ZacharyZhang-NYandClaude Opus 5.5
bcce34cda1
MyGo v0.5.5 returns ui.Element as a checked value handle instead of a
pointer. Migrated with `mygo migrate-ui`, then fixed what the codemod
leaves to review:
- Element nil checks become .Valid(); absent elements are ui.Element{}.
- Input handlers and paint callbacks run outside the build pass, where
elements expire and Context methods are inert: read IsDisabled into a
local during the build, keep a ui.Handle for Focus, use c.Services()
for clipboard access, create ui.Local state during the build.
- Add core.AutoFocus: v0.5.5 records an overlay's opener after its
content builds, so same-frame autofocus lost focus restore on close.
It focuses one frame later; cascader rows defer their focus likewise.
- core.OverlayLayer identifies build passes by the root element, not
c.Now(), which repeats across passes and under the Tester clock.
- Context menus survive the opening press counted as PressedOutside;
split button tooltip no longer reorders its open menu; disabled
menubar rows pass presses to the panel; Form defers blur-started
async checks so the growing message no longer moves Submit away
from the release; Combobox drops its disabled copy now that MyGo
blocks typing under a disabled wrapper (canary flipped to a guard).
- The Tester clock is virtual: tests use Advance/Now instead of
time.Sleep/time.Now and read element state inside the view. The web
mirror advances the clock to wall time before each frame and input.
- AGENTS.md and docs describe the value Element API and the new pin.
Snapshot goldens are darwin-only and were not re-verified here.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
1.1 KiB
1.1 KiB
219 ScrollToBottomButton 回到底部按钮
用途
离开底部时出现在容器底部居中的圆角按钮，带未读计数；点击回到底部。MessageList 已内置，也可单独用于其他滚动区域。
最小示例
ui.Box(c).Fill().Children(func() {
if chat.ScrollToBottomButton(c, !list.AtEnd(), 3).Clicked() {
list.ScrollToEnd()
}
})
签名：func ScrollToBottomButton(c *ui.Context, away bool, unread int) ui.Element
参数
| 字段 | 类型 | 默认值 | 含义 |
|---|---|---|---|
away |
bool |
必填 | 是否已离开底部；false 时返回不可见的空元素，其 Clicked 为 false。 |
unread |
int |
0 | 未读数，大于 0 时显示；负数 panic。 |
状态
出现时 160 毫秒淡入（减少动画时直接显示）；悬停时底色加深。
事件
Clicked()：点击或 Enter、Space；滚动由调用方完成。
键盘操作
Tab 聚焦，Enter 或 Space 触发。辅助技术读到“回到最新，n 条新消息”。
限制
- 按钮以绝对定位贴在父元素底部，父元素需要占满滚动区域。