Ticket #4165: 0001-Add-MultiSearch-command-a-multi-term-AND-conjugated-.patch

lib/keybind.c

@@ -93 +93 @@
     ADD_KEYMAP_NAME (SearchContinue),
     ADD_KEYMAP_NAME (Replace),
     ADD_KEYMAP_NAME (ReplaceContinue),
+    ADD_KEYMAP_NAME (MultiSearch),
     ADD_KEYMAP_NAME (Help),
     ADD_KEYMAP_NAME (Shell),
     ADD_KEYMAP_NAME (Edit),

lib/keybind.h

@@ -82 +82 @@
     CK_SearchContinue,
     CK_Replace,
     CK_ReplaceContinue,
+    CK_MultiSearch,
     CK_SearchStop,
     CK_Help,
     CK_Edit,

lib/widget/group.c

@@ -749 +749 @@
  * @param w Widget object
  */
 void
-group_remove_widget (void *w)
+group_remove_widget (void *wid)
 {
+    Widget *w = WIDGET(wid);
     WGroup *g;
     GList *d;
 
     /* Don't accept NULL widget. This shouldn't happen */
     assert (w != NULL);
 
-    g = WIDGET (w)->owner;
+    /* Invoke widget's pre unlink callback. */
+    if (w->pre_unlink_func)
+        w->pre_unlink_func(w);
+
+    g = w->owner;
 
     d = g_list_find (g->widgets, w);
     if (d == g->current)
@@ -774 +779 @@
         group_select_current_widget (g);
     }
 
-    WIDGET (w)->owner = NULL;
+    w->owner = NULL;
 }
 
 /* --------------------------------------------------------------------------------------------- */

lib/widget/history.c

@@ -66 +66 @@
 /*** file scope functions ************************************************************************/
 
 static cb_ret_t
-history_dlg_reposition (WDialog * dlg_head)
+history_dlg_reposition (WDialog * dlg_head, WRect *resize)
 {
-    history_dlg_data *data;
-    int x = 0, y, he, wi;
     WRect r;
 
-    /* guard checks */
-    if ((dlg_head == NULL) || (dlg_head->data == NULL))
-        return MSG_NOT_HANDLED;
+    if (!resize) {
+        history_dlg_data *data;
+        int x = 0, y, he, wi;
 
-    data = (history_dlg_data *) dlg_head->data;
+        /* guard checks */
+        if ((dlg_head == NULL) || (dlg_head->data == NULL))
+            return MSG_NOT_HANDLED;
 
-    y = data->y;
-    he = data->count + 2;
+        data = (history_dlg_data *) dlg_head->data;
 
-    if (he <= y || y > (LINES - 6))
-    {
-        he = MIN (he, y - 1);
-        y -= he;
-    }
-    else
-    {
-        y++;
-        he = MIN (he, LINES - y);
+        y = data->y;
+        he = data->count + 2;
+
+        if (he <= y || y > (LINES - 6))
+        {
+            he = MIN (he, y - 1);
+            y -= he;
+        }
+        else
+        {
+            y++;
+            he = MIN (he, LINES - y);
+        }
+
+        if (data->x > 2)
+            x = data->x - 2;
+
+        wi = data->max_width + 4;
+
+        if ((wi + x) > COLS)
+        {
+            wi = MIN (wi, COLS);
+            x = COLS - wi;
+        }
+        rect_init (&r, y, x, he, wi);
+    } else {
+        /* A resize from some other code (currently from the listbox filter). */
+        r = *resize;
     }
 
-    if (data->x > 2)
-        x = data->x - 2;
-
-    wi = data->max_width + 4;
-
-    if ((wi + x) > COLS)
-    {
-        wi = MIN (wi, COLS);
-        x = COLS - wi;
-    }
-
-    rect_init (&r, y, x, he, wi);
 
     return dlg_default_callback (WIDGET (dlg_head), NULL, MSG_RESIZE, 0, &r);
 }
@@ -116 +122 @@
     switch (msg)
     {
     case MSG_RESIZE:
-        return history_dlg_reposition (DIALOG (w));
+        return history_dlg_reposition (DIALOG (w), data);
 
     case MSG_NOTIFY:
         {
@@ -257 +263 @@
             listbox_select_entry (hd->listbox, hd->current);
     }
 
