On 2024-01-01 05:14 +0100, наб wrote:
> Package: libncursesw6
> Version: 6.4+20231121-1
> Severity: normal
>
> Dear Maintainer,
>
> I am attaching a repro.c program that when built with
> cc -O3 -g -Wall -Wextra -DNCURSES_WIDECHAR -D_GNU_SOURCE repro.c
> -lncursesw -ltinfo -o repro
You might just as well have said that you are hacking on the urlview package…
> presents a UI in the form of
> first line
> -> L1
> L2
> L3
> L4
> L5
> last line
>
> Mousing is enabled, and if you click on a line the cursor on the left
> moves to select it.
>
> The first line and last line are on stdscr, the rest of the screen is
> urlswin = newpad(LINES, COLS), rendered via
> pnoutrefresh(urlswin, /**/ url[first_on_page].cursor_y + fudge, 0, /**/ 1
> /*title line*/, 0, LINES - 2, COLS);
>
> On KEY_MOUSE and BUTTON1_CLICKED:
> getmouse(&ev);
> if(!wmouse_trafo(urlswin, &ev.y, &ev.x, false))
> break;
> and the line targeted is found and selected.
>
> Clicking on first line correctly hits the break.
> Clicking on last line incorrectly continues on.
>
> This shows as scrolling to the next screen
> (since the line selected is L6, which would be under last line).
>
> This /only happens/ if the lines go all the way to the line above last.
> If you click on any line below a non-full screen (s/1000/10/ or scroll down),
> nothing happens.
> Is this a weird thing with the edge of the screen?
> Or with how pnoutrefresh accounts for the undrawn parts of the pad?
Neither. It's that the urlswin pad is larger than what fits on the
screen, and the wmouse_trafo() function is not designed to work with
that. If you look at its source[1], you can see that it calls
wenclose() to decide if the mouse event happened inside the window, and
the latter simply looks at the window coordinates[2].
If you insist on using a pad larger than the screen size, you will have
to work around that limitation somehow, I am afraid. For instance,
after calling getmouse(&ev), check if ev.y is in the area that you
allocated on the screen for the visible parts of urlswin.
Cheers,
Sven
1.
https://sources.debian.org/src/ncurses/6.4%2B20240113-1/ncurses/base/lib_mouse.c/#L2051
2.
https://sources.debian.org/src/ncurses/6.4%2B20240113-1/ncurses/base/lib_mouse.c/#L1993
