<div dir="ltr"><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt" id="gmail-docs-internal-guid-52f25365-7fff-1884-20c9-5b7d531c6a4f"><font size="2"><span style="font-family:"Open Sans",sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Hi folks,</span></font></p><font size="2"><br></font><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><font size="2"><span style="font-family:"Open Sans",sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">I'm planning to remove the XUL `mousethrough` attribute in</span><a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1597120" style="text-decoration:none"><span style="font-family:"Open Sans",sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"> </span><span style="font-family:"Open Sans",sans-serif;color:rgb(17,85,204);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:underline;vertical-align:baseline;white-space:pre-wrap">bug 1597120</span></a><span style="font-family:"Open Sans",sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">. This was used to allow a certain layout frame to ignore mouse events and forward them to the element underneath it. Unfortunately, it came with some behavior that was under-documented. It can also now be replaced with the CSS `pointer-events` property.</span></font></p><font size="2"><br></font><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><font size="2"><span style="font-family:"Open Sans",sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">It is also currently the only way to make popups that ignore mouse events. This functionality will be achievable afterwards by setting `pointer-events: none` on the relevant popup.</span></font></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><font size="2"><span style="font-family:"Open Sans",sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap"><br></span></font></p><p style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><font size="2"><span style="font-family:"Open Sans",sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Please let me know if you have any questions or concerns.<br></span></font></p><font size="2"><br></font><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><font size="2"><span style="font-family:"Open Sans",sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Cheers,</span></font></p><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt"><font size="2"><span style="font-family:"Open Sans",sans-serif;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre-wrap">Tim</span></font></p><br><br></div>