+    /* Option of starting the listbox with MultiSearch pre-activated. */
+    listbox_conditionally_enable_multi_search(hd->listbox);
+
     dlg_ret = dlg_run (query_dlg);
     if (dlg_ret != B_CANCEL)
     {
@@ -278 +287 @@
         hd->text = g_strdup (q);
     }
 
+    /* If needed, restore normal listbox state, with no backlist (list_keep). */
+    listbox_ensure_unfiltered_state(hd->listbox);
+
     /* get modified history from dialog */
     z = NULL;
     for (hi = listbox_get_first_link (hd->listbox); hi != NULL; hi = g_list_next (hi))

lib/widget/input.c

@@ -827 +827 @@
         break;
     }
 
+    /* Signal the listbox about any text-altering command. */
+    switch (command)
+    {
+        case CK_BackSpace:
+        case CK_Delete:
+        case CK_Clear:
+        case CK_Complete:
+        case CK_Paste:
+        case CK_Cut:
+        case CK_DeleteToWordBegin:
+        case CK_DeleteToWordEnd:
+        case CK_Remove:
+        case CK_DeleteToEnd:
+        case CK_HistoryPrev:
+        case CK_HistoryNext:
+        case CK_History:
+            send_message(WIDGET(in->forward_listbox), NULL, MSG_UPDATE_LIST, -1, in->buffer);
+            break;
+        default:
+            break;
+    }
     return res;
 }
 
@@ -871 +892 @@
     (void) event_group_name;
     (void) event_name;
 
-    if (!in->is_password && (DIALOG (WIDGET (in)->owner)->ret_value != B_CANCEL))
+    if (!in->is_password && WIDGET (in)->owner && (DIALOG (WIDGET (in)->owner)->ret_value != B_CANCEL))
     {
         ev_history_load_save_t *ev = (ev_history_load_save_t *) data;
 
@@ -970 +991 @@
     }
 }
 
+/* --------------------------------------------------------------------------------------------- */
+
+static
+void listbox_unregister_history_events_cb(gpointer wid_ptr)
+{
+    Widget *w = WIDGET(wid_ptr);
+    WDialog *h = DIALOG(w->owner);
+
+    /* unsubscribe from "history_load" event */
+    mc_event_del (h->event_group, MCEVENT_HISTORY_LOAD, input_load_history, w);
+    /* unsubscribe from "history_save" event */
+    mc_event_del (h->event_group, MCEVENT_HISTORY_SAVE, input_save_history, w);
+}
+
 /* --------------------------------------------------------------------------------------------- */
 /*** public functions ****************************************************************************/
 /* --------------------------------------------------------------------------------------------- */
@@ -1028 +1063 @@
     if ((histname != NULL) && (*histname != '\0'))
         in->history.name = g_strdup (histname);
     /* history will be loaded later */
-
     in->label = NULL;
+    in->forward_listbox = NULL;
 
     return in;
 }
@@ -1050 +1085 @@
         mc_event_add (h->event_group, MCEVENT_HISTORY_LOAD, input_load_history, w, NULL);
         /* subscribe to "history_save" event */
         mc_event_add (h->event_group, MCEVENT_HISTORY_SAVE, input_save_history, w, NULL);
+        /* unregister (via the func) the events in case of removal from dialog */
+        w->pre_unlink_func = listbox_unregister_history_events_cb;
         if (in->label != NULL)
             widget_set_state (WIDGET (in->label), WST_DISABLED, widget_get_state (w, WST_DISABLED));
         return MSG_HANDLED;
@@ -1063 +1100 @@
             return v;
         }
 
