From 8aa1e349fc468c13f4b153db3611b07bd9acf580 Mon Sep 17 00:00:00 2001
From: Norman Feske <norman.feske@genode-labs.com>
Date: Wed, 7 Feb 2018 17:03:19 +0100
Subject: [PATCH] terminal session: propagate resize events

The new 'Terminal_session::size_changed_sigh' RPC function registers a
signal handler that is triggered each time when the terminal size
changes. It enables the client to adjust itself to the new size by
subsequently calling the 'size' RPC function. Of all terminal servers,
only the graphical terminal triggers this signal.
---
 .../dde_linux/src/server/usb_terminal/main.cc | 14 ++--
 repos/gems/src/server/file_terminal/main.cc   | 20 ++---
 repos/gems/src/server/tcp_terminal/main.cc    | 14 ++--
 repos/gems/src/server/terminal/main.cc        | 16 ++--
 repos/gems/src/server/terminal/session.h      | 75 ++++++++++++++-----
 repos/gems/src/server/terminal_mux/main.cc    |  3 +
 repos/os/include/terminal_session/client.h    |  5 ++
 .../terminal_session/terminal_session.h       |  8 +-
 repos/os/include/uart_session/client.h        |  5 ++
 repos/os/src/drivers/uart/uart_component.h    | 14 ++--
 repos/os/src/server/log_terminal/main.cc      | 12 +--
 .../terminal_session_component.h              | 14 ++--
 12 files changed, 134 insertions(+), 66 deletions(-)

diff --git a/repos/dde_linux/src/server/usb_terminal/main.cc b/repos/dde_linux/src/server/usb_terminal/main.cc
index ca144b559b..e64157d1c1 100644
--- a/repos/dde_linux/src/server/usb_terminal/main.cc
+++ b/repos/dde_linux/src/server/usb_terminal/main.cc
@@ -252,18 +252,20 @@ class Terminal::Session_component : public Rpc_object<Session, Session_component
 			_driver(driver)
 		{ }
 
-		void read_avail_sigh(Signal_context_capability sigh)
+		void read_avail_sigh(Signal_context_capability sigh) override
 		{
 			_driver.read_avail_sigh(sigh);
 		}
 
-		void connected_sigh(Signal_context_capability sigh)
+		void connected_sigh(Signal_context_capability sigh) override
 		{
 			_driver.connected_sigh(sigh);
 		}
 
-		Size size()  { return Size(0, 0); }
-		bool avail() { return _driver.avail(); }
+		void size_changed_sigh(Signal_context_capability) override { }
+
+		Size size()  override { return Size(0, 0); }
+		bool avail() override { return _driver.avail(); }
 
 		size_t _read(size_t dst_len)
 		{
@@ -289,8 +291,8 @@ class Terminal::Session_component : public Rpc_object<Session, Session_component
 
 		Dataspace_capability _dataspace() { return _io_buffer.cap(); }
 
-		size_t read(void *buf, size_t) { return 0; }
-		size_t write(void const *buf, size_t) { return 0; }
+		size_t read(void *buf, size_t) override { return 0; }
+		size_t write(void const *buf, size_t) override { return 0; }
 };
 
 
diff --git a/repos/gems/src/server/file_terminal/main.cc b/repos/gems/src/server/file_terminal/main.cc
index 26ee8e27d7..c48928c67c 100644
--- a/repos/gems/src/server/file_terminal/main.cc
+++ b/repos/gems/src/server/file_terminal/main.cc
@@ -104,9 +104,9 @@ class Open_file
 				Genode::Signal_transmitter(_read_avail_sigh).submit();
 		}
 
-		 /**
-		  * Return true if the file was successfully openend
-		  */
+		/**
+		 * Return true if the file was successfully openend
+		 */
 		bool file_opened() const { return _fd != -1; }
 
 		/**
@@ -167,9 +167,9 @@ namespace Terminal {
 			 ** Terminal session interface **
 			 ********************************/
 
-			Size size() { return Size(0, 0); }
+			Size size() override { return Size(0, 0); }
 
-			bool avail()
+			bool avail() override
 			{
 				return !read_buffer_empty();
 			}
@@ -209,18 +209,20 @@ namespace Terminal {
 				return _io_buffer.cap();
 			}
 
-			void read_avail_sigh(Genode::Signal_context_capability sigh)
+			void read_avail_sigh(Genode::Signal_context_capability sigh) override
 			{
 				Open_file::read_avail_sigh(sigh);
 			}
 
