From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Wed, 14 Oct 2020 00:38:12 +0000 (+0100)
Subject: log scroll to bottom, try to defend against rounding error
X-Git-Tag: otter-0.2.0~653
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=01d593323ec755c2f62bbaa33e6b73fd1d4883e0;p=otter.git

log scroll to bottom, try to defend against rounding error

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/templates/script.ts b/templates/script.ts
index 5b83cb8d..64207a86 100644
--- a/templates/script.ts
+++ b/templates/script.ts
@@ -790,10 +790,12 @@ function add_log_message(msg_html: string) {
     // rejected
       //   https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API
       (() => {
+	let le_top = lastent.getBoundingClientRect()!.top;
 	let le_bot = lastent.getBoundingClientRect()!.bottom;
 	let ld_bot = logdiv.getBoundingClientRect()!.bottom;
-	console.log("ADD_LOG_MESSAGE bboxes: le, bb", le_bot, ld_bot);
-	return le_bot > ld_bot;
+	console.log("ADD_LOG_MESSAGE bboxes: le t b, bb",
+		    le_top, le_bot, ld_bot);
+	return 0.5 * (le_bot + le_top) > ld_bot;
       })();
 
   console.log('ADD LOG MESSAGE ',in_scrollback, msg_html);