Plugin API

This document describes the API that plugins can use to interact with HexPatch.

Functions

For the explanation of the types used in the functions, see the Types section.

Initialization

function init(context) end

This function is called when the plugin is loaded.

Argument Type Description
context Context The application context.

Events

On Open

function on_open(context) end

This function is called when a file is opened.

Argument Type Description
context Context The application context.

On Close

function on_save(context) end

This function is called when a file is saved (both save and save as).

Argument Type Description
context Context The application context.

On Edit

function on_edit(new_bytes, context) end

This function is called when the user edits the file, either directly or through a command.

Argument Type Description
new_bytes Data The new bytes of the file.
context Context The application context.

On Key

function on_key(key_event, context) end

This function is called when a key is pressed.

Argument Type Description
key_event KeyEvent The key event.
context Context The application context.

On Mouse

function on_mouse(mouse_event, context) end

This function is called when an action is performed with the mouse.

Argument Type Description
mouse_event MouseEvent The mouse event.
context Context The application context.

On Focus

function on_focus(context) end

This function is called when the terminal gains focus.

Argument Type Description
context Context The application context.

On Blur

function on_blur(context) end

This function is called when the terminal loses focus.

Argument Type Description
context Context The application context.

On Paste

function on_paste(text, context) end

This function is called when text is pasted into the terminal.

Argument Type Description
text String The text that was pasted.
context Context The application context.

On Resize

function on_resize(width, height, context) end

This function is called when the terminal is resized. The size stored in the context is the old size, before the resize.

Argument Type Description
width usize The new width of the terminal.
height usize The new height of the terminal.
context Context The application context.

Commands

function COMMAND_NAME(context) end

This function is called when the user runs the command COMMAND_NAME. The command must be registered using context.add_command("COMMAND_NAME", "COMMAND_DESCRIPTION").

Argument Type Description
context Context The application context.

Popups

function FILL_POPUP_NAME(popup_context, context) end

This function is called each time the popup FILL_POPUP_NAME is drawn. The popup must be opened using context.open_popup("FILL_POPUP_NAME").

Argument Type Description
popup_context PopupContext The popup context.
context Context The application context.

Custom Headers

function HEADER_PARSER_NAME(header_context, context) end

This function is called whenever a new header is parsed, the first parser that returns a valid header will be used. If during the parsing you decide that the header is not valid, you can raise an error or avoid setting values in the header_context. The parser must be registered using context.add_header_parser("HEADER_PARSER_NAME").

Argument Type Description
header_context HeaderContext The header context.
context Context The application context.

Types

Context

This table contains the following fields:

Field Type Description
screen_height usize The height of the screen.
screen_width usize The width of the screen.
data Data The current file's data.
offset usize The current offset in the file.
settings Settings The settings of the application.
current_instruction Option<InstructionInfo> The current instruction at the current offset. nil if the current offset is not in an instruction or in a data section. The InstructionInfo type is explained at InstructionInfo.
header Header The header of the file, if not valid or present, the default header will be used.

And the following functions:

Function Arguments Description
log (level: u8, message: String) Logs a message in the UI.
add_command (command_name: String) Registers a command, this must be called to make the command appear in the command list.
remove_command (command_name: String) Removes a command, this removes the command from the command list.
add_header_parser (parser_name: String) Registers a header parser, this must be called to make the parser be used when a new file is opened.
remove_header_parser (parser_name: String) Removes a header parser, this removes the parser from the list of parsers.
open_popup (popup_handler: String) Opens a popup, each time the popup is drawn the handler function is called
get_popup () -> Option<String> Returns the name of the popup_handler of the currently open popup if there is one opened by this plugin. nil otherwise.
close_popup (popup_handler: Option<String>) Closes a popup opened by this plugin. If popup_handler is not nil it will also check if that is the currently open popup. If no popup is open, this plugin does not own the currently open popup, or the provided handler does not match the function will raise an error.
get_instant_now () -> Instant Gets an instant relative to the time this function was called. The Instant type is explained at Instant.
jump_to (file_address: usize) Makes the UI jump to the specified file address.

