From a9bc337202ac7614821958063c5cec51e16dd48c Mon Sep 17 00:00:00 2001
From: Mattias Andrée <maandree@kth.se>
Date: Fri, 9 Apr 2021 22:47:17 +0200
Subject: Add libterminput_is_ready
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Signed-off-by: Mattias Andrée <maandree@kth.se>
---
 Makefile                |  3 ++-
 TODO                    |  1 -
 libterminput.7          |  4 ++++
 libterminput.c          |  3 +++
 libterminput.h          | 10 +++++++++
 libterminput_is_ready.3 | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
 libterminput_read.3     |  1 +
 7 files changed, 76 insertions(+), 2 deletions(-)
 create mode 100644 libterminput_is_ready.3

diff --git a/Makefile b/Makefile
index 10796c5..763a966 100644
--- a/Makefile
+++ b/Makefile
@@ -58,7 +58,7 @@ install: libterminput.a libterminput.$(LIBEXT)
 	cp -- libterminput.$(LIBEXT) "$(DESTDIR)$(PREFIX)/lib/libterminput.$(LIBMINOREXT)"
 	ln -sf -- libterminput.$(LIBMINOREXT) "$(DESTDIR)$(PREFIX)/lib/libterminput.$(LIBMAJOREXT)"
 	ln -sf -- libterminput.$(LIBMAJOREXT) "$(DESTDIR)$(PREFIX)/lib/libterminput.$(LIBEXT)"
-	cp -- libterminput_read.3 libterminput_set_flags.3 "$(DESTDIR)$(MANPREFIX)/man3"
+	cp -- libterminput_read.3 libterminput_set_flags.3 libterminput_is_ready.3 "$(DESTDIR)$(MANPREFIX)/man3"
 	ln -sf -- libterminput_set_flags.3 "$(DESTDIR)$(MANPREFIX)/man3/libterminput_clear_flags.3"
 	cp -- libterminput.7 "$(DESTDIR)$(MANPREFIX)/man7"
 
@@ -71,6 +71,7 @@ uninstall:
 	-rm -f -- "$(DESTDIR)$(MANPREFIX)/man3/libterminput_read.3"
 	-rm -f -- "$(DESTDIR)$(MANPREFIX)/man3/libterminput_set_flags.3"
 	-rm -f -- "$(DESTDIR)$(MANPREFIX)/man3/libterminput_clear_flags.3"
+	-rm -f -- "$(DESTDIR)$(MANPREFIX)/man3/libterminput_is_ready.3"
 	-rm -f -- "$(DESTDIR)$(MANPREFIX)/man7/libterminput.7"
 
 clean:
diff --git a/TODO b/TODO
index 3c37d72..50b03d9 100644
--- a/TODO
+++ b/TODO
@@ -1,3 +1,2 @@
-Add libterminput_is_ready()
 Add cursor position report support
 Add test
diff --git a/libterminput.7 b/libterminput.7
index db4c751..d56a6d3 100644
--- a/libterminput.7
+++ b/libterminput.7
@@ -13,6 +13,9 @@ libterminput provides the following functions:
 .BR libterminput_read (3)
 Read and parse input from the terminal.
 .TP
+.BR libterminput_is_ready (3)
+Check if there is read data buffered.
+.TP
 .BR libterminput_set_flags (3)
 Add input parsing flags.
 .TP
@@ -20,5 +23,6 @@ Add input parsing flags.
 Remove input parsing flags.
 
 .SH SEE ALSO
+.BR libterminput_is_ready (3),
 .BR libterminput_read (3),
 .BR libterminput_set_flags (3)
diff --git a/libterminput.c b/libterminput.c
index 7ca36de..147e756 100644
--- a/libterminput.c
+++ b/libterminput.c
@@ -888,3 +888,6 @@ libterminput_clear_flags(struct libterminput_state *ctx, enum libterminput_flags
 	ctx->flags ^= flags;
 	return 0;
 }
+
+
+extern inline int libterminput_is_ready(union libterminput_input *input, struct libterminput_state *ctx);
diff --git a/libterminput.h b/libterminput.h
index 45ac2a4..0182a54 100644
--- a/libterminput.h
+++ b/libterminput.h
@@ -183,6 +183,16 @@ struct libterminput_state {
  */
 int libterminput_read(int fd, union libterminput_input *input, struct libterminput_state *ctx);
 
+inline int
+libterminput_is_ready(union libterminput_input *input, struct libterminput_state *ctx)
+{
+	if (!ctx->inited)
+		return 0;
+	if (input->type == LIBTERMINPUT_KEYPRESS && input->keypress.times > 1)
+		return 1;
+	return ctx->stored_head > ctx->stored_tail;
+}
+
 int libterminput_set_flags(struct libterminput_state *ctx, enum libterminput_flags flags);
 int libterminput_clear_flags(struct libterminput_state *ctx, enum libterminput_flags flags);
 
diff --git a/libterminput_is_ready.3 b/libterminput_is_ready.3
new file mode 100644
index 0000000..293d60e
--- /dev/null
+++ b/libterminput_is_ready.3
@@ -0,0 +1,56 @@
+.TH LIBTERMINPUT_IS_READY 3 LIBTERMINPUT
+.SH NAME
+libterminput_is_ready \- Check if there is read data buffered
+
+.SH SYNOPSIS
+.nf
+#include <libterminput.h>
+
+inline int libterminput_is_ready(union libterminput_input *input, struct libterminput_state *ctx);
+.fi
+.PP
+Link with
+.IR \-lterminput .
+
+.SH DESCRIPTION
+The
+.BR libterminput_is_ready ()
+function check if a call to the
+.BR libterminput_read (3)
+function will skip reading from the file
+descriptor passed to it because it already
+has read data buffered.
+
+.SH RETURN VALUE
+The
+.BR libterminput_is_ready ()
+function return 1 if the next call to the
+.BR libterminput_read (3)
+function will not from file descriptor
+passed to it, and 0 otherwise.
+
+.SH ERRORS
+The
+.BR libterminput_is_ready ()
+function cannot fail.
+
+.SH EXAMPLES
+None.
+
+.SH APPLICATION USAGE
+None.
+
+.SH RATIONALE
+None.
+
+.SH FUTURE DIRECTIONS
+None.
+
+.SH NOTES
+None.
+
+.SH BUGS
+None.
+
+.SH SEE ALSO
+.BR libterminput_read (3)
diff --git a/libterminput_read.3 b/libterminput_read.3
index 904342c..2cf401b 100644
--- a/libterminput_read.3
+++ b/libterminput_read.3
@@ -433,4 +433,5 @@ None.
 None.
 
 .SH SEE ALSO
+.BR libterminput_is_ready (3),
 .BR libterminput_set_flags (3)
-- 
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