ncurses with panels a customizable window inside terminal - but not very functional :)

panel_browse.c

#include <curses.h>
#include <panel.h>
#include <string.h>
#include <stdlib.h>

#define NLINES 10
#define NCOLS 40
#define COUNT 3
#define TEELINE 2


typedef struct __PANEL_DATA {
	int x,y, height, width;
	int label_color;
	char label[80];
	PANEL* next;
} PANEL_DATA;


void init(WINDOW **wins, PANEL **all_panels);
void win_show(WINDOW *win, char *label, int label_color);
void print_in_middle(WINDOW* win, int maxx, int teeline, char *string,
 chtype color);
void operate_on_panel(PANEL* top);
void move_mode(PANEL* top);
void resize_mode(PANEL* top);


int main()
{
	WINDOW *my_wins[COUNT];
	PANEL  *my_panels[COUNT];
	PANEL  *top;
	int ch;

	/* Initialize curses */
	initscr();
	start_color();
	cbreak();
	noecho();
	keypad(stdscr, TRUE);

	/* Initialize all the colors */
	init_pair(1, COLOR_RED, COLOR_BLACK);
	init_pair(2, COLOR_GREEN, COLOR_BLACK);
	init_pair(3, COLOR_BLUE, COLOR_BLACK);
	init_pair(4, COLOR_CYAN, COLOR_BLACK);

	chtype notice_color = COLOR_PAIR(4);

	init(my_wins, my_panels);


	/* Update the stacking order. 3rd panel will be on top */
	update_panels();

	/* Show it on the screen */
	attron(notice_color);
	mvprintw(LINES - 2, 0, "Use <tab> to browse, <m> to move, <r> to resize, <Enter> to write (F1 to Exit)");
	attroff(notice_color);
	refresh();

	top = my_panels[2];
	PANEL_DATA* current_data = (PANEL_DATA*)panel_userptr(top);
	while((ch = getch()) != KEY_F(1))
	{	switch(ch)
		{
			case 'm':
				attron(notice_color);
				mvprintw(LINES-3, 0, "You can move panels with arrow keys (use <Enter> to exit!)");
				attroff(notice_color);
				refresh();
				move_mode(top);
				break;
			case 'r':
				attron(notice_color);
				mvprintw(LINES-3, 0, "Use arrow keys to resize window and press <Enter> when you're done!");
				attroff(notice_color);
				refresh();
				resize_mode(top);
				break;
			case '\t':
				top_panel(current_data->next);
				top = current_data->next;
				current_data = (PANEL_DATA*)panel_userptr(top);
				update_panels();
				doupdate();
				break;
			case '\n': // allow user to insert text in the current panel
				attron(notice_color);
				mvprintw(LINES - 3, 0, "Entered writing mode use <Esc> to exit");
				attroff(notice_color);
				refresh();
				operate_on_panel(top);
				break;
		}
	}
	endwin();
	return 0;
}

void move_mode(PANEL* top)
{
	PANEL_DATA* data = (PANEL_DATA*)panel_userptr(top);

	int c;
	while ((c = getch()) != 10) {
		switch (c) {
			case KEY_UP:
				--data->y;
				break;
			case KEY_DOWN:
				++data->y;
				break;
			case KEY_LEFT:
				--data->x;
				break;
			case KEY_RIGHT:
				++data->x;
				break;
		}
		move_panel(top, data->y, data->x);
		update_panels();
		doupdate();
	}

	move(LINES-3, 0);
	clrtoeol();
	refresh();
	update_panels();
	doupdate();
}

void resize_mode(PANEL* top)
{
	PANEL_DATA* data = (PANEL_DATA*)panel_userptr(top);

	int ch;
	while ((ch = getch()) != 10) {
		switch (ch) {
			case KEY_UP:
				--(data->y);
				++(data->height);
				break;
			case KEY_DOWN:
				++(data->y);
				--(data->height);
				break;
			case KEY_LEFT:
				--(data->x);
				++(data->width);
				break;
			case KEY_RIGHT:
				++(data->x);
				--(data->width);
				break;
		}

		WINDOW* tmp = newwin(data->height, data->width, data->y, data->x);
		WINDOW* old_win = panel_window(top);
		replace_panel(top, tmp);
		delwin(old_win);

		// replacing panel doesn't automatically show the new window
		win_show(tmp, data->label, data->label_color);
		update_panels();
		doupdate();
	}

	move(LINES-3, 0);
	clrtoeol();
	refresh();
	update_panels();
	doupdate();
}

/* Put all the windows */
void init(WINDOW **wins, PANEL **panels_arr)
{	int x, y, i;
	char label[80];

	PANEL_DATA* panels = (PANEL_DATA*)calloc(COUNT, sizeof(PANEL_DATA));

	y = 2;
	x = 10;
	for(i = 0; i < COUNT; ++i)
	{	wins[i] = newwin(NLINES, NCOLS, y, x);
		sprintf(label, "Window Number %d", i + 1);
		win_show(wins[i], label, i + 1);

		// attach panels
		panels_arr[i] = new_panel(wins[i]);

		// create data
		strcpy(panels[i].label, label);
		panels[i].label_color = i+1;
		panels[i].x = x;
		panels[i].y = y;
		panels[i].height = NLINES;
		panels[i].width = NCOLS;

		set_panel_userptr(panels_arr[i], &panels[i]);


		// do something :)
		y += 3;
		x += 7;
	}
	panels[0].next = panels_arr[1];
	panels[1].next = panels_arr[2];
	panels[2].next = panels_arr[0];
}

/* Show the window with a border and a label */
void win_show(WINDOW *win, char *label, int label_color)
{	int startx, starty, maxy, maxx;

	getbegyx(win, starty, startx);
	getmaxyx(win, maxy, maxx);

	box(win, 0, 0);
	mvwaddch(win, TEELINE, 0, ACS_LTEE);
	mvwhline(win, TEELINE, 1, ACS_HLINE, maxx - 2);
	mvwaddch(win, TEELINE, maxx - 1, ACS_RTEE);

	print_in_middle(win, maxx, TEELINE, label, COLOR_PAIR(label_color));
}

void print_in_middle(WINDOW* win, int maxx, int teeline, char *string,
					 chtype color)
{
	int length = strlen(string);
	int middle = (maxx - length) / 2;

	wattron(win, color);
	mvwprintw(win, teeline/2, middle, "%s", string);
	wattroff(win, color);
	wrefresh(win);
}

void operate_on_panel(PANEL* p)
{
	WINDOW *top_win = panel_window(p);

	int curs_x, curs_y;
	getyx(top_win, curs_y, curs_x);
	int cols = getmaxx(top_win);

	wmove(top_win, TEELINE+1, 1); /* set cursor ready to write */
	int c = 0;
	while ((c = wgetch(top_win)) != 27) {
		int x,y;
		getyx(top_win, y, x);

		if (x == cols-1)
			wmove(top_win, y+1, 1);

		waddch(top_win, c); // print what user has typed
		wrefresh(top_win);
	}
	/* clear notice */
	move(LINES-3,0);
	clrtoeol();
	refresh();
	// return cursor back to initial position
	wmove(top_win, curs_y, curs_x);
	wrefresh(top_win);
}

Also if you wanted to solve a problem :) take a look at line 209-211. I couldn't put these lines inside the loop which somehow didn't initialized at runtime. I've tried if-else to set last parameter to first one and also used this line panels[i].next = panels_arr[(i+1) % COUNT] but didn't have any luck.