gtk3 tests, tried clipping using a scrolled windew. this works but results in unwanted scrollbars.

2 files changed, 45 insertions, 3 deletions

diff --git a/README.xwidget b/README.xwidget
index 24b11286ca2..fd6c769866a 100644
--- a/README.xwidget
+++ b/README.xwidget
@@ -361,3 +361,40 @@ http://gtkplus-p3.0.sourcearchive.com/documentation/2.91.5-0ubuntu1/testoffscree
 *** firefox
 http://www-archive.mozilla.org/unix/gtk-embedding.html
 seems to be severly bitrotted
+
+** TODO clipping of controllers
+
+Emacs uses a big GTK window and does its own clipping against Emacs
+windows inside this area. So, in order to layout gtk widgets in emacs
+windows we must clip thim ourselves. 
+
+The following method worked well for a long time:
+- make a gtk widget, say a button, xw
+- make a clipping area, of type gtkfixed(many types have been tested)
+- put the clip area in the main emacs gtk window
+- figure out clip area changes during emacs redisplay
+
+the only weirdness was that one has to tell gtk the clip area has a
+window in order to get clipping. This is weird because all gtkwidgets
+are windows in a sense and a window is almost by definition also a
+clipping area.
+
+Anyway, in GTK3 the   gtk_widget_set_has_window(GTK_WIDGET (
+xv->widgetwindow), TRUE); call is ignored. 
+
+The gtkeventbox which is documented to have its own window doesnt work
+either.
+
+http://www.lanedo.com/~carlos/gtk3-doc/chap-drawing-model.html
+
+*** TODO subclass my own clipping widget
+http://www.lanedo.com/~carlos/gtk3-doc/GtkWidget.html#gtk-widget-set-has-window
+mentions that it has_window can only be called inside a widget
+impementation.
+
+*** TODO try scrolled window
+clipping does in fact work with
+gtk_scrolled_window_add_with_viewport (xv->widgetwindow, xv->widget);
+!!
+
+I get unwanted scrollbars in the widget though.
diff --git a/src/xwidget.c b/src/xwidget.c
index ea880458dc1..b612bc3b283 100644
--- a/src/xwidget.c
+++ b/src/xwidget.c
@@ -553,14 +553,16 @@ xwidget_init_view (
   //xw->widgetwindow = GTK_CONTAINER (gtk_layout_new (NULL, NULL));
   //xw->widgetwindow = GTK_CONTAINER (gtk_offscreen_window_new ());
 
-  xv->widgetwindow = GTK_CONTAINER (gtk_fixed_new ()); //works well for clipping on gtk2 not gtk3
+  //xv->widgetwindow = GTK_CONTAINER (gtk_fixed_new ()); //works well for clipping on gtk2 not gtk3
   //xv->widgetwindow = GTK_CONTAINER (gtk_event_box_new ()); //doesnt help clipping gtk3
+  xv->widgetwindow = GTK_CONTAINER (gtk_scrolled_window_new (NULL, NULL)); //doesnt help clipping gtk3
+  
   gtk_widget_set_size_request (GTK_WIDGET (xv->widgetwindow), xww->width, xww->height);
   /* GtkAllocation a; */
   /* a.x=0;  a.y=0;   a.width=xww->width;  a.height=xww->height; */
   /* gtk_widget_set_allocation (GTK_WIDGET (xv->widget), &a); */
 
-  gtk_widget_set_has_window(GTK_WIDGET (  xv->widgetwindow), TRUE);
+  //gtk_widget_set_has_window(GTK_WIDGET (  xv->widgetwindow), TRUE);
   //if gtk_fixed doesnt have a window it will surprisingly not honor
   //setsize so that children gets clipped later. the documentation is
   //not consistent regarding if its legal to call this method.
@@ -571,7 +573,10 @@ xwidget_init_view (
 
 
   //gtk_layout_set_size (GTK_LAYOUT (xw->widgetwindow), xw->width, xw->height);
-  gtk_container_add (xv->widgetwindow, xv->widget);
+  //gtk_container_add (xv->widgetwindow, xv->widget);
+
+  gtk_scrolled_window_add_with_viewport (xv->widgetwindow, xv->widget);
+
   gtk_widget_set_size_request (GTK_WIDGET (xv->widget), xww->width, xww->height);
   gtk_fixed_put (GTK_FIXED (s->f->gwfixed), GTK_WIDGET (xv->widgetwindow), x, y);
   xv->x = x;  xv->y = y;