Version Detection?

[Andy Puckett]

Can someone tell me if there is a java routine that will detect which version of ImageJ is
being run?  I would like to
incorporate this into a plugin.

Thanks,
Andy

[Wayne Rasband]

Use the IJ.getVersion() method to get the ImageJ version as a string  
(e.g., "1.30f") or add a line like this

      if (IJ.versionLessThan("1.39f")) return;

which will abort the plugin and displays an error message if the  
version is not 1.39f or later.

In a macro, use the getVersion() and requires("1.39j") functions.

-wayne


On Oct 6, 2007, at 2:15 PM, Andy Puckett wrote:

> Can someone tell me if there is a java routine that will detect
> which version of ImageJ is being run?  I would like to
> incorporate this into a plugin.
>
> Thanks,
> Andy

[Andy Puckett]

I would also accept a routine that tells me whether a certain class is defined or not.  
Specifically, this concerns
the change as of ImageJ 1.38f from FITS to FITS_Reader/FITS_Writer.

Thanks,
Andy

----- Original Message -----
From: Andy Puckett <[hidden email]>
Date: Saturday, October 6, 2007 10:15 am
Subject: Version Detection?

> Can someone tell me if there is a java routine that will detect
> which version of ImageJ is
> being run?  I would like to
> incorporate this into a plugin.
>
> Thanks,
> Andy
>

[John Hayes-5]

If you're interested in dynamically determining if a class or method  
is available, check out the introspection features of Java. This page  
has a brief overview: http://www.cs.grinnell.edu/~rebelsky/Courses/ 
CS223/2004F/Handouts/introspection.html. Also, checkout the "Class"  
class in Javadocs and this tutorial: http://java.sun.com/docs/books/ 
tutorial/reflect/class/index.html.

To my knowledge there is no way to determine that a class exists in  
Java without throwing an exception with the Class.forName
("ij.plugin.FITS_Reader") method (unless you'd like to write your own  
ClassLoader). It's not ideal, but in the exception handler you can  
redirect the control flow such that you can attempt to create a new  
instance of the FITS class.

The simplest and cleanest solution would be to just require at least  
version 1.38f and use Rasband's suggestion to abort the plugin if  
that requirement is not satisfied.

Best regards,

John

On Oct 6, 2007, at 4:16 PM, Andy Puckett wrote:

> I would also accept a routine that tells me whether a certain class  
> is defined or not.
> Specifically, this concerns
> the change as of ImageJ 1.38f from FITS to FITS_Reader/FITS_Writer.
>
> Thanks,
> Andy
>
> ----- Original Message -----
> From: Andy Puckett <[hidden email]>
> Date: Saturday, October 6, 2007 10:15 am
> Subject: Version Detection?
>
>> Can someone tell me if there is a java routine that will detect
>> which version of ImageJ is
>> being run?  I would like to
>> incorporate this into a plugin.
>>
>> Thanks,
>> Andy
>>

--
John A. Hayes, Ph.D.
Department of Applied Science
The College of William & Mary

[Wayne Rasband]

Use the Class.ForName() method to determine if a given class exits.  
This method

    boolean exits(String className) {
       try {
          Class c = Class.forName(className);
          return true;
       }
       catch (ClassNotFoundException e) {}
       return false;
    }

returns true if the specified class exists. For example, I get

    FITS: false
    FITS_Reader: true
    LSM_Reader: true

in the Log window when I run this code

    IJ.log("FITS: "+ exits("ij.plugin.FITS"));
    IJ.log("FITS_Reader: "+ exits("ij.plugin.FITS_Reader"));
    IJ.log("LSM_Reader: "+ exits("LSM_Reader"));

-wayne

On Oct 6, 2007, at 4:16 PM, Andy Puckett wrote:

> I would also accept a routine that tells me whether a certain class  
> is defined or not.
> Specifically, this concerns
> the change as of ImageJ 1.38f from FITS to FITS_Reader/FITS_Writer.
>
> Thanks,
> Andy
>
> ----- Original Message -----
> From: Andy Puckett <[hidden email]>
> Date: Saturday, October 6, 2007 10:15 am
> Subject: Version Detection?
>
>> Can someone tell me if there is a java routine that will detect
>> which version of ImageJ is
>> being run?  I would like to
>> incorporate this into a plugin.
>>
>> Thanks,
>> Andy
>>

[Andy Puckett]

Ok, I find this really annoying.  I'm running the following code:

