port of EQL/Qt4 to Qt5

examples/9-simple-lisp-editor/input-hook.lisp

@@ -0,0 +1,59 @@
+;;; idea & most code from "ecl-readline.lisp"
+
+(defpackage input-hook
+    (:use :common-lisp)
+  (:export
+   #:new))
+
+(provide :input-hook)
+
+(in-package :input-hook)
+
+(defvar *functions* nil)
+
+(defun new (function)
+  (let ((stream (make-instance 'gray::input-hook-stream)))
+    (push (cons stream function) *functions*)
+    stream))
+
+(in-package :gray)
+
+(defclass input-hook-stream (fundamental-character-input-stream)
+  ((in-buffer  :initform (make-string 0))
+   (in-index   :initform 0)
+   (out-buffer :initform (make-array 0 :element-type 'character :adjustable t :fill-pointer t))))
+
+(defmethod stream-read-char ((stream input-hook-stream))
+  (if (ensure-stream-data stream)
+      (with-slots (in-buffer in-index) stream
+        (let ((ch (char in-buffer in-index)))
+          (incf in-index)
+          ch))
+      :eof))
+
+(defmethod stream-unread-char ((stream input-hook-stream) character)
+  (with-slots (in-index) stream
+    (when (> in-index 0)
+      (decf in-index))))
+
+(defmethod stream-listen ((stream input-hook-stream))
+  nil)
+
+(defmethod stream-clear-input ((stream input-hook-stream))
+  nil)
+
+(defmethod stream-close ((stream input-hook-stream) &key abort)
+  (call-next-method))
+
+(defmethod stream-peek-char ((stream input-hook-stream))
+  (if (ensure-stream-data stream)
+      (with-slots (in-buffer in-index) stream
+        (char in-buffer in-index))
+      :eof))
+
+(defun ensure-stream-data (stream)
+  (with-slots (in-buffer in-index) stream
+    (when (= in-index (length in-buffer))
+      (setf in-buffer (funcall (cdr (assoc stream input-hook::*functions*)))
+            in-index 0))
+    in-buffer))