-        /* Keys we want others to handle */
-        if (parm == KEY_UP || parm == KEY_DOWN || parm == ESC_CHAR
-            || parm == KEY_F (10) || parm == '\n')
-            return MSG_NOT_HANDLED;
-
-        /* When pasting multiline text, insert literal Enter */
-        if ((parm & ~KEY_M_MASK) == '\n')
-        {
-            quote = TRUE;
-            v = input_handle_char (in, '\n');
-            quote = FALSE;
-            return v;
+        /* If not forwarding the keys to a paired listbox forward_listbox… */
+        if (!in->forward_listbox || parm == ESC_CHAR || parm == '\n') {
+            /* Keys we want others to handle, if not forwarding them to a paired listbox */
+            if (parm == KEY_UP || parm == KEY_DOWN || parm == ESC_CHAR
+                || parm == KEY_F (10) || parm == '\n')
+                return MSG_NOT_HANDLED;
+            /* When pasting multiline text, insert literal Enter */
+            if ((parm & ~KEY_M_MASK) == '\n')
+            {
+                quote = TRUE;
+                v = input_handle_char (in, '\n');
+                quote = FALSE;
+                return v;
+            }
         }
 
         return input_handle_char (in, parm);
@@ -1097 +1136 @@
         return MSG_HANDLED;
 
     case MSG_DESTROY:
-        /* unsubscribe from "history_load" event */
-        mc_event_del (h->event_group, MCEVENT_HISTORY_LOAD, input_load_history, w);
-        /* unsubscribe from "history_save" event */
-        mc_event_del (h->event_group, MCEVENT_HISTORY_SAVE, input_save_history, w);
+        /* …only, if there is an owner WGroup. */
+        if(h)
+        {
+            /* unsubscribe from "history_load" event */
+            mc_event_del (h->event_group, MCEVENT_HISTORY_LOAD, input_load_history, w);
+            /* unsubscribe from "history_save" event */
+            mc_event_del (h->event_group, MCEVENT_HISTORY_SAVE, input_save_history, w);
+        }
         input_destroy (in);
         return MSG_HANDLED;
 
@@ -1140 +1183 @@
     command = widget_lookup_key (WIDGET (in), key);
     if (command == CK_IgnoreKey)
     {
-        if (key > 255)
-            return MSG_NOT_HANDLED;
-        if (in->first)
-            port_region_marked_for_delete (in);
-        input_complete_free (in);
-        v = insert_char (in, key);
+        /* Should we forward keys to a paired listbox? */
+        if (in->forward_listbox)
+            command = widget_lookup_key (WIDGET (in->forward_listbox), key);
+        if (command == CK_IgnoreKey)
+        {
+            if (key > 255)
+                return MSG_NOT_HANDLED;
+            if (in->first)
+                port_region_marked_for_delete (in);
+            input_complete_free (in);
+            v = insert_char (in, key);
+        } else {
+            /* Forward the listbox command to the paired listbox. */
+            send_message (WIDGET(in->forward_listbox), NULL, MSG_KEY, key, NULL);
+            send_message (WIDGET(in->forward_listbox), NULL, MSG_DRAW, 0, NULL);
+            return MSG_HANDLED;
+        }
     }
     else
     {
@@ -1158 +1212 @@
     }
 
     input_update (in, TRUE);
+
+    /* Signal any filtering listbox that the query has been updated. */
+    if (in->forward_listbox)
+        send_message(WIDGET(in->forward_listbox), NULL, MSG_UPDATE_LIST, key, in->buffer);
     return v;
 }
 

lib/widget/input.h

@@ -70 +70 @@
         GList *current;         /* current history item */
         gboolean changed;       /* the history has changed */
     } history;
+    WListbox *forward_listbox;  /* a listbox that should have some of the actions forwarded to */
+
 } WInput;
 
 /*** global variables defined in .c file *********************************************************/

lib/widget/listbox-window.c

@@ -130 +130 @@
 {
     int val = -1;
 
+    /* Option of starting the listbox with MultiSearch activated. */
+    listbox_conditionally_enable_multi_search(l->list);
+
     if (dlg_run (l->dlg) != B_CANCEL)
-        val = l->list->pos;
+        /* Get the virtual index first, to support filtered listboxes. */
+        val = l->list->virtual_pos;
+
+    /* If needed, restore normal listbox state, with no back-list (list_keep). */
+    listbox_ensure_unfiltered_state(l->list);
+
     dlg_destroy (l->dlg);
     g_free (l);
     return val;
@@ -167 +175 @@
         }
     }
 
+    /* If needed, restore normal listbox state, with no back-list (list_keep). */
+    listbox_ensure_unfiltered_state(l->list);
+
     dlg_destroy (l->dlg);
     g_free (l);
     return val;

lib/widget/listbox.c

@@ -77 +77 @@
 {
     WLEntry *e = data;
 
