feat(ui): the gamepad moves the focus, presses and goes back; a held direction repeats on the clock

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/library/ui_gamepad.ludic

@@ -0,0 +1,52 @@
+# ui_gamepad.ludic — the pad and held keys, on the program's clock: a direction held presses once,
+# again after 0.42 s and every 0.11 s after that, at any frame rate; A presses what has the focus,
+# left and right step a range and a select, and B closes a popover.
+import "ludic.ui"
+import "ui_gamepad_parts/Pad.ludic"
+program UiGamepad {
+  numbers float
+  var now: float = 0.0
+  function clock() -> float { return now }
+  function frame(i: UiInput) -> string {
+    ui_input(i)
+    ui_show("Pad", null, 0.0, 0.0, 400.0, 600.0)
+    let page = ui_nodes("Pad", null).children[0]
+    return page.children[len(page.children) - 1].text
+  }
+  # `what` held for `secs` at `hz`, then let go
+  function hold(what: string, secs: float, hz: int) -> string {
+    let frames = int(secs * float(hz) + 0.5)
+    for k in 0 .. frames + 1 {
+      now = now + 1.0 / float(hz)
+      let i = new UiInput
+      i.held_up = what == "up"
+      i.held_down = what == "down"
+      i.held_left = what == "left"
+      i.held_right = what == "right"
+      i.pad_a = what == "a"
+      i.pad_b = what == "b"
+      frame(i)
+    }
+    now = now + 1.0 / float(hz)
+    return frame(new UiInput)
+  }
+  function tap(what: string) -> string { return hold(what, 0.0, 60) }
+  entry {
+    ui_backend(new UiBackend)
+    ui_clock(fn clock)
+    frame(new UiInput)
+    hold("down", 1.0, 240)
+    let fast = tap("a")
+    hold("down", 1.0, 60)
+    hold("up", 0.5, 60)
+    let slow = tap("a")
+    for k in 0 .. 8 { tap("down") }
+    let vol = hold("right", 0.5, 60)
+    tap("down")
+    let q = tap("left")
+    tap("down")
+    let open = tap("a")
+    let shut = tap("b")
+    print(`{fast} | {slow} | {vol} | {q} | {open} | {shut}`)
+  }
+}

examples/library/ui_gamepad_parts/Pad.ludic

@@ -0,0 +1,7 @@
+# Pad.ludic - eight buttons, a range, a select and a button that opens a popover, for a gamepad
+component Pad {
+  state last: int = -1
+  state vol: int = 0
+  state q: int = 0
+  state open: bool = false
+}

examples/library/ui_gamepad_parts/Pad.xml

@@ -0,0 +1,8 @@
+<div class="page">
+  <each in="{range(8)}" as="r"><button on-click="set last = r">{r}</button></each>
+  <input type="range" min="{0}" max="{10}" value="{vol}" on-change="set vol = event.value"/>
+  <select value="{q}" on-change="set q = event.value"><option>a</option><option>b</option><option>c</option></select>
+  <button on-click="set open = true">more</button>
+  <if test="{open}"><div popover on-close="set open = false"><button>x</button></div></if>
+  <p>last {last} vol {vol} q {q} open {open}</p>
+</div>