-			void connected_sigh(Genode::Signal_context_capability sigh)
+			void connected_sigh(Genode::Signal_context_capability sigh) override
 			{
 				Open_file::connected_sigh(sigh);
 			}
 
-			Genode::size_t read(void *buf, Genode::size_t) { return 0; }
-			Genode::size_t write(void const *buf, Genode::size_t) { return 0; }
+			void size_changed_sigh(Genode::Signal_context_capability) override { }
+
+			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; }
 	};
 
 
diff --git a/repos/gems/src/server/tcp_terminal/main.cc b/repos/gems/src/server/tcp_terminal/main.cc
index b363ef85f7..695cd0e6c4 100644
--- a/repos/gems/src/server/tcp_terminal/main.cc
+++ b/repos/gems/src/server/tcp_terminal/main.cc
@@ -437,9 +437,9 @@ class Terminal::Session_component : public Genode::Rpc_object<Session, Session_c
 		 ** Terminal session interface **
 		 ********************************/
 
-		Size size() { return Size(0, 0); }
+		Size size() override { return Size(0, 0); }
 
-		bool avail()
+		bool avail() override
 		{
 			bool ret = false;
 			Libc::with_libc([&] () { ret = !read_buffer_empty(); });
@@ -490,18 +490,20 @@ class Terminal::Session_component : public Genode::Rpc_object<Session, Session_c
 			return _io_buffer.cap();
 		}
 
-		void read_avail_sigh(Genode::Signal_context_capability sigh)
+		void read_avail_sigh(Genode::Signal_context_capability sigh) override
 		{
 			Open_socket::read_avail_sigh(sigh);
 		}
 
-		void connected_sigh(Genode::Signal_context_capability sigh)
+		void connected_sigh(Genode::Signal_context_capability sigh) override
 		{
 			Open_socket::connected_sigh(sigh);
 		}
 
-		Genode::size_t read(void *buf, Genode::size_t) { return 0; }
-		Genode::size_t write(void const *buf, Genode::size_t) { return 0; }
+		void size_changed_sigh(Genode::Signal_context_capability) override { }
+
+		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; }
 };
 
 
diff --git a/repos/gems/src/server/terminal/main.cc b/repos/gems/src/server/terminal/main.cc
index 73b5e0b8c8..09f0201bf4 100644
--- a/repos/gems/src/server/terminal/main.cc
+++ b/repos/gems/src/server/terminal/main.cc
@@ -124,7 +124,7 @@ struct Terminal::Main : Character_consumer
 	Read_buffer _read_buffer { };
 
 	/* create root interface for service */
-	Root_component _root { _env, _heap, _read_buffer, *this, _terminal_size };
+	Root_component _root { _env, _heap, _read_buffer, *this };
 
 	/*
 	 * builtin keyboard-layout handling
@@ -152,6 +152,7 @@ struct Terminal::Main : Character_consumer
 	Main(Env &env) : _env(env)
 	{
 		_handle_config();
+		_config.sigh(_config_handler);
 
 		_input.sigh(_input_handler);
 
@@ -198,13 +199,12 @@ void Terminal::Main::_handle_config()
 	/*
 	 * Adapt terminal to framebuffer mode changes
 	 */
-	if (_framebuffer.mode_changed() || !_text_screen_surface.constructed()) {
-		_framebuffer.switch_to_new_mode();
-		_text_screen_surface.construct(_heap, *_font_family,
-		                               _color_palette, _framebuffer);
-		_terminal_size = _text_screen_surface->size();
-		_schedule_flush();
-	}
+	_framebuffer.switch_to_new_mode();
+	_text_screen_surface.construct(_heap, *_font_family,
+	                               _color_palette, _framebuffer);
+	_terminal_size = _text_screen_surface->size();
+	_root.notify_resized(_terminal_size);
+	_schedule_flush();
 
 	/*
 	 * Read keyboard layout from config file
diff --git a/repos/gems/src/server/terminal/session.h b/repos/gems/src/server/terminal/session.h
index 9eef841d3d..8b38ab52c3 100644
--- a/repos/gems/src/server/terminal/session.h
+++ b/repos/gems/src/server/terminal/session.h
@@ -31,10 +31,12 @@ class Terminal::Session_component : public Rpc_object<Session, Session_component
 {
 	private:
 
