Saving Layouts in XML

[Fairall]

Hi All

We are developing a product based on Jide Dockable Framework which
employs a number of (Eclipse-like) perspectives.
Each perspective is a DockableHolder.
When we do a SaveLayout, we have to save each Layout file separately
using the perspective names to identify the layouts.

We would really like to have the option of saving the Layouts to file in
XML format and combine all the perspective layouts. If this is too much then perhaps access to the classes and information on what is saved in the binary files.
'Twould be marvellous !
Thanks

Rich Fairall

[JIDE Support]

You don't need to always save layout to a file. There are many ways to save a layout. One method you can use is getLayoutData(). It will get the layout data as a String. Later on, you can use setLayoutData(String layout) to restore the layout. Once you have the layout string, you can do whatever you want to it including save the string as part of an xml file which has all the perspective layouts you want.

Let me know if this solution works.

Thanks.

[Fairall]

Thanks for the reply.
I invoked dockingManager.getLayoutData() and see that the string
is non-readable (lots of hieroglyphics), is this to be expected?
XML files are always readable, and I had expected something readable here.
I could stuff it into an attribute in one lump I suppose.
Rich

[JIDE Support]

I guess it depends how you define readable. It's readable (pure ASCII) but not understandable because it is encoded. However you have no problem dump it into XML using CDATA.

Thanks.

[m.bruni]

However you have no problem dump it into XML using CDATA.

Since CDATA sections accept only unicode chars

#x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF] /* any Unicode character, excluding the surrogate blocks, FFFE, and FFFF. */

and the layoutString contains 0x0, parsing the XML file would result in a SAXParseException...
I think I will encode it using Base64 before putting it in an XML node...

--
Matteo Bruni

[JIDE Support]

That's correct. There are several Base64 encoder out there on the web. You can use them.

Thanks,

[Jii]

How do i go about encoding the layout string?

There is a method which takes in the specified encoding also as string (getLayoutData(String encode)). What should i hand it as the param to get base64?


edit:
Also i just noticed this:

The most exciting feature is probably the new Visual Designer. Visual Designer allows you to use drag-n-drop to visually design the layout of dockable frames and command bars, and save it as an xml file. In your application, instead of calling setInitXxx method to hard code the initial side, mode and index of each dockable frame, you just call loadInitialLayout to load the layout xml file you created. Both JIDE Docking Framework and JIDE Action Framework now support to load initial layouts.

If you're going to let people save layouts to xml from the visual designer anyway, why not make that possible in persistence saving?


edit2:
Additionally, Base64 encoding it doesn't seem to work. Tyring to decode ends up in:
org.apache.commons.codec.DecoderException: RFC 1522 violation: malformed encoded content

What the christ are you putting into this stuff?

[JIDE Support]

Base64 should work. I heard one customer used Base64 encoding/decoding at http://iharder.sourceforge.net/base64/.

Initial layout saved by Visual Designer is much simpler. After user drag-n-drop to rearrange the layout, the actual layout saved using saveLayoutData() is much more complex. One reason we don't want to save it as xml because we don't want to other people find out what information we saved by looking at the layout file.

Thanks,

[Jii]

Base64 should work. I heard one customer used Base64 encoding/decoding at http://iharder.sourceforge.net/base64/.

Initial layout saved by Visual Designer is much simpler. After user drag-n-drop to rearrange the layout, the actual layout saved using saveLayoutData() is much more complex. One reason we don't want to save it as xml because we don't want to other people find out what information we saved by looking at the layout file.

What about is more complex? Suppose we wanted to just save the very basic stuff about dockable frames (location, size, docking status etc)? Would this be possible using xml?

[JIDE Support]

Even the basic stuff is beyond the cability of initial layout xml. Initial layout only allows one level of hierarchy. In the other word, you can only define one level of dockable frames on each dock side. However docking framework supports any level of nested dockable frames which initial layout can't support.

Any reason you can't use Base64 to save layout as string into your own xml format?

Thanks,

[Jii]

Any reason you can't use Base64 to save layout as string into your own xml format?

Thanks,

Just that it doesn't seem to work at all. DockingManager.getLayoutData() encoded to base64 and then decoded and applied with setLayoutData(String) doesn't work. Also the two strings look slightly different after the operation, which is probably why

[JIDE Support]

It absolutely should work. Here is what I tried in DockingFrameworkDemo.

