Scrolling List loses selection when switching card

[tluyben]

When I put a List on Card 1 and selection of an item in that list + button click goes to Card 2, clicking back from Card 2 to Card 1 then shows the selected item on the List is now no longer selected. How can I make it hold selection when switching cards?

[richmond62]

The listField contains this script:

on mouseUp
put the selectedLine of me into fld "SELECTION"
end mouseUp

The script to make sure the line is reselected when you return to this card is in the cardScript:

Code: Select all

on openCard
   put fld "SELECTION" into XXX
   select XXX
end openCard

Hold The Selection.livecode.zip

Here's the stack.

(1.43 KiB) Downloaded 179 times

[FourthWorld]

Set the field's sharedText to true, place it in a group, set the group's sharedBehavior and backgroundBehavior to true.

[richmond62]

Set the field's sharedText to true, place it in a group, set the group's sharedBehavior and backgroundBehavior to true.

While I am quite sure that is a far more elegant solution than my one,
could you possibly rephrase it in a somewhat less opaque fashion so
us "bottom feeders" could understand it.

[FourthWorld]

These are properties available in the Inspector. Throughout LiveCode, as with many dev tools, objects have properties which govern common behavior. That set of property settings addresses the OP's need. For details on each they're described betterin the Dictionary than I could replicate here.

[jacque]

Set the field's sharedText to true, place it in a group, set the group's sharedBehavior and backgroundBehavior to true.

I did all that but it doesn't work here I'm afraid, though I have vague memories that it used to. I had to do this:

In field script:

Code: Select all

on mouseUp
  set the cLine of me to the hilitedline of me
  go next
end mouseUp

In group script:

Code: Select all

on preOpenControl
  set the hilitedline of fld 1 of me to the cLine of fld 1
end preOpenControl

The preOpenControl handler will only work if the card you're coming from doesn't have that group placed.

[richmond62]

Does this mean that hilitedLine is a synonym for selectedLine ?

[FourthWorld]

Set the field's sharedText to true, place it in a group, set the group's sharedBehavior and backgroundBehavior to true.

I did all that but it doesn't work here I'm afraid, though I have vague memories that it used to. I had to do this:

In field script:

Code: Select all

on mouseUp
  set the cLine of me to the hilitedline of me
  go next
end mouseUp

In group script:

Code: Select all

on preOpenControl
  set the hilitedline of fld 1 of me to the cLine of fld 1
end preOpenControl

The preOpenControl handler will only work if the card you're coming from doesn't have that group placed.

I used to do that, and double-checked before posting to make sure a property-only approach would work. It does here in v9RC1, at least under Ubuntu 14.04. Just to make sure I just ran the recipe again - continues to work.

If the working behavior is limited to a single platform, that would seem a bug. And given how common this need is, it would seem a bug worth addressing.

[FourthWorld]

Does this mean that hilitedLine is a synonym for selectedLine ?

No. They can sometimes be used in similar tasks, but return very different values. When in doubt the Dictionary contains useful details.

[jacque]

Someone else should check the property method. I tested it as written and it didn't work in 9.rc1 on Mac. I may have missed something though.

[FourthWorld]

I just tested on Mac and got the same good result. What are we doing differently? The complete steps I take are:
1. Create a new stack
2. Create a scrolling list field put
3. Use the Inspector to put some text in it.
4. In the Inspector, set the field's sharedText
5. Group it
6. In the Inspector, set the group's backgroundBehavior and the sharedBehavior
7. Choose browse tool
8. Click a line other than the first one to hilite it
9. Choose "Go Next" from the View menu

RESULT: the line I selected remains selected as I switch cards

[jacque]

I turned off the group's sharedBehavior and it started working.

Odd, that.

Edit: I just noticed I'm in 8.1.9. I have several versions of LC running and got mixed up.

[dunbarx]

I have only just skimmed this thread, but isn't the easiest way to simply set a custom property of the list field to its hilitedLine , and on openCard, hilite that line?

Craig

[FourthWorld]

I have only just skimmed this thread, but isn't the easiest way to simply set a custom property of the list field to its hilitedLine , and on openCard, hilite that line?

There are many ways to solve many things. We can write custom scripts to mirror most built-in property-driven behaviors if we want to. Personally, I prefer to let the engine do the work where I can, leaving script space free and open for things property settings can't do.

[richmond62]

There are many ways to solve many things.

Indeed.

set the script of the listField to this:

Code: Select all

on mouseUp
   set the LYNE of me to the selectedLine of me
end mouseUp

where LYNE is a custom property of the listField

then in the cardScript:

Code: Select all

on openCard
   put the LYNE of fld "myList" into LLINE
   select LLINE
end openCard

I am sure someone a bit craftier than me can reduce the last script to something shorter.