Method onKnobValueChanged

Engine/Project.cpp:1636–1738

this function is only called on the main thread

///this function is only called on the main thread
bool
Project::onKnobValueChanged(KnobI* knob,
                            ValueChangedReasonEnum reason,
                            double /*time*/,
                            ViewSpec /*view*/,
                            bool /*originatedFromMainThread*/)
{
    bool ret = true;
    bool shouldAutoSave = false;

    if ( knob == _imp->viewsList.get() ) {
        /**
         * All cache entries are linked to a view index which may no longer be correct since the user changed the project settings.
         * The only way to overcome this is to wipe the cache.
         **/
        appPTR->clearAllCaches();

        std::vector<std::string> viewNames = getProjectViewNames();
        getApp()->setupViewersForViews(viewNames);
        if (reason == eValueChangedReasonUserEdited) {
            ///views change, notify all OneView nodes via getClipPreferences
            forceComputeInputDependentDataOnAllTrees();
        }
        Q_EMIT projectViewsChanged();
        shouldAutoSave = true;
    } else if  ( knob == _imp->defaultLayersList.get() ) {
        if (reason == eValueChangedReasonUserEdited) {
            ///default layers change, notify all nodes so they rebuild their layers menus
            forceComputeInputDependentDataOnAllTrees();
        }
        shouldAutoSave = true;
    } else if ( knob == _imp->setupForStereoButton.get() ) {
        setupProjectForStereo();
        shouldAutoSave = true;
    } else if ( knob == _imp->formatKnob.get() ) {
        int index = _imp->formatKnob->getValue();
        Format frmt;
        bool found = _imp->findFormat(index, &frmt);
        NodesList nodes;
        getNodes_recursive(nodes, true);

        // Refresh nodes with a format parameter
        std::vector<ChoiceOption> entries = _imp->formatKnob->getEntries_mt_safe();
        for (NodesList::iterator it = nodes.begin(); it != nodes.end(); ++it) {
            (*it)->refreshFormatParamChoice(entries, index, false);
        }
        if (found) {
            if (reason == eValueChangedReasonUserEdited) {
                ///Increase all nodes age in the project so all cache is invalidated: some effects images might rely on the project format
                for (NodesList::iterator it = nodes.begin(); it != nodes.end(); ++it) {
                    (*it)->incrementKnobsAge();
                }


            }
            ///Format change, hence probably the PAR so run getClipPreferences again
            forceComputeInputDependentDataOnAllTrees();
            Q_EMIT formatChanged(frmt);