genode/repos/gems/src/server/terminal_mux/main.cc

725 lines
16 KiB
C++

/*
* \brief Ncurses-based terminal multiplexer
* \author Norman Feske
* \date 2013-02-20
*/
/*
* Copyright (C) 2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
/* Genode includes */
#include <base/env.h>
#include <libc/component.h>
#include <base/heap.h>
#include <base/session_label.h>
#include <util/arg_string.h>
#include <root/component.h>
#include <os/attached_ram_dataspace.h>
#include <timer_session/connection.h>
/* terminal includes */
#include <terminal/decoder.h>
#include <terminal/types.h>
#include <terminal/read_buffer.h>
#include <terminal/char_cell_array_character_screen.h>
#include <terminal_session/terminal_session.h>
/* local includes */
#include <ncurses_cxx.h>
/*
* Convert character array into ncurses window
*/
static void convert_char_array_to_window(Cell_array<Char_cell> *cell_array,
Ncurses::Window &window)
{
for (unsigned line = 0; line < cell_array->num_lines(); line++) {
if (!cell_array->line_dirty(line))
continue;
window.move_cursor(0, line);
for (unsigned column = 0; column < cell_array->num_cols(); column++) {
Char_cell cell = cell_array->get_cell(column, line);
unsigned char ascii = cell.ascii;
if (ascii == 0) {
window.print_char(' ', false, false);
continue;
}
/* XXX add color */
window.print_char(ascii, cell.highlight(), cell.inverse());
}
}
}
/**
* Registry of clients of the multiplexer
*/
struct Registry
{
struct Entry : Genode::List<Entry>::Element
{
/**
* Flush pending drawing operations
*/
virtual void flush() = 0;
/**
* Redraw and flush complete entry
*/
virtual void flush_all() = 0;
/**
* Return session label
*/
virtual Genode::Session_label const & label() const = 0;
/**
* Submit character into entry
*/
virtual void submit_input(char c) = 0;
};
/**
* List of existing terminal sessions
*
* The first entry of the list has the current focus
*/
Genode::List<Entry> _list;
/**
* Lookup entry at specified index
*
* \return entry, or 0 if index is out of range
*/
Entry *entry_at(unsigned index)
{
Entry *curr = _list.first();
for (; curr && index--; curr = curr->next());
return curr;
}
void add(Entry *entry)
{
/*
* Always insert new entry at the second position. The first is
* occupied by the current focused entry.
*/
Entry *first = _list.first();
if (first)
_list.remove(first);
_list.insert(entry);
if (first)
_list.insert(first);
}
void remove(Entry *entry)
{
_list.remove(entry);
}
void to_front(Entry *entry)
{
if (!entry) return;
/* make entry the first one of the list */
_list.remove(entry);
_list.insert(entry);
}
bool first(Entry const *entry)
{
return _list.first() == entry;
}
};
class Status_window;
class Menu;
class Session_manager
{
private:
Ncurses &_ncurses;
Registry &_registry;
Status_window &_status_window;
Menu &_menu;
/**
* Update menu if it has the current focus
*/
void _refresh_menu();
public:
Session_manager(Ncurses &ncurses, Registry &registry,
Status_window &status_window, Menu &menu);
void activate_menu();
void submit_input(char c);
void update_ncurses_screen();
void add(Registry::Entry *entry);
void remove(Registry::Entry *entry);
};
namespace Terminal {
class Session_component;
class Root_component;
}
class Terminal::Session_component : public Genode::Rpc_object<Session, Session_component>,
public Registry::Entry
{
private:
Genode::Env &_env;
Read_buffer _read_buffer;
Ncurses &_ncurses;
Ncurses::Window &_window;
Genode::Session_label const _label;
Session_manager &_session_manager;
Genode::Attached_ram_dataspace _io_buffer;
Cell_array<Char_cell> _char_cell_array;
Char_cell_array_character_screen _char_cell_array_character_screen;
Terminal::Decoder _decoder;
Terminal::Position _last_cursor_pos;
public:
Session_component(Genode::size_t io_buffer_size,
Ncurses &ncurses,
Session_manager &session_manager,
Genode::Session_label const &label,
Genode::Env &env,
Genode::Allocator &heap)
:
_env(env),
_ncurses(ncurses),
_window(*ncurses.create_window(0, 1, ncurses.columns(), ncurses.lines() - 1)),
_label(label),
_session_manager(session_manager),
_io_buffer(_env.ram(), _env.rm(), io_buffer_size),
_char_cell_array(ncurses.columns(), ncurses.lines() - 1, &heap),
_char_cell_array_character_screen(_char_cell_array),
_decoder(_char_cell_array_character_screen)
{
_session_manager.add(this);
}
~Session_component()
{
_session_manager.remove(this);
_ncurses.destroy_window(&_window);