For more information on the types, see the following sections.

Settings

This type contains the settings of the application. A setting can be accessed using the . operator with its full name (dots are replaced with underscores). e.g. context.settings.color_address_selected, context.settings.key_up, context.settings.app_history_limit.

WARNING: You should get and set the setting altogether, e.g. context.settings.color_address_selected = {fg = "Red"}. Trying to set a single field will not work.

To access custom settings, use the following functions:

Function Arguments Description
get_custom (setting_name: String) -> CustomSetting Gets the value of a custom setting.
set_custom (setting_name: String, value: CustomSetting) Sets the value of a custom setting.

Data

A mutable vector of bytes.

The following functions are available:

Function Arguments Description
get (index: usize) -> u8 Gets the byte at the specified index. THE INDEX IS 0 BASED!
set (index: usize, value: u8) Sets the byte at the specified index. THE INDEX IS 0 BASED!
len () -> usize Gets the length of the vector.

KeyEvent

This table contains the following fields:

Field Type Description
code String The key that was pressed, a list of possible values is available at KeyEvent.code
modifiers Table A table containing the modifiers that were pressed, the entries are explained at KeyEvent.modifiers
kind String The kind of key event, either Press, Repeat or Release
state Table A table containing the state of the keys, the entries are explained at KeyEvent.state

KeyEvent.code

The following values are possible for the code field:

KeyEvent.modifiers

The table contains the following fields:

Field Type Description
alt bool Whether the alt key was pressed.
control bool Whether the control key was pressed.
hyper bool Whether the hyper key was pressed.
meta bool Whether the meta key was pressed.
shift bool Whether the shift key was pressed.
super bool Whether the super key was pressed.

KeyEvent.state

The table contains the following fields:

Field Type Description
caps_lock bool Whether the caps lock key is active.
keypad bool Whether the event origins from the keypad.
num_lock bool Whether the num lock key is active.

MouseEvent

This table contains the following fields:

Field Type Description
kind String The kind of mouse event, a list of possible values is available at MouseEvent.kind
column usize The column of the terminal where the event happened.
row usize The row of the terminal where the event happened.
modifiers Table A table containing the modifiers that were pressed, the entries are explained at KeyEvent.modifiers (This is the same table of the KeyEvent).
location Option<Table> A table containing the location of the mouse event, the entries are explained at MouseEvent.location. This can be nil if the event is not on a specific component of the UI.

MouseEvent.kind

The following values are possible for the kind field:

MouseEvent.location

This table contains the following fields:

Field Type Description
info Table A table containing info about the location of the mouse event, the entries are explained at MouseEvent.location.info.
relative_location Table A table containing the position of the event relative to the UI section (e.g. the offset from the top left corner of a popup when the popup window is clicked). The contents of this table are just x and y integer offsets from the top left corner of the container.
MouseEvent.location.info

This table has different values depending on which component of the UI is involved with the event. The table always contains the type key and depending on the corresponding value, it may contain other keys. These are the possible values for the type key and the corresponding additional keys:

PopupContext

This table contains the following fields:

Field Type Description
text Text The content of the popup.
title MutString The title of the popup.
height MutUsize The height of the popup.
width MutUsize The width of the popup.

Text

To add text to a popup, use the following functions:

Function Arguments Description
push_line (line: String) Adds a line of text to the popup.
push_span (span: String) Adds text without a newline to the popup.
set_style (style: Style) Sets the style of the text, this will be applied to every line or span until another style is set or reset_style is used.
reset_style () Resets the style to the default one. If this function is not called before the end of the FILL_POPUP function, the previously set style will replace the default style for the popup.
set_alignment (alignment: String) Sets the alignment of the text, the possible values are left, center and right, this will be applied to every line until another alignment is set or reset_alignment is used.
reset_alignment () Resets the alignment to the default one. If this function is not called before the end of the FILL_POPUP function, the previously set alignment will replace the default alignment for the popup.

