Remove TermWin's is_minimised method.

Again, I've replaced it with a push-based notification going in the
other direction, so that when the terminal output stream includes a
query for 'is the window minimised?', the Terminal doesn't have to
consult the TermWin, because it already knows the answer.

The GTK API I'm using here (getting a GdkEventWindowState via
GtkWidget's window-state-event) is not present in GTK 1. The API I was
previously using (gdk_window_is_viewable) _is_, but it turns out that
that API doesn't reliably give the right answer: it only checks
visibility of GDK window ancestors, not X window ancestors. So in fact
GTK 1 PuTTY/pterm was only ever _pretending_ to reliably support the
'am I minimised' terminal query. Now it won't pretend any more.

fuzzterm.c

@@ -88,7 +88,6 @@ static void fuzz_request_resize(TermWin *tw, int w, int h) {}
 static void fuzz_set_title(TermWin *tw, const char *title) {}
 static void fuzz_set_icon_title(TermWin *tw, const char *icontitle) {}
 static void fuzz_set_minimised(TermWin *tw, bool minimised) {}
-static bool fuzz_is_minimised(TermWin *tw) { return false; }
 static void fuzz_set_maximised(TermWin *tw, bool maximised) {}
 static void fuzz_move(TermWin *tw, int x, int y) {}
 static void fuzz_set_zorder(TermWin *tw, bool top) {}
@@ -117,7 +116,6 @@ static const TermWinVtable fuzz_termwin_vt = {
     .set_title = fuzz_set_title,
     .set_icon_title = fuzz_set_icon_title,
     .set_minimised = fuzz_set_minimised,
-    .is_minimised = fuzz_is_minimised,
     .set_maximised = fuzz_set_maximised,
     .move = fuzz_move,
     .set_zorder = fuzz_set_zorder,

putty.h

@@ -1138,7 +1138,6 @@ struct TermWinVtable {
      * the window it remembers whether to go back to normal or
      * maximised. */
     void (*set_minimised)(TermWin *, bool minimised);
-    bool (*is_minimised)(TermWin *);
     void (*set_maximised)(TermWin *, bool maximised);
     void (*move)(TermWin *, int x, int y);
     void (*set_zorder)(TermWin *, bool top);
@@ -1638,6 +1637,7 @@ void term_keyinput(Terminal *, int codepage, const void *buf, int len);
 void term_keyinputw(Terminal *, const wchar_t * widebuf, int len);
 void term_get_cursor_position(Terminal *term, int *x, int *y);
 void term_setup_window_titles(Terminal *term, const char *title_hostname);
+void term_notify_minimised(Terminal *term, bool minimised);
 
 typedef enum SmallKeypadKey {
     SKK_HOME, SKK_END, SKK_INSERT, SKK_DELETE, SKK_PGUP, SKK_PGDN,

terminal.c

@@ -1792,6 +1792,7 @@ Terminal *term_init(Conf *myconf, struct unicode_data *ucsdata, TermWin *win)
 
     term->window_title = dupstr("");
     term->icon_title = dupstr("");
+    term->minimised = false;
 
     return term;
 }
@@ -4425,8 +4426,7 @@ static void term_out(Terminal *term)
                                 break;
                               case 11:
                                 if (term->ldisc)
-                                    ldisc_send(term->ldisc,
+                                    ldisc_send(term->ldisc, term->minimised ?
-                                               win_is_minimised(term->win) ?
                                                "\033[2t" : "\033[1t", 4,
                                                false);
                                 break;
@@ -7322,3 +7322,8 @@ int term_get_userpass_input(Terminal *term, prompts_t *p, bufchain *input)
         return +1; /* all done */
     }
 }
+
+void term_notify_minimised(Terminal *term, bool minimised)
+{
+    term->minimised = minimised;
+}

terminal.h

@@ -344,6 +344,7 @@ struct terminal_tag {
     int mouse_paste_clipboard;
 
     char *window_title, *icon_title;
+    bool minimised;
 };
 
 static inline bool in_utf(Terminal *term)

unix/gtkwin.c

@@ -565,15 +565,6 @@ static void gtkwin_set_maximised(TermWin *tw, bool maximised)
 #endif
 }
 
