TextBlock.h

#ifndef GENERIC_TEXTBLOCK_H
#define GENERIC_TEXTBLOCK_H

#define MAXCHARS_TEXTBLOCK 50
#define MAXCHARS_TEXTBLOCK_TF 30

class TextBlock
{
  public:
    void begin( RA8875 &tft, uint8_t fontSize, uint16_t fontColor = 0 ){
      _tft = &tft;
      _tft->setFontScale(0);
      _fontSize = fontSize;
      _fontColor = fontColor;
    }

    void setDirty(){
      _isDirty = true;
    }

    void draw()
    {
      if( _isDirty )
      {
        _tft->setFontScale(0);
        _tft->setFontSize(X16);
        _tft->setTextColor(_fontColor);

        // out with the old ...
        _tft->fillRect(_oldx, _oldy-7, int(_width-_oldx), int(_fontSize+20), _clearColor);

        // ... in with the new
        _tft->setCursor(_x, _y);
        _tft->print(_text);

        // When text is written, we need to save the last metrics
        _tft->getCursor(_width, _height);
        _oldx = _x;
        _oldy = _y;

        // Always end by setting as clean
        _isDirty = false;
      }
    }

    bool getDirty()
    {
       return _isDirty;
    }

    void setPos(int x, int y)
    {
      if( _x != x){
        _isDirty = true;
        _x = x;
      }
      if( _y != y){
        _isDirty = true;
        _y = y;
      }
    }

    void setText(char const * newText)
    {
      uint8_t comp = strcmp(_text,newText);
      if( comp != 0){
        strlcpy(_oldtext,_text,_textLength); // copy the old text so we can overwrite it
        _textLength = strlen(newText)+1; // always add one to include NUL-character

        // Check that we don't go over max length
        if (_textLength > MAXCHARS_TEXTBLOCK_TF)
          _textLength = MAXCHARS_TEXTBLOCK_TF;

        strlcpy(_text,newText,_textLength); // save the new text for display
        _isDirty = true;
      }
    }

    void setText(int newText)
    {
      _tft->print(newText);
    }

  protected:
    uint8_t _fontSize;
    uint16_t _fontColor;
    uint8_t _textLength = 0;
    int _available_width;
    char _text[MAXCHARS_TEXTBLOCK_TF+1] = {};
    char _oldtext[MAXCHARS_TEXTBLOCK_TF+1] = {};
    char *_name;
    int16_t _x = 0;
    int16_t _y = 0;
    int16_t _width;
    int16_t _height;
    int16_t _oldx = 800;
    int16_t _oldy = 800;
    bool _isDirty = true;

    int _clearColor = RA8875_WHITE;
    RA8875 *_tft;
};

#endif /*GENERIC_TEXTBLOCK_H*/