-    g_free (e->text);
+    if (e->free_text)
+        g_free (e->text);
     if (e->free_data)
         g_free (e->data);
     g_free (e);
@@ -85 +86 @@
 
 /* --------------------------------------------------------------------------------------------- */
 
+static WLEntry* listbox_shallow_copy_entry(WLEntry *src, gboolean take_ownership)
+{
+        WLEntry *copy;
+        copy = g_new(WLEntry, 1);
+        *copy = *src;
+
+        /* Who has the ownership of the data? */
+        src->free_text  = src->free_text && !take_ownership;
+        src->free_data  = src->free_data && !take_ownership;
+        copy->free_text  = copy->free_text && take_ownership;
+        copy->free_data  = copy->free_data && take_ownership;
+
+        return copy;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+/*
+ * Sets the listbox into ·filter· state. In this state, there's a separate copy of all list
+ * entries, while the original (and displayed) field ->list is being a filtered version of the
+ * full copy.
+ */
+static gboolean
+listbox_set_to_filter_state (WListbox * l)
+{
+    GList *le;
+
+    /* The listbox is already in filter state? */
+    if (WIDGET(l)->state & WST_FILTER) {
+        /* Return doing no change, just signal the error. */
+        return FALSE;
+    }
+
+    /* Mark the new state. */
+    WIDGET(l)->set_state(WIDGET(l), WST_FILTER, 1);
+
+    /* No list copy when entering filter mode. */
+    g_assert(!l->list_keep);
+    l->list_keep = g_queue_new();
+
+    /* Skip empty lists. */
+    if (listbox_is_empty (l))
+        return TRUE;
+
+    /*
+     * Remember the original position in the list in the field. It'll be used to determine the
+     * virtual_pos field.
+     */
+    listbox_init_indices(l);
+
+    /* Perform a shallow copy of the original list. */
+    for (le = g_queue_peek_head_link (l->list); le != NULL; le = g_list_next (le))
+    {
+        WLEntry *copy = listbox_shallow_copy_entry(LENTRY (le->data), TRUE);
+        g_queue_push_tail(l->list_keep, copy);
+    }
+
+    return TRUE;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+/* Restores original elements of the list (from l->list_keep) and turns off the WST_FILTER state. */
+static gboolean
+listbox_set_to_normal_state (WListbox * l)
+{
+    /* The listbox is already in non-filter state? */
+    if ((WIDGET(l)->state & WST_FILTER) == 0) {
+        /* Return doing no change, just signal the error. */
+        return FALSE;
+    }
+
+    /* The keep-list must be allocated (even if it's empty). */
+    g_assert(l->list_keep);
+
+    /* Mark the new state. */
+    WIDGET(l)->set_state(WIDGET(l), WST_FILTER, 0);
+
+    /* Release the filtered list and replace it with the original, complete list. */
+    g_queue_free_full(l->list, g_free);
+    l->list = g_steal_pointer(&l->list_keep);
+
+    return TRUE;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+/* Return TRUE if given listbox is in WST_FILTER state. */
+static gboolean
+listbox_is_filter_state(WListbox *l) {
+    return ((WIDGET(l)->state & WST_FILTER) != 0);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static
+void listbox_filter_list(WListbox * l, const char *text)
+{
+    int i, size;
+    GList *le;
+    g_auto(GStrv) query_terms = NULL;
+
+    /* Remove the list and allocate a new one. */
+    if (l->list)
+        g_queue_free_full(l->list, g_free);
+    l->list = g_queue_new();
+
+    /* Split the query into space delimeted strings. */
+    query_terms = g_strsplit(text, " ", 10);
+
+    /*
+     * Get the size of the listbox and iterate over it testing each element against ·all· words in 
+     * query_terms.
+     */
+    size = g_queue_get_length(l->list_keep);
+    le = g_queue_peek_head_link (l->list_keep);
+    for (i = 0; i<size; i++, le = g_list_next (le))
+    {
+        WLEntry *e = LENTRY (le->data);
+        gboolean match = TRUE;
+
+        /* Test the query against the list entry. */
+        for (gchar **p=query_terms; *p; p++) {
+            if (**p && !strcasestr(e->text, *p)) {
+                match = FALSE;
+                break;
+            }
+        }
+
+        /* If all the terms matched, then add the element to the list. */
+        if (match)
+            g_queue_push_tail(l->list, listbox_shallow_copy_entry(e, FALSE));
+    }
+    if (listbox_is_empty(l)) {
+        listbox_add_item(l, LISTBOX_APPEND_AT_END, 0, "<no search results>", NULL, FALSE);
+        LENTRY(g_queue_peek_head_link (l->list)->data)->index = -1;
+    }
+    size = g_queue_get_length(l->list);
+    if (l->pos >= size)
+        listbox_select_entry (l, size - 1);
+    else
+        listbox_select_entry (l, l->pos);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
 static void
 listbox_drawscroll (WListbox * l)
 {
@@ -267 +414 @@
 
