Implementing a new ROI type

[Jean-Yves Tinevez-2]

Hi all,

I would like to implement a new type of ROI that would behave like any  
existing ImageJ ROI.
Could someone point me to the interface to implement, or what methods  
are key to have the nice floating drawing we currently have?
Cheers
jy

--
Jean-Yves Tinevez
PFID - Imagopole
Institut Pasteur
25-28, rue du Docteur Roux
75724 Paris cedex 15
France
tel: [phone]

[dscho]

Hi J-Y,

On Mon, 23 Nov 2009, Jean-Yves Tinevez wrote:

> I would like to implement a new type of ROI that would behave like any
> existing ImageJ ROI.
>
> Could someone point me to the interface to implement, or what methods
> are key to have the nice floating drawing we currently have?

As far as I can tell, there is no easy way to have a floating drawing
except using the overlay mechanism:

http://pacific.mpi-cbg.de/cgi-bin/gitweb.cgi?p=imagej.git;a=blob;f=ij/ImagePlus.java;h=2757dccd0bd37c2e94ee90d32b91140be10d8c44;hb=1394c52029d82c2a791355d8e533f04c442a5067#l1963

(It might be better to use the next one, where you have to specify a
Shape, a Color and a BasicStroke instead of an untyped list.)

You'll have to represent your ROI in the form of a Shape (which should be
easy, as java.awt.geom.GeneralPath is an implementation of Shape).

The trickier part is to interact with the mouse.  You have at least two
options:

- use a macro-based approach, such as was done with the original ROIBrush:

http://pacific.mpi-cbg.de/cgi-bin/gitweb.cgi?p=VIB.git;a=blob;f=ROIBrush_.java;h=739c4e989279a32879ae9b812a12e321cf914a44;hb=8abc8d608b729752a84ad633ed53c1e78316a982

- register mouse and mouse motion listeners with the image window
  (possibly checking that the correct tool is selected in the Toolbar all
  the time).  Here you have to make sure that you register/deregister the
  listeners appropriately with a WindowListener that you register with the
  addImageListener() method of the class ij.ImageJ.

If you go with the second approach, I would be interested in helping you
turn this into an abstract Tool class which can then be reused by other
plugins implementing tools.

Ciao,
Johannes

[Michael Schmid]

Hi Jean-Yves,

you could try to implement your own subclass of ij.gui.Roi - I have  
not tried, but I guess that it would work. See e.g. OvalRoi.java and  
PolygonRoi.java.

public void draw(Graphics g)
   should do the display on the screen.

Your roi should have x, y positions and width, height like all other  
rois.
For modifying the roi with the mouse, you have to supersede isHandle,  
moveHandle(int sx, int sy), mouseDownInHandle(int handle, int sx, int  
sy), handleMouseUp(int sx, int sy),

Your class should also have getMask(), contains(x, y), getLength(),  
drawPixels(ImageProcessor ip) and (if possible) getPolygon methods.

Another problem occurs if you want to create the the roi via a  
suitable tool. Currently, as far as I know, 'external' tools have to  
be macros, so you need a macro (in your startup macros) that calls a  
static method, but this won't interface so easily with the  
ImageCanvas methods that finally call the moveHandle etc. methods.

Michael
________________________________________________________________

On 23 Nov 2009, at 12:59, Jean-Yves Tinevez wrote:

> Hi all,
>
> I would like to implement a new type of ROI that would behave like  
> any existing ImageJ ROI.
> Could someone point me to the interface to implement, or what  
> methods are key to have the nice floating drawing we currently have?
> Cheers
> jy
>
> --
> Jean-Yves Tinevez
> PFID - Imagopole
> Institut Pasteur
> 25-28, rue du Docteur Roux
> 75724 Paris cedex 15
> France
> tel: [phone]