Fixed grid line input bug introduced in [9f52ac]

[projects/chimara/chimara.git] / libchimara / input.c

#include "charset.h"
#include "magic.h"
#include "input.h"
#include "pager.h"
#include "chimara-glk-private.h"
#include "garglk.h"

extern GPrivate *glk_data_key;

/* Forward declarations */
static int finish_text_buffer_line_input(winid_t win, gboolean emit_signal);
static int finish_text_grid_line_input(winid_t win, gboolean emit_signal);
static void cancel_old_input_request(winid_t win);

/* Internal function: code common to both flavors of char event request */
void
request_char_event_common(winid_t win, gboolean unicode)
{
        VALID_WINDOW(win, return);
        g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);

        cancel_old_input_request(win);

        flush_window_buffer(win);

        ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);

        win->input_request_type = unicode? INPUT_REQUEST_CHARACTER_UNICODE : INPUT_REQUEST_CHARACTER;
        g_signal_handler_unblock( win->widget, win->char_input_keypress_handler );

        gdk_threads_enter();
        gtk_widget_grab_focus( GTK_WIDGET(win->widget) );
        gdk_threads_leave();

        /* Emit the "waiting" signal to let listeners know we are ready for input */
        g_signal_emit_by_name(glk_data->self, "waiting");
}

/**
 * glk_request_char_event:
 * @win: A window to request char events from.
 *
 * Request input of a Latin-1 character or special key. A window cannot have
 * requests for both character and line input at the same time. Nor can it have
 * requests for character input of both types (Latin-1 and Unicode). It is
 * illegal to call glk_request_char_event() if the window already has a pending
 * request for either character or line input.
 */
void
glk_request_char_event(winid_t win)
{
        request_char_event_common(win, FALSE);
}

/**
 * glk_request_char_event_uni:
 * @win: A window to request char events from.
 *
 * Request input of a Unicode character or special key. See
 * glk_request_char_event().
 */
void
glk_request_char_event_uni(winid_t win)
{
        request_char_event_common(win, TRUE);
}

/**
 * glk_cancel_char_event:
 * @win: A window to cancel the latest char event request on.
 *
 * This cancels a pending request for character input. (Either Latin-1 or
 * Unicode.) For convenience, it is legal to call glk_cancel_char_event() even
 * if there is no charcter input request on that window. Glk will ignore the
 * call in this case.
 */
void
glk_cancel_char_event(winid_t win)
{
        VALID_WINDOW(win, return);
        g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);

        if(win->input_request_type == INPUT_REQUEST_CHARACTER || win->input_request_type == INPUT_REQUEST_CHARACTER_UNICODE)
        {
                win->input_request_type = INPUT_REQUEST_NONE;
                g_signal_handler_block( win->widget, win->char_input_keypress_handler );
        }
}

/* Internal function: Request either latin-1 or unicode line input, in a text grid window. */
static void
text_grid_request_line_event_common(winid_t win, glui32 maxlen, gboolean insert, gchar *inserttext)
{
        /* All outstanding printing _must_ be finished before putting an input entry
         into the buffer */
        flush_window_buffer(win);

        gdk_threads_enter();

        GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );

    GtkTextMark *cursor = gtk_text_buffer_get_mark(buffer, "cursor_position");
    GtkTextIter start_iter, end_iter;
    gtk_text_buffer_get_iter_at_mark(buffer, &start_iter, cursor);

    /* Determine the maximum length of the line input */
    gint cursorpos = gtk_text_iter_get_line_offset(&start_iter);
    /* Odd; the Glk spec says the maximum input length is
    windowwidth - 1 - cursorposition. I say no, because if cursorposition is
    zero, then the input should fill the whole line. FIXME??? */
    win->input_length = MIN(win->width - cursorpos, win->line_input_buffer_max_len);
    end_iter = start_iter;
    gtk_text_iter_set_line_offset(&end_iter, cursorpos + win->input_length);

        /* If the buffer currently has a selection with one bound in the middle of
        the input field, then deselect it. Otherwise the input field gets trashed */
        GtkTextIter start_sel, end_sel;
        if( gtk_text_buffer_get_selection_bounds(buffer, &start_sel, &end_sel) )
        {
                if( gtk_text_iter_in_range(&start_sel, &start_iter, &end_iter) )
                        gtk_text_buffer_place_cursor(buffer, &end_sel);
                if( gtk_text_iter_in_range(&end_sel, &start_iter, &end_iter) )
                        gtk_text_buffer_place_cursor(buffer, &start_sel);
        }

    /* Erase the text currently in the input field and replace it with a GtkEntry */
    gtk_text_buffer_delete(buffer, &start_iter, &end_iter);
    win->input_anchor = gtk_text_buffer_create_child_anchor(buffer, &start_iter);
    win->input_entry = gtk_entry_new();
        /* Set the entry's font to match that of the window */
    GtkRcStyle *style = gtk_widget_get_modifier_style(win->widget);     /* Don't free */
        gtk_widget_modify_font(win->input_entry, style->font_desc);
        /* Make the entry as small as possible to fit with the text */
        gtk_entry_set_has_frame(GTK_ENTRY(win->input_entry), FALSE);
        GtkBorder border = { 0, 0, 0, 0 };

        /* COMPAT: */
#if GTK_CHECK_VERSION(2,10,0)
        gtk_entry_set_inner_border(GTK_ENTRY(win->input_entry), &border);
#endif
    gtk_entry_set_max_length(GTK_ENTRY(win->input_entry), win->input_length);
    gtk_entry_set_width_chars(GTK_ENTRY(win->input_entry), win->input_length);

