How can I set the highlighted button according to the last chapter viewed?

Question

I have a main menu with four buttons, each one of which takes me to a different chapter of track 1. When I press the MENU button on the remote and return to the main menu, I would like for the highlighted button to be the one corresponding to the last chapter viewed. How can I do this?
Page 247 of the DVDSP manual says the following:
Highlight Condition: Provides an alternative method to the Default Button setting for determining which button to highlight. When Highlight Condition is set to Default, the Default Button setting supplies the button highlight setting. When Highlight Condition is set to one of its stream settings (audio, subtitle, camera angle), the number of the stream last played determines the button to highlight. This setting can be overridden by any element that jumps to this menu, based on its jump setting.
I know that SPRM 7 contains the value of the current chapter, so when returning to the main menu I would like to use SPRM 7 to set the Highlight Condition, but I don't see a way to do that, since the only options for Highlight Condition are audio stream, subtitle stream, and camera angle.

Answer 1

Ah. Pre-scripts.
I would do this by tracking the menu, certainly, but I'd do that by using a set of scripts not as prescripts. So, if your main menu is the start up item for the disc, create a script that reads:
mov GPRM0, 1
Jump main menu
and set that as the start up item instead. Now create a second script:
mov GPRM0, 2
Jump Menu2
and use both of these scripts on any button that goes to a menu. For example, on the Main Menu you'll have a button that links to menu2... point that button to script 2 instead of the menu itself. Similarly, on the chapter menu if you've got a button that takes you back to the main menu, point that button to the first script.
For your menu call script you can now do this:
mov GPRM1, SPRM8
div GPRM1, 1024
Jump Main menu \[GPRM1\] if (GPRM0 = 1)
Jump Menu2 \[GPRM1\] if (GPRM0 = 2)
This could also be the end jump script for both tracks, too.
Now, Main menu will have three buttons, one for track 1, one for track 2 and one to go to the second script. Track 1 menu call and end jump goes to the last script, track 2 does the same. On the chapter select menu you point each button to the relevant chapter in track 1 and let the scripts do their job whenever a menu call is made or the track ends. The script will see you were on Menu2 and send you there, and SPRM8 will get you back to the button you last selected.
If, instead of this, you want to go to the button that represents the last chapter played on the chapter menu, and not the last button pressed, but still be able to get to the last button on the main menu then the script changes a bit:
Goto 5 if (GPRM0 = 2)
mov GPRM1, SPRM8
div GPRM1, 1024
Jump Main menu \[GPRM1\]
mov GPRM1, SPRM7
Jump Menu2 \[GPRM1\]
This sends you to the button relevant to the last chapter played if you came from the chapter menu, by jumping through the script to the bit that deals with Menu2, else it will work out the last button selected (and we assume this must have been on the Main menu because GPRM0 !=2 in that case), and send you to the main menu with that button highlighted.
If you've got any more scripts than that running, you've got too many... and get rid of the pre-scripts - they are more trouble than not, and don't work if you are using GPRM based button jumps anyway.