diff options
Diffstat (limited to 'contrib/syslinux-4.02/gpxe/src/hci/editstring.c')
-rw-r--r-- | contrib/syslinux-4.02/gpxe/src/hci/editstring.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/hci/editstring.c b/contrib/syslinux-4.02/gpxe/src/hci/editstring.c new file mode 100644 index 0000000..648f338 --- /dev/null +++ b/contrib/syslinux-4.02/gpxe/src/hci/editstring.c @@ -0,0 +1,192 @@ +/* + * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <assert.h> +#include <string.h> +#include <gpxe/keys.h> +#include <gpxe/editstring.h> + +/** @file + * + * Editable strings + * + */ + +static void insert_delete ( struct edit_string *string, size_t delete_len, + const char *insert_text ) + __attribute__ (( nonnull (1) )); +static void insert_character ( struct edit_string *string, + unsigned int character ) __nonnull; +static void delete_character ( struct edit_string *string ) __nonnull; +static void backspace ( struct edit_string *string ) __nonnull; +static void kill_eol ( struct edit_string *string ) __nonnull; + +/** + * Insert and/or delete text within an editable string + * + * @v string Editable string + * @v delete_len Length of text to delete from current cursor position + * @v insert_text Text to insert at current cursor position, or NULL + */ +static void insert_delete ( struct edit_string *string, size_t delete_len, + const char *insert_text ) { + size_t old_len, max_delete_len, insert_len, max_insert_len, new_len; + + /* Calculate lengths */ + old_len = strlen ( string->buf ); + assert ( string->cursor <= old_len ); + max_delete_len = ( old_len - string->cursor ); + if ( delete_len > max_delete_len ) + delete_len = max_delete_len; + insert_len = ( insert_text ? strlen ( insert_text ) : 0 ); + max_insert_len = ( ( string->len - 1 ) - ( old_len - delete_len ) ); + if ( insert_len > max_insert_len ) + insert_len = max_insert_len; + new_len = ( old_len - delete_len + insert_len ); + + /* Fill in edit history */ + string->mod_start = string->cursor; + string->mod_end = ( ( new_len > old_len ) ? new_len : old_len ); + + /* Move data following the cursor */ + memmove ( ( string->buf + string->cursor + insert_len ), + ( string->buf + string->cursor + delete_len ), + ( max_delete_len + 1 - delete_len ) ); + + /* Copy inserted text to cursor position */ + memcpy ( ( string->buf + string->cursor ), insert_text, insert_len ); + string->cursor += insert_len; +} + +/** + * Insert character at current cursor position + * + * @v string Editable string + * @v character Character to insert + */ +static void insert_character ( struct edit_string *string, + unsigned int character ) { + char insert_text[2] = { character, '\0' }; + insert_delete ( string, 0, insert_text ); +} + +/** + * Delete character at current cursor position + * + * @v string Editable string + */ +static void delete_character ( struct edit_string *string ) { + insert_delete ( string, 1, NULL ); +} + +/** + * Delete character to left of current cursor position + * + * @v string Editable string + */ +static void backspace ( struct edit_string *string ) { + if ( string->cursor > 0 ) { + string->cursor--; + delete_character ( string ); + } +} + +/** + * Delete to end of line + * + * @v string Editable string + */ +static void kill_eol ( struct edit_string *string ) { + insert_delete ( string, ~( ( size_t ) 0 ), NULL ); +} + +/** + * Edit editable string + * + * @v string Editable string + * @v key Key pressed by user + * @ret key Key returned to application, or zero + * + * Handles keypresses and updates the content of the editable string. + * Basic line editing facilities (delete/insert/cursor) are supported. + * If edit_string() understands and uses the keypress it will return + * zero, otherwise it will return the original key. + * + * This function does not update the display in any way. + * + * The string's edit history will be updated to allow the caller to + * efficiently bring the display into sync with the string content. + */ +int edit_string ( struct edit_string *string, int key ) { + int retval = 0; + size_t len = strlen ( string->buf ); + + /* Prepare edit history */ + string->last_cursor = string->cursor; + string->mod_start = string->cursor; + string->mod_end = string->cursor; + + /* Interpret key */ + if ( ( key >= 0x20 ) && ( key <= 0x7e ) ) { + /* Printable character; insert at current position */ + insert_character ( string, key ); + } else switch ( key ) { + case KEY_BACKSPACE: + /* Backspace */ + backspace ( string ); + break; + case KEY_DC: + case CTRL_D: + /* Delete character */ + delete_character ( string ); + break; + case CTRL_K: + /* Delete to end of line */ + kill_eol ( string ); + break; + case KEY_HOME: + case CTRL_A: + /* Start of line */ + string->cursor = 0; + break; + case KEY_END: + case CTRL_E: + /* End of line */ + string->cursor = len; + break; + case KEY_LEFT: + case CTRL_B: + /* Cursor left */ + if ( string->cursor > 0 ) + string->cursor--; + break; + case KEY_RIGHT: + case CTRL_F: + /* Cursor right */ + if ( string->cursor < len ) + string->cursor++; + break; + default: + retval = key; + break; + } + + return retval; +} |