    /* Insert pre-entered text if needed */
    if(insert)
        gtk_entry_set_text(GTK_ENTRY(win->input_entry), inserttext);

    /* Set background color of entry (TODO: implement as property) */
    GdkColor background;
        gdk_color_parse("grey", &background);
    gtk_widget_modify_base(win->input_entry, GTK_STATE_NORMAL, &background);

    g_signal_connect(win->input_entry, "activate", G_CALLBACK(on_input_entry_activate), win);
    g_signal_connect(win->input_entry, "key-press-event", G_CALLBACK(on_input_entry_key_press_event), win);
    win->line_input_entry_changed = g_signal_connect(win->input_entry, "changed", G_CALLBACK(on_input_entry_changed), win);

    gtk_widget_show(win->input_entry);
    gtk_text_view_add_child_at_anchor(GTK_TEXT_VIEW(win->widget), win->input_entry, win->input_anchor);

        gtk_widget_grab_focus(win->input_entry);

        gdk_threads_leave();
}

/* Internal function: Request either latin-1 or unicode line input, in a text buffer window. */
static void
text_buffer_request_line_event_common(winid_t win, glui32 maxlen, gboolean insert, gchar *inserttext)
{
        flush_window_buffer(win);

        gdk_threads_enter();

        GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );

    /* Move the input_position mark to the end of the window_buffer */
    GtkTextMark *input_position = gtk_text_buffer_get_mark(buffer, "input_position");
    GtkTextIter end_iter;
    gtk_text_buffer_get_end_iter(buffer, &end_iter);
    gtk_text_buffer_move_mark(buffer, input_position, &end_iter);

    /* Set the entire contents of the window_buffer as uneditable
     * (so input can only be entered at the end) */
    GtkTextIter start_iter;
    gtk_text_buffer_get_start_iter(buffer, &start_iter);
    gtk_text_buffer_remove_tag_by_name(buffer, "uneditable", &start_iter, &end_iter);
    gtk_text_buffer_apply_tag_by_name(buffer, "uneditable", &start_iter, &end_iter);

    /* Insert pre-entered text if needed */
    if(insert) {
        gtk_text_buffer_insert(buffer, &end_iter, inserttext, -1);
                gtk_text_buffer_get_end_iter(buffer, &end_iter); /* update after text insertion */
        }

        /* Apply the correct style to the input prompt */
        GtkTextIter input_iter;
    gtk_text_buffer_get_iter_at_mark(buffer, &input_iter, input_position);
    gtk_text_buffer_apply_tag_by_name(buffer, "input", &input_iter, &end_iter);

    gtk_text_view_set_editable(GTK_TEXT_VIEW(win->widget), TRUE);

        g_signal_handler_unblock(buffer, win->insert_text_handler);
        gtk_widget_grab_focus(win->widget);

        gdk_threads_leave();
}

/**
 * glk_request_line_event:
 * @win: A text buffer or text grid window to request line input on.
 * @buf: A buffer of at least @maxlen bytes.
 * @maxlen: Length of the buffer.
 * @initlen: The number of characters in @buf to pre-enter.
 *
 * Requests input of a line of Latin-1 characters. A window cannot have requests
 * for both character and line input at the same time. Nor can it have requests
 * for line input of both types (Latin-1 and Unicode). It is illegal to call
 * glk_request_line_event() if the window already has a pending request for
 * either character or line input.
 *
 * The @buf argument is a pointer to space where the line input will be stored.
 * (This may not be %NULL.) @maxlen is the length of this space, in bytes; the
 * library will not accept more characters than this. If @initlen is nonzero,
 * then the first @initlen bytes of @buf will be entered as pre-existing input
 * — just as if the player had typed them himself. (The player can continue
 * composing after this pre-entered input, or delete it or edit as usual.)
 *
 * The contents of the buffer are undefined until the input is completed (either
 * by a line input event, or glk_cancel_line_event(). The library may or may not
 * fill in the buffer as the player composes, while the input is still pending;
 * it is illegal to change the contents of the buffer yourself.
 */
void
glk_request_line_event(winid_t win, char *buf, glui32 maxlen, glui32 initlen)
{
        VALID_WINDOW(win, return);
        g_return_if_fail(buf);
        g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);
        g_return_if_fail(initlen <= maxlen);

        cancel_old_input_request(win);

        ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);

        /* Register the buffer */
        if(glk_data->register_arr)
        win->buffer_rock = (*glk_data->register_arr)(buf, maxlen, "&+#!Cn");

        win->input_request_type = INPUT_REQUEST_LINE;
        win->line_input_buffer = buf;
        win->line_input_buffer_max_len = maxlen;
        win->echo_current_line_input = win->echo_line_input;
        win->current_extra_line_terminators = g_slist_copy(win->extra_line_terminators);

        gchar *inserttext = (initlen > 0)? g_strndup(buf, initlen) : g_strdup("");
        switch(win->type)
        {
            case wintype_TextBuffer:
                text_buffer_request_line_event_common(win, maxlen, (initlen > 0), inserttext);
                break;
            case wintype_TextGrid:
                text_grid_request_line_event_common(win, maxlen, (initlen > 0), inserttext);
                break;
    }
        g_free(inserttext);
        g_signal_handler_unblock(win->widget, win->line_input_keypress_handler);

        /* Emit the "waiting" signal to let listeners know we are ready for input */
        g_signal_emit_by_name(glk_data->self, "waiting");
}

