StateManager: Only one parameter updating when using load_preset

[JamesWenlock]

Hey! Using the template to build a preset manager and when attempting to load presets, the UI only updates one parameter. Should have time this week to debug.

[ncblair]

Have you copied this pattern for each of your UI elements?

[ncblair]

The code should end up looking something like this

void AudioPluginAudioProcessorEditor::timerCallback() {
    ...

    // handle parameter values in the UI (repaint relevant components)
    if (state->any_parameter_changed.exchange(false)) {
        if (state->get_parameter_modified(PARAM::GAIN)) {
            gain_slider->repaint();
        }
        if (state->get_parameter_modified(PARAM::PARAM2)) {
            parameter_2_slider->repaint();
        }
    }
    ...`
}

[JamesWenlock]

At the moment I'm repainting all of the sliders upon any parameter change so I don't think it's an issue on the UI side. I have some time tonight to do some digging. I'll let you know what I find.

[JamesWenlock]

Confirmed, save_preset is only saving the gain parameter. I'll let you know when I have a fix.

[ncblair]

@JamesWenlock Have you resolved this? Is the issue that save_preset didn't register your other parameters, so load_preset also didn't update the other parameters?

save_preset should just get param info from get_state(), so it's weird that would be missing anything. Maybe it was a plugin version issue?

[JamesWenlock]

Not sure! My current hacky fix is to build a new ValueTree in the get_state method rather than copying from the APVST.

juce::ValueTree StateManager::get_state() {
    state_tree = juce::ValueTree(STATE_ID);
    juce::ValueTree paramTree (PARAMETERS_ID);
    for (auto p_id = 0; p_id < TOTAL_NUMBER_PARAMETERS; ++p_id)
    {
        juce::ValueTree thisParam (PARAMETER_HEADER);
        thisParam.setProperty(ID, PARAMETER_IDS[p_id].toString(), nullptr);
        thisParam.setProperty(VALUE, param_value(p_id), nullptr);
        paramTree.addChild(thisParam, p_id, nullptr);
    }
    state_tree.appendChild(paramTree, nullptr);
    state_tree.appendChild(property_tree.createCopy(), nullptr);
    state_tree.appendChild(preset_tree.createCopy(), nullptr);
    return state_tree;
}

Not sure why the other parameters aren't showing up when copying the state of the APVTS, especially considering they're showing up in Reaper.