 /* --------------------------------------------------------------------------------------------- */
 
+static void
+listbox_make_one_line_room(WListbox *l, int should_add_free_room) {
+    Widget *w = WIDGET (l), *owner = WIDGET (WIDGET(w)->owner);
+    WRect r_dialog, r_listbox;
+    int new_dialog_height, new_listbox_height, take_give_from_to_owner = 1;
+
+    /* IF the enlarged dialog won't fit the screen, don't resize it but the listbox instead. */
+    if (LINES <= owner->lines+2)
+        take_give_from_to_owner = 0;
+    
+    // Increase the height of the dialog by 1, so that the new input fits.
+    if (should_add_free_room) {
+        new_dialog_height = owner->lines + take_give_from_to_owner;
+        new_listbox_height = w->lines + (-1+take_give_from_to_owner);
+    } else {
+        new_dialog_height = owner->lines - take_give_from_to_owner;
+        new_listbox_height = w->lines - (-1+take_give_from_to_owner);
+    }
+    rect_init (&r_dialog, owner->y, owner->x, new_dialog_height, owner->cols);
+    rect_init (&r_listbox, w->y, w->x, new_listbox_height, w->cols);
+    send_message (w, NULL, MSG_RESIZE, 0, &r_listbox);
+    send_message (owner, NULL, MSG_RESIZE, 0, &r_dialog);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+listbox_show_multi_search_input(WListbox *l) {
+    Widget *w = WIDGET(l), *owner = WIDGET(WIDGET(l)->owner);
+    WInput *multi_search_in;
+    int distance_y = owner->y + owner->lines - (w->y + w->lines) + 1;
+    int distance_x = w->cols > 40 ? 5 : 1, small = w->cols <= 15 ? 1 : 0;
+
+    listbox_make_one_line_room(l,1);
+    multi_search_in = input_new (owner->lines - distance_y, distance_x,
+        input_colors, w->cols-2-distance_x+small, "",
+            "multi_search", INPUT_COMPLETE_NONE);
+    multi_search_in->forward_listbox = l;
+    group_add_widget_autopos (GROUP(owner), multi_search_in, WPOS_KEEP_TOP | WPOS_CENTER_HORZ , NULL);
+
+    repaint_screen();
+    send_message (l, NULL, MSG_DRAW, 0, NULL);
+    send_message (multi_search_in, NULL, MSG_DRAW, 0, NULL);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+static void
+listbox_hide_multi_search_widget(WListbox *l) {
+    Widget *in;
+    in = WIDGET(WIDGET(l)->owner)->find_by_type(WIDGET(WIDGET(l)->owner), input_callback);
+    if (in) {
+        group_remove_widget(in);
+        listbox_make_one_line_room(l,0);
+        group_select_next_widget(WIDGET(l)->owner);
+        send_message (l, NULL, MSG_DRAW, 0, NULL);
+        widget_destroy(in);
+    }
+    repaint_screen();
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
 static cb_ret_t
 listbox_execute_cmd (WListbox * l, long command)
 {
@@ -320 +530 @@
                               D_ERROR, 2, _("&Yes"), _("&No")) == 0))
             listbox_remove_list (l);
         break;
+    case CK_MultiSearch:
+        /* Toggle the multi term searching of any listbox. */
+        if (listbox_is_filter_state(l)) {
+            /* Remove the input widget from the dialog. */
+            listbox_hide_multi_search_widget(l);
+            /* Restore original (unfiltered) listbox contents. */
+            ret = listbox_set_to_normal_state(l);
+        } else {
+            /* Add input widget for the filter query at the bottom of the dialog window. */
+            listbox_show_multi_search_input(l);
+            /* … and then turn on the filter state. */
+            ret = listbox_set_to_filter_state(l);
+        }
+        break;
     case CK_View:
     case CK_Edit:
     case CK_Enter:
@@ -358 +582 @@
 
