		final double x = xm - d * DY, y = ym + d * DX;
		// compute size of the screen
		final double a = Math.max(zc.maxX() - zc.minX(), zc.maxY() - zc.minY());
		if (Math.abs(d) > a)
			return;
		// compute distance from closest point to source
		final double b = (x - X1) * DX + (y - Y1) * DY;
		// compute the two visible endpoints
		k1 = b - a;
		k2 = b + a;
		k12valid = true;
		final double dd = (zc.maxX() - zc.minX()) / 20;
		double dmin = -dd, dmax = R + dd;
		if (Dep != null) {
			for (int i = 0; i < NDep; i++) {
				if (!Dep[i].valid() || Dep[i].mustHide(zc))
					continue;
				final double s = project(Dep[i].getX(), Dep[i].getY());
				if (s - dd < dmin)
					dmin = s - dd;
				else if (s + dd > dmax)
					dmax = s + dd;
			}
		}
		if (k1 < dmin)
			k1 = dmin;
		if (k2 > dmax)
			k2 = dmax;
		final double c1 = zc.col(X1 + k1 * DX), c2 = zc.col(X1 + k2 * DX), r1 = zc
		.row(Y1 + k1 * DY), r2 = zc.row(Y1 + k2 * DY);
		// paint:
		if (isStrongSelected() && g instanceof MainGraphics) {
			((MainGraphics) g).drawMarkerLine(c1, r1, c2, r2);
		}
		g.setColor(this);
		g.drawLine(c1, r1, c2, r2, this);
		final String s = getDisplayText();
		if (!s.equals("")) {
			g.setLabelColor(this);
			setFont(g);
			DisplaysText = true;
			if (KeepClose) {
				final double side = (YcOffset < 0) ? 1 : -1;
				drawLabel(g, s, zc, X1 + XcOffset * DX, Y1 + XcOffset * DY,
						side * DX, side * DY, 0, 0);
			} else
				drawLabel(g, s, zc, X1 + k2 * DX / 2, Y1 + k2 * DY / 2, DX, DY,
						XcOffset, YcOffset);
		}
	}

	@Override
	public void printArgs(final XmlWriter xml) {
		xml.printArg("from", P1.getName());
		xml.printArg("to", P2.getName());
		super.printArgs(xml);
	}

	@Override
	public void setDefaults() {
		super.setDefaults();
		setPartial(Cn.PartialLines);
	}

	@Override
	public void toggleHidden() {
		if (Hidden) {
			Partial = false;
			Hidden = false;
		} else {
			if (Partial) {
				Partial = false;
				Hidden = true;
			} else
				Partial = true;
		}
	}

	@Override
	public boolean hasUnit() {
		return false;
	}

	@Override
	public boolean nearto(final int c, final int r, final ZirkelCanvas zc) {
		if (!displays(zc))
			return false;
		if (zc.showHidden() || !Partial || Dep == null || !k12valid)
			return super.nearto(c, r, zc);
		// compute point at c,r
		final double x = zc.x(c), y = zc.y(r);
		// test, if on visible part
		final double s = project(x, y);
		if (s < k1 || s > k2)
			return false;
		// compute distance from x,y
		final double d = (x - X1) * DY - (y - Y1) * DX;
		// scale in screen coordinates
		Value = Math.abs(zc.col(zc.minX() + d) - zc.col(zc.minX()));
		return Value < zc.selectionSize() * 2;
	}
}