SDL Text Input returning white squares

Question

I created an event class and wanted to get text with it. Unfortunately the text isn't reading correctly...

I've set it up so that all text that is gotten is output to the command line when a new key is input, but it obviously isn't working.

Here's my "EventManager" code for my update function:

void EventManager::update(){
    while(SDL_PollEvent(&e)){

        switch(e.type){
            case SDL_QUIT:
                running = false;
                break;
            case SDL_MOUSEBUTTONDOWN:
                mousePressed = true;
                break;
            case SDL_KEYDOWN:
                if(shouldCollectText && e.key.keysym.sym == SDLK_BACKSPACE && currentCollectedText.length() > 0){
                    currentCollectedText.pop_back();
                }else if(shouldCollectText && e.key.keysym.sym != SDLK_BACKSPACE){
                    currentCollectedText += e.text.text; //The problem
                    std::cout << currentCollectedText << std::endl;
                }
        }
    }
}

I followed the Lazy Foo tutorials, and I can't find the problem.

Some other things to note:

I start text input in my "main.cpp" class:

int main( int argc, char *argv[] ) {
    Game *game = new Game();
    game->init();

    SDL_StartTextInput();

    while(game->isRunning()){
        game->handleEvents();
        game->update();
        game->render();
    }

    game->close();
    SDL_StopTextInput();
    return 0;
}

I create some of my variables in "EventManager.h":

bool shouldCollectText;
std::string currentCollectedText;

And define them in an "init()" function:

shouldCollectText = false;
currentCollectedText = "";

Answer 1

Your problem is that you are using the wrong event type. Take a second look at Lazy Foo's tutorial and here:

TextInputEvent

e.text.text is reserved for Text Input events and nothing else. Being SDL_Event an union of structures, overlaps may occur in the used memory. That is exactly what you see in the terminal output.

Remove the SDL_KEYDOWN event and try this instead:

case SDL_TEXTINPUT:
     currentCollectedText += e.text.text;
     break;

I'm not sure about std::cout << currentCollectedText << std::endl; though. It depends on when you want to get output of the text content.

If you want to use SDL_KEYDOWN you will have to access the keysym tables and maybe calculate to which letter they correspond and print those out. I would say, that approach is more complicated for what you want to achieve.

So in conclusion e.text.text will only work if e.type has the SDL_TEXTINPUT value as event. With all the other settings in your code that event should be triggered and may get the text you type in.

So your complete example could look like this:

void EventManager::update(){
    while(SDL_PollEvent(&e)){

        switch(e.type){
            case SDL_QUIT:
                running = false;
                break;
            case SDL_MOUSEBUTTONDOWN:
                mousePressed = true;
                break;
            case SDL_TEXTINPUT:
                if(shouldCollectText && currentCollectedText.length() > 0){
                    currentCollectedText.pop_back();
                }else if(shouldCollectText) {
                    currentCollectedText += e.text.text; //The problem
                    std::cout << currentCollectedText << std::endl;
                }
                break;
           default: break;
        }
    }
}