<!
DOCTYPE HTML>
<
html>
<
head>
<
title>Test for Bug 1120705</
title>
<
script src=
"/tests/SimpleTest/SimpleTest.js"></
script>
<
script src=
"/tests/SimpleTest/EventUtils.js"></
script>
<
script type=
"text/javascript" src=
"/tests/gfx/layers/apz/test/mochitest/apz_test_utils.js"></
script>
<
link rel=
"stylesheet" type=
"text/css" href=
"/tests/SimpleTest/test.css" />
</
head>
<
body>
<p id=
"display"></p>
<
select id=
"sel">
<
option value=
"1">1</
option>
<
option value=
"2">2</
option>
<
option value=
"3">3</
option>
<
option value=
"4">4</
option>
<
option value=
"5">5</
option>
<
option value=
"6">6</
option>
<
option value=
"7">7</
option>
<
option value=
"8">8</
option>
<
option value=
"9">9</
option>
<
option value=
"10">10</
option>
<
option value=
"11">11</
option>
<
option value=
"12">12</
option>
<
option value=
"13">13</
option>
<
option value=
"14">14</
option>
<
option value=
"15">15</
option>
<
option value=
"16">16</
option>
<
option value=
"17">17</
option>
<
option value=
"18">18</
option>
<
option value=
"19">19</
option>
<
option value=
"20">20</
option>
</
select>
<
pre id=
"test">
<
script class=
"testbody" type=
"text/javascript">
function clickDownButton() {
var sel = document.getElementById(
"sel");
var scrollbar_width = sel.offsetWidth - sel.clientWidth;
synthesizeMouse(sel,
sel.offsetWidth - scrollbar_width / 2,
sel.offsetHeight - scrollbar_width / 2,
{ type:
"mousedown" });
synthesizeMouse(sel,
sel.offsetWidth - scrollbar_width / 2,
sel.offsetHeight - scrollbar_width / 2,
{ type:
"mouseup" });
}
function waitForScrollEvent(aWindow) {
return new Promise(resolve => {
aWindow.addEventListener(
"scroll", () => { SimpleTest.executeSoon(resolve); }, {once: tr
ue, capture: true});
});
}
SimpleTest.waitForExplicitFinish();
addLoadEvent(function() {
SpecialPowers.pushPrefEnv({
"set": [["general.smoothScroll", false],
["toolkit.scrollbox.verticalScrollDistance", 3]]},
async function() {
var sel = document.getElementById("sel");
sel.size = 2;
sel.scrollTo(0, 0);
await waitToClearOutAnyPotentialScrolls(window);
is(sel.scrollTop, 0, "sanity check that we start scrolling from 0");
let waitForScrolling = waitForScrollEvent(window);
clickDownButton();
await waitForScrolling;
var restricted_top = sel.scrollTop;
isnot(restricted_top, 0,
"Expected to scroll when clicking scrollbar button");
sel.size = 10;
sel.scrollTo(0, 0);
await waitToClearOutAnyPotentialScrolls(window);
is(sel.scrollTop, 0, "sanity check that we start scrolling from 0");
waitForScrolling = waitForScrollEvent(window);
clickDownButton();
await waitForScrolling;
isnot(sel.scrollTop, 0,
"Expected to scroll when clicking scrollbar button");
isnot(sel.scrollTop, restricted_top,
"Scrollbar button scrolling should be limited by page size");
SimpleTest.finish();
});
});
</script>
</pre>
</body>
</html>
