From f3cc3fbe78146894ba9c46cf7aa0f5364ea25567 Mon Sep 17 00:00:00 2001
From: Joshua Laymon <joshlaymon@icloud.com>
Date: Sun, 7 Sep 2025 17:18:36 +0000
Subject: [PATCH] Add web/static/js/swipe-nav.js

---
 web/static/js/swipe-nav.js | 117 +++++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 web/static/js/swipe-nav.js

diff --git a/web/static/js/swipe-nav.js b/web/static/js/swipe-nav.js
new file mode 100644
index 0000000..2e964fa
--- /dev/null
+++ b/web/static/js/swipe-nav.js
@@ -0,0 +1,117 @@
+/* Swipe/Keyboard navigation for Entry View
+   - Respects localStorage 'swipeNavEnabled' (default ON)
+   - Touch swipe on mobile, ArrowLeft/ArrowRight on keyboards
+   - Edge protection and input-safe
+*/
+(function () {
+  // Feature flag (client-side). Default ON.
+  let swipeEnabled = true;
+  try { swipeEnabled = (localStorage.getItem('swipeNavEnabled') !== 'false'); } catch (e) {}
+
+  // Only attach if enabled
+  if (!swipeEnabled) return;
+
+  // Forms to submit for previous/next (your existing IDs)
+  const prevForm = document.getElementById('navPrevForm');
+  const nextForm = document.getElementById('navNextForm');
+
+  // Create toast + hints lazily to keep HTML clean
+  const toast = document.createElement('div');
+  toast.id = 'toast-swipe-error';
+  toast.style.cssText = [
+    'position:fixed', 'left:50%', 'bottom:16px', 'transform:translateX(-50%)',
+    'padding:10px 14px', 'border-radius:10px', 'background:#111827', 'color:#fff',
+    'box-shadow:0 6px 20px rgba(0,0,0,.25)', 'opacity:0', 'pointer-events:none',
+    'transition:opacity .25s', 'z-index:1200', 'font-size:14px'
+  ].join(';');
+  toast.textContent = "Can't navigate here.";
+  document.body.appendChild(toast);
+
+  function showToast() {
+    toast.style.opacity = '1';
+    setTimeout(() => { toast.style.opacity = '0'; }, 1200);
+  }
+
+  // Only show swipe hints on touch devices, once per session
+  const isTouch = ('ontouchstart' in window) || (navigator.maxTouchPoints > 0);
+  let hintL, hintR;
+  if (isTouch) {
+    try {
+      if (!sessionStorage.getItem('swipeHintShown')) {
+        sessionStorage.setItem('swipeHintShown', '1');
+
+        const base = 'position:fixed;width:34px;height:34px;display:flex;align-items:center;justify-content:center;' +
+                     'background:rgba(0,0,0,.35);color:#fff;border-radius:999px;box-shadow:0 6px 20px rgba(0,0,0,.25);' +
+                     'z-index:1100;opacity:0;transform:scale(.9);transition:opacity .25s,transform .25s;top:45%';
+
+        hintL = document.createElement('div');
+        hintL.style.cssText = base + ';left:10px;';
+        hintL.textContent = '‹';
+        document.body.appendChild(hintL);
+
+        hintR = document.createElement('div');
+        hintR.style.cssText = base + ';right:10px;';
+        hintR.textContent = '›';
+        document.body.appendChild(hintR);
+
+        setTimeout(() => { hintL.style.opacity = '1'; hintR.style.opacity = '1'; hintL.style.transform = 'scale(1)'; hintR.style.transform = 'scale(1)'; }, 300);
+        setTimeout(() => { hintL.style.opacity = '0'; hintR.style.opacity = '0'; }, 2200);
+      }
+    } catch (e) {}
+  }
+
+  function navigate(dir) {
+    try {
+      if (dir < 0 && prevForm) { prevForm.submit(); return true; }
+      if (dir > 0 && nextForm) { nextForm.submit(); return true; }
+    } catch (e) {}
+    showToast();
+    return false;
+  }
+
+  // Keyboard shortcuts
+  document.addEventListener('keydown', function (e) {
+    if (!swipeEnabled) return;
+    const tag = (e.target && e.target.tagName) || '';
+    if (/INPUT|TEXTAREA|SELECT/.test(tag)) return;
+    if (e.key === 'ArrowLeft') { e.preventDefault(); navigate(-1); }
+    if (e.key === 'ArrowRight') { e.preventDefault(); navigate(1); }
+  });
+
+  // Touch swipe (edge-protected, vertical tolerance)
+  if (isTouch) {
+    let startX = 0, startY = 0, tracking = false;
+    const EDGE = 20, THRESH = 40;
+    const area = document.querySelector('main.page') || document.body;
+
+    function isInteractive(el) {
+      return !!(el.closest && el.closest('input, textarea, select, button, a, [contenteditable], .no-swipe'));
+    }
+
+    area.addEventListener('touchstart', function (e) {
+      const t = e.touches[0];
+      if (!t) return;
+      if (isInteractive(e.target)) return;
+      startX = t.clientX; startY = t.clientY; tracking = true;
+    }, { passive: true });
+
+    area.addEventListener('touchmove', function (e) {
+      if (!tracking) return;
+      const t = e.touches[0];
+      if (!t) return;
+      const dx = t.clientX - startX;
+      const dy = t.clientY - startY;
+
+      if (Math.abs(dx) > THRESH && Math.abs(dy) < 28) {
+        // Edge-protection: avoid accidental from extreme edges
+        if (startX < EDGE && dx > 0) { tracking = false; return; }
+        if (startX > (window.innerWidth - EDGE) && dx < 0) { tracking = false; return; }
+        e.preventDefault();
+        navigate(dx > 0 ? -1 : 1);
+        tracking = false;
+      }
+    }, { passive: false });
+
+    area.addEventListener('touchend', function () { tracking = false; }, { passive: true });
+  }
+})();
\ No newline at end of file