/*
* org.openmicroscopy.shoola.util.ui.colourpicker.MatrixStack
*
*------------------------------------------------------------------------------
* Copyright (C) 2006 University of Dundee. All rights reserved.
*
*
* This program is 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; either version 2 of the License, or
* (at your option) any later version.
* This program 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, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
*------------------------------------------------------------------------------
*/
package org.openmicroscopy.shoola.util.ui.colourpicker;
//Java imports
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.util.Stack;
//Third-party libraries
//Application-internal dependencies
/**
* This is a matrix stack, it will save the current affine transformation of
* the graphic device when pushed onto the stack and return that context when
* popped.
* <p>
* I did think of saving the graphics context inside the matrix stack and using
* simply push and pop to set the states of the graphics context itself. I
* decided that this had less utility (also a danger of dangling references)
* than passing the affine transform.
* </p>
*
* @author Jean-Marie Burel
* <a href="mailto:j.burel@dundee.ac.uk">j.burel@dundee.ac.uk</a>
* @author Donald MacDonald
* <a href="mailto:donald@lifesci.dundee.ac.uk">donald@lifesci.dundee.ac.uk</a>
* @version 3.0
* <small>
* (<b>Internal version:</b> $Revision: $ $Date: $)
* </small>
* @since OME2.2
*/
class MatrixStack
{
/** Stack containing affinetransform. */
private Stack stack;
/** Creates a new instance and constructs the matrix stack. */
MatrixStack()
{
stack = new Stack();
}
/**
* Pushes the passed transformation onto the stack.
*
* @param saveMatrix The transformation to push.
*/
void push(AffineTransform saveMatrix) { stack.push(saveMatrix); }
/**
* Pushes the current trasformation of the Graphics context onto the stack.
*
* @param saveMatrix The transformation to push.
*/
void push(Graphics2D saveMatrix)
{
stack.push(saveMatrix.getTransform());
}
/**
* Retrieves top transform from stack and returns it.
*
* @return See above.
*/
AffineTransform pop() { return (AffineTransform) stack.pop(); }
/**
* Retrieves the top transform from stack and puts it onto the current
* graphics context.
*
* @param g The graphic context.
*/
void pop(Graphics2D g)
{
g.setTransform((AffineTransform) stack.pop());
}
/** Removes all elements from the stack. */
void clear() { stack.clear(); }
}