Implement form-sizing behavior for <select>
* Drop down:
The width depends on the selected OPTION label, instead of the maximum
width of all OPTION labels.
* List box:
The height depends on the total height of OPTION labels, instead of
the 'size' attribute value.
They have zero content height if there are no OPTIONs.
Bug: 1447058
Change-Id: I16cfb423a8caa776e2c6df1b0bd1bf82413c1447
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4893426
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1201354}
diff --git a/html/rendering/widgets/form-sizing-select.tentative.html b/html/rendering/widgets/form-sizing-select.tentative.html
new file mode 100644
index 0000000..f9efdc7
--- /dev/null
+++ b/html/rendering/widgets/form-sizing-select.tentative.html
@@ -0,0 +1,87 @@
+<!DOCTYPE html>
+<link rel="help" href="https://github.com/w3c/csswg-drafts/pull/9251">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<body>
+<style>
+.disable-default {
+ form-sizing: normal;
+}
+</style>
+<div id="container"></div>
+<script>
+const container = document.querySelector('#container');
+const DISABLE = 'class="disable-default"';
+
+// Tests for drop-down box ====================================================
+
+test(() => {
+ const s = '<select>><option>1<option>quick brown<option>fox</select>';
+ container.innerHTML = s + s;
+ container.lastElementChild.style.formSizing = 'normal';
+ const widthForContent1 = container.lastElementChild.offsetWidth;
+ assert_greater_than(container.firstElementChild.offsetWidth,
+ widthForContent1);
+ container.lastElementChild.selectedIndex = 1;
+ const widthForContentQuickBrown = container.lastElementChild.offsetWidth;
+ assert_greater_than(widthForContentQuickBrown, widthForContent1);
+}, 'dropdown: The width should depend on the selected OPTION');
+
+test(() => {
+ container.innerHTML = '<select><option>foo<option>quick brown fox</select>';
+ const select = container.firstElementChild;
+ const initialWidth = select.offsetWidth;
+ select.style.formSizing = 'normal';
+ assert_less_than(select.offsetWidth, initialWidth);
+ select.style.formSizing = 'auto';
+ assert_equals(select.offsetWidth, initialWidth);
+}, 'dropdown: Change the form-sizing value dynamically');
+
+// Tests for list box =========================================================
+
+// Some paltforms don't support list box rendering.
+container.innerHTML = '<select></select><select multiple></select>';
+if (container.firstElementChild.offsetHeight != container.lastElementChild.offsetHeight) {
+
+ test(() => {
+ container.innerHTML = `<select multiple><option>fox</select>` +
+ `<select multiple ${DISABLE}><option>fox</select>`;
+ const former = container.firstElementChild;
+ const latter = container.lastElementChild;
+ const widthForOneItem = latter.offsetWidth;
+ const heightForOneItem = latter.offsetHeight;
+ assert_equals(former.offsetWidth, widthForOneItem);
+ assert_greater_than(former.offsetHeight, heightForOneItem);
+
+ latter.add(new Option('quick brown'));
+ assert_greater_than(latter.offsetWidth, widthForOneItem);
+ assert_greater_than(latter.offsetHeight, heightForOneItem);
+ }, 'listbox: The size depend on the content');
+
+ test(() => {
+ container.innerHTML = `<select size="4"></select><select size="4" ${DISABLE}></select>`;
+ const former = container.firstElementChild;
+ const latter = container.lastElementChild;
+ const widthForZeroItem = latter.offsetWidth;
+ const heightForZeroItem = latter.offsetHeight;
+ assert_equals(former.offsetWidth, widthForZeroItem);
+ assert_greater_than(former.offsetHeight, heightForZeroItem);
+
+ latter.add(new Option('quick brown'));
+ assert_greater_than(latter.offsetWidth, widthForZeroItem);
+ assert_greater_than(latter.offsetHeight, heightForZeroItem);
+ }, 'listbox: The size attribute value is ignored');
+
+ test(() => {
+ container.innerHTML = '<select multiple><option>foo<option>quick brown fox</select>';
+ const select = container.firstElementChild;
+ const initialHeight = select.offsetHeight;
+ select.style.formSizing = 'normal';
+ assert_less_than(select.offsetHeight, initialHeight);
+ select.style.formSizing = 'auto';
+ assert_equals(select.offsetHeight, initialHeight);
+ }, 'listbox: Change the form-sizing value dynamically');
+
+}
+</script>
+</body>