/**
 * glk_request_line_event_uni:
 * @win: A text buffer or text grid window to request line input on.
 * @buf: A buffer of at least @maxlen characters.
 * @maxlen: Length of the buffer.
 * @initlen: The number of characters in @buf to pre-enter.
 *
 * Request input of a line of Unicode characters. This works the same as
 * glk_request_line_event(), except the result is stored in an array of
 * <type>glui32</type> values instead of an array of characters, and the values
 * may be any valid Unicode code points.
 *
 * If possible, the library should return fully composed Unicode characters,
 * rather than strings of base and composition characters.
 *
 * <note><para>
 *   Fully-composed characters are the norm for Unicode text, so an
 *   implementation that ignores this issue will probably produce the right
 *   result. However, the game may not want to rely on that. Another factor is
 *   that case-folding can (occasionally) produce non-normalized text.
 *   Therefore, to cover all its bases, a game should call
 *   glk_buffer_to_lower_case_uni(), followed by
 *   glk_buffer_canon_normalize_uni(), before parsing.
 * </para></note>
 *
 * <note><para>
 *   Earlier versions of this spec said that line input must always be in
 *   Unicode Normalization Form C. However, this has not been universally
 *   implemented. It is also somewhat redundant, for the results noted above.
 *   Therefore, we now merely recommend that line input be fully composed. The
 *   game is ultimately responsible for all case-folding and normalization. See
 *   <link linkend="chimara-Unicode-String-Normalization">Unicode String
 *   Normalization</link>.
 * </para></note>
 */
void
glk_request_line_event_uni(winid_t win, glui32 *buf, glui32 maxlen, glui32 initlen)
{
        VALID_WINDOW(win, return);
        g_return_if_fail(buf);
        g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);
        g_return_if_fail(initlen <= maxlen);

        cancel_old_input_request(win);
        ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);

        /* Register the buffer */
        if(glk_data->register_arr)
        win->buffer_rock = (*glk_data->register_arr)(buf, maxlen, "&+#!Iu");

        win->input_request_type = INPUT_REQUEST_LINE_UNICODE;
        win->line_input_buffer_unicode = buf;
        win->line_input_buffer_max_len = maxlen;
        win->echo_current_line_input = win->echo_line_input;
        win->current_extra_line_terminators = g_slist_copy(win->extra_line_terminators);

        gchar *utf8;
        if(initlen > 0) {
                utf8 = convert_ucs4_to_utf8(buf, initlen);
                if(utf8 == NULL)
                        return;
        }
        else
                utf8 = g_strdup("");

    switch(win->type)
        {
            case wintype_TextBuffer:
                text_buffer_request_line_event_common(win, maxlen, (initlen > 0), utf8);
                break;
            case wintype_TextGrid:
                text_grid_request_line_event_common(win, maxlen, (initlen > 0), utf8);
                break;
    }
    g_signal_handler_unblock(win->widget, win->line_input_keypress_handler);
        g_free(utf8);

        /* Emit the "waiting" signal to let listeners know we are ready for input */
        g_signal_emit_by_name(glk_data->self, "waiting");
}

/**
 * glk_cancel_line_event:
 * @win: A text buffer or text grid window to cancel line input on.
 * @event: Will be filled in if the user had already input something.
 *
 * This cancels a pending request for line input. (Either Latin-1 or Unicode.)
 *
 * The event pointed to by the event argument will be filled in as if the
 * player had hit <keycap>enter</keycap>, and the input composed so far will be
 * stored in the buffer; see below. If you do not care about this information,
 * pass %NULL as the @event argument. (The buffer will still be filled.)
 *
 * For convenience, it is legal to call glk_cancel_line_event() even if there
 * is no line input request on that window. The event type will be set to
 * %evtype_None in this case.
 */
void
glk_cancel_line_event(winid_t win, event_t *event)
{
        VALID_WINDOW(win, return);
        g_return_if_fail(win->type != wintype_TextBuffer || win->type != wintype_TextGrid);

        if(event != NULL) {
                event->type = evtype_None;
                event->win = win;
                event->val1 = 0;
                event->val2 = 0;
        }

        if(win->input_request_type != INPUT_REQUEST_LINE && win->input_request_type != INPUT_REQUEST_LINE_UNICODE)
                return;

        g_signal_handler_block( win->widget, win->line_input_keypress_handler );

        int chars_written = 0;

        gdk_threads_enter();
        if(win->type == wintype_TextGrid) {
                chars_written = finish_text_grid_line_input(win, FALSE);
        } else if(win->type == wintype_TextBuffer) {
                gtk_text_view_set_editable( GTK_TEXT_VIEW(win->widget), FALSE );
                GtkTextBuffer *window_buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
                g_signal_handler_block(window_buffer, win->insert_text_handler);
                chars_written = finish_text_buffer_line_input(win, FALSE);
        }
        gdk_threads_leave();

        ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
        if(glk_data->unregister_arr)
        {
                if(win->input_request_type == INPUT_REQUEST_LINE_UNICODE)
                        (*glk_data->unregister_arr)(win->line_input_buffer_unicode, win->line_input_buffer_max_len, "&+#!Iu", win->buffer_rock);
                else
                (*glk_data->unregister_arr)(win->line_input_buffer, win->line_input_buffer_max_len, "&+#!Cn", win->buffer_rock);
    }

        if(event != NULL && chars_written > 0) {
                event->type = evtype_LineInput;
                event->val1 = chars_written;
        }
}

/* Helper function: Turn off shutdown key-press-event signal handler */
static gboolean
turn_off_handler(GNode *node)
{
        winid_t win = node->data;
        g_signal_handler_block(win->widget, win->shutdown_keypress_handler);
        return FALSE; /* don't stop */
}