-		Read_buffer            &_read_buffer;
-		Character_consumer     &_character_consumer;
-		Size             const &_terminal_size;
-		Attached_ram_dataspace  _io_buffer;
+		Read_buffer              &_read_buffer;
+		Character_consumer       &_character_consumer;
+		Size                      _terminal_size { };
+		Size                      _reported_terminal_size { };
+		Attached_ram_dataspace    _io_buffer;
+		Signal_context_capability _size_changed_sigh { };
 
 		Terminal::Position _last_cursor_pos { };
 
@@ -46,21 +48,36 @@ class Terminal::Session_component : public Rpc_object<Session, Session_component
 		Session_component(Env                &env,
 		                  Read_buffer        &read_buffer,
 		                  Character_consumer &character_consumer,
-		                  Size         const &terminal_size,
 		                  size_t              io_buffer_size)
 		:
 			_read_buffer(read_buffer),
 			_character_consumer(character_consumer),
-			_terminal_size(terminal_size),
 			_io_buffer(env.ram(), env.rm(), io_buffer_size)
 		{ }
 
+		void notify_resized(Size new_size)
+		{
+			_terminal_size = new_size;
+
+			bool const client_is_out_of_date =
+				(_reported_terminal_size.columns() != new_size.columns()) ||
+				(_reported_terminal_size.lines()   != new_size.lines());
+
+			if (client_is_out_of_date && _size_changed_sigh.valid())
+				Signal_transmitter(_size_changed_sigh).submit();
+		}
+
 
 		/********************************
 		 ** Terminal session interface **
 		 ********************************/
 
-		Size size() override { return _terminal_size; }
+		Size size() override
+		{
+			_reported_terminal_size = _terminal_size;
+
+			return _terminal_size;
+		}
 
 		bool avail() override { return !_read_buffer.empty(); }
 
@@ -104,6 +121,13 @@ class Terminal::Session_component : public Rpc_object<Session, Session_component
 			_read_buffer.sigh(cap);
 		}
 
+		void size_changed_sigh(Signal_context_capability cap) override
+		{
+			_size_changed_sigh = cap;
+
+			notify_resized(_terminal_size);
+		}
+
 		size_t read(void *, size_t) override { return 0; }
 		size_t write(void const *, size_t) override { return 0; }
 };
@@ -116,23 +140,30 @@ class Terminal::Root_component : public Genode::Root_component<Session_component
 		Env                &_env;
 		Read_buffer        &_read_buffer;
 		Character_consumer &_character_consumer;
-		Session::Size      &_terminal_size;
+		Session::Size       _terminal_size { };
+
+		Registry<Registered<Session_component> > _sessions { };
 
 	protected:
 
-		Session_component *_create_session(const char *)
+		Session_component *_create_session(const char *) override
 		{
 			/*
 			 * XXX read I/O buffer size from args
 			 */
 			size_t io_buffer_size = 4096;
 
-			return new (md_alloc())
-				Session_component(_env,
-				                  _read_buffer,
-				                  _character_consumer,
-				                  _terminal_size,
-				                  io_buffer_size);
+			Session_component &session = *new (md_alloc())
+				Registered<Session_component>(_sessions,
+				                              _env,
+				                              _read_buffer,
+				                              _character_consumer,
+				                              io_buffer_size);
+
+			/* propagate current terminal size to client */
+			session.notify_resized(_terminal_size);
+
+			return &session;
 		}
 
 	public:
@@ -143,15 +174,21 @@ class Terminal::Root_component : public Genode::Root_component<Session_component
 		Root_component(Env                &env,
 		               Allocator          &md_alloc,
 		               Read_buffer        &read_buffer,
-		               Character_consumer &character_consumer,
-		               Session::Size      &terminal_size)
+		               Character_consumer &character_consumer)
 		:
 			Genode::Root_component<Session_component>(env.ep(), md_alloc),
 			_env(env),
 			_read_buffer(read_buffer),
-			_character_consumer(character_consumer),
-			_terminal_size(terminal_size)
+			_character_consumer(character_consumer)
 		{ }
+
+		void notify_resized(Session::Size size)
+		{
+			_terminal_size = size;
+
+			_sessions.for_each([&] (Session_component &session) {
+				session.notify_resized(size); });
+		}
 };
 