}
/*******************************
** Registry::Entry interface **
*******************************/
void flush() override
{
convert_char_array_to_window(&_char_cell_array, _window);
int first_dirty_line = 10000,
last_dirty_line = -10000;
for (int line = 0; line < (int)_char_cell_array.num_lines(); line++) {
if (!_char_cell_array.line_dirty(line)) continue;
first_dirty_line = Genode::min(line, first_dirty_line);
last_dirty_line = Genode::max(line, last_dirty_line);
_char_cell_array.mark_line_as_clean(line);
}
Terminal::Position cursor_pos =
_char_cell_array_character_screen.cursor_pos();
_window.move_cursor(cursor_pos.x, cursor_pos.y);
_window.refresh();
}
void flush_all() override
{
for (unsigned line = 0; line < _char_cell_array.num_lines(); line++)
_char_cell_array.mark_line_as_dirty(line);
_window.erase();
flush();
}
Genode::Session_label const & label() const override { return _label; }
void submit_input(char c) override { _read_buffer.add(c); }
/********************************
** Terminal session interface **
********************************/
Size size() override { return Size(_char_cell_array.num_cols(),
_char_cell_array.num_lines()); }
bool avail() override { return !_read_buffer.empty(); }
Genode::size_t _read(Genode::size_t dst_len)
{
/* read data, block on first byte if needed */
unsigned num_bytes = 0;
unsigned char *dst = _io_buffer.local_addr<unsigned char>();
Genode::size_t dst_size = Genode::min(_io_buffer.size(), dst_len);
do {
dst[num_bytes++] = _read_buffer.get();
} while (!_read_buffer.empty() && num_bytes < dst_size);
return num_bytes;
}
void _write(Genode::size_t num_bytes)
{
unsigned char *src = _io_buffer.local_addr<unsigned char>();
for (unsigned i = 0; i < num_bytes; i++) {
/* submit character to sequence decoder */
_decoder.insert(src[i]);
}
}
Genode::Dataspace_capability _dataspace()
{
return _io_buffer.cap();
}
void connected_sigh(Genode::Signal_context_capability sigh) override
{
/*
* Immediately reflect connection-established signal to the
* client because the session is ready to use immediately after
* creation.
*/
Genode::Signal_transmitter(sigh).submit();
}
void read_avail_sigh(Genode::Signal_context_capability cap) override
{
_read_buffer.sigh(cap);
}
Genode::size_t read(void *buf, Genode::size_t) override { return 0; }
Genode::size_t write(void const *buf, Genode::size_t) override { return 0; }
};
class Terminal::Root_component : public Genode::Root_component<Session_component>
{
private:
Genode::Env &_env;
Ncurses &_ncurses;
Session_manager &_session_manager;
/*
* FIXME The heap is shared between all clients. The allocator should
* be moved into the session component but this increases per-session
* RAM costs significantly, which would break all connections to this
* server.
*/
Genode::Heap _heap { _env.ram(), _env.rm() };
protected:
Session_component *_create_session(const char *args)
{
/*
* XXX read I/O buffer size from args
*/
Genode::size_t io_buffer_size = 4096;
return new (md_alloc())
Session_component(io_buffer_size, _ncurses, _session_manager,
Genode::label_from_args(args), _env, _heap);
}
public:
/**
* Constructor
*/
Root_component(Genode::Env &env,
Genode::Allocator &md_alloc,
Ncurses &ncurses,
Session_manager &session_manager)
:
Genode::Root_component<Session_component>(env.ep(), md_alloc),
_env(env),
_ncurses(ncurses),
_session_manager(session_manager)
{ }
};
class Status_window
{
private:
Ncurses &_ncurses;
Ncurses::Window &_window;
public:
Status_window(Ncurses &ncurses)
:
_ncurses(ncurses),
_window(*_ncurses.create_window(0, 0, ncurses.columns(), 1))
{ }
~Status_window()
{
_ncurses.destroy_window(&_window);
}
void label(Genode::Session_label const &label)
{
_window.erase();
_window.move_cursor(0, 0);
_window.print_char('[', false, false);
unsigned const max_columns = _ncurses.columns() - 2;
char const *_label = label.string();
for (unsigned i = 0; i < max_columns && _label[i]; i++)
_window.print_char(_label[i], false, false);
_window.print_char(']', false, false);
_window.refresh();
}
};
class Menu : public Registry::Entry
{
private:
Ncurses &_ncurses;
Ncurses::Window &_window;
Status_window &_status_window;
Registry &_registry;
unsigned _selected_idx;
unsigned _max_idx;
Genode::Session_label const _label { "-" };
/**
* State tracker for escape sequences within user input
*
* This tracker is used to decode special keys (e.g., cursor keys).
