A question that is not final but is my final question about AffineTransforms - hopefu

[Kieran Murray]

Dear Ranchers,

I think if I can answer this I will have about wrapped it up for my Drawing Canvas.
I can now dynamically draw a line on a canvas - yippee.
I can also lengthen or shorten the line.

The only problem is when I lengthen or shorten the line and the line has been translated on the canvas before then the start point of the line - when it is being lengthened returns to its original start point - where it was before I moved it a couple of minutes ago.

I am pretty sure this is because my methods under the boolean tranLineExtending do not take into account that the line has previously been
Affine transformed.

Would one of you guys mind taking a look at the code snippets.
Any suggestions would be most gratefully appreciated.

package translation;
 
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;
import java.util.List;
import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
 
class PathWrangler2 extends MouseInputAdapter{
 
    ShapePanel component;
 
    // Used to move individual paths.
    AffineTransform at = new AffineTransform();
 
    Shapes clickedShape;
 
    private int mouseX, mouseY;   
 
    private int prevX, prevY;     
 
    int  count1, count2, count3, startcount=0, count4;
 
    double startX, startY, dragX, dragY;
 
    double startExtendX, startExtendY, extendX, extendY, EndExtendX, EndExtendY;
 
    int gg;
 
    public PathWrangler2(ShapePanel sdr) {
        component = sdr;
        component.addMouseListener(this);
        component.addMouseMotionListener(this);  
    }
 
    public void mousePressed(MouseEvent e) {
 
      p = e.getPoint();
          /* List list = component.paths1;*/
       List list1 = component.genpaths;
           List list2 = component.buspaths;
           List list3 = component.transmissionLinepaths;
           Point2D xp = getXformedPoint(p);
           net.setFrame(xp.getX()-S/2, xp.getY()-S/2, S, S);
            if(tranLineExtending==true)
           {
            for(int m = 0; m < list3.size(); m++) {
                    path3 = (Shapes)list3.get(m);
                    Path2D.Double transmissionLinenew = ((TransmissionLine) path3).getShape();
                    if(transmissionLinenew.contains(xp) || transmissionLinenew.intersects(net)) {
                        selectedPath = transmissionLinenew;
                        clickedShape=path3;
                        Point2D mmm = clickedShape.getEndPoint();
                        Point2D ppp = clickedShape.getStartPoint();
                        startExtendX = ppp.getX();
                        startExtendY = ppp.getY();
                        break;
                    }
                }           
           }
 
    public Point2D getXformedPoint(Point p) {
 
        // Transform a point in the component coordinate system
        // to a point in the transformed path coordinate system
        // so mousePressed points can find the transformed shapes
        // drawn to the screen in component view.
        AffineTransform xform = component.getTransform();
        double determinant = xform.getDeterminant();
        if(determinant != 0) {            // okay to invert
            AffineTransform inv = null;
            try {
                inv = xform.createInverse();
            } catch(NoninvertibleTransformException e) {
                System.out.println("can't invert: " + e.getMessage());
                return null;
            }
            return inv.transform(p, null);
        }
        return null;
    }
 
    public void mouseDragged(MouseEvent evt) {
 if(draggingScreen) {
             Point p = evt.getPoint();
             int x = p.x - offset.x;
             int y = p.y - offset.y;
             component.movePrimitives(x, y);
             offset.setLocation(p);
        }
         else if(dragging) {
            int x = evt.getX() - offset.x;
            int y = evt.getY() - offset.y;
            Rectangle r = selectedPath.getBounds();
            at.setToTranslation(x-r.x, y-r.y);
            component.transformPath(selectedPath, at, clickedShape);
        }
         else if(tranLineExtending)
         {
         pg = evt.getPoint();
         Point2D ggg = getXformedPoint(pg);
         System.out.println("Oh missus");
         extendX = ggg.getX();
         extendY = ggg.getY();
         component.resetValues(startExtendX, startExtendY, extendX, extendY, clickedShape);
         }
 
public void mouseReleased(MouseEvent e) {
 pp = e.getPoint();
    if(tranLineExtending == true)
    {
        tranLineExtending = false;
        clickedShape.setColor(Color.black);
    }
         if(dragging==true)
     {
    dragging = false;
    clickedShape.setColor(Color.BLACK);
     }
    if(draggingScreen == true)
    {
        draggingScreen = false;
    }
        component.repaint();
    }

Kind regards,

Kieran
[ August 04, 2008: Message edited by: Rob Prime ]

[Rob Spoor]

Kieran,

Could you please reduce the number of enters in your code? I don't know if you insert those manually or if something just goes wrong while copy-pasting from your IDE / editor, but it really makes your posts long.

I've removed several enters your post, and the code part has been reduced from 249 lines to 127 - a reduction of almost 50%.

[Kieran Murray]

Dear Ranchers,

I managed to solve this problems by continuously updating the start point and end point of my line so that I know where the start point of the line is always.

That now works.

I am going to send the zoom method - because unfortunately this is moving my cursor out slightly and this is having a knock on effect when I redraw the line when zoomed.

If this one can be solved then it really is good night Vienna.

Kind regards,

Kieran