Invalidate a listview seems to not invalidate and trigger the update callback

[RonaldWerkhoven]

Hi all,

For a project, I made a simple tab structure where I can put all kind of settings, The list is divided under the tabs and shown in 2 list views next to each other. In the class, I have a variable keeping track of the currently selected tab. After clicking a tab button this variable is set to the new tab. I set the number of items for the list views to the amount needed for the number of options and invalidate the list views.

After doing this, if the number of items in the listview did not change, the invalidate will not trigger an updateCallback so the list items will not be updated, and instead, the old items will stay in the view. For now, I solved this by setting the number of items first to 0 and calling the invalidate function before I set the number of items to the correct amount.

Is this expected behavior, or have I run into a bug here?

I attached a screenshot of the view and the code to give you more of an idea of the implementation

Code:

/**
*	Set the selected tab
*	Set the number of items for the list views
*/
void SettingsContainer::setSelectedTab(baulds::settingsTabs tab)
{
	// Set the selected tab internally
	this->selectedTab = tab;

	// Tell the menu controller to set the current scene
	this->menuController->setCurrentScene((int)tab);

	/**
	*	First we set the number of items to 0, this to make sure the invalidate is called
	*	If we set the number of items the same as it already had the invalidate wil not trigger properly
	*/

	SettingsListLeft.setNumberOfItems(0);				
	SettingsListRight.setNumberOfItems(0);
	this->invalidate();

	/**
	*	Set the number of items for the left and right menu
	*/
	SettingsListLeft.setNumberOfItems(this->_getLeftMenuSize());
	SettingsListRight.setNumberOfItems(this->_getRightMenuSize());
	this->invalidate();
}

/**
* Callback for the left menu to update
*/
void SettingsContainer::SettingsListLeftUpdateItem(SettingsContainerItem& item, int16_t itemIndex)
{
	baulds::settingsNode* node = this->settingsController->getSettingByIndex(itemIndex, this->selectedTab);
	if (node != nullptr)
	{
		item.setNode(*node);
	}
}

/**
* callback for the right menu to update
*/
void SettingsContainer::SettingsListRightUpdateItem(SettingsContainerItem& item, int16_t itemIndex)
{
	baulds::settingsNode* node = this->settingsController->getSettingByIndex(this->_getLeftMenuSize() + itemIndex, this->selectedTab);
	if (node != nullptr)
	{
		item.setNode(*node);
	}
}