web: don't read a desktop window resize as a keyboard inset

web/fizzy.js

@@ -142,15 +142,22 @@ export function keyboardInset(win, send, canvas = null, owns = () => true) {
   const vv = win.visualViewport;
   const viewport = win.document?.querySelector('meta[name="viewport"]')?.content ?? "";
   const overlays = /(?:^|[,;])\s*interactive-widget\s*=\s*overlays-content\s*(?:[,;]|$)/i.test(viewport);
+  // Only phones and tablets have a soft keyboard. On a desktop, a window shrinking after
+  // focusin would otherwise read as one and pin the canvas height to the stale focusin rect.
+  const softKeyboard = win.matchMedia?.("(pointer: coarse) and (hover: none)").matches ?? true;
   // A resizing viewport and VK geometry can use different origins. Measure only the
   // visual viewport unless the page explicitly requests an overlay (or has no VV API).
-  const vk = overlays || !vv ? win.navigator?.virtualKeyboard : null;
+  const vk = softKeyboard && (overlays || !vv) ? win.navigator?.virtualKeyboard : null;
+  const keyboardTop = () => {
+    if (!softKeyboard) return Infinity;
+    if (!vk) return vv ? vv.height + vv.offsetTop : win.innerHeight;
+    const { y, height } = vk.boundingRect;
+    return height ? y ?? win.innerHeight - height : Infinity;
+  };
   const update = () => {
     const current = rect();
     const base = rest ?? current;
-    const edge = vk ? (vk.boundingRect.height ? vk.boundingRect.y ?? win.innerHeight - vk.boundingRect.height : Infinity)
-      : vv ? vv.height + vv.offsetTop : win.innerHeight;
-    const next = owns() ? Math.max(0, base.bottom - edge) : 0;
+    const next = owns() ? Math.max(0, base.bottom - keyboardTop()) : 0;
     // resizes-content pages shrink the CSS canvas as well. Keep the focused canvas's layout
     // height until the keyboard closes, so both dvui loops see the same backing-store size.
     if (canvas && next > 0 && current.height < base.height) {

web/tests/embed.test.mjs

@@ -61,7 +61,7 @@ const document = Object.assign(new Target(), {
 const window = Object.assign(new Target(), {
   visualViewport: Object.assign(new Target(), { height: 100, offsetTop: 0 }),
   devicePixelRatio: 1, scrollX: 0, scrollY: 0, localStorage: new Map(), parent: null,
-  dispatchEvent() {}, matchMedia: () => ({ matches: false, addEventListener() {} }),
+  dispatchEvent() {}, matchMedia: (q) => ({ matches: q === "(pointer: coarse) and (hover: none)", addEventListener() {} }),
 });
 window.parent = window;
 Object.assign(globalThis, {

web/tests/keyboard-inset.test.mjs

@@ -14,6 +14,20 @@ class Target {
   fire(type) { this.listeners[type]?.(); }
 }
 
+// A desktop has no soft keyboard: a window shrinking after focusin is not an inset.
+{
+  const vv = Object.assign(new Target(), { height: 800, offsetTop: 0 });
+  const win = Object.assign(new Target(), { navigator: {}, innerHeight: 800, visualViewport: vv, matchMedia: () => ({ matches: false }) });
+  const canvas = { style: { height: '100%' }, getBoundingClientRect: () => ({ bottom: 800, height: 800 }) };
+  const sent = [];
+  keyboardInset(win, (m) => sent.push(m), canvas);
+  win.fire('focusin');
+  vv.height = win.innerHeight = 500;
+  win.fire('resize');
+  assert.deepEqual(sent, []);
+  assert.equal(canvas.style.height, '100%');
+}
+
 // Chrome on Android: the VirtualKeyboard API, with the browser told not to resize or pan.
 {
   const vk = Object.assign(new Target(), { overlaysContent: false, boundingRect: { height: 0 } });