/* Internal function: Callback for signal key-press-event while waiting for shutdown. */
gboolean
on_shutdown_key_press_event(GtkWidget *widget, GdkEventKey *event, winid_t win)
{
        ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(widget, CHIMARA_TYPE_GLK));
        g_assert(glk);
        CHIMARA_GLK_USE_PRIVATE(glk, priv);
        
        /* Turn off all the signal handlers */
        if(priv->root_window)
                g_node_traverse(priv->root_window, G_IN_ORDER, G_TRAVERSE_LEAVES, -1, (GNodeTraverseFunc)turn_off_handler, NULL);
        
        /* Signal the Glk library that it can shut everything down now */
        g_mutex_lock(priv->shutdown_lock);
        g_cond_signal(priv->shutdown_key_pressed);
        g_mutex_unlock(priv->shutdown_lock);
        
        return TRUE; /* block the event */
}

/* Internal function: General callback for signal key-press-event on a text buffer or text grid window. Used in character input on both text buffers and grids. Blocked when not in use. */
gboolean
on_char_input_key_press_event(GtkWidget *widget, GdkEventKey *event, winid_t win)
{
        /* Ignore modifier keys, otherwise the char input will already trigger on 
        the shift key when the user tries to type a capital letter */
        if(event->is_modifier)
                return FALSE; /* don't stop the event */

        /* All text up to the input position is now regarded as being read by the user */
        if(win->type == wintype_TextBuffer)
                pager_update(win);
        
        glui32 keycode = keyval_to_glk_keycode(event->keyval, win->input_request_type == INPUT_REQUEST_CHARACTER_UNICODE);

        ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(widget, CHIMARA_TYPE_GLK));
        g_assert(glk);
        event_throw(glk, evtype_CharInput, win, keycode, 0);
        g_signal_emit_by_name(glk, "char-input", win->rock, event->keyval);

        /* Only one keypress will be handled */
        win->input_request_type = INPUT_REQUEST_NONE;
        g_signal_handler_block(win->widget, win->char_input_keypress_handler);

        return TRUE;
}

gboolean
on_line_input_key_press_event(GtkWidget *widget, GdkEventKey *event, winid_t win)
{
        switch(win->type)
        {
                case wintype_TextBuffer:
                {
                        /* All text up to the input position is now regarded as being read by the user */
                        pager_update(win);

                        GtkTextBuffer *buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(win->widget));

                        /* History up/down */
                        if(event->keyval == GDK_Up || event->keyval == GDK_KP_Up
                                || event->keyval == GDK_Down || event->keyval == GDK_KP_Down)
                        {
                                /* Prevent falling off the end of the history list */
                                if(win->history == NULL)
                                        return TRUE;
                                if( (event->keyval == GDK_Up || event->keyval == GDK_KP_Up)
                                        && win->history_pos && win->history_pos->next == NULL)
                                        return TRUE;
                                if( (event->keyval == GDK_Down || event->keyval == GDK_KP_Down)
                                        && (win->history_pos == NULL || win->history_pos->prev == NULL) )
                                        return TRUE;

                                GtkTextIter start, end;
                                /* Erase any text that was already typed */
                                GtkTextMark *input_position = gtk_text_buffer_get_mark(buffer, "input_position");
                                gtk_text_buffer_get_iter_at_mark(buffer, &start, input_position);
                                gtk_text_buffer_get_end_iter(buffer, &end);

                                if(win->history_pos == NULL) {
                                        gchar *current_input = gtk_text_buffer_get_text(buffer, &start, &end, FALSE);
                                        win->history = g_list_prepend(win->history, current_input);
                                        win->history_pos = win->history;
                                }

                                gtk_text_buffer_delete(buffer, &start, &end);

                                if(event->keyval == GDK_Up || event->keyval == GDK_KP_Up)
                                {
                                        if(win->history_pos)
                                                win->history_pos = g_list_next(win->history_pos);
                                        else
                                                win->history_pos = win->history;
                                }
                                else /* down */
                                        win->history_pos = g_list_previous(win->history_pos);

                                /* Insert the history item into the window */
                                gtk_text_buffer_get_end_iter(buffer, &end);

                                g_signal_handler_block(buffer, win->insert_text_handler);
                                gtk_text_buffer_insert_with_tags_by_name(buffer, &end, win->history_pos->data, -1, "default", "input", NULL);
                                g_signal_handler_unblock(buffer, win->insert_text_handler);
                                return TRUE;
                        }

                        /* Move to beginning/end of input field */
                        else if(event->keyval == GDK_Home) {
                                GtkTextIter input_iter;
                                GtkTextMark *input_position = gtk_text_buffer_get_mark(buffer, "input_position");
                                gtk_text_buffer_get_iter_at_mark(buffer, &input_iter, input_position);
                                gtk_text_buffer_place_cursor(buffer, &input_iter);
                                return TRUE;
                        }
                        else if(event->keyval == GDK_End) {
                                GtkTextIter end_iter;
                                gtk_text_buffer_get_end_iter(buffer, &end_iter);
                                gtk_text_buffer_place_cursor(buffer, &end_iter);
                                return TRUE;
                        }

                        /* Handle the line terminators */
                        else if(event->keyval == GDK_Return || event->keyval == GDK_KP_Enter
                           || g_slist_find(win->current_extra_line_terminators, GUINT_TO_POINTER(event->keyval)))
                        {
                                /* Remove signal handlers */
                                g_signal_handler_block(buffer, win->insert_text_handler);
                                g_signal_handler_block(win->widget, win->line_input_keypress_handler);

                                /* Insert a newline (even if line input was terminated with a different key */
                                GtkTextIter end;
                                gtk_text_buffer_get_end_iter(buffer, &end);
                                gtk_text_buffer_insert(buffer, &end, "\n", 1);
                                gtk_text_buffer_place_cursor(buffer, &end);

