From c47730f2cc8becbd57975da07b6e84184efe7326 Mon Sep 17 00:00:00 2001
From: Viktor Lofgren <vlofgren@marginalia.nu>
Date: Tue, 9 Jan 2024 13:30:30 +0100
Subject: [PATCH] (search) Mobile UX improvements.

Swipe right to show filter menu.

Fix CSS bug that caused parts of the menu to not have a background.
---
 .../src/main/resources/static/search/menu.js  | 75 ++++++++++++++++---
 .../main/resources/static/search/serp.scss    |  1 -
 2 files changed, 66 insertions(+), 10 deletions(-)

diff --git a/code/services-application/search-service/src/main/resources/static/search/menu.js b/code/services-application/search-service/src/main/resources/static/search/menu.js
index a8b4c0b3..5832fd36 100644
--- a/code/services-application/search-service/src/main/resources/static/search/menu.js
+++ b/code/services-application/search-service/src/main/resources/static/search/menu.js
@@ -1,3 +1,26 @@
+function hideMenu() {
+    document.getElementById('filters').style.display = 'none';
+}
+function showMenu() {
+    document.getElementById('filters').style.display = 'block';
+
+    // Defer creation of the close button until the menu is opened.  This is needed because the script for creating
+    // the filter button is run early to avoid layout shifts.
+
+    if (document.getElementById('menu-close') === null) {
+        registerCloseButton();
+    }
+
+    document.getElementById('filters').style.display = 'block';
+
+    // scroll to the top of the page so the user can see the filters
+    window.scrollTo({
+        top: 0,
+        left: 0,
+        behavior: "instant",
+    });
+}
+
 const registerCloseButton = () => {
     // Add a button to close the filters for mobile; we do this in js to not pollute the DOM for text-only browsers
     const closeButton = document.createElement('button');
@@ -6,7 +29,7 @@ const registerCloseButton = () => {
     closeButton.setAttribute('aria-controls', '#filters');
     closeButton.innerHTML = 'X';
     closeButton.onclick = (event) => {
-        document.getElementById('filters').style.display = 'none';
+        hideMenu();
         event.stopPropagation();
         return false;
     }
@@ -20,15 +43,49 @@ filtersButton.setAttribute('aria-controls', '#filters');
 filtersButton.innerHTML = '&Xi;';
 filtersButton.setAttribute('title', 'Open the filters menu');
 filtersButton.onclick = (event) => {
-    // Defer creation of the close button until the menu is opened.  This is needed because the script for creating
-    // the filter button is run early to avoid layout shifts.
-
-    if (document.getElementById('menu-close') === null) {
-        registerCloseButton();
-    }
-
-    document.getElementById('filters').style.display = 'block';
+    showMenu();
     event.stopPropagation();
     return false;
 }
+
 document.getElementById('search-box').getElementsByTagName('h1')[0].append(filtersButton);
+
+// swipe affordances for mobile
+if (window.matchMedia('(pointer: coarse)').matches) {
+    // capture swipes to the left and right to open and close the filters
+    let touchStartX = 0;
+    let touchEndX = 0;
+    let touchStartY = 0;
+    let touchEndY = 0;
+
+    const swipeThreshold = 100;
+    const maxVerticalDistance = 75;
+    document.addEventListener('touchstart', (event) => {
+        touchStartX = event.changedTouches[0].screenX;
+        touchStartY = event.changedTouches[0].screenY;
+    });
+    document.addEventListener('touchend', (event) => {
+        touchEndX = event.changedTouches[0].screenX;
+        touchEndY = event.changedTouches[0].screenY;
+        let verticalDistance = Math.abs(touchStartY - touchEndY);
+
+        if (verticalDistance > maxVerticalDistance) {
+            return;
+        }
+
+        if (touchEndX - touchStartX > swipeThreshold) {
+            showMenu();
+            event.stopPropagation();
+        } else if (touchStartX - touchEndX > swipeThreshold) {
+            hideMenu();
+            event.stopPropagation();
+        }
+    });
+
+
+    // Add a floating panel to the bottom of the page to show a message when the filters are hidden
+    const floatingPanel = document.createElement('div');
+    floatingPanel.setAttribute('style', 'position: fixed; bottom: 0; left: 0; right: 0; background-color: #fff; padding: 1em; text-align: center; display: block; border-top: 1px solid #ccc; box-shadow: 0 0 -5px #eee;');
+    floatingPanel.innerHTML = '&larr; right/left open/close the filters &rarr;';
+    document.body.appendChild(floatingPanel);
+}
\ No newline at end of file
diff --git a/code/services-application/search-service/src/main/resources/static/search/serp.scss b/code/services-application/search-service/src/main/resources/static/search/serp.scss
index 3ab845bc..0c44415c 100644
--- a/code/services-application/search-service/src/main/resources/static/search/serp.scss
+++ b/code/services-application/search-service/src/main/resources/static/search/serp.scss
@@ -668,7 +668,6 @@ footer {
       top: 0;
       left: 0;
       width: 100%;
-      height: 100%;
       margin: 0;
       padding: 0;
       z-index: 100;