 #endif /* _SESSION_H_ */
diff --git a/repos/gems/src/server/terminal_mux/main.cc b/repos/gems/src/server/terminal_mux/main.cc
index bfa9409a48..f46d9837c0 100644
--- a/repos/gems/src/server/terminal_mux/main.cc
+++ b/repos/gems/src/server/terminal_mux/main.cc
@@ -330,6 +330,9 @@ class Terminal::Session_component : public Genode::Rpc_object<Session, Session_c
 			_read_buffer.sigh(cap);
 		}
 
+		void size_changed_sigh(Genode::Signal_context_capability cap) override
+		{ }
+
 		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; }
 };
diff --git a/repos/os/include/terminal_session/client.h b/repos/os/include/terminal_session/client.h
index 2ed4823c1b..733198b12f 100644
--- a/repos/os/include/terminal_session/client.h
+++ b/repos/os/include/terminal_session/client.h
@@ -107,6 +107,11 @@ class Terminal::Session_client : public Genode::Rpc_client<Session>
 			call<Rpc_read_avail_sigh>(cap);
 		}
 
+		void size_changed_sigh(Genode::Signal_context_capability cap)
+		{
+			call<Rpc_size_changed_sigh>(cap);
+		}
+
 		Genode::size_t io_buffer_size() const { return _io_buffer.size(); }
 };
 
diff --git a/repos/os/include/terminal_session/terminal_session.h b/repos/os/include/terminal_session/terminal_session.h
index ada3478cc8..1ecf828172 100644
--- a/repos/os/include/terminal_session/terminal_session.h
+++ b/repos/os/include/terminal_session/terminal_session.h
@@ -93,6 +93,11 @@ struct Terminal::Session : Genode::Session
 	 */
 	virtual void read_avail_sigh(Genode::Signal_context_capability cap) = 0;
 
+	/**
+	 * Register signal handler to be notified on terminal-size changes
+	 */
+	virtual void size_changed_sigh(Genode::Signal_context_capability cap) = 0;
+
 
 	/*******************
 	 ** RPC interface **
@@ -104,11 +109,12 @@ struct Terminal::Session : Genode::Session
 	GENODE_RPC(Rpc_write, Genode::size_t, _write, Genode::size_t);
 	GENODE_RPC(Rpc_connected_sigh, void, connected_sigh, Genode::Signal_context_capability);
 	GENODE_RPC(Rpc_read_avail_sigh, void, read_avail_sigh, Genode::Signal_context_capability);
+	GENODE_RPC(Rpc_size_changed_sigh, void, size_changed_sigh, Genode::Signal_context_capability);
 	GENODE_RPC(Rpc_dataspace, Genode::Dataspace_capability, _dataspace);
 
 	GENODE_RPC_INTERFACE(Rpc_size, Rpc_avail, Rpc_read, Rpc_write,
 	                     Rpc_connected_sigh, Rpc_read_avail_sigh,
-	                     Rpc_dataspace);
+	                     Rpc_size_changed_sigh, Rpc_dataspace);
 };
 
 #endif /* _INCLUDE__TERMINAL_SESSION__TERMINAL_SESSION_H_ */
diff --git a/repos/os/include/uart_session/client.h b/repos/os/include/uart_session/client.h
index 02dd965212..2d11d341ed 100644
--- a/repos/os/include/uart_session/client.h
+++ b/repos/os/include/uart_session/client.h
@@ -78,6 +78,11 @@ class Uart::Session_client : public Genode::Rpc_client<Session>
 			_terminal.read_avail_sigh(cap);
 		}
 
+		void size_changed_sigh(Genode::Signal_context_capability cap)
+		{
+			_terminal.size_changed_sigh(cap);
+		}
+
 		Genode::size_t io_buffer_size() const
 		{
 			return _terminal.io_buffer_size();
diff --git a/repos/os/src/drivers/uart/uart_component.h b/repos/os/src/drivers/uart/uart_component.h
index 5583431d3d..3c4069660b 100644
--- a/repos/os/src/drivers/uart/uart_component.h
+++ b/repos/os/src/drivers/uart/uart_component.h
@@ -152,9 +152,9 @@ class Uart::Session_component : public Rpc_object<Uart::Session,
 		 ** Terminal session interface **
 		 ********************************/
 
-		Size size() { return _size; }
+		Size size() override { return _size; }
 
-		bool avail() { return _driver.char_avail(); }
+		bool avail() override { return _driver.char_avail(); }
 