MutString

This type is a mutable string, it can be manipulated using the following functions:

Function Arguments Description
get () -> String Gets the string.
set (value: String) Sets the string.

MutUsize

This type is a mutable usize, it can be manipulated using the following functions:

Function Arguments Description
get () -> usize Gets the value.
set (value: usize) Sets the value.

InstructionInfo

This table contains the following fields:

Field Type Description
instruction String The line of assembly code, the format depends on the architecture.
physical_address u64 The offset in the file where the instruction starts.
virtual_address u64 The virtual address at which the instruction will be mapped.
size usize The size of the instruction in bytes.

This type has the following fields:

Field Type Description
bitness u32 The bitness of the file. (The default value is 64)
entry_point u64 The virtual address of the entry point. (The default value is 0)
architecture String The architecture of the file, the possible values are listed in Header.architecture.
sections Vec<Section> The sections of the file, the vector is a lua vector. The Section type is explained at Section. (The default value is an empty vector.)
text_section Option<Section> The text section of the file. nil if not present. The Section type is explained at Section. (The default value is nil)
symbols Vec<String> The symbols of the file. (The default value is an empty vector.)

And the following functions:

Function Arguments Description
symbol_to_address (symbol: String) -> Option<u64> Gets the virtual address of a symbol. nil if no such symbol is found.
virtual_to_physical_address (virtual_address: u64) -> Option<u64> Gets the file offset of a virtual address. nil if no section contains the virtual address specified.

Header.architecture

The following values are possible for the architecture field:

Section

This type has the following fields:

Field Type Description
name String The name of the section.
virtual_address u64 The starting virtual address of the section.
file_offset u64 The starting file offset of the section.
size usize The size of the section.

HeaderContext

This table contains the following fields:

Function Arguments Description Required
set_bitness (bitness: u8) Sets the bitness of the file. bitness must be either 32 or 64 Yes
set_entry (entry_point: u64) Sets the virtual address of the entry point. Yes
set_endianness (endianness: String) Sets the endianness of the file. endianness mut be either little or big. Yes
set_architecture (architecture: String) Sets the architecture of the file. The possible values are listed in Header.architecture. Yes
add_section (name: String, virtual_address: u64, file_offset: u64, size: u64) Adds a section to the file. No
add_symbol (address: u64, name: String) Adds a symbol to the file. No

A function marked as required must be called to create a valid header. Those functions can only be called once.

Style

This table contains the following fields:

Field Type Description
fg Option<Color> The foreground color. nil if transparent. The Color type is explained at Color.
bg Option<Color> The background color. nil if transparent. The Color type is explained at Color.
underline Option<Color> The underline color. nil if transparent. The Color type is explained at Color.
add_modifier u16 A bitflag of the modifiers to add. The possible values are listed in Style.modifier.
sub_modifier u16 A bitflag of the modifiers to remove. The possible values are listed in Style.modifier.

Style.modifier

The bitflags work as follows:

Attribute Bitflag
BOLD 0b0000_0000_0001
DIM 0b0000_0000_0010
ITALIC 0b0000_0000_0100
UNDERLINED 0b0000_0000_1000
SLOW_BLINK 0b0000_0001_0000
RAPID_BLINK 0b0000_0010_0000
REVERSED 0b0000_0100_0000
HIDDEN 0b0000_1000_0000
CROSSED_OUT 0b0001_0000_0000

Color

This type is serialized and deserialized as a string. The following values are possible:

CustomSetting

A custom setting can be one of the following types:

In the case of a Style or KeyEvent, the value is effectively a table with the same fields as the type.

Instant

This type represents a point in time.

This type has the following functions:

Function Arguments Description
elapsed () -> f64 Gets the time elapsed in seconds since the instant was created. This is a float so the precision should go up to nanoseconds.