Copyright (C) 2000, 2001, Geert Vernaeve. All Rights Reserved. 
package gve.calc.formula;

import java.awt.*;
import java.awt.event.*;
import awt.Button;

 @author Geert Vernaeve 

public class InfixBinaryOpView extends HasBaselineContainer implements HasCursorPos,KeydnListener,View,CreatesPopup,ActionListener,MouseSensitive {
	private InfixBinaryOp model;

	public InfixBinaryOpView(InfixBinaryOp model,FormulaView view) {
		this(model,view,new CursorPosLabel(model.getName()));
	}

	public InfixBinaryOpView(InfixBinaryOp model,FormulaView view,Component operatorView) {
		this.model = model;
		add(view.getView(model.left));
		add(operatorView);
		add(view.getView(model.right));
		setLayout(new HorizontalLayoutMgr());
		MVC.registerView(model,this);
	}

	
 Called when menu "Swap Operands" is chosen. 
	public void updateView(Object with) {
		FormulaView view = FormulaView.get(this);
		// Note: we may not do the following:
		//	remove(0); add(getView(left),0);
		//	remove (2); add(getView(right),0);
		// because remove(0) unlinks the right component
		// off the tree, so getView(right) would give us null.
		Component lview = view.getView(model.left);
		Component rview = view.getView(model.right);
		// Note that
		//	remove(0); add(lview,0); remove(2); add(lview,2);
		// also not works. This is because adding lview at position 0
		// removes it at the position where it was (being position 2),
		// so remove(2); would fail.
		remove(2);
		remove(0);
		add(lview,0);
		add(rview,2);
		validate();
	}

	public Object getModel() { return model; }

	public void setCursorPos(int pos) {
		switch (pos) {
		case Somewhere_LEFT:
			FormulaView.get(this).setCursorPart(model.left,Somewhere_LEFT);
			break;
		case Somewhere_RIGHT:
			FormulaView.get(this).setCursorPart(model.right,Somewhere_RIGHT);
			break;
		case Somewhere_MYLEFT:
			getOperatorView().setCursorPos(Somewhere_LEFT);
			break;
		case Somewhere_MYRIGHT:
			getOperatorView().setCursorPos(Somewhere_RIGHT);
			break;
		default:
			getOperatorView().setCursorPos(pos >=0 ? pos : Somewhere);
		}
	}

	public int getCursorPos() {
		FormulaView view = FormulaView.get(this);
		Part cursorpart = view.getCursorPart();
		if (Part.isDescendantOr(cursorpart,model.left))
			return Somewhere_LEFT;
		if (Part.isDescendantOr(cursorpart,model.right))
			return Somewhere_RIGHT;
		if (cursorpart == model)
			return getOperatorView().getCursorPos();
		return Somewhere;
	}

	public void activate() {
		if (getComponentCount() == 3)
			getOperatorView().activate();
	}

	public void deactivate() {
		// While dismantling etc., left or right child could
		// already be removed. In that case, do nothing
		if (getComponentCount() == 3)
			getOperatorView().deactivate();
	}

	
 Return the View of the operator itself (i.e. without the left
	  and right arguments). This is our middle child. 
	HasCursorPos getOperatorView() {
		return (HasCursorPos)getComponent(1);
	}

	public boolean keydn(int key) {
		return InfixBinaryOpController.keydn(key,this);
	}

	public Component createPopup(int x,int y) {
		Button b = new Button("Swap operands");
		b.addActionListener(this);
		return b;
	}

	public void actionPerformed(ActionEvent evt) {
		String cmd = evt.getActionCommand();
		if (cmd.equals("Swap operands")) {
			Part swap = model.left;
			model.left = model.right;
			model.right = swap;
			MVC.changed(model);
		}
	}

	public boolean mousePressed(int flags,int x,int y) { return false; }

	public void mouseDown(int flags,int x,int y) {
		FormulaView view = FormulaView.get(this);
		int w = getComponent(0).getSize().width + getComponent(1).getSize().width/2;
		view.setCursorComp(this,x<w ? Somewhere_MYLEFT : Somewhere_MYRIGHT);
	}
}