 /* --------------------------------------------------------------------------------------------- */
 
+/* When called via g_queue_foreach it assigns the index field with an incremented int. */
+static void
+listbox_foreach_apply_index (gpointer data,
+          gpointer user_data)
+{
+    WLEntry *e = data;
+    int *cur_idx = user_data;
+    e->index = *cur_idx;
+    *cur_idx = *cur_idx + 1;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
 /* Listbox item adding function */
 static inline void
 listbox_append_item (WListbox * l, WLEntry * e, listbox_append_t pos)
@@ -482 +719 @@
         widget_gotoyx (l, l->cursor_y, 0);
         return MSG_HANDLED;
 
+    case MSG_UPDATE_LIST:
+        listbox_filter_list(l, (char *) data);
+        repaint_screen();
+        return MSG_HANDLED;
+
     case MSG_DRAW:
         listbox_draw (l, widget_get_state (w, WST_FOCUSED));
         return MSG_HANDLED;
@@ -556 +798 @@
     l = g_new (WListbox, 1);
     w = WIDGET (l);
     widget_init (w, y, x, height, width, listbox_callback, listbox_mouse_callback);
-    w->options |= WOP_SELECTABLE | WOP_WANT_HOTKEY;
+    w->options |= WOP_SELECTABLE;
     w->keymap = listbox_map;
 
     l->list = NULL;
+    l->list_keep = NULL;
     l->top = l->pos = 0;
     l->deletable = deletable;
     l->callback = callback;
@@ -571 +814 @@
 
 /* --------------------------------------------------------------------------------------------- */
 
+/*
+ * If the list is filtered it replaces from the back list (list_keep). It returns whether such 
+ * change occurred – FALSE means that the list was already unfiltered.
+ */
+gboolean listbox_ensure_unfiltered_state(WListbox *l)
+{
+    gboolean ret = FALSE;
+    if (listbox_is_filter_state(l))
+        ret = listbox_set_to_normal_state(l);
+    return ret;
+}
+
+gboolean listbox_conditionally_enable_multi_search(WListbox *l)
+{
+    int start_with_multi_search_active;
+
+    /* Option of starting the listbox with MultiSearch pre-activated. */
+    start_with_multi_search_active =
+        mc_config_get_bool (mc_global.main_config, CONFIG_APP_SECTION,
+                            "multi_search_active_by_default", 1);
+
+    /* CK_MultiSearch toggles the state. */
+    if (start_with_multi_search_active)
+        send_message(l, NULL, MSG_ACTION, CK_MultiSearch, NULL);
+
+    return start_with_multi_search_active;
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
 /**
  * Finds item by its label.
  */
@@ -673 +946 @@
                 if (l->pos - l->top >= lines)
                     l->top = l->pos - lines + 1;
             }
+            /*
+             * Set the virtual position, i.e.: a position in the initial, unfiltered list if the 
+             * same element would be selected.
+             */
+            if (listbox_is_filter_state(l)) {
+                WLEntry *e = listbox_get_nth_item(l, l->pos);
+                if (e)
+                    l->virtual_pos = e->index;
+                else
+                    l->virtual_pos = -1;
+            } else {
+                l->virtual_pos = pos;
+            }
             return;
         }
     }
@@ -802 +1088 @@
 
 /* --------------------------------------------------------------------------------------------- */
 
