Choices: review r3 fix

docs/components/034-slider.md

@@ -45,6 +45,6 @@ ui.Render(view, 400, 300, 1)
 ## 限制
 
 - 基于 `ui.SliderBase`，它向辅助技术报告 Slider 角色、范围与当前值（ui/base.go:128）。
-- MyGo 只把方向键、Home、End 交给 `SliderBase` 本身（ui/base.go:118，按键路由见 ui/input.go:495），以范围的 1% 移动并把结果舍入到 1e-9（ui/widgets.go:375）。本组件让它操作副本，按方向判断按键后自己按 `Step` 移动。两种情况下按键结果无法区分：距端点不足 1% 时方向键与 Home/End 结果相同；步长细到 MyGo 舍入后不动。这时组件改看松开的是哪个键（`HandleInput` 能收到 KeyUp），在键松开时才改值；按住不放也只移动一步。
+- MyGo 只把方向键、Home、End 的按下交给 `SliderBase` 本身（ui/base.go:118，按键路由见 ui/input.go:495），以范围的 1% 移动并把结果舍入到 1e-9（ui/widgets.go:375），舍入可能让移动方向看起来相反。本组件让它操作副本，只用它判断“有按键按下”；方向与跳转取自松开的键（`HandleInput` 能收到 KeyUp），再按步长网格移动。因此键盘调整在松开按键时生效；按住不放时，松开后按 MyGo 收到的按下次数一次移动多步。
 - 步长网格复用 NumberInput 的实现：值为 `Min + n·Step`，小数位取 `Min` 与 `Step` 所需，端点跳转（End/Home、另一端）先对齐网格再写值并触发事件；例如 `Max=10, Step=3` 时 End 得到 9。
 - `SliderBase` 在构建时就处理指针（ui/base.go:111），禁用时外层先禁用，且只操作副本，保证值不变。

docs/components/035-range-slider.md

@@ -48,4 +48,4 @@ ui.Render(view, 400, 300, 1)
 
 - MyGo 自带的 `ui.RangeSlider` 使用玻璃质感滑块（ui/widgets.go:419），不符合本库风格；MyGo 也没有双滑块 Base，故每个滑块各是一个 `SliderBase`（报告 Slider 角色、范围与当前值，ui/base.go:128），拖动由外层的 `Dragged`、`PointerPosition` 处理。
 - 两个滑块的范围都报告为整条轨道 `Min`–`Max`；“不能越过另一端”这一动态上下限无法告诉辅助技术。
-- 按键处理与 Slider 相同：距端点不足 1% 时等到按键松开再移动（见 034 限制）。
+- 按键处理与 Slider 相同：方向取自松开的键，在松开时移动（见 034 限制）。

examples/gallery/pages_choice.go

@@ -42,7 +42,7 @@ view := func(c *ui.Context) {
 view := func(c *ui.Context) {
 	mujica.Use(c, mujica.Settings{})
 	mujica.Slider(c, &volume, mujica.SliderOptions{Step: 5, ShowValue: true, Label: "Volume"})
-}`, Keys: "Arrows move one step; Home and End go to the ends."},
+}`, Keys: "Arrows move one step, Home and End go to the ends; the move applies when the key is released."},
 	{ID: "035", Name: "RangeSlider", ZhName: "范围滑块", Category: choiceCategory, Demo: rangeSliderDemo, Code: `low, high := 20.0, 80.0
 view := func(c *ui.Context) {
 	mujica.Use(c, mujica.Settings{})

slider.go

@@ -2,7 +2,6 @@ package mujica
 
 import (
 	"log/slog"
-	"math"
 	"strconv"
 	"strings"
 
@@ -69,11 +68,10 @@ func (g sliderGeom) move(v float64, n int) float64 {
 	return g.grid.stepBy(v, n)
 }
 