 		Genode::size_t _read(Genode::size_t dst_len)
 		{
@@ -183,7 +183,7 @@ class Uart::Session_component : public Rpc_object<Uart::Session,
 		Genode::Dataspace_capability _dataspace() {
 			return _io_buffer.cap(); }
 
-		void connected_sigh(Genode::Signal_context_capability sigh)
+		void connected_sigh(Genode::Signal_context_capability sigh) override
 		{
 			/*
 			 * Immediately reflect connection-established signal to the
@@ -193,15 +193,17 @@ class Uart::Session_component : public Rpc_object<Uart::Session,
 			Genode::Signal_transmitter(sigh).submit();
 		}
 
-		void read_avail_sigh(Genode::Signal_context_capability sigh)
+		void read_avail_sigh(Genode::Signal_context_capability sigh) override
 		{
 			_char_avail.sigh = sigh;
 
 			if (_driver.char_avail()) _char_avail();
 		}
 
-		Genode::size_t read(void *, Genode::size_t) { return 0; }
-		Genode::size_t write(void const *, Genode::size_t) { return 0; }
+		void size_changed_sigh(Genode::Signal_context_capability) override { }
+
+		Genode::size_t read(void *, Genode::size_t) override { return 0; }
+		Genode::size_t write(void const *, Genode::size_t) override { return 0; }
 };
 
 
diff --git a/repos/os/src/server/log_terminal/main.cc b/repos/os/src/server/log_terminal/main.cc
index 3c36bcada3..901919e26e 100644
--- a/repos/os/src/server/log_terminal/main.cc
+++ b/repos/os/src/server/log_terminal/main.cc
@@ -111,9 +111,9 @@ class Terminal::Session_component : public Rpc_object<Session, Session_component
 		 ** Terminal session interface **
 		 ********************************/
 
-		Size size() { return Size(0, 0); }
+		Size size() override { return Size(0, 0); }
 
-		bool avail() { return false; }
+		bool avail() override { return false; }
 
 		size_t _read(size_t) { return 0; }
 
@@ -134,7 +134,9 @@ class Terminal::Session_component : public Rpc_object<Session, Session_component
 
 		Dataspace_capability _dataspace() { return _io_buffer.cap(); }
 
-		void read_avail_sigh(Signal_context_capability) { }
+		void read_avail_sigh(Signal_context_capability) override { }
+
+		void size_changed_sigh(Signal_context_capability) override { }
 
 		void connected_sigh(Signal_context_capability sigh)
 		{
@@ -146,8 +148,8 @@ class Terminal::Session_component : public Rpc_object<Session, Session_component
 			Signal_transmitter(sigh).submit();
 		}
 
-		size_t read(void *, size_t) { return 0; }
-		size_t write(void const *, size_t) { return 0; }
+		size_t read(void *, size_t) override { return 0; }
+		size_t write(void const *, size_t) override { return 0; }
 };
 
 
diff --git a/repos/os/src/server/terminal_crosslink/terminal_session_component.h b/repos/os/src/server/terminal_crosslink/terminal_session_component.h
index 9c4e70b7c9..3abe89f322 100644
--- a/repos/os/src/server/terminal_crosslink/terminal_session_component.h
+++ b/repos/os/src/server/terminal_crosslink/terminal_session_component.h
@@ -68,9 +68,9 @@ namespace Terminal_crosslink {
 			 ** Terminal session interface **
 			 ********************************/
 
-			Size size();
+			Size size() override;
 
-			bool avail();
+			bool avail() override;
 
 			Genode::size_t _read(Genode::size_t dst_len);
 
@@ -78,12 +78,14 @@ namespace Terminal_crosslink {
 
 			Genode::Dataspace_capability _dataspace();
 
-			void connected_sigh(Genode::Signal_context_capability sigh);
+			void connected_sigh(Genode::Signal_context_capability sigh) override;
 
-			void read_avail_sigh(Genode::Signal_context_capability sigh);
+			void read_avail_sigh(Genode::Signal_context_capability sigh) override;
 
-			Genode::size_t read(void *, Genode::size_t);
-			Genode::size_t write(void const *, Genode::size_t);
+			void size_changed_sigh(Genode::Signal_context_capability) override { }
+
+			Genode::size_t read(void *, Genode::size_t) override;
+			Genode::size_t write(void const *, Genode::size_t) override;
 	};
 
 }