editstring.c File Reference

Editable strings. More...

#include <assert.h>
#include <string.h>
#include <gpxe/keys.h>
#include <gpxe/editstring.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER)
static void	insert_delete (struct edit_string *string, size_t delete_len, const char *insert_text)
	Insert and/or delete text within an editable string.
static void	insert_character (struct edit_string *string, unsigned int character)
	Insert character at current cursor position.
static void	delete_character (struct edit_string *string)
	Delete character at current cursor position.
static void	backspace (struct edit_string *string)
	Delete character to left of current cursor position.
static void	kill_eol (struct edit_string *string)
	Delete to end of line.
int	edit_string (struct edit_string *string, int key)
	Edit editable string.

---

Detailed Description

Editable strings.

Definition in file editstring.c.

---

Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

static void insert_delete	(	struct edit_string *	string,
		size_t	delete_len,
		const char *	insert_text
	)			[static]

Insert and/or delete text within an editable string.

Parameters:

	string	Editable string
	delete_len	Length of text to delete from current cursor position
	insert_text	Text to insert at current cursor position, or NULL

Definition at line 48 of file editstring.c.

References assert, edit_string::buf, edit_string::cursor, memcpy, memmove(), and strlen().

Referenced by delete_character(), insert_character(), and kill_eol().

                                                      {
        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;
}

static void insert_character	(	struct edit_string *	string,
		unsigned int	character
	)			[static]

Insert character at current cursor position.

Parameters:

	string	Editable string
	character	Character to insert

Definition at line 84 of file editstring.c.

References insert_delete().

Referenced by edit_string().

                                                       {
        char insert_text[2] = { character, '\0' };
        insert_delete ( string, 0, insert_text );
}

static void delete_character

(

struct edit_string *

string

)

[static]

Delete character at current cursor position.

Parameters:

string

Editable string

Definition at line 95 of file editstring.c.

References insert_delete(), and NULL.

Referenced by backspace(), and edit_string().

                                                            {
        insert_delete ( string, 1, NULL );
}

static void backspace

(

struct edit_string *

string

)

[static]

Delete character to left of current cursor position.

Parameters:

string

Editable string

Definition at line 104 of file editstring.c.

References edit_string::cursor, and delete_character().

Referenced by edit_string().

                                                     {
        if ( string->cursor > 0 ) {
                string->cursor--;
                delete_character ( string );
        }
}

static void kill_eol

(

struct edit_string *

string

)

[static]

Delete to end of line.

Parameters:

string

Editable string

Definition at line 116 of file editstring.c.

References insert_delete(), and NULL.

Referenced by edit_string().

                                                    {
        insert_delete ( string, ~( ( size_t ) 0 ), NULL );
}

int edit_string	(	struct edit_string *	string,
		int	key
	)

Edit editable string.

Parameters:

	string	Editable string
	key	Key pressed by user

Return values:

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.

Definition at line 137 of file editstring.c.

References backspace(), edit_string::buf, CTRL_A, CTRL_B, CTRL_D, CTRL_E, CTRL_F, CTRL_K, edit_string::cursor, delete_character(), insert_character(), KEY_BACKSPACE, KEY_DC, KEY_END, KEY_HOME, KEY_LEFT, KEY_RIGHT, kill_eol(), and strlen().

Referenced by edit_editbox(), and readline().

                                                        {
        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;
}