Re: MacOS Tahoe painfully slow a wxChoice containing 6k entries.

Sadly it's not going to be as simple as solution 2 above as any 
"Bind(wxEVT_CHOICE" on the control will need reworking.


On Wednesday, 10 December 2025 at 10:12:33 UTC Tony Kennedy wrote:

> An update as this potentially impacts all MacOS controls that have a 
> NSMenu internally.
>
> I had a feeling it was "Spotlight" that was the problem based on 
> https://discussions.apple.com/thread/256145409?sortBy=rank.
>
> Using chatgpt (I'm not familiar with Apple and Spotlight which seems to be 
> the cause of the problem), it gave me a workaround.
>
> From chatgpt,
> On macOS, wxChoice is implemented using a *native NSPopUpButton*, which 
> internally creates an *NSMenu* with 6000 NSMenuItems. macOS 
> Spotlight/Accessibility *automatically scans every NSMenuItem* for 
> metadata every time the menu changes — especially when
>
>    - 
>    
>    clearing all items
>    - 
>    
>    recreating items
>    - 
>    
>    calling Clear()
>    - 
>    
>    calling Append() thousands of times
>    
> This is why your app hangs for *60+ seconds*.
>
>
> Two solutions.
>
> 1. Don't use "Clear", instead create a wxArrayString object, add all the 
> strings and then call pChoice->Set(items);
>
>
> 2. Replace wxChoice with wxOwnerDrawnComboBox.
> #if defined(__WXMAC__)
>     #define WX_CHOICE wxOwnerDrawnComboBox
>     #define WX_CHOICE_FLAGS(parent, id, value, pos, size, choices, style) \
>         wxOwnerDrawnComboBox(parent, id, value, pos, size, choices, style)
> #else
>     #define WX_CHOICE wxChoice
>     #define WX_CHOICE_FLAGS(parent, id, value, pos, size, choices, style) \
>         wxChoice(parent, id, value, pos, size, choices, style)
> #endif
>
> and then replace
>
> wxChoice* myChoice = new wxChoice(this, wxID_ANY, wxDefaultPosition, 
> wxDefaultSize, items);
>
> with
>
> WX_CHOICE* myChoice = WX_CHOICE_FLAGS(this, wxID_ANY, wxEmptyString,
>                                       wxDefaultPosition, wxDefaultSize,
>                                       items, 0);
>
>
>
>
>
>
>
>
>
>
>
>
> On Wednesday, 10 December 2025 at 09:31:15 UTC Tony Kennedy wrote:
>
>> Hi all,
>>
>> Using MacOS Tahoe and wx 3.3.0.0.
>>
>> A user has reported that there is a crazy slowdown when using MacOS Tahoe.
>>
>> The offending line in my code is 
>>
>> m_pChoice->Clear();
>>
>> The wxChoice control has 6500 entries and takes approximately a minute to 
>> clear all entries.
>>
>> Has anyone else experienced something similar?
>>
>> All is fine on both Windows and other versions of MacOS. And previous 
>> versions of my app that used earlier wx (3.2.6) is also fine.
>>
>> Any advice would be very welcome.
>>
>> Thanks in advance,
>>
>> Tony.
>>
>>

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