/*

 * QuickTime for Java SDK Sample Code

   Usage subject to restrictions in SDK License Agreement

 * Copyright: © 1996-1999 Apple Computer, Inc.

 */

package ds.actions;

import quicktime.app.actions.*;

import quicktime.qd.*;

import quicktime.*;

import quicktime.std.image.Matrix;

import quicktime.app.image.Transformable;

import quicktime.app.display.Drawable;

import java.awt.Dimension;

import java.awt.event.MouseEvent;

/**

 * A class that provides the implementation of where a dragged object will be skewed

 * The amount of skew is determined by the distance between the original mouse click and the 

 * current mouse-moved location divided by the specified skewFactors.

 */

public class Skewer extends Dragger {

//____________________________ CLASS METHODS

    /**

     * Set some parameters that will create DragActions. 

     * @param modifierKeyMask - if specified will determine which modifier keys must

     * be depressed for the action to be invoked.

     */

    public Skewer (int xSkewFactor, int ySkewFactor, int modifierKeyMask) {

        this (xSkewFactor, ySkewFactor, modifierKeyMask, MouseResponder.kModifiersExactMatch, 0);

    }

    /**

     * Set some parameters that will create DragActions. 

     * @param modifierKeyMask - if specified will determine which modifier keys must

     * be depressed for the action to be invoked.

     * @param modifierTestConditions the test conditions under which the modifier mask is tested

     */

    public Skewer (int xSkewFactor, int ySkewFactor, int modifierKeyMask, int modifierTestConditions, int addedEventInvoker) {

        super (modifierKeyMask, modifierTestConditions, addedEventInvoker);

        xSkew = xSkewFactor;

        ySkew = ySkewFactor;

    }   

//____________________________ INSTANCE VARIABLES

    private int xOrigin, yOrigin;   

    private int xSkew, ySkew;

    private Matrix originalMat;

//____________________________ INSTANCE METHODS

    /**

     * This method is used by the DragController when the mouse is first pressed down on 

     * the draggable object. If you wish to do anything to your draggable object before it

     * is dragged then you should overide this method. The default implementation does nothing.

     * @param event the mouse down event that may begin the drag action

     */

    public void mousePressed (MouseEvent event) {

        try {

            xOrigin = event.getX();

            yOrigin = event.getY();

            originalMat = target.getMatrix();

        } catch (QTException e) {

            throw new QTRuntimeException (e);

        }

    }

    /**

     * This method is called by Dragger when an event is received that meets the conditions for 

     * the object to be dragged.

     * <P>

     * This method will allow the user to skew the object by dragging on it.

     * @param event the mouse drag event that triggered the drag action.

     * @param space The drawable object is the space within which the event has occured.

     */

    public void mouseDragged (MouseEvent event) {

        try {

            // protect against a zero divide

            float skewX = (xSkew != 0 ? (event.getX() - xOrigin) / (float)xSkew : 0);

            float skewY = (ySkew != 0 ? (event.getY() - yOrigin) / (float)ySkew : 0);

            Matrix mat = (Matrix)originalMat.clone();

            mat.skew (skewX, skewY, mat.getTx(), mat.getTy());

            target.setMatrix (mat);

        } catch (QTException e) {

            throw new QTRuntimeException (e);

        }

    }

}