-// sliderKey is the last key released on a slider, a move waiting for it, and whether its press moved.
+// sliderKey is the last key released on a slider and how many presses MyGo saw before it.
 type sliderKey struct {
 	up      ui.Key
-	pending int
-	acted   bool
+	presses int
 }
 
 type sliderKeyID struct{}
@@ -91,69 +89,32 @@ func sliderControl(c *ui.Context, v float64, g sliderGeom, from, to float64) (s
 		ks.up = ev.Key
 		return true
 	})
-	up, pending, acted := ks.up, ks.pending, ks.acted
-	ks.up, ks.pending = 0, 0
-	if up != 0 {
-		ks.acted = false
-	}
+	up := ks.up
+	ks.up = 0
 	if _, _, dragged = s.Dragged(); dragged {
+		ks.presses = 0
 		return s, max(from, min(to, g.snap(raw))), true
 	}
-	dir, jump, known := 0, false, true
-	switch {
-	case raw != v:
-		// MyGo moved the copy 1% (an arrow) or to an end (Home, End), rounded to 1e-9 (ui/widgets.go:375).
-		dir = 1
-		if raw < v {
-			dir = -1
-		}
-		end := g.lo
-		if dir > 0 {
-			end = g.hi
-		}
-		arrow := max(g.lo, min(g.hi, v+float64(dir)*(g.hi-g.lo)/100))
-		jump = math.Abs(raw-end) < math.Abs(raw-arrow)
-		if math.Abs(arrow-end) <= 1e-9+math.Abs(end)*1e-12 {
-			// Near an end an arrow and Home/End agree: the released key tells which it was.
-			dir, jump, known = sliderKeyMove(up, dir)
-		}
-		if up == 0 {
-			ks.acted = true
-		}
-	case pending != 0:
-		dir, jump, known = sliderKeyMove(up, pending)
-	case up != 0 && !acted:
-		// A step finer than MyGo's rounding leaves the copy still: act on the release.
-		dir, jump, known = sliderKeyMove(up, 0)
+	if raw != v {
+		// A key press MyGo applied to the copy; its rounded result (ui/widgets.go:375) says nothing of the direction.
+		ks.presses++
 	}
-	if !known {
-		ks.pending = dir
+	if up == 0 {
 		return s, v, false
 	}
-	switch {
-	case dir == 0:
-		return s, v, false
-	case jump && dir < 0:
-		return s, g.snap(from), false
-	case jump:
-		return s, g.snap(to), false
-	}
-	return s, max(from, min(to, g.move(v, dir))), false
-}
-
-// sliderKeyMove reads a released key as direction and jump; an unknown key keeps dir, unresolved.
-func sliderKeyMove(up ui.Key, dir int) (int, bool, bool) {
+	n := max(1, ks.presses)
+	ks.presses = 0
 	switch up {
 	case ui.KeyLeft, ui.KeyDown:
-		return -1, false, true
+		return s, max(from, min(to, g.move(v, -n))), false
 	case ui.KeyRight, ui.KeyUp:
-		return 1, false, true
+		return s, max(from, min(to, g.move(v, n))), false
 	case ui.KeyHome:
-		return -1, true, true
+		return s, g.snap(from), false
 	case ui.KeyEnd:
-		return 1, true, true
+		return s, g.snap(to), false
 	}
-	return dir, false, dir == 0
+	return s, v, false
 }
 
 func sliderSetup(min, max, step float64, marks []SliderMark, showValue bool, c *ui.Context) (sliderGeom, float32) {

slider_direction_test.go

@@ -0,0 +1,28 @@
+package mujica
+
+import (
+	"testing"
+
+	"github.com/egoist/mygo/ui"
+)
+
+// MyGo rounds its 1% move to 1e-9, which can flip the apparent direction; the key decides it.
+func sliderDirectionRun(t *testing.T, key ui.Key, want float64) {
+	t.Helper()
+	r := &sliderRecord{v: 6e-10, low: 6e-10, high: 8e-10}
+	tt := sliderGridTester(r, 0, 1e-8, 1e-10)
+	tt.Key(0, ui.KeyTab)
+	tt.Key(0, key)
+	if r.v != want || len(r.single) != 1 {
+		t.Errorf("Slider: %v, reported %v; want %v", r.v, r.single, want)
+	}
+	tt.Key(0, ui.KeyTab)
+	tt.Key(0, key)
+	if r.low != want || len(r.lows) != 1 {
+		t.Errorf("RangeSlider low: %v, reported %v; want %v", r.low, r.lows, want)
+	}
+}
+
+func TestSliderLeftUnderMyGoRounding(t *testing.T) { sliderDirectionRun(t, ui.KeyLeft, 5e-10) }
+
+func TestSliderRightUnderMyGoRounding(t *testing.T) { sliderDirectionRun(t, ui.KeyRight, 7e-10) }