                                /* Make the window uneditable again and retrieve the text that was input */
                                gtk_text_view_set_editable(GTK_TEXT_VIEW(win->widget), FALSE);

                                int chars_written = finish_text_buffer_line_input(win, TRUE);
                                ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
                                event_throw(glk, evtype_LineInput, win, chars_written, 0);
                                return TRUE;
                        }
                }
                        return FALSE;

                /* If this is a text grid window, then redirect the key press to the line input GtkEntry */
                case wintype_TextGrid:
                {
                        if(event->keyval == GDK_Up || event->keyval == GDK_KP_Up
                                || event->keyval == GDK_Down || event->keyval == GDK_KP_Down
                                || event->keyval == GDK_Left || event->keyval == GDK_KP_Left
                                || event->keyval == GDK_Right || event->keyval == GDK_KP_Right
                                || event->keyval == GDK_Tab || event->keyval == GDK_KP_Tab
                                || event->keyval == GDK_Page_Up || event->keyval == GDK_KP_Page_Up
                                || event->keyval == GDK_Page_Down || event->keyval == GDK_KP_Page_Down
                                || event->keyval == GDK_Home || event->keyval == GDK_KP_Home
                                || event->keyval == GDK_End || event->keyval == GDK_KP_End)
                                return FALSE; /* Don't redirect these keys */
                        gtk_widget_grab_focus(win->input_entry);
                        gtk_editable_set_position(GTK_EDITABLE(win->input_entry), -1);
                        gboolean retval = TRUE;
                        g_signal_emit_by_name(win->input_entry, "key-press-event", event, &retval);
                        return retval; /* Block this key event if the entry handled it */
                }
        }
        return FALSE;
}

/* Internal function: finish handling a line input request, for both text grid and text buffer windows. */
static int
write_to_window_buffer(winid_t win, const gchar *inserted_text)
{
        int copycount = 0;

    /* Convert the string from UTF-8 to Latin-1 or Unicode */
    if(win->input_request_type == INPUT_REQUEST_LINE)
    {
        gsize bytes_written;
        gchar *latin1 = convert_utf8_to_latin1(inserted_text, &bytes_written);

        if(latin1 == NULL)
            return 0;

        /* Place input in the echo stream */
        if(win->echo_stream != NULL)
            glk_put_string_stream(win->echo_stream, latin1);

        /* Copy the string (bytes_written does not include the NULL at the end) */
        copycount = MIN(win->line_input_buffer_max_len, bytes_written);
        memcpy(win->line_input_buffer, latin1, copycount);
        g_free(latin1);
    }
    else if(win->input_request_type == INPUT_REQUEST_LINE_UNICODE)
    {
        glong items_written;
        gunichar *unicode = convert_utf8_to_ucs4(inserted_text, &items_written);

        if(unicode == NULL)
            return 0;

        /* Place input in the echo stream */
        if(win->echo_stream != NULL)
            glk_put_string_stream_uni(win->echo_stream, unicode);

        /* Copy the string (but not the NULL at the end) */
        copycount = MIN(win->line_input_buffer_max_len, items_written);
        memcpy(win->line_input_buffer_unicode, unicode, copycount * sizeof(gunichar));
        g_free(unicode);
    }
    else
        WARNING("Wrong input request type");

    win->input_request_type = INPUT_REQUEST_NONE;
        return copycount;
}

/* Internal function: Retrieves the input of a TextBuffer window and stores it in the window buffer.
 * Returns the number of characters written, suitable for inclusion in a line input event. */
static int
finish_text_buffer_line_input(winid_t win, gboolean emit_signal)
{
        VALID_WINDOW(win, return 0);
        g_return_val_if_fail(win->type == wintype_TextBuffer, 0);

        GtkTextIter start_iter, end_iter;

        GtkTextBuffer *window_buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
        GtkTextMark *input_position = gtk_text_buffer_get_mark(window_buffer, "input_position");
        gtk_text_buffer_get_iter_at_mark(window_buffer, &start_iter, input_position);
        gtk_text_buffer_get_end_iter(window_buffer, &end_iter);

        gchar *inserted_text = gtk_text_buffer_get_text(window_buffer, &start_iter, &end_iter, FALSE);

        /* If echoing is turned off, remove the text from the window */
        if(!win->echo_current_line_input)
                gtk_text_buffer_delete(window_buffer, &start_iter, &end_iter);

        /* Don't include the newline in the input */
        char *last_char = inserted_text + strlen(inserted_text) - 1;
        if(*last_char == '\n')
                *last_char = '\0';

        int chars_written = write_to_window_buffer(win, inserted_text);
        if(emit_signal)
        {
                ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
                g_assert(glk);
                g_signal_emit_by_name(glk, "line-input", win->rock, inserted_text);
        }

        /* Add the text to the window input history */
        if(win->history_pos != NULL)
        {
                g_free(win->history->data);
                win->history = g_list_delete_link(win->history, win->history);
        }
        if(*inserted_text != 0)
                win->history = g_list_prepend(win->history, g_strdup(inserted_text));

        win->history_pos = NULL;

        g_free(inserted_text);

        return chars_written;
}

/* Internal function: Retrieves the input of a TextGrid window and stores it in the window buffer.
 * Returns the number of characters written, suitable for inclusion in a line input event. */
static int
finish_text_grid_line_input(winid_t win, gboolean emit_signal)
{
        VALID_WINDOW(win, return 0);
        g_return_val_if_fail(win->type == wintype_TextGrid, 0);

        GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );

        gchar *text = g_strdup( gtk_entry_get_text(GTK_ENTRY(win->input_entry)) );
        /* Move the focus back into the text view */
        gtk_widget_grab_focus(win->widget);
        /* Remove entry widget from text view */
        /* Should be ok even though this is the widget's own signal handler */
        gtk_container_remove( GTK_CONTAINER(win->widget), GTK_WIDGET(win->input_entry) );
        win->input_entry = NULL;
        /* Delete the child anchor */
        GtkTextIter start, end;
        gtk_text_buffer_get_iter_at_child_anchor(buffer, &start, win->input_anchor);
        end = start;
        gtk_text_iter_forward_char(&end); /* Point after the child anchor */
        gtk_text_buffer_delete(buffer, &start, &end);
        win->input_anchor = NULL;

    gchar *spaces = g_strnfill(win->input_length - g_utf8_strlen(text, -1), ' ');
    gchar *text_to_insert = g_strconcat(text, spaces, NULL);
        g_free(spaces);
    gtk_text_buffer_insert(buffer, &start, text_to_insert, -1);
    g_free(text_to_insert);

    int chars_written = write_to_window_buffer(win, text);
    if(emit_signal)
    {
                ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
                g_assert(glk);
                g_signal_emit_by_name(glk, "line-input", win->rock, text);
    }

        /* Add the text to the window input history */
        if(win->history_pos != NULL)
        {
                g_free(win->history->data);
                win->history = g_list_delete_link(win->history, win->history);
        }
        if(*text != 0)
                win->history = g_list_prepend(win->history, g_strdup(text));
        win->history_pos = NULL;

        g_free(text);
        return chars_written;
}

/* Internal function: Callback for signal insert-text on a text buffer window.
Runs after the default handler has already inserted the text. */
void
after_window_insert_text(GtkTextBuffer *textbuffer, GtkTextIter *location, gchar *text, gint len, winid_t win)
{
        GtkTextBuffer *window_buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );

        /* Set the history position to NULL and erase the text we were already editing */
        if(win->history_pos != NULL)
        {
                g_free(win->history->data);
                win->history = g_list_delete_link(win->history, win->history);
                win->history_pos = NULL;
        }

        /* Apply the 'input' style to the text that was entered */
        GtkTextIter end_iter;
        gtk_text_buffer_get_end_iter(window_buffer, &end_iter);
        GtkTextIter input_iter;
        GtkTextMark *input_position = gtk_text_buffer_get_mark(window_buffer, "input_position");
        gtk_text_buffer_get_iter_at_mark(window_buffer, &input_iter, input_position);
        gtk_text_buffer_apply_tag_by_name(window_buffer, "input", &input_iter, &end_iter);
}

/* Internal function: Callback for signal activate on the line input GtkEntry
in a text grid window. */
void
on_input_entry_activate(GtkEntry *input_entry, winid_t win)
{
        g_signal_handler_block(win->widget, win->line_input_keypress_handler);

        int chars_written = finish_text_grid_line_input(win, TRUE);
        ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
        event_throw(glk, evtype_LineInput, win, chars_written, 0);
}

/* Internal function: Callback for signal key-press-event on the line input
GtkEntry in a text grid window. */
gboolean
on_input_entry_key_press_event(GtkEntry *input_entry, GdkEventKey *event, winid_t win)
{
        if(event->keyval == GDK_Up || event->keyval == GDK_KP_Up
                || event->keyval == GDK_Down || event->keyval == GDK_KP_Down)
        {
                /* Prevent falling off the end of the history list */
                if( (event->keyval == GDK_Up || event->keyval == GDK_KP_Up)
                        && win->history_pos && win->history_pos->next == NULL)
                        return TRUE;
                if( (event->keyval == GDK_Down || event->keyval == GDK_KP_Down)
                        && (win->history_pos == NULL || win->history_pos->prev == NULL) )
                        return TRUE;

                if(win->history_pos == NULL)
                {
                        const gchar *current_input = gtk_entry_get_text(input_entry);
                        win->history = g_list_prepend(win->history, g_strdup(current_input));
                        win->history_pos = win->history;
                }

                if(event->keyval == GDK_Up || event->keyval == GDK_KP_Up)
                {
                        if(win->history_pos)
                                win->history_pos = g_list_next(win->history_pos);
                        else
                                win->history_pos = win->history;
                }
                else /* down */
                        win->history_pos = g_list_previous(win->history_pos);

                /* Insert the history item into the window */
                g_signal_handler_block(input_entry, win->line_input_entry_changed);
                gtk_entry_set_text(input_entry, win->history_pos->data);
                g_signal_handler_unblock(input_entry, win->line_input_entry_changed);
                return TRUE;
        }
        return FALSE;
}

void
on_input_entry_changed(GtkEditable *editable, winid_t win)
{
        /* Set the history position to NULL and erase the text we were already editing */
        if(win->history_pos != NULL)
        {
                g_free(win->history->data);
                win->history = g_list_delete_link(win->history, win->history);
                win->history_pos = NULL;
        }
}

