#include "screen.h"
#include <stddef.h>
#include <stdlib.h>

Screen* newScreen(unsigned short rows, unsigned short columns, void (*update)(Screen)) {
    unsigned short i;
    
    Screen* screen = calloc(1, sizeof(Screen));
    if (screen == NULL)
        return NULL;
    
    screen->data = (unsigned char**) calloc(rows, sizeof(unsigned char*));
    if (screen->data == NULL) 
        return NULL;
    for (i = 0; i < rows; i++) {
        screen->data[i] = (unsigned char*) calloc(columns + 1, sizeof(unsigned char));
        if (screen->data[i] == NULL) {
            for (; i >= 0; i--)
                free(screen->data[i]);
            free(screen->data);
            return NULL;
        }
    }
    
    screen->rows = rows;
    screen->columns = columns;
    screen->first_visible_row = screen->first_visible_column = NULL;
    screen->cursor_x = screen->cursor_y = NULL;
    screen->update = update;
    return screen;
}

inline void freeScreen(Screen* screen) {
    unsigned short i;
    for (i = 0; i < screen->rows; i++) 
        free(screen->data[i]);
    free(screen->data);
}