[Mica] Fix crash accessing BaseWindowHandler::m_capabilities from Capabilities::Changed handler #6288
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…abilities::Changed handler (#6288) * use weak refs to avoid crashes accessing captured data * remove unnecessary weak refs * clean up commented code Co-authored-by: Dmitriy Komin <dkomin@windows.microsoft.com>
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BaseWindowHandler (owned by MicaController) subscribes to Windows::UI::Composition::CompositionCapabilities::Changed event. The current Changed handler captures 'this' by reference and tries to access this->m_capabilities. It's possible the handler is invoked after BaseWindowHandler is already cleaned up and access via this is invalid. To fix, capture this as a weak_ptr and resolve it before accessing class members in the handler.
Originally BaseWindowHandler was a simple C++ struct; make it derive from winrt::implements<..., IInspectable> to support ref counting and strong/weak refs.
The same problematic pattern was used for UISettings::AdvancedEffectsEnabledChanged and PowerManager::EnergySaverStatusChanged, so apply the fix there as well.