glui32
keyval_to_glk_keycode(guint keyval, gboolean unicode)
{
        glui32 keycode;
        switch(keyval) {
                case GDK_Up:
                case GDK_KP_Up: return keycode_Up;
                case GDK_Down:
                case GDK_KP_Down: return keycode_Down;
                case GDK_Left:
                case GDK_KP_Left: return keycode_Left;
                case GDK_Right:
                case GDK_KP_Right: return keycode_Right;
                case GDK_Linefeed:
                case GDK_Return:
                case GDK_KP_Enter: return keycode_Return;
                case GDK_Delete:
                case GDK_BackSpace:
                case GDK_KP_Delete: return keycode_Delete;
                case GDK_Escape: return keycode_Escape;
                case GDK_Tab:
                case GDK_KP_Tab: return keycode_Tab;
                case GDK_Page_Up:
                case GDK_KP_Page_Up: return keycode_PageUp;
                case GDK_Page_Down:
                case GDK_KP_Page_Down: return keycode_PageDown;
                case GDK_Home:
                case GDK_KP_Home: return keycode_Home;
                case GDK_End:
                case GDK_KP_End: return keycode_End;
                case GDK_F1:
                case GDK_KP_F1: return keycode_Func1;
                case GDK_F2:
                case GDK_KP_F2: return keycode_Func2;
                case GDK_F3:
                case GDK_KP_F3: return keycode_Func3;
                case GDK_F4:
                case GDK_KP_F4: return keycode_Func4;
                case GDK_F5: return keycode_Func5;
                case GDK_F6: return keycode_Func6;
                case GDK_F7: return keycode_Func7;
                case GDK_F8: return keycode_Func8;
                case GDK_F9: return keycode_Func9;
                case GDK_F10: return keycode_Func10;
                case GDK_F11: return keycode_Func11;
                case GDK_F12: return keycode_Func12;
                default:
                        keycode = gdk_keyval_to_unicode(keyval);
                        /* If keycode is 0, then keyval was not recognized; also return
                        unknown if Latin-1 input was requested and the character is not in
                        Latin-1 */
                        if(keycode == 0 || (!unicode && keycode > 255))
                                return keycode_Unknown;
                        return keycode;
        }
}

void
force_char_input_from_queue(winid_t win, event_t *event)
{
        ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
        guint keyval = GPOINTER_TO_UINT(g_async_queue_pop(glk_data->char_input_queue));

        glk_cancel_char_event(win);

        gdk_threads_enter();
        ChimaraGlk *glk = CHIMARA_GLK(gtk_widget_get_ancestor(win->widget, CHIMARA_TYPE_GLK));
        g_assert(glk);
        g_signal_emit_by_name(glk, "char-input", win->rock, keyval);
        gdk_threads_leave();

        event->type = evtype_CharInput;
        event->win = win;
        event->val1 = keyval_to_glk_keycode(keyval, win->input_request_type == INPUT_REQUEST_CHARACTER_UNICODE);
        event->val2 = 0;
}

void
force_line_input_from_queue(winid_t win, event_t *event)
{
        ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
        const gchar *text = g_async_queue_pop(glk_data->line_input_queue);
        glui32 chars_written = 0;

        gdk_threads_enter();
        if(win->type == wintype_TextBuffer)
        {
                GtkTextBuffer *buffer = gtk_text_view_get_buffer( GTK_TEXT_VIEW(win->widget) );
                GtkTextIter start, end;

                /* Remove signal handlers so the line input doesn't get picked up again */
                g_signal_handler_block(buffer, win->insert_text_handler);
                g_signal_handler_block(win->widget, win->line_input_keypress_handler);

                /* Erase any text that was already typed */
                GtkTextMark *input_position = gtk_text_buffer_get_mark(buffer, "input_position");
                gtk_text_buffer_get_iter_at_mark(buffer, &start, input_position);
                gtk_text_buffer_get_end_iter(buffer, &end);
                gtk_text_buffer_delete(buffer, &start, &end);

                /* Make the window uneditable again */
                gtk_text_view_set_editable(GTK_TEXT_VIEW(win->widget), FALSE);

                /* Insert the forced input into the window */
                if(win->echo_current_line_input)
                {
                        gtk_text_buffer_get_end_iter(buffer, &end);
                        gchar *text_to_insert = g_strconcat(text, "\n", NULL);
                        gtk_text_buffer_insert_with_tags_by_name(buffer, &end, text_to_insert, -1, "default", "input", NULL);
                }

                chars_written = finish_text_buffer_line_input(win, TRUE);
        }
        else if(win->type == wintype_TextGrid)
        {
                /* Remove signal handlers so the line input doesn't get picked up again */
                g_signal_handler_block(win->widget, win->char_input_keypress_handler);

                /* Insert the forced input into the window */
                gtk_entry_set_text(GTK_ENTRY(win->input_entry), text);
                chars_written = finish_text_grid_line_input(win, TRUE);
        }
        gdk_threads_leave();

        event->type = evtype_LineInput;
        event->win = win;
        event->val1 = chars_written;
        event->val2 = 0;
}

/*** Internal function: cancels any pending input requests on the window and presents a warning if not INPUT_REQUEST_NONE ***/
void
cancel_old_input_request(winid_t win)
{
        switch(win->input_request_type) {
        case INPUT_REQUEST_NONE:
                break; /* All is well */
        case INPUT_REQUEST_CHARACTER:
        case INPUT_REQUEST_CHARACTER_UNICODE:
                glk_cancel_char_event(win);
                WARNING("Cancelling pending char event");
                break;
        case INPUT_REQUEST_LINE:
        case INPUT_REQUEST_LINE_UNICODE:
                glk_cancel_line_event(win, NULL);
                WARNING("Cancelling pending line event");
                break;
        default:
                WARNING("Could not cancel pending input request: unknown input request");
        }
}

