Problem Allocating Memory For Structure Within Structure In A Function

Here's the structs for my window(s):

Code:

struct _display {
        int top_limit;
        int bottom_limit;
        int current;
        int max_y;
        int max_x;
        int total;
};

typedef struct _sub_window {
        WINDOW *win;
        struct _display *display;
} Sub_window;

typedef struct _wnode {
        WINDOW *win;
        struct _sub_window sub_window;
        struct _display *display;
        struct _wnode *next;
        struct _wnode *prev;
} Windownode;

Within my main Windownode, I found the need to have another derived window within it, so I'm trying to add that derived window with this...

Code:

int init_sub_window(Windownode **node, int sub_rows, int sub_cols, int start_y, int start_x)
{
        WINDOW *derived_window;
        struct _display *local_display;
        Sub_window *temp;

        temp = safemalloc(sizeof(Sub_window));
        local_display = safemalloc(sizeof(struct _display));

        /* TODO: Safe malloc for derived windows. */
        derived_window = derwin((*node)->win, (*node)->display->max_y - sub_rows, (*node)->display->max_x - sub_cols, \
                start_y, start_x);

        if(!derived_window) {
                fprintf(stderr, "Error in derived window allocation!");
                exit(1);
        }

        temp->win = derived_window;
        temp->display = local_display;

        getmaxyx(temp->win, temp->display->max_y, temp->display->max_x);

        temp->display->top_limit = 0;
        temp->display->bottom_limit = temp->display->max_y;
        temp->display->current = 0;
        temp->display->total = 0;

        (*node)->sub_window = temp; 
}

In main, I'm calling the function like this...

Code:

init_sub_window(&win_parent[MAIN], 4, 2, 1, 1);

But, the error I'm getting for this setup is...

Code:

gcc -g3 -c main.c 
gcc -g3 -c color.c 
gcc -g3 -c print.c 
gcc -g3 -c tree.c 
gcc -g3 -c window.c 
window.c: In function 'init_sub_window':
window.c:81: error: incompatible types in assignment
make: *** [window.o] Error 1

Line 81 is that last line, (*node)->sub_window = temp;. Within the function, I've tried *node->sub_window, (*node)->sub_window, and *(node)->sub_window, but no success. Where I get the derived window part of the function, where I have (*node)->win and all, I don't get any errors, but that was after tinkering with the parentheses and asterisk. I don't think I understand why those take but the (*node)->sub_window at the bottom doesn't. What I had thought about doing was passing the parent window's Sub_window AND the entire parent window's structure so that I could get it's max_y and max_x, but that seems to be overkill. What am I doing wrong? Thanks.

sub_window is an actual object. In that case, no room need be allocated for it; it is already there. If you feel you want/need dynamic allocation, then sub_window should be a pointer instead.

Hint: temp is a pointer and sub_window, the member of the struct is not.

"(*node)->sub_window" is of type Sub_Window, where temp is of type Sub_Window*.
Maybe you intended (*node)->sub_window = *temp;?

Oh, snap! Thanks claudiu! I didn't see that one!!! Aaaah! I meant to make that a pointer! It works! Thank you both!