A few days ago I found another rare BlackBerry bug. I was playing with some list elements and everything was working fine until I ran the code on a BlackBerry Curve 8300.

I was suddenly presented with this popup.



I have never seen this error so I googled for it. Unfortunately there was no reasonable explanation. So I decided to investigate it.
First thing I did was to take a peek at the event log. I did it by pressing ALT+L+G+L+G and I got this.



Taking a look at the exception trace showed this.



I needed to see the full log for details, so I used

javaloader -u eventlog

to dump the event log (for this to work you need to check the  USB Cable Connected under the Simulate menu item of the emulator).
My javaloader file is located at c:\eclipse_g_341_jde7\plugins\ net.rim.eide.componentpack4.5.0_4.5.0.14\components\bin\JavaLoader.exe

The log looked like this.

guid:0x9C3CD62E3320B498 time: Mon Nov 23 15:05:00 2009  severity:1 type:3 app:Java Exception data:
        IllegalStateException
        ArticInterface::DocPosToCaret: error 3; formatted text length = 40;
        net_rim_cldc-11
         TextArea
         getTextBounds
         0x7B8E
        net_rim_cldc-9
         LabelField
         layout
         0x9D99
        net_rim_cldc-8
         Manager
         layoutChild
         0x1B98
        net_rim_cldc-11
         VerticalFieldManager
         sublayout
         0xC6F0
        net_rim_cldc-8
         Manager
         layout
         0x1A95
        net_rim_cldc-8
         Manager
         layoutChild
         0x1B98
        net_rim_cldc-11
         VerticalFieldManager
         sublayout
         0xC6F0
        net_rim_cldc-8
         Manager
         layout
         0x1A95
        net_rim_cldc-8
         Manager
         layoutChild
         0x1B98
        net_rim_cldc-11
         VerticalFieldManager
         sublayout
         0xC6F0
        net_rim_cldc-8
         Manager
         layout
         0x1A95
        net_rim_cldc-8
         Manager
         layoutChild
         0x1B98
        net_rim_cldc-11
         VerticalFieldManager
         sublayout
         0xC6F0
        net_rim_cldc-8
         Manager
         layout
         0x1A95
        net_rim_cldc-8
         Manager
         layoutChild
         0x1B98
        net_rim_cldc-8
         Screen
         layoutDelegate
         0x5375
        net_rim_cldc-2
         MIDPScreen
         sublayout
         0x9781
        net_rim_cldc-8
         Manager
         layout
         0x1A95
        net_rim_cldc-8
         Screen
         doLayout
         0x4B51
        net_rim_cldc-8
         UiEngineImpl
         pushScreen
         0xA538
        net_rim_cldc-8
         UiApplication
         pushScreen
         0x8A4B
        net_rim_cldc-2
         Display
         switchDisplayables
         0x3A60
        net_rim_cldc-2
         Display$SwitchDisplayablesRunnable
         run
         0x3FF5
        net_rim_cldc-5
         Application
         dispatchInvokeLater
         0xAAC
        net_rim_cldc-3
         MIDletMain
         dispatchInvokeLater
         0x4F78
        net_rim_cldc-5
         Application
         processNextMessage
         0x123D
        net_rim_cldc-5
         Application
         enterEventDispatcher
         0xA51
        net_rim_cldc-3
         MIDletMain
         main
         0x51FA
guid:0x97C9F5F641D25E5F time: Mon Nov 23 15:05:00 2009  severity:0 type:2 app:System data:JVM Error 104
guid:0x97C9F5F641D25E5F time: Mon Nov 23 15:05:00 2009  severity:0 type:2 app:System data:Uncaught: IllegalStateException

The event log shows a very interesting thing. It seems the J2ME list is rendered as a VerticalLayout that contains Labels.

We start by looking for TextArea. We cannot find it in the SDK so we look for the LabelField class. We find the LabelField in
C:\eclipse_g_341_jde7\plugins\net.rim.eide.componentpack4.5.0_4.5.0.14\components\lib\net_rim_api\net\rim\device\api\ui\component\LabelField.class
A quick look in the documentation of LabelField shows us the setText method can truly throw an IllegalStateException.

public void setText(Object text)

    Sets this field's label text.

