CODEWITHSUNDEEP
c++ccursorncursescurses
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Reputation: 16148

ncurses: wgetch fails to read correctly after moving / resizing window

I am having a hard time trying to get wgetch to read data from a window after moving and resizing it.

Upon input, I move the window up and increase it's height by 1 too. I then clear the window and write data back to it. The problem is when I do wgetch (or mvwgetch) it positions the input cursor at the previous position before I moved the window up.

Here's my code:

#include <ncurses.h>

int main() {
    WINDOW *win=initscr();
    int y,x,i=1;
    getmaxyx(win, y, x);

    //creates a sub windows 1 col high
    WINDOW *child=derwin(win, i, x, y-i, 0); 

    //doc says to touch before refresh
    touchwin(win);

    //print to child
    waddstr(child, "hello");
    wrefresh(child);
    wrefresh(win);

    noecho();
    while(wgetch(child)!='q') {
            ++i;
            mvderwin(child, y-i, 0);
            wresize(child, i, x);
            touchwin(win);

            wclear(child);

            waddstr(child,"hello");
            wrefresh(child);
            wrefresh(win);
    }
    delwin(child);
    delwin(win);
    endwin();
}

Here the word "hello" does move up as expected, however, the input cursor is in the wrong place. Using mvwgetch still causes the same problem. cbreak(), noecho() and scrollok(child) also don't seem to be helping.

Thanks

EDIT: updated version better displaying the problem http://liveworkspace.org/code/31DruQ$0

Upvotes: 2

Views: 2037

Answers (1)

Anonymous
Anonymous

Reputation: 21

You have to catch SIGWINCH, that signal is sent when you resize the terminal. Do an endwin(), a refresh(), and then repaint your windows. Cursor position is relative to the windows, not the actual terminal size. The windows are not resized automatically.

Edit: Right, you're actually resizing the windows, not the terminal. In that case, first of all, do a wrefresh on the child LAST, the cursor shown on the screen is the one of the refresh that happened last.

Put a box around your subwindows and check that they're actually getting resized / moved properly.

Upvotes: 1

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