-/*
- * Report whether the window is minimised, for terminal reports.
- */
-static bool gtkwin_is_minimised(TermWin *tw)
-{
-    GtkFrontend *inst = container_of(tw, GtkFrontend, termwin);
-    return !gdk_window_is_viewable(gtk_widget_get_window(inst->window));
-}
-
 /*
  * Report the window's position, for terminal reports.
  */
@@ -670,6 +661,16 @@ gint delete_window(GtkWidget *widget, GdkEvent *event, GtkFrontend *inst)
     return false;
 }
 
+#if GTK_CHECK_VERSION(2,0,0)
+static void window_state_event(GtkWidget *widget, GdkEventWindowState *event,
+                               gpointer user_data)
+{
+    GtkFrontend *inst = (GtkFrontend *)user_data;
+    term_notify_minimised(
+        inst->term, event->new_window_state & GDK_WINDOW_STATE_ICONIFIED);
+}
+#endif
+
 static void update_mouseptr(GtkFrontend *inst)
 {
     switch (inst->busy_status) {
@@ -5148,7 +5149,6 @@ static const TermWinVtable gtk_termwin_vt = {
     .set_title = gtkwin_set_title,
     .set_icon_title = gtkwin_set_icon_title,
     .set_minimised = gtkwin_set_minimised,
-    .is_minimised = gtkwin_is_minimised,
     .set_maximised = gtkwin_set_maximised,
     .move = gtkwin_move,
     .set_zorder = gtkwin_set_zorder,
@@ -5506,6 +5506,12 @@ void new_session_window(Conf *conf, const char *geometry_string)
     term_size(inst->term, inst->height, inst->width,
               conf_get_int(inst->conf, CONF_savelines));
 
+#if GTK_CHECK_VERSION(2,0,0)
+    /* Delay this signal connection until after inst->term exists */
+    g_signal_connect(G_OBJECT(inst->window), "window_state_event",
+                     G_CALLBACK(window_state_event), inst);
+#endif
+
     inst->exited = false;
 
     start_backend(inst);

windows/window.c

@@ -244,7 +244,6 @@ static void wintw_request_resize(TermWin *, int w, int h);
 static void wintw_set_title(TermWin *, const char *title);
 static void wintw_set_icon_title(TermWin *, const char *icontitle);
 static void wintw_set_minimised(TermWin *, bool minimised);
-static bool wintw_is_minimised(TermWin *);
 static void wintw_set_maximised(TermWin *, bool maximised);
 static void wintw_move(TermWin *, int x, int y);
 static void wintw_set_zorder(TermWin *, bool top);
@@ -272,7 +271,6 @@ static const TermWinVtable windows_termwin_vt = {
     .set_title = wintw_set_title,
     .set_icon_title = wintw_set_icon_title,
     .set_minimised = wintw_set_minimised,
-    .is_minimised = wintw_is_minimised,
     .set_maximised = wintw_set_maximised,
     .move = wintw_move,
     .set_zorder = wintw_set_zorder,
@@ -2980,6 +2978,7 @@ static LRESULT CALLBACK WndProc(HWND hwnd, UINT message,
               "...",
               LOWORD(lParam), HIWORD(lParam));
 #endif
+        term_notify_minimised(term, wParam == SIZE_MINIMIZED);
         if (wParam == SIZE_MINIMIZED)
             SetWindowText(hwnd,
                           conf_get_bool(conf, CONF_win_name_always) ?
@@ -5611,14 +5610,6 @@ static void wintw_set_maximised(TermWin *tw, bool maximised)
     }
 }
 
-/*
- * Report whether the window is iconic, for terminal reports.
- */
-static bool wintw_is_minimised(TermWin *tw)
-{
-    return IsIconic(wgs.term_hwnd);
-}
-
 /*
  * Report the window's position, for terminal reports.
  */