+/*
+ * Initializes the listbox elements with their position index. This allows to alter (filter, in
+ * particular) the listbox elements order and still get the original index (when selecting an
+ * element).
+ */
+void listbox_init_indices(WListbox *l) {
+    int index = 0;
+    g_queue_foreach(l->list, listbox_foreach_apply_index, &index);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
 char *
 listbox_add_item (WListbox * l, listbox_append_t pos, int hotkey, const char *text, void *data,
                   gboolean free_data)
@@ -815 +1113 @@
         return NULL;
 
     entry = g_new (WLEntry, 1);
+    entry->index = -1; /* Will be initialized when switching to the filter state */
     entry->text = g_strdup (text);
+    entry->free_text = 1;
     entry->data = data;
     entry->free_data = free_data;
     entry->hotkey = hotkey;

lib/widget/listbox.h

@@ -35 +35 @@
 
 typedef struct WLEntry
 {
+    int index;                  /* The location in the list (useful when it's filtered) */
     char *text;                 /* Text to display */
+    gboolean free_text;         /* Whether to free the text on entry's removal */
     int hotkey;
     void *data;                 /* Client information */
     gboolean free_data;         /* Whether to free the data on entry's removal */
@@ -45 +47 @@
 {
     Widget widget;
     GQueue *list;               /* Pointer to the list of WLEntry */
+    GQueue *list_keep;          /* Unfiltered list (used in the WST_FILTER state). */
     int pos;                    /* The current element displayed */
+    int virtual_pos;            /* The initial index of the current element, works also for filtered listbox */
     int top;                    /* The first element displayed */
     gboolean allow_duplicates;  /* Do we allow duplicates on the list? */
     gboolean scrollbar;         /* Draw a scrollbar? */
@@ -61 +65 @@
 /*** declarations of public functions ************************************************************/
 
 WListbox *listbox_new (int y, int x, int height, int width, gboolean deletable, lcback_fn callback);
+gboolean listbox_ensure_unfiltered_state(WListbox *l);
+gboolean listbox_conditionally_enable_multi_search(WListbox *l);
 int listbox_search_text (WListbox * l, const char *text);
 int listbox_search_data (WListbox * l, const void *data);
 void listbox_select_first (WListbox * l);
@@ -74 +80 @@
 gboolean listbox_is_empty (const WListbox * l);
 void listbox_set_list (WListbox * l, GQueue * list);
 void listbox_remove_list (WListbox * l);
+void listbox_init_indices(WListbox *l);
 char *listbox_add_item (WListbox * l, listbox_append_t pos, int hotkey, const char *text,
                         void *data, gboolean free_data);
 

lib/widget/widget-common.c

@@ -338 +338 @@
     w->find_by_type = widget_default_find_by_type;
     w->find_by_id = widget_default_find_by_id;
 
+    w->pre_unlink_func = NULL;
+
     w->set_state = widget_default_set_state;
     w->get_colors = widget_default_get_colors;
 }

lib/widget/widget-common.h

@@ -43 +43 @@
     MSG_ACTION,                 /* Send to widget to handle command */
     MSG_NOTIFY,                 /* Typically sent to dialog to inform it of state-change
                                  * of listboxes, check- and radiobuttons. */
+    MSG_UPDATE_LIST,            /* Sent to listboxes to request the list regeneration (filtering)
+                                 * in the MultiSearch mode. */
     MSG_CURSOR,                 /* Sent to widget to position the cursor */
     MSG_IDLE,                   /* The idle state is active */
     MSG_RESIZE,                 /* Screen size has changed */
@@ -88 +90 @@
     WST_CONSTRUCT = (1 << 15),  /* Widget has been constructed but not run yet */
     WST_ACTIVE = (1 << 16),     /* Dialog is visible and active */
     WST_SUSPENDED = (1 << 17),  /* Dialog is suspended */
-    WST_CLOSED = (1 << 18)      /* Dialog is closed */
+    WST_CLOSED = (1 << 18),     /* Dialog is closed */
+
+    WST_FILTER = (1 << 19)      /* Listbox is filtering its contents */
 } widget_state_t;
 
 /* Flags for widget repositioning on dialog resize */
@@ -165 +169 @@
     cb_ret_t (*set_state) (Widget * w, widget_state_t state, gboolean enable);
     /* *INDENT-ON* */
 