/**
 * glk_set_echo_line_event:
 * @win: The window in which to change the echoing behavior.
 * @val: Zero to turn off echoing, nonzero for normal echoing.
 *
 * Normally, after line input is completed or cancelled in a buffer window, the
 * library ensures that the complete input line (or its latest state, after
 * cancelling) is displayed at the end of the buffer, followed by a newline.
 * This call allows you to suppress this behavior. If the @val argument is zero,
 * all <emphasis>subsequent</emphasis> line input requests in the given window
 * will leave the buffer unchanged after the input is completed or cancelled;
 * the player's input will not be printed. If @val is nonzero, subsequent input
 * requests will have the normal printing behavior.
 *
 * <note><para>
 *   Note that this feature is unrelated to the window's echo stream.
 * </para></note>
 *
 * If you turn off line input echoing, you can reproduce the standard input
 * behavior by following each line input event (or line input cancellation) by
 * printing the input line, in the Input style, followed by a newline in the
 * original style.
 *
 * The glk_set_echo_line_event() does not affect a pending line input request.
 * It also has no effect in non-buffer windows.
 * <note><para>
 *   In a grid window, the game can overwrite the input area at will, so there
 *   is no need for this distinction.
 * </para></note>
 *
 * Not all libraries support this feature. You can test for it with
 * %gestalt_LineInputEcho.
 */
void
glk_set_echo_line_event(winid_t win, glui32 val)
{
        VALID_WINDOW(win, return);

        if(win->type != wintype_TextBuffer)
                return; /* Quietly do nothing */

        win->echo_line_input = val? TRUE : FALSE;
}

/* Internal function to convert from a Glk keycode to a GDK keyval. */
static unsigned
keycode_to_gdk_keyval(glui32 keycode)
{
        switch (keycode)
        {
                case keycode_Left:
                        return GDK_Left;
                case keycode_Right:
                        return GDK_Right;
                case keycode_Up:
                        return GDK_Up;
                case keycode_Down:
                        return GDK_Down;
                case keycode_Return:
                        return GDK_Return;
                case keycode_Delete:
                        return GDK_Delete;
                case keycode_Escape:
                        return GDK_Escape;
                case keycode_Tab:
                        return GDK_Tab;
                case keycode_PageUp:
                        return GDK_Page_Up;
                case keycode_PageDown:
                        return GDK_Page_Down;
                case keycode_Home:
                        return GDK_Home;
                case keycode_End:
                        return GDK_End;
                case keycode_Func1:
                        return GDK_F1;
                case keycode_Func2:
                        return GDK_F2;
                case keycode_Func3:
                        return GDK_F3;
                case keycode_Func4:
                        return GDK_F4;
                case keycode_Func5:
                        return GDK_F5;
                case keycode_Func6:
                        return GDK_F6;
                case keycode_Func7:
                        return GDK_F7;
                case keycode_Func8:
                        return GDK_F8;
                case keycode_Func9:
                        return GDK_F9;
                case keycode_Func10:
                        return GDK_F10;
                case keycode_Func11:
                        return GDK_F11;
                case keycode_Func12:
                        return GDK_F12;
                case keycode_Erase:
                        return GDK_BackSpace;
        }
        unsigned keyval = gdk_unicode_to_keyval(keycode);
        if(keyval < 0x01000000) /* magic number meaning illegal unicode point */
                return keyval;
        return 0;
}

/* Internal function to decide whether @keycode is a valid line terminator. */
gboolean
is_valid_line_terminator(glui32 keycode)
{
        switch(keycode) {
                case keycode_Escape:
                case keycode_Func1:
                case keycode_Func2:
                case keycode_Func3:
                case keycode_Func4:
                case keycode_Func5:
                case keycode_Func6:
                case keycode_Func7:
                case keycode_Func8:
                case keycode_Func9:
                case keycode_Func10:
                case keycode_Func11:
                case keycode_Func12:
                        return TRUE;
        }
        return FALSE;
}

/**
 * glk_set_terminators_line_event:
 * @win: The window for which to set the line input terminator keys.
 * @keycodes: An array of <code>keycode_</code> constants, of length @count.
 * @count: The array length of @keycodes.
 *
 * It is possible to request that other keystrokes complete line input as well.
 * (This allows a game to intercept function keys or other special keys during
 * line input.) To do this, call glk_set_terminators_line_event(), and pass an
 * array of @count keycodes. These must all be special keycodes (see <link
 * linkend="chimara-Character-Input">Character Input</link>). Do not include
 * regular printable characters in the array, nor %keycode_Return (which
 * represents the default <keycap>enter</keycap> key and will always be
 * recognized). To return to the default behavior, pass a %NULL or empty array.
 *
 * The glk_set_terminators_line_event() affects <emphasis>subsequent</emphasis>
 * line input requests in the given window. It does not affect a pending line
 * input request.
 *
 * <note><para>
 *   This distinction makes life easier for interpreters that set up UI
 *   callbacks only at the start of input.
 * </para></note>
 *
 * A library may not support this feature; if it does, it may not support all
 * special keys as terminators. (Some keystrokes are reserved for OS or
 * interpreter control.) You can test for this with %gestalt_LineTerminators and
 * %gestalt_LineTerminatorKey.
 */
void
glk_set_terminators_line_event(winid_t win, glui32 *keycodes, glui32 count)
{
        VALID_WINDOW(win, return);

        g_slist_free(win->extra_line_terminators);
        win->extra_line_terminators = NULL;

        if(keycodes == NULL || count == 0)
                return;

        int i;
        for(i = 0; i < count; i++)
        {
                unsigned key = keycode_to_gdk_keyval(keycodes[i]);
                if(is_valid_line_terminator(keycodes[i]))
                        win->extra_line_terminators = g_slist_prepend(win->extra_line_terminators, GUINT_TO_POINTER(key));
                else
                   WARNING_S("Ignoring invalid line terminator", gdk_keyval_name(key));
        }
}