Participant

P: Problem with LrView:combo_box and binding for items

Forum|Forum|1 year ago
November 9, 2024
3 replies
517 views

Hello,

I try to use a combo_box with a binding for the items:

local function main()
  LrFunctionContext.callWithContext('showDialog', function(context)

    local props = LrBinding.makePropertyTable( context )
    props.items = { '1', '2', '3'}
    props.value = ''

    logDebug('main', '#Items = ' .. #props.items ) 
    
    local f = LrView.osFactory()
    local view = f:column {
      bind_to_object = props,
      f:row{ 
        f:combo_box{ items = LrView.bind('items'), value = LrView.bind('value'), width = 50 },  
        f:push_button{ 
          title = 'Remove',
          action = function()
            if #props.items > 1 then table.remove(props.items, #props.items ) end
            logDebug('main', 'After remove #Items = ' .. #props.items ) 
          end,
        }, 
      },
    }    
  
    status = LrDialogs.presentModalDialog {
      title = 'test combo box',
      contents = view,
    }      
  end )
end

Initially all three items are displayed. By pressing the 'Remove' button the last item is removed from the item table, but still all three items are displayed. After selecting the last (non-existing) item Lightroom crashes.

Any ideas what's the code?

Regards. Roland

Rikk Flohr_Photography

Updating Status - Adding Bug Number

Rikk Flohr: Adobe Photography Org

johnrellis

Legend

Removing an item from the array of items of a viewFactory:combo_box() can crash LR 14.0.1 on Windows 11 (but not Mac OS 15). To reproduce:

1. Save the script below to the file "combo_box-bug.lua" in the Lightroom settings Scripts folder and restart LR.

2. Do Scripts > combo_box-bug.

3. Click on the combo box's dropdown and observe two items. Don't select either item:

4. Click Remove.

5. Click on the dropdown and select item "2". In a few seconds LR will crash (incorrect). I've submitted a crash report under my Adobe Id.

I've posted above a fix to the code for correctly removing an item from a combo box. But plugins should never be able to crash LR.

local LrBinding = import "LrBinding"
local LrDialogs = import "LrDialogs"
local LrFunctionContext = import "LrFunctionContext"
local LrView = import "LrView"
local bind = LrView.bind
local f = LrView.osFactory ()

LrFunctionContext.callWithContext ("Test", function (context)
    local prop = LrBinding.makePropertyTable (context, context)
    prop.items = {1, 2}
    prop.value = ""

    LrDialogs.presentModalDialog {title = "combo_box bug", contents = f:row {
        bind_to_object = prop,
        f:combo_box {items = bind "items", value = bind "value", width = 100},  
        f:push_button {title = "Remove",  action = function ()
            table.remove (prop.items, #prop.items) end}}}
    end)

johnrellis

Legend

@Rikk Flohr: Photography, I posted above a simple recipe for reliably crashing LR and submitted a crash report under my Adobe Id. Please move to Bugs, thanks.

johnrellis

Legend

LR should never crash -- I'll start a bug report.

The issue with your code is that observable tables (LrObservableTable) only observe assignments to the key values themselves. If a key value is a table, they don't notice changes to the contents of that table.

The fix for your code is easy. After the call to table.remove(), add this line:

props.items = props.items

The assignment to the key "items" will be observed, and the combo_box() will get updated appropriately.

rolandp92181609Author

Participant

Thanks!! After the simple change it works.

With your explanations it is clear why it didn't work before.

Thanks Roland

PS: I also submit an bug report via the Lightroom popup message.

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