# HG changeset patch
# User Adam Chlipala <adam@chlipala.net>
# Date 1315764889 14400
# Node ID df6a7a22760aa26e82fcb676b9e588d0216b4428
# Parent  6fe6bda2b92858c766da56e1ef1d865c37857299
New Basis functions: preventDefault and stopPropagation (code contributed by Vladimir Shabanov)

diff -r 6fe6bda2b928 -r df6a7a22760a doc/manual.tex
--- a/doc/manual.tex	Sun Sep 11 11:37:26 2011 -0400
+++ b/doc/manual.tex	Sun Sep 11 14:14:49 2011 -0400
@@ -1983,6 +1983,13 @@
  \mt{val} \; \mt{onMouseup} : \mt{transaction} \; \mt{unit} \to \mt{transaction} \; \mt{unit}
 \end{array}$$
 
+Versions of standard JavaScript functions are provided that event handlers may call to mask default handling or prevent bubbling of events up to parent DOM nodes, respectively.
+
+$$\begin{array}{l}
+  \mt{val} \; \mt{preventDefault} : \mt{transaction} \; \mt{unit} \\
+  \mt{val} \; \mt{stopPropagation} : \mt{transaction} \; \mt{unit}
+\end{array}$$
+
 \subsubsection{Node IDs}
 
 There is an abstract type of node IDs that may be assigned to \cd{id} attributes of most HTML tags.
diff -r 6fe6bda2b928 -r df6a7a22760a lib/js/urweb.js
--- a/lib/js/urweb.js	Sun Sep 11 11:37:26 2011 -0400
+++ b/lib/js/urweb.js	Sun Sep 11 14:14:49 2011 -0400
@@ -215,9 +215,9 @@
 function uw_handler(name, f) {
     var old = document[name];
     if (old == undefined)
-        document[name] = function() { execF(f); return false; };
+        document[name] = function(event) { uw_event = event; execF(f); };
     else
-        document[name] = function() { old(); execF(f); return false; };
+        document[name] = function(event) { uw_event = event; old(); execF(f); };
 }
 
 function uw_onClick(f) {
@@ -239,9 +239,9 @@
 function uw_keyHandler(name, f) {
     var old = document[name];
     if (old == undefined)
-        document[name] = function(event) { uw_event = event; execF(execF(f, kc())); return false; };
+        document[name] = function(event) { uw_event = event; execF(execF(f, kc())); };
     else
-        document[name] = function(event) { uw_event = event; old(); execF(execF(f, kc())); return false; };
+        document[name] = function(event) { uw_event = event; old(); execF(execF(f, kc())); };
 }
 
 function uw_onKeydown(f) {
@@ -256,6 +256,19 @@
     uw_keyHandler("onkeyup", f);
 }
 
+// Cancelling of further event processing
+
+function uw_preventDefault() {
+    var e = window.event ? window.event : uw_event;
+    e.returnValue = false;
+    if (e.preventDefault) e.preventDefault();
+}
+
+function uw_stopPropagation() {
+    var e = window.event ? window.event : uw_event;
+    e.cancelBubble = true;
+    if (e.stopPropagation) e.stopPropagation();
+}
 
 // Embedding closures in XML strings
 
diff -r 6fe6bda2b928 -r df6a7a22760a lib/ur/basis.urs
--- a/lib/ur/basis.urs	Sun Sep 11 11:37:26 2011 -0400
+++ b/lib/ur/basis.urs	Sun Sep 11 14:14:49 2011 -0400
@@ -870,6 +870,11 @@
 val onMousedown : transaction unit -> transaction unit
 val onMouseup : transaction unit -> transaction unit
 
+(* Prevents default handling of current event *)
+val preventDefault : transaction unit
+(* Stops propagation of current event *)
+val stopPropagation : transaction unit
+
 val show_xml : ctx ::: {Unit} -> use ::: {Type} -> bind ::: {Type} -> show (xml ctx use bind)
 
 
diff -r 6fe6bda2b928 -r df6a7a22760a src/settings.sml
--- a/src/settings.sml	Sun Sep 11 11:37:26 2011 -0400
+++ b/src/settings.sml	Sun Sep 11 14:14:49 2011 -0400
@@ -156,6 +156,8 @@
                         "onKeyup",
                         "onMousedown",
                         "onMouseup",
+                        "preventDefault",
+                        "stopPropagation",
                         "fresh"]
 
 val benign = ref benignBase
@@ -182,7 +184,9 @@
                         "onKeypress",
                         "onKeyup",
                         "onMousedown",
-                        "onMouseup"]
+                        "onMouseup",
+                        "preventDefault",
+                        "stopPropagation"]
 val client = ref clientBase
 fun setClientOnly ls = client := S.addList (clientBase, ls)
 fun isClientOnly x = S.member (!client, x)
@@ -280,6 +284,8 @@
                           ("onKeyup", "uw_onKeyup"),
                           ("onMousedown", "uw_onMousedown"),
                           ("onMouseup", "uw_onMouseup"),
+                          ("preventDefault", "uw_preventDefault"),
+                          ("stopPropagation", "uw_stopPropagation"),
 
                           ("fresh", "fresh")]
 val jsFuncs = ref jsFuncsBase