Implement INCR transfers in the clipboard.

diff --git a/st.c b/st.c
index 274ac5d..17e0a65 100644 (file)
--- a/st.c
+++ b/st.c
@@ -452,6 +452,7 @@ static void focus(XEvent *);
 static void brelease(XEvent *);
 static void bpress(XEvent *);
 static void bmotion(XEvent *);
+static void propnotify(XEvent *);
 static void selnotify(XEvent *);
 static void selclear(XEvent *);
 static void selrequest(XEvent *);
@@ -500,6 +501,11 @@ static void (*handler[LASTEvent])(XEvent *) = {
  */
 /*     [SelectionClear] = selclear, */
        [SelectionNotify] = selnotify,
+/*
+ * PropertyNotify is only turned on when there is some INCR transfer happening
+ * for the selection retrieval.
+ */
+       [PropertyNotify] = propnotify,
        [SelectionRequest] = selrequest,
 };
 
@@ -1028,21 +1034,41 @@ selcopy(Time t)
        xsetsel(getsel(), t);
 }
 
+void
+propnotify(XEvent *e)
+{
+       XPropertyEvent *xpev;
+       Atom clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);
+
+       xpev = &e->xproperty;
+       if (xpev->state == PropertyNewValue &&
+                       (xpev->atom == XA_PRIMARY ||
+                        xpev->atom == clipboard)) {
+               slenotify(e);
+       }
+}
+
 void
 selnotify(XEvent *e)
 {
        ulong nitems, ofs, rem;
        int format;
        uchar *data, *last, *repl;
-       Atom type;
-       XSelectionEvent *xsev;
+       Atom type, incratom, property;
 
        ofs = 0;
-       xsev = &e->xselection;
-       if (xsev->property == None)
-           return;
+       if (e->type == SelectionNotify) {
+               property = e->xselection.property;
+       } else if(e->type == PropertyNotify) {
+               property = e->xproperty.atom;
+       } else {
+               return;
+       }
+       if (property == None)
+               return;
+
        do {
-               if (XGetWindowProperty(xw.dpy, xw.win, xsev->property, ofs,
+               if (XGetWindowProperty(xw.dpy, xw.win, property, ofs,
                                        BUFSIZ/4, False, AnyPropertyType,
                                        &type, &format, &nitems, &rem,
                                        &data)) {
@@ -1050,6 +1076,35 @@ selnotify(XEvent *e)
                        return;
                }
 
+               if (e->type == PropertyNotify && nitems == 0 && rem == 0) {
+                       /*
+                        * If there is some PropertyNotify with no data, then
+                        * this is the signal of the selection owner that all
+                        * data has been transferred. We won't need to receive
+                        * PropertyNotify events anymore.
+                        */
+                       MODBIT(xw.attrs.event_mask, 0, PropertyChangeMask);
+                       XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
+                                       &xw.attrs);
+               }
+
+               if (type == incratom) {
+                       /*
+                        * Activate the PropertyNotify events so we receive
+                        * when the selection owner does send us the next
+                        * chunk of data.
+                        */
+                       MODBIT(xw.attrs.event_mask, 1, PropertyChangeMask);
+                       XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
+                                       &xw.attrs);
+
+                       /*
+                        * Deleting the property is the transfer start signal.
+                        */
+                       XDeleteProperty(xw.dpy, xw.win, (int)property);
+                       continue;
+               }
+
                /*
                 * As seen in getsel:
                 * Line endings are inconsistent in the terminal and GUI world
@@ -1072,6 +1127,13 @@ selnotify(XEvent *e)
                /* number of 32-bit chunks returned */
                ofs += nitems * format / 32;
        } while (rem > 0);
+
+       /*
+        * Deleting the property again tells the selection owner to send the
+        * next data chunk in the property.
+        */
+       if (e->type == PropertyNotify)
+               XDeleteProperty(xw.dpy, xw.win, (int)property);
 }
 
 void