                String ijvers = IJ.getVersion();
               
                if (ijvers.compareTo("1.38f") < 0) {
                        IJ.log("ImageJ: older");
                        if (imp.getStackSize() < 2 && !(imp instanceof ij.plugin.FITS)) {
                                IJ.error( "Must select a Nova compatible FITS image." );
                                return;
                        }
                } else {
                        IJ.log("ImageJ: newer");
                        if (imp.getStackSize() < 2 && !(imp instanceof  
ij.plugin.FITS_Reader)) {
                                IJ.error( "Must select a Nova compatible FITS image." );
                                return;
                        }
                }

Now, even though I'm running ImageJ 1.38x and the code correctly  
responds with "ImageJ: newer" in the log file (so the ELSE clause is  
being used), I still get this error message:

        /Applications/ImageJ/plugins/Nova20071008/Nova_Plugin_.java:54:
         Class ij.plugin.FITS not found.
                        if (imp.getStackSize() < 2 && !(imp instanceof ij.plugin.FITS)) {

So, Java will still examine (and reject) the code of the THEN clause,  
even though I've told it to use the ELSE clause for versions of  
ImageJ that don't have the FITS class???  That's idiotic.

Ok, bitching aside... any suggestions?

Thanks,
Andy

[ctrueden]

Hi Andy,

My experience is that any direct class references you make in a Java
application, sometimes even in branches of code that aren't actually
executed, will result in the class loader trying to load that class.

Instead of:
   imp instanceof ij.plugin.FITS
you could try:
   imp.getClass().getName().equals("ij.plugin.FITS")

There is a difference in behavior regarding subclasses, but in your
case that shouldn't be an issue.

-Curtis

On 10/8/07, Andy Puckett <[hidden email]> wrote:

> Ok, I find this really annoying.  I'm running the following code:
>
>                 String ijvers = IJ.getVersion();
>
>                 if (ijvers.compareTo("1.38f") < 0) {
>                         IJ.log("ImageJ: older");
>                         if (imp.getStackSize() < 2 && !(imp instanceof ij.plugin.FITS)) {
>                                 IJ.error( "Must select a Nova compatible FITS image." );
>                                 return;
>                         }
>                 } else {
>                         IJ.log("ImageJ: newer");
>                         if (imp.getStackSize() < 2 && !(imp instanceof
> ij.plugin.FITS_Reader)) {
>                                 IJ.error( "Must select a Nova compatible FITS image." );
>                                 return;
>                         }
>                 }
>
> Now, even though I'm running ImageJ 1.38x and the code correctly
> responds with "ImageJ: newer" in the log file (so the ELSE clause is
> being used), I still get this error message:
>
>         /Applications/ImageJ/plugins/Nova20071008/Nova_Plugin_.java:54:
>          Class ij.plugin.FITS not found.
>                         if (imp.getStackSize() < 2 && !(imp instanceof ij.plugin.FITS)) {
>
> So, Java will still examine (and reject) the code of the THEN clause,
> even though I've told it to use the ELSE clause for versions of
> ImageJ that don't have the FITS class???  That's idiotic.
>
> Ok, bitching aside... any suggestions?
>
> Thanks,
> Andy
>

[Wayne Rasband]

You can modify Nova_Plugin so it does not reference the FITS or  
FITS_Reader classes. Use

     imp = IJ.openImage(path);

to open the image and

     String info = (String)imp.getProperty("Info");
     boolean isFITS = info!=null && info.startsWith("SIMPLE");

to test to see if it is a FITS image.

-wayne

On Oct 8, 2007, at 3:12 PM, Andy Puckett wrote:

> Ok, I find this really annoying.  I'm running the following code:
>
> String ijvers = IJ.getVersion();
>
> if (ijvers.compareTo("1.38f") < 0) {
> IJ.log("ImageJ: older");
> if (imp.getStackSize() < 2 && !(imp instanceof ij.plugin.FITS)) {
> IJ.error( "Must select a Nova compatible FITS image." );
> return;
> }
> } else {
> IJ.log("ImageJ: newer");
> if (imp.getStackSize() < 2 && !(imp instanceof  
> ij.plugin.FITS_Reader)) {
> IJ.error( "Must select a Nova compatible FITS image." );
> return;
> }
> }
>
> Now, even though I'm running ImageJ 1.38x and the code correctly  
> responds with "ImageJ: newer" in the log file (so the ELSE clause  
> is being used), I still get this error message:
>
> /Applications/ImageJ/plugins/Nova20071008/Nova_Plugin_.java:54:
> Class ij.plugin.FITS not found.
> if (imp.getStackSize() < 2 && !(imp instanceof ij.plugin.FITS)) {
>
> So, Java will still examine (and reject) the code of the THEN  
> clause, even though I've told it to use the ELSE clause for  
> versions of ImageJ that don't have the FITS class???  That's idiotic.
>
> Ok, bitching aside... any suggestions?
>
> Thanks,
> Andy