From 281406e3f0b3780b80440ef2e23ef4c732df2667 Mon Sep 17 00:00:00 2001
From: Jonathan Wilkes <jon.w.wilkes@gmail.com>
Date: Mon, 23 Oct 2017 23:45:10 -0400
Subject: [PATCH] throttle the Pd window scrollbar to prevent layout thrashing
---
pd/nw/pdgui.js | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/pd/nw/pdgui.js b/pd/nw/pdgui.js
index 277517292..ddf9f6e0d 100644
--- a/pd/nw/pdgui.js
+++ b/pd/nw/pdgui.js
@@ -491,6 +491,20 @@ function set_audioapi(val) {
pd_whichapi = val;
}
+var throttle_console_scroll = (function() {
+ var scroll_delay;
+ return function() {
+ if (!scroll_delay) {
+ scroll_delay = setTimeout(function() {
+ var printout = pd_window.document
+ .getElementById("console_bottom");
+ printout.scrollTop = printout.scrollHeight;
+ scroll_delay = undefined;
+ }, 30);
+ }
+ }
+}());
+
// Hmm, probably need a closure here...
var current_string = "";
var last_string = "";
@@ -518,13 +532,14 @@ function do_post(string, type) {
text = pd_window.document.createTextNode(current_string);
span.appendChild(text);
myp.appendChild(span);
- printout = pd_window.document.getElementById("console_bottom");
- printout.scrollTop = printout.scrollHeight;
last_string = current_string;
current_string = "";
last_child = span;
last_object_id = "";
duplicate = 0;
+ // update the scrollbars to the bottom, but throttle it
+ // since it is expensive
+ throttle_console_scroll();
}
}
}
@@ -5234,7 +5249,7 @@ function canvas_params(cid)
}
function do_getscroll(cid) {
- // Since we're debouncing these getscroll calls, they can happen after
+ // Since we're throttling these getscroll calls, they can happen after
// the patch has been closed. We remove the cid from the patchwin
// object on close, so we can just check to see if our Window object has
// been set to null, and if so just return.
--
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