Add bindings for text input event handling.

* sdl2/bindings.scm (sdl-start-text-input, sdl-stop-text-input,
sdl-is-text-input-active): New procedures.
* sdl2/events.scm (<text-input-event>): New record type.
(make-text-input-event, text-input-event?, text-input-event-timestamp,
text-input-event-window-id, text-input-event-text,
parse-text-input-event): New procedures.
* sdl2/input/text.scm: New file.
* Makefile.am (SOURCES): Add it.

3 files changed, 89 insertions, 2 deletions

diff --git a/sdl2/bindings.scm b/sdl2/bindings.scm
index e3167a0..e48ce64 100644
--- a/sdl2/bindings.scm
+++ b/sdl2/bindings.scm
@@ -1,5 +1,5 @@
 ;;; guile-sdl2 --- FFI bindings for SDL2
-;;; Copyright © 2015 David Thompson <davet@gnu.org>
+;;; Copyright © 2015, 2016 David Thompson <davet@gnu.org>
 ;;;
 ;;; This file is part of guile-sdl2.
 ;;;
@@ -817,6 +817,20 @@ RETURN-TYPE and accept arguments of ARG-TYPES."
 
 
 ;;;
+;;; Text Input
+;;;
+
+(define-foreign sdl-start-text-input
+  void "SDL_StartTextInput" '())
+
+(define-foreign sdl-stop-text-input
+  void "SDL_StopTextInput" '())
+
+(define-foreign sdl-is-text-input-active
+  sdl-bool "SDL_IsTextInputActive" '())
+
+
+;;;
 ;;; Mouse
 ;;;
 
diff --git a/sdl2/events.scm b/sdl2/events.scm
index aa08fff..c9e391b 100644
--- a/sdl2/events.scm
+++ b/sdl2/events.scm
@@ -1,5 +1,5 @@
 ;;; guile-sdl2 --- FFI bindings for SDL2
-;;; Copyright © 2015 David Thompson <davet@gnu.org>
+;;; Copyright © 2015, 2016 David Thompson <davet@gnu.org>
 ;;;
 ;;; This file is part of guile-sdl2.
 ;;;
@@ -70,6 +70,12 @@
             keyboard-event-scancode
             keyboard-event-modifiers
 
+            make-text-input-event
+            text-input-event?
+            text-input-event-timestamp
+            text-input-event-window-id
+            text-input-event-text
+
             make-mouse-button-event
             mouse-button-event?
             mouse-button-down-event?
@@ -812,6 +818,28 @@
 
 
 ;;;
+;;; Text Input
+;;;
+
+(define-record-type <text-input-event>
+  (make-text-input-event timestamp window-id text)
+  text-input-event?
+  (timestamp text-input-event-timestamp)
+  (window-id text-input-event-window-id)
+  (text text-input-event-text))
+
+(define (parse-text-input-event ptr)
+  ;; Separate the first 3 struct fields which are all uint32s from the
+  ;; 32-byte UTF-8 encoded character buffer at the end of the struct.
+  (let* ((len (* (sizeof uint32) 3))
+         (bv (pointer->bytevector ptr len))
+         (timestamp (u32vector-ref bv 1))
+         (window-id (u32vector-ref bv 2))
+         (text (pointer->string (make-pointer (+ (pointer-address ptr) len)))))
+    (make-text-input-event timestamp window-id text)))
+
+
+;;;
 ;;; Mouse
 ;;;
 
@@ -991,6 +1019,8 @@
             ((or (= type ffi:SDL_KEYDOWN)
                  (= type ffi:SDL_KEYUP))
              (parse-keyboard-event ptr))
+            ((= type ffi:SDL_TEXTINPUT)
+             (parse-text-input-event ptr))
             ((or (= type ffi:SDL_MOUSEBUTTONDOWN)
                  (= type ffi:SDL_MOUSEBUTTONUP))
              (parse-mouse-button-event ptr))
diff --git a/sdl2/input/text.scm b/sdl2/input/text.scm
new file mode 100644
index 0000000..ea441d5
--- /dev/null
+++ b/sdl2/input/text.scm
@@ -0,0 +1,43 @@
+;;; guile-sdl2 --- FFI bindings for SDL2
+;;; Copyright © 2016 David Thompson <davet@gnu.org>
+;;;
+;;; This file is part of guile-sdl2.
+;;;
+;;; Guile-sdl2 is free software; you can redistribute it and/or modify
+;;; it under the terms of the GNU Lesser General Public License as
+;;; published by the Free Software Foundation; either version 3 of the
+;;; License, or (at your option) any later version.
+;;;
+;;; Guile-sdl2 is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;; General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU Lesser General Public
+;;; License along with guile-sdl2.  If not, see
+;;; <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; Unicode text input.
+;;
+;;; Code:
+
+(define-module (sdl2 input text)
+  #:use-module (system foreign)
+  #:use-module ((sdl2 bindings) #:prefix ffi:)
+  #:export (start-text-input
+            stop-text-input
+            text-input-active?))
+
+(define (start-text-input)
+  "Enable text input events."
+  (ffi:sdl-start-text-input))
+
+(define (stop-text-input)
+  "Disable text input events."
+  (ffi:sdl-stop-text-input))
+
+(define (text-input-active?)
+  "Return #t if text input events are enabled."
+  (= (ffi:sdl-is-text-input-active) 1))