Update of /project/cells-gtk/cvsroot/public_html In directory common-lisp.net:/tmp/cvs-serv17298/public_html
Modified Files: faq.html Log Message: New questions and answers. Date: Sat Oct 8 17:03:29 2005 Author: pdenno
Index: public_html/faq.html diff -u public_html/faq.html:1.10 public_html/faq.html:1.11 --- public_html/faq.html:1.10 Mon Oct 3 16:43:46 2005 +++ public_html/faq.html Sat Oct 8 17:03:29 2005 @@ -36,6 +36,7 @@ <li><a href="#q6">What GTK Widgets are implemented in cells-gtk?</a></li> <li><a href="#q7">Do I have to use cells?</a></li> <li><a href="#q8">What is libcellsgtk.so about?</a></li> + <li><a href="#q8.4">What is in libcellsgtk.so?</a></li> <li><a href="#q8.5">What is the difference between using c-input (AKA c-in) and c-formula (AKA c?) in a slot's :initform?</a></li> <li><a href="#q9">Why do I need :owner here? It looks like c? would bind self to the mk-whatever @@ -46,7 +47,7 @@ <li><a href="#q12">Changing a cell value causes dependencies to fire, but what is considered a change?</li> <li><a href="#q13">Can I keep a window around for redisplay after using the window border 'delete' button to delete it?</a></li> - + <li><a href="#q14">Can I use streams with a TextView widget?</a></li> </ul>
<p/> @@ -205,17 +206,30 @@ the libgtk.so you are using.
<p/> +<strong id="q8.4">Q: What is in libcellsgtk.so?</strong><p/> +<strong>A:</strong>For details look at the source gtk-ffi/gtk-adds.c, but generally: +<ul> + <li>Get a dialog's vbox (so that you can add children to it).</li> + <li>Get the popup menu of a textview</li> + <li>Allocate text iters and tree iters</li> + <li>Check whether or not a widget is mapped and visible</li> + <li>Get the window of a widget (useful for DrawingArea).</li> + <li>Allocate GdkColor objects</li> + <li>Set the RGB values of GdkColor objects.</li> +</ul>
<p/> <strong id="q8.5">Q: What is the difference between using c-input (AKA c-in) and c-formula (AKA c?) in a slot's :initform ?</strong><p/> <strong>A:</strong>The two define different kinds of cells:<br/> A c-input cell is a cell whose value may be set through explicit procedural code, using setf on the slot. +Note: When the cell is referenced by other cells in a cells constraint network, setf-ing the cell +causes the values of other cells to be recomputed. <br/> A c-formula cell is a cell whose value is obtained through evaluation of a formula. <br/> Note that the usual semantics of :initform do not apply when :initform is given by c-formula. -Instead of just setting the value at initialization, the c-formula (an arbitrary lisp form) +Instead of just setting the value at initialization, the c-formula (generated from the supplied lisp form) specifies the dynamic relationship between the slot's value and other aspects of the program state. <p/>
@@ -266,8 +280,9 @@ <p/> <strong id="q11">Q: What does this error mean? : "cellular slot FOO of #<BAR 21B555A4> cannot be setf unless initialized as inputp."</strong><p/> - <strong>A:</strong> This error is signalled because you tried to setf an invariant slot. - 'inputp' refers to c-in which should have been used to initialize the slot. + <strong>A:</strong>This error is signalled because you tried to setf a c-formula slot. + 'inputp' refers to c-input (declaration of an input cell) which should have been used + to initialize the slot. Read the <a href="cgtk-primer.html">cells-gtk primer</a> for more information. <p/> @@ -295,12 +310,66 @@ ... and, of course, store the widget somewhere so you can later display it with (gtk-widget-show-all (widget-id my-pseudo-dialog)).
+<p/> + +<strong id="q14">Q:Can I use streams with a TextView widget?</strong><p/> + <strong>A:</strong>Sure. Do something like this: + +<pre> +(defmethod initialize-instance :after ((self your-gtk-app) &key) + (let ((message-textview [wherever it is])) + (setf *message-stream* + (make-instance 'pane-stream + :buffer (buffer message-textview) + :view message-textview)))) + +(defclass pane-stream (stream:fundamental-character-output-stream) + ((view :initarg :view) + (buffer :initarg :buffer) + (mark :initarg :mark) + (offset :initform 0 :accessor offset))) + +(defmethod initialize-instance :after ((self pane-stream) &key) + (with-slots (buffer mark view) self + (let ((b (widget-id buffer)) + (v (widget-id view))) + (with-text-iters (iter) + (cgtk:gtk-text-buffer-get-iter-at-offset b iter 0) + (setf mark (cgtk:gtk-text-buffer-create-mark b "visibility" iter t))) + (cgtk:gtk-text-view-set-wrap-mode v 1) ; optional, of course. + (cgtk:gtk-text-view-set-editable v nil)))) ; also optional. + +; Some lisps might not need this one. Some might need other methods. +(defmethod stream:stream-line-column ((s pane-stream)) nil) + +(defmethod stream:stream-write-char ((s pane-stream) (c character)) + (with-slots (view buffer offset mark) s + (cgtk:text-buffer-insert-text buffer offset (string c)) + (incf offset) + (let ((buf (widget-id buffer))) + (with-text-iters (iter) + (cgtk:gtk-text-buffer-get-iter-at-offset buf iter offset) + (cgtk:gtk-text-buffer-move-mark buf mark iter) + (cgtk:gtk-text-view-scroll-mark-onscreen (cgtk::id view) mark ))))) + +(defmethod stream:stream-write-string ((s pane-stream) string &optional start end) + (with-slots (view buffer offset mark) s + (cgtk:text-buffer-insert-text buffer offset string) + (incf offset (length string)) + (let ((buf (widget-id buffer))) + (with-text-iters (iter) + (cgtk:gtk-text-buffer-get-iter-at-offset buf iter offset) + (cgtk:gtk-text-buffer-move-mark buf mark iter) + (cgtk:gtk-text-view-scroll-mark-onscreen (widget-id view) mark))))) + +</pre> +
<hr/> <address><a href="mailto:peter.denno@nist.gov">Peter Denno</a></address> <!-- Created: Thu Mar 3 18:45:35 EST 2005 --> <!-- hhmts start --> -Last modified: Sun Mar 6 18:32:15 EST 2005 +Last modified: 2005-10-08 <!-- hhmts end --> </div> </body>
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