allow <CTRL/C> to be typed; aborts last typed char

 * CTRL/C will be a command so it is important to be able to type it directly
 * aborting character processing is important because it allows aborting infinite loops
 * since the loop interruption currently relies on SIGINT handling, there is only limited
   support for XCurses and GTK - CTRL/C has to be typed in the terminal window.
   later support for input queue polling might be added

5 files changed, 42 insertions, 2 deletions

diff --git a/src/interface-ncurses.cpp b/src/interface-ncurses.cpp
index 97c050d..98f2dca 100644
--- a/src/interface-ncurses.cpp
+++ b/src/interface-ncurses.cpp
@@ -43,7 +43,7 @@ InterfaceNCurses interface;
 
 extern "C" {
 static void scintilla_notify(Scintilla *sci, int idFrom,
-			     void *notify, void *user_data);
+			    void *notify, void *user_data);
 }
 
 #define UNNAMED_FILE "(Unnamed)"
@@ -63,7 +63,6 @@ static void scintilla_notify(Scintilla *sci, int idFrom,
 InterfaceNCurses::InterfaceNCurses()
 {
 	init_screen();
-	raw();
 	cbreak();
 	noecho();
 	curs_set(0); /* Scintilla draws its own cursor */
@@ -368,7 +367,12 @@ InterfaceNCurses::event_loop(void)
 		if (popup.window)
 			wrefresh(popup.window);
 
+		/* no special <CTRL/C> handling */
+		raw();
 		key = wgetch(cmdline_window);
+		/* allow asynchronous interruptions on <CTRL/C> */
+		cbreak();
+
 		switch (key) {
 #ifdef KEY_RESIZE
 		case ERR:
@@ -403,6 +407,8 @@ InterfaceNCurses::event_loop(void)
 			if (key <= 0xFF)
 				cmdline_keypress((gchar)key);
 		}
+
+		sigint_occurred = FALSE;
 	}
 }
 
diff --git a/src/interface.h b/src/interface.h
index 28be9fe..38cd725 100644
--- a/src/interface.h
+++ b/src/interface.h
@@ -19,6 +19,7 @@
 #define __INTERFACE_H
 
 #include <stdarg.h>
+#include <signal.h>
 
 #include <glib.h>
 
@@ -29,6 +30,7 @@
 /* avoid include dependency conflict */
 class QRegister;
 class Buffer;
+extern sig_atomic_t sigint_occurred;
 
 /*
  * Base class for all user interfaces - used mereley as a class interface.
@@ -107,6 +109,12 @@ public:
 	virtual void popup_show(void) = 0;
 	virtual void popup_clear(void) = 0;
 
+	virtual inline bool
+	is_interrupted(void)
+	{
+		return sigint_occurred != FALSE;
+	}
+
 	/* main entry point */
 	virtual void event_loop(void) = 0;
 
diff --git a/src/main.cpp b/src/main.cpp
index 2adb505..f5cd780 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -23,6 +23,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <signal.h>
 
 #include <glib.h>
 #include <glib/gprintf.h>
@@ -51,6 +52,12 @@ namespace Flags {
 
 static gchar *mung_file = NULL;
 
+sig_atomic_t sigint_occurred = FALSE;
+
+extern "C" {
+static void sigint_handler(int signal);
+}
+
 void
 Interface::stdio_vmsg(MessageType type, const gchar *fmt, va_list ap)
 {
@@ -160,6 +167,8 @@ main(int argc, char **argv)
 	static GotoTable	cmdline_goto_table;
 	static QRegisterTable	local_qregs;
 
+	signal(SIGINT, sigint_handler);
+
 	process_options(argc, argv);
 
 	interface.ssm(SCI_SETCARETSTYLE, CARETSTYLE_BLOCK);
@@ -213,3 +222,13 @@ main(int argc, char **argv)
 
 	return 0;
 }
+
+/*
+ * Callbacks
+ */
+
+static void
+sigint_handler(int signal __attribute__((unused)))
+{
+	sigint_occurred = TRUE;
+}
diff --git a/src/parser.cpp b/src/parser.cpp
index 1843b1d..658dbe5 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -79,6 +79,9 @@ Execute::step(const gchar *macro) throw (State::Error)
 			 States::current, mode);
 #endif
 
+		if (interface.is_interrupted())
+			throw State::Error("Interrupted");
+
 		State::input(macro[macro_pc]);
 		macro_pc++;
 	}
diff --git a/src/sciteco.h b/src/sciteco.h
index 92014e2..a03c1d5 100644
--- a/src/sciteco.h
+++ b/src/sciteco.h
@@ -18,6 +18,8 @@
 #ifndef __SCITECO_H
 #define __SCITECO_H
 
+#include <signal.h>
+
 #include <glib.h>
 
 #include "interface.h"
@@ -30,6 +32,8 @@ namespace Flags {
 	extern gint64 ed;
 }
 
+extern sig_atomic_t sigint_occurred;
+
 extern gchar *cmdline;
 extern bool quit_requested;