+    GDestroyNotify pre_unlink_func; /* a function invoked right before removing from a WGroup by
+                                 * group_remove_widget; it can unregister any events, what depends
+                                 * on the `event_group` field of the group; */
+
     const int *(*get_colors) (const Widget * w);
 };
 

src/editor/choosesyntax.c

@@ -87 +87 @@
             listbox_select_entry (syntaxlist->list, i + N_DFLT_ENTRIES);
     }
 
+    /*
+     * Initialize the `index` fields in the WLEntry elements so that it's possible to get
+     * the correct selected element index even when listbox is filtered (MultiSearch).
+     */
+    listbox_init_indices(syntaxlist->list);
+
     return run_listbox (syntaxlist);
 }
 

src/editor/editcmd_dialogs.c

@@ -394 +394 @@
         listbox_add_item (compl_list, LISTBOX_APPEND_AT_END, 0, (char *) compl[i]->str, NULL,
                           FALSE);
 
+    /* Option to start in the MultiSearch state. */
+    listbox_conditionally_enable_multi_search(compl_list);
+
     /* pop up the dialog and apply the chosen completion */
     if (dlg_run (compl_dlg) == B_ENTER)
     {
@@ -401 +404 @@
         curr = g_strdup (curr);
     }
 
+    /* If needed, restore normal listbox state, with no back list (list_keep). */
+    listbox_ensure_unfiltered_state(compl_list);
+
     /* destroy dialog before return */
     dlg_destroy (compl_dlg);
 

src/editor/editwidget.c

@@ -327 +327 @@
             g_free (fname);
         }
 
+    /* Option of starting the listbox with MultiSearch pre-activated. */
+    listbox_conditionally_enable_multi_search(listbox->list);
+
     selected = run_listbox_with_data (listbox, g->current->data);
     if (selected != NULL)
         widget_select (WIDGET (selected));

src/editor/spell_dialogs.c

@@ -174 +174 @@
     for (i = 0; i < languages->len; i++)
         LISTBOX_APPEND_TEXT (lang_list, 0, g_array_index (languages, char *, i), NULL, FALSE);
 
+    /*
+     * Initialize the `index` fields in the WLEntry elements so that it's possible to get
+     * the correct selected element index even when listbox is filtered (MultiSearch).
+     */
+    listbox_init_indices(lang_list->list);
+
     res = run_listbox (lang_list);
     if (res >= 0)
         selected_lang = g_strdup (g_array_index (languages, char *, (unsigned int) res));

src/filemanager/listmode.c

@@ -124 +124 @@
                           FALSE);
     }
 
+    /*
+     * Initialize the `index` fields in the WLEntry elements so that it's possible to get
+     * the correct selected element index even when listbox is filtered (MultiSearch).
+     */
+    listbox_init_indices(listbox->list);
+
     i = run_listbox (mylistbox);
     if (i >= 0)
         ret = g_strdup (possible_items[i]);

src/keybind-defaults.c

@@ -293 +293 @@
     {"Bottom", "end; alt-gt; c1"},
     {"PageUp", "pgup; alt-v"},
     {"PageDown", "pgdn; ctrl-v"},
-    {"Delete", "delete; d"},
-    {"Clear", "shift-delete; shift-d"},
+    {"Delete", "delete"},
+    {"Clear", "shift-delete"},
     {"View", "f3"},
     {"Edit", "f4"},
+    {"MultiSearch", "alt-space; ctrl-space"},
     {"Enter", "enter"},
     {NULL, NULL}
 };

src/selcodepage.c

@@ -109 +109 @@
 
     listbox_select_entry (listbox->list, i);
 
+    /*
+     * Initialize the `index` fields in the WLEntry elements so that it's possible to get
+     * the correct selected element index even when listbox is filtered (MultiSearch).
+     */
+    listbox_init_indices(listbox->list);
+
     listbox_result = run_listbox (listbox);
 
     if (listbox_result < 0)

src/usermenu.c

@@ -1124 +1124 @@
             /* Select the default entry */
             listbox_select_entry (listbox->list, selected);
 
+            /*
+             * Initialize the `index` fields in the WLEntry elements so that it's possible to get
+             * the correct selected element index even when listbox is filtered (MultiSearch).
+             */
+            listbox_init_indices(listbox->list);
+
             selected = run_listbox (listbox);
         }
         if (selected >= 0)