    Parameters:
        text - Label text which may be a string, string buffer, character array, or byte array (may be null for an empty label).
    Throws:
        IllegalArgumentException - if text parameter is an unsupported type.

Source: BlackBerry JDE 4.5.0 API Reference: Class LabelField

Looking for the getTextBounds method gives us a few results, like
C:\eclipse_g_341_jde7\plugins\net.rim.eide.componentpack4.5.0_4.5.0.14\components\lib\net_rim_api\net\rim\device\internal\ui\Formatter.class
c:\eclipse_g_341_jde7\plugins\net.rim.eide.componentpack4.5.0_4.5.0.14\components\lib\net_rim_api\net\rim\device\api\ui\component\TextField.class
the method signature looks like
getTextBounds(IILnet/rim/device/api/ui/XYRect;Lnet/rim/device/internal/ui/ArticInterface$Line;II)

Since the TextArea is not available and the ArticInterface is also missing, we must move our search somewhere else.

What we can notice is the exception thrown has something to do with the caret - DocPosToCaret.

After a little bit of testing, I was able to reproduce the bug. It seems the bug appears when the list item contains a ‘\n’ char right in the beginning of the text and the text following will be long enough to need to be split on different lines.
Also, setting many ‘\n’ chars in the beginning will make the exception pop up for a smaller following text length.
Unfortunately, without the code we cannot say exactly how the algorithm in getTextBounds() works, but still, we now have a good picture of why this happens and how it can be avoided(for example, by removing the ‘\n’ chars from the beginning of the text, or by adding a space “ “ char in front of the text).

Some tech details:
1. this behavior only seems to exist in net.rim.eide.componentpack4.5.0_4.5.0.14 and not other emulators.
2. the bug appears on the BlackBerry Curve 8300 phone
3. you can download the code to reproduce the bug here ws_DocPosToCaretException.zip (599.40 kb)
4. the emulator specification looks like this


I hope you have enjoyed this rare to find bug, and if you want to see another one, a really funny one, then please also check this one here BlackBerry - This is sexy, isn’t it?.

Some time ago I found an interesting “feature” on the BlackBerry emulator.
It seems under special conditions we get some funny messages.

Luckily I was able to reproduce the behavior and here are the steps, the screens and the funny messages.

1. Run clean.bat in C:\eclipse_g_341_jde7\plugins\net.rim.eide.componentpack4.6.0_4.6.0.16\components\simulator\
or skip this but make sure the Contacts list is empty.

2. Copy my application to the simulator folder.

3. Run the application – should look like this.

4. Add any dummy contact, like this.

5. Run the application – you should get an error and get to this menu screen.

6. Choose “VM internal test” from the menu.

7. You should now get a series of screens looking like this. (1)

8. Screen 2.

9. Screen 3.

10. Screen 4.

11. Screen 5.

12. Screen 6.

So I got curious as to where the text comes from.

I looked for the “This is sexy, isn’t it?” string, but could not find it anywhere.
I almost gave up until I decided to try “bill” from the last screen, and to my surprise I got a result in Jvm.dll. Most of the strings were there. The file excerpt looks like this:

This *is* Banner    (1/1)   Patching Java   This *is* BANNER!   A Message   (too of fwee)   Oh no mr bill, something has gone horribly horribly wrong. oh nooo. o nooooooooo.

I was happy to find the source, but still no trace of “This is sexy, isn’t it?”.
Well, in my opinion this special text comes from some image memory copy operation, something like BitBlit in GDI.BitBlit.

Finally, mystery solved :)

Some tech details:
1. this behavior only seems to exist in net.rim.eide.componentpack4.6.0_4.6.0.16 and not other emulators.
2. other emulators offer the “VM internal test” menu option but do not show anything. They don’t even show a new screen.

As conclusion, I leave you with a question:

Who in the name of H and H is Bill and what is his role into all this?

If you find out, please let me know :)

Edit 2009-11-24: If you liked this article, you should also check another rare bug here BlackBerry - IllegalStateException ArticInterface::DocPosToCaret