Code: Select all

String layoutData = _frame.getDockingManager().getLayoutData();
byte[] layout = Base64.encode(layoutData.getBytes());
String newLayoutData = new String(Base64.decode(layout));
if(newLayoutData.equals(layoutData)) {
    System.out.println("equal");
}

I simply used the Base64 class in xerces since I happen to have xerces.jar in my class path.

Thanks,

[Jii]

It absolutely should work. Here is what I tried in DockingFrameworkDemo.

Code: Select all

String layoutData = _frame.getDockingManager().getLayoutData();
byte[] layout = Base64.encode(layoutData.getBytes());
String newLayoutData = new String(Base64.decode(layout));
if(newLayoutData.equals(layoutData)) {
    System.out.println("equal");
}

I simply used the Base64 class in xerces since I happen to have xerces.jar in my class path.

Thanks,

Any chance that hashing the string mid-way might mess this up?

Because i just tried in a simple tester program and it worked, yet it doesn't in my application.

[m.bruni]

Any chance that hashing the string mid-way might mess this up?

I'm actually using this method to save my layouts and works fine (using Base64 library from apache commons codec project

--
Matteo Bruni

[Jii]

Ok now i tried this:

Code: Select all

         FileWriter writer = new FileWriter(new File("layout"));
         String layoutData = getDockingManager().getLayoutData();
         layoutData = Base64.encode(layoutData.getBytes());
         writer.write(layoutData);


And then this:

Code: Select all

         BufferedReader reader = new BufferedReader(new FileReader("layout"));
         String layoutData = reader.readLine();
         System.out.println(layoutData);
         layoutData = new String(Base64.decode(layoutData));


The system.out doesnt indicate that the String is null, yet i get a nullpointerexception on the next line.

Suggestions?

[Jii]

Ditching the xml thing, i tried to keep it simple:

Code: Select all

getDockingManager().saveLayoutDataToFile("backup.layout");


and

Code: Select all

getDockingManager().loadLayoutDataFromFile("backup.layout");


... after creating the components.

The layout still doesn't work, looks nothing like the one i saved.


edit: an update on this, it seems to work if i first save the layout, then move some components and then load it again.

However, if i do:

Code: Select all

layoutData = getDockingManager().getLayoutData("utf-8");


, move a component and then do:

Code: Select all

getDockingManager().setLayoutData(layoutData, "utf-8");


it doesn't work, the layout reverts to default. Even though the two strings are identical according to equals :/

[Jii]

Just an update to say this issue is resolved now, thanks for all the swift help

[JIDE Support]

So how do you resolve it? I want to know in case someone gets the same error?

BTW, our initial test found out getLayoutData("utf-8")/setLayoutData(layoutData, "utf-8") pair doesn't work. We will try to fix it. getLayoutData()/setLayoutData() works all the time even I don't rearrange component in between.

Thanks,

[Jii]

So how do you resolve it? I want to know in case someone gets the same error?

BTW, our initial test found out getLayoutData("utf-8")/setLayoutData(layoutData, "utf-8") pair doesn't work. We will try to fix it. getLayoutData()/setLayoutData() works all the time even I don't rearrange component in between.

Thanks,

Well it was a doozy. Here's how we do it now:

Code: Select all

   private String getLayout(DockingManager manager) {
      ByteArrayOutputStream bout = new ByteArrayOutputStream();
      bout.reset();
      try {
         manager.saveLayoutTo(bout);
      } catch (IOException e) {
         // TODO Auto-generated catch block
         e.printStackTrace();
      }
      BASE64Encoder b64 = new BASE64Encoder();
      return b64.encode(bout.toByteArray());
   }


and

Code: Select all

   private void setLayout(DockingManager manager, String layout) {
      BASE64Decoder d64 = new BASE64Decoder();
      try {
         if(layout == null){
            manager.loadLayoutData();
         }
         else{
            manager.loadLayoutFrom(new ByteArrayInputStream(d64.decodeBuffer(layout)));
         }
      } catch (IOException e) {
         // TODO Auto-generated catch block
         e.printStackTrace();
      }
   }


and those seem to do the trick. The layout is still saved as a String in the xml, it was just some weird bytearray/String/encoding problem.

[JIDE Support]

Thanks for the code. I think it will be very helpful for other people who wants to do the same thing.

Thanks,