/* Copyright (c) 2010, Carl Burch. License information is located in the
* com.cburch.logisim.Main source code and at www.cburch.com/logisim/. */
package com.cburch.logisim.std.gates;
import java.awt.Graphics;
import com.cburch.logisim.analyze.model.Expression;
import com.cburch.logisim.analyze.model.Expressions;
import com.cburch.logisim.data.AttributeSet;
import com.cburch.logisim.data.Value;
import com.cburch.logisim.instance.Instance;
import com.cburch.logisim.instance.InstancePainter;
import com.cburch.logisim.instance.InstanceState;
import com.cburch.logisim.tools.WireRepairData;
import com.cburch.logisim.util.GraphicsUtil;
class XnorGate extends AbstractGate {
public static XnorGate FACTORY = new XnorGate();
private XnorGate() {
super("XNOR Gate", Strings.getter("xnorGateComponent"), true);
setNegateOutput(true);
setAdditionalWidth(10);
setIconNames("xnorGate.gif", "xnorGateRect.gif", "dinXnorGate.gif");
setPaintInputLines(true);
}
@Override
protected String getRectangularLabel(AttributeSet attrs) {
return XorGate.FACTORY.getRectangularLabel(attrs);
}
@Override
public void paintIconShaped(InstancePainter painter) {
Graphics g = painter.getGraphics();
GraphicsUtil.drawCenteredArc(g, 0, - 5, 22, -90, 53);
GraphicsUtil.drawCenteredArc(g, 0, 23, 22, 90, -53);
GraphicsUtil.drawCenteredArc(g, -8, 9, 16, -30, 60);
GraphicsUtil.drawCenteredArc(g, -10, 9, 16, -30, 60);
g.drawOval(16, 8, 4, 4);
}
@Override
protected void paintShape(InstancePainter painter, int width, int height) {
PainterShaped.paintXor(painter, width, height);
}
@Override
protected void paintDinShape(InstancePainter painter, int width, int height,
int inputs) {
PainterDin.paintXnor(painter, width, height, false);
}
@Override
protected Value computeOutput(Value[] inputs, int numInputs, InstanceState state) {
Object behavior = state.getAttributeValue(GateAttributes.ATTR_XOR);
if (behavior == GateAttributes.XOR_ODD) {
return GateFunctions.computeOddParity(inputs, numInputs).not();
} else {
return GateFunctions.computeExactlyOne(inputs, numInputs).not();
}
}
@Override
protected boolean shouldRepairWire(Instance instance, WireRepairData data) {
return !data.getPoint().equals(instance.getLocation());
}
@Override
protected Expression computeExpression(Expression[] inputs, int numInputs) {
return Expressions.not(XorGate.xorExpression(inputs, numInputs));
}
@Override
protected Value getIdentity() { return Value.FALSE; }
}