Trait vtparse::VTActor

source · [−]
pub trait VTActor {
    fn print(&mut self, b: char);
    fn execute_c0_or_c1(&mut self, control: u8);
    fn dcs_hook(
        &mut self,
        mode: u8,
        params: &[i64],
        intermediates: &[u8],
        ignored_excess_intermediates: bool
    );
    fn dcs_put(&mut self, byte: u8);
    fn dcs_unhook(&mut self);
    fn esc_dispatch(
        &mut self,
        params: &[i64],
        intermediates: &[u8],
        ignored_excess_intermediates: bool,
        byte: u8
    );
    fn csi_dispatch(
        &mut self,
        params: &[CsiParam],
        parameters_truncated: bool,
        byte: u8
    );
    fn osc_dispatch(&mut self, params: &[&[u8]]);
    fn apc_dispatch(&mut self, data: Vec<u8>);
}
Expand description

VTActor is a trait that allows the host application to process the different kinds of sequence as they are parsed from the input stream.

The functions defined by this trait correspond to the actions defined in the state machine.

Terminology:

An intermediate is a character in the range 0x20-0x2f that occurs before the final character in an escape sequence.

ignored_excess_intermediates is a boolean that is set in the case where there were more than two intermediate characters; no standard defines any codes with more than two. Intermediates after the second will set this flag and are discarded.

params in most of the functions of this trait are decimal integer parameters in escape sequences. They are separated by semicolon characters. An omitted parameter is returned in this interface as a zero, which represents the default value for that parameter.

Other jargon used here is defined in ECMA-48.

Required Methods

The current code should be mapped to a glyph according to the character set mappings and shift states in effect, and that glyph should be displayed.

If the input was UTF-8 then it will have been mapped to a unicode code point. Invalid sequences are represented here using the unicode REPLACEMENT_CHARACTER.

Otherwise the parameter will be a 7-bit printable value and may be subject to mapping depending on other state maintained by the embedding application.

Some commentary from the state machine documentation:

GL characters (20 to 7F) are printed. 20 (SP) and 7F (DEL) are included in this area, although both codes have special behaviour. If a 94-character set is mapped into GL, 20 will cause a space to be displayed, and 7F will be ignored. When a 96-character set is mapped into GL, both 20 and 7F may cause a character to be displayed. Later models of the VT220 included the DEC Multinational Character Set (MCS), which has 94 characters in its supplemental set (i.e. the characters supplied in addition to ASCII), so terminals only claiming VT220 compatibility can always ignore 7F. The VT320 introduced ISO Latin-1, which has 96 characters in its supplemental set, so emulators with a VT320 compatibility mode need to treat 7F as a printable character.

The C0 or C1 control function should be executed, which may have any one of a variety of effects, including changing the cursor position, suspending or resuming communications or changing the shift states in effect.

See ECMA-48 for more information on C0 and C1 control functions.

invoked when a final character arrives in the first part of a device control string. It determines the control function from the private marker, intermediate character(s) and final character, and executes it, passing in the parameter list. It also selects a handler function for the rest of the characters in the control string.

See ECMA-48 for more information on device control strings.

This action passes characters from the data string part of a device control string to a handler that has previously been selected by the dcs_hook action. C0 controls are also passed to the handler.

See ECMA-48 for more information on device control strings.

When a device control string is terminated by ST, CAN, SUB or ESC, this action calls the previously selected handler function with an “end of data” parameter. This allows the handler to finish neatly.

See ECMA-48 for more information on device control strings.

The final character of an escape sequence has arrived, so determine the control function to be executed from the intermediate character(s) and final character, and execute it.

See ECMA-48 for more information on escape sequences.

A final character of a Control Sequence Initiator has arrived, so determine the control function to be executed from private marker, intermediate character(s) and final character, and execute it, passing in the parameter list.

See ECMA-48 for more information on control functions.

Called when an OSC string is terminated by ST, CAN, SUB or ESC.

params is an array of byte strings (which may also be valid utf-8) that were passed as semicolon separated parameters to the operating system command.

Called when an APC string is terminated by ST data is the data contained within the APC sequence.

Implementors