*/
struct Seq_tracker
{
enum State { INIT, GOT_ESC, GOT_FIRST } _state;
char _normal, _first, _second;
bool _sequence_complete;
Seq_tracker() : _state(INIT), _sequence_complete(false) { }
void input(char c)
{
switch (_state) {
case INIT:
if (c == 27)
_state = GOT_ESC;
else
_normal = c;
_sequence_complete = false;
break;
case GOT_ESC:
_first = c;
_state = GOT_FIRST;
break;
case GOT_FIRST:
_second = c;
_state = INIT;
_sequence_complete = true;
break;
}
}
bool normal() const { return _state == INIT && !_sequence_complete; }
char normal_char() const { return _normal; }
bool _normal_matches(char c) const { return normal() && _normal == c; }
bool _fn_complete(char match_first, char match_second) const
{
return _sequence_complete
&& _first == match_first
&& _second == match_second;
}
bool key_up() const {
return _fn_complete(91, 65) || _normal_matches('k'); }
bool key_down() const {
return _fn_complete(91, 66) || _normal_matches('j'); }
};
Seq_tracker _seq_tracker;
public:
Menu(Ncurses &ncurses, Registry &registry, Status_window &status_window)
:
_ncurses(ncurses),
_window(*_ncurses.create_window(0, 1,
ncurses.columns(),
ncurses.lines() - 1)),
_status_window(status_window),
_registry(registry),
_selected_idx(0),
_max_idx(0)
{ }
~Menu()
{
_ncurses.destroy_window(&_window);
}
void reset_selection() { _selected_idx = 0; }
void flush() override { }
void flush_all() override
{
_window.erase();
unsigned const max_columns = _ncurses.columns() - 1;
for (unsigned i = 0; i < _ncurses.lines() - 2; i++) {
Registry::Entry *entry = _registry.entry_at(i + 1);
if (!entry) {
_max_idx = i - 1;
break;
}
bool const highlight = (i == _selected_idx);
if (highlight)
_window.horizontal_line(i + 1);
unsigned const padding = 2;
_window.move_cursor(padding, 1 + i);
char const *label = entry->label().string();
for (unsigned j = 0; j < (max_columns - padding) && label[j]; j++)
_window.print_char(label[j], highlight, highlight);
}
_ncurses.cursor_visible(false);
_window.refresh();
}
Genode::Session_label const & label() const { return _label; }
void submit_input(char c)
{
_seq_tracker.input(c);
if (_seq_tracker.key_up()) {
if (_selected_idx > 0)
_selected_idx--;
flush_all();
}
if (_seq_tracker.key_down()) {
if (_selected_idx < _max_idx)
_selected_idx++;
flush_all();
}
/*
* Detect selection of menu entry via [enter]
*/
if (_seq_tracker.normal() && _seq_tracker.normal_char() == 13) {
Entry *entry = _registry.entry_at(_selected_idx + 1);
if (entry) {
_registry.to_front(entry);
/* update status window */
_status_window.label(_registry.entry_at(0)->label());
_ncurses.cursor_visible(true);
entry->flush_all();
}
}
}
};
struct User_input
{
Ncurses &_ncurses;
User_input(Ncurses &ncurses) : _ncurses(ncurses) { }
int read_character()
{
return _ncurses.read_character();
}
};
/************************************
** Session manager implementation **
************************************/
Session_manager::Session_manager(Ncurses &ncurses, Registry &registry,
Status_window &status_window, Menu &menu)
:
_ncurses(ncurses), _registry(registry), _status_window(status_window),
_menu(menu)
{ }
void Session_manager::_refresh_menu()
{
if (_registry.first(&_menu))
activate_menu();
}
void Session_manager::activate_menu()
{
_menu.reset_selection();
_registry.to_front(&_menu);
_status_window.label(_menu.label());
_ncurses.clear_ok();
_menu.flush_all();
}
void Session_manager::submit_input(char c)
{
Registry::Entry *focused = _registry.entry_at(0);
if (focused)
focused->submit_input(c);
}
void Session_manager::update_ncurses_screen()
{
Registry::Entry *focused = _registry.entry_at(0);
if (focused)
focused->flush();
_ncurses.do_update();
}
void Session_manager::add(Registry::Entry *entry)
{
_registry.add(entry);
_refresh_menu();
}
void Session_manager::remove(Registry::Entry *entry)
{
_registry.remove(entry);
_refresh_menu();
}
/***************
** Component **
***************/
struct Main
{
Genode::Env &env;
Genode::Sliced_heap sliced_heap { env.ram(), env.rm() };
Registry registry;
Ncurses ncurses;
Status_window status_window { ncurses };
Menu menu { ncurses, registry, status_window };
User_input user_input { ncurses };
Session_manager session_manager { ncurses, registry, status_window, menu };
Terminal::Root_component root { env, sliced_heap, ncurses, session_manager };
Timer::Connection timer { env };
Genode::Signal_handler<Main> timer_handler { env.ep(), *this, &Main::handle_timer };
Main(Genode::Env &env) : env(env)
{
Genode::log("--- terminal_mux service started ---");
registry.add(&menu);
session_manager.activate_menu();
env.parent().announce(env.ep().manage(root));
timer.sigh(timer_handler);
timer.trigger_periodic(10*1000);
}
void handle_timer()
{
for (;;) {
int c = user_input.read_character();
if (c == -1)
break;
/*
* Quirk needed when using 'qemu -serial stdio'. In this case,
* backspace is wrongly reported as 127.
*/
if (c == 127)
c = 8;
/*
* Handle C-y by switching to the menu
*/
enum { KEYCODE_C_X = 24 };
if (c == KEYCODE_C_X) {
session_manager.activate_menu();
} else {
session_manager.submit_input(c);
}
}
session_manager.update_ncurses_screen();
}
};
void Libc::Component::construct(Libc::Env &env) { static Main inst(env); }