sending a callback from a button inside a container (wheel item) to the view

[nico23]

I have a scroll wheel languageSelectorWheel with several items. Every item is a container languageSelectorItem

On the container I have a toggle button. When I click any toggle button, I want to send a trigger on the view of the scroll wheel to execute a function.

On the toggle button I have added an interaction onClick via TouchGFX that emits the trigger languageChanged. The trigger is set on the languageSelectorItem container

On the view where the languageSelectorWheel is added, I have set the callback

void languageSettingsView::languageChanged()

Unfortunatly, it seems it is not called when i toggle the button (settings a breakpoint on the line that call 

emitLanguageChangedCallback(); in languageSelectorBase where void languageSelectorBase::buttonCallbackHandler(const touchgfx::AbstractButton& src) is defined enters)

My thought is that because the trigger is set on the container, it won't be passed to the view

[nico23 · Accepted solution]

Ok so I figure it out. I set a trigger on the container that returns its index

On the interactions I have added a button click that both call a function and executes the trigger

languageItem.hpp (container)

Here you must register the trigger

    void setLanguageSelectedCallback(touchgfx::GenericCallback<const int16_t>& callback)
    {
        languageSelectedCallback = &callback;
    }

protected:
    int16_t itemNumber;
    touchgfx::GenericCallback<const int16_t>* languageSelectedCallback;

languageItem.cpp (container)

here you execute the callback

void languageItem::buttonClicked()
{
    // Call the callback when the button is clicked, passing the item number
    if (languageSelectedCallback && languageSelectedCallback->isValid())
    {
        languageSelectedCallback->execute(itemNumber);
    }
}

languageSettingsView.hpp

Here you register the callback from the container

protected:
    /*
     * Callback Declarations
     */
    touchgfx::Callback<languageSettingsView, const int16_t> languageItemLanguageSelectedCallback;

    /*
     * Callback Handler Declarations
     */
    void languageItemLanguageSelectedCallbackHandler(const int16_t itemIndex);

languageSettingsView.cpp (view)

Finally in the view you can initialize all the callback, one for each element of the wheel

languageSettingsView::languageSettingsView():
    languageItemLanguageSelectedCallback(this, &languageSettingsView::languageItemLanguageSelectedCallbackHandler)
{

    for (int i = 0; i < languageSelectorScrollListItems.getNumberOfDrawables(); i++)
    {       languageSelectorScrollListItems[i].setLanguageSelectedCallback(languageItemLanguageSelectedCallback);
    }
}

And then you can use the callback on the View to react according to the index

void languageSettingsView::languageItemLanguageSelectedCallbackHandler(const int16_t itemIndex)
{


}

Clearly on the View you need a function that set the itemNumber, something like

void languageSettingsView::languageSelectorScrollUpdateItem(languageItem& item, int16_t itemIndex)
{
    item.setItemNumber(itemIndex);
}

Where the setItemNumber function must be added to the container