From f84b0da5d1ec539e9e02b2a68358b3eaa3a20497 Mon Sep 17 00:00:00 2001
From: Adrian Heine <mail@adrianheine.de>
Date: Tue, 22 Nov 2022 17:47:02 +0100
Subject: [PATCH] Bessere Auswahl

---
 index.php | 125 ++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 92 insertions(+), 33 deletions(-)

diff --git a/index.php b/index.php
index c1f5861..ca9a112 100644
--- a/index.php
+++ b/index.php
@@ -165,7 +165,8 @@ main > * {
   border: 1px solid #722CA2;
   margin: -1px;
 }
-:checked + label {
+:checked + label:not(.unselecting),
+.selecting {
   background: #f1cc37;
 }
 .invalid {
@@ -248,38 +249,6 @@ main > * {
 }
 
 </style>
-<script>
-let checking = null
-addEventListener("selectstart", (event) => {
-  let target = event.target
-  if (target.nodeType == 3) target = target.parentNode
-  if (target.tagName == "LABEL") {
-    const checkbox = document.getElementById(target.htmlFor)
-    checking = !checkbox.checked
-    checkbox.checked = checking
-  } else checking = null
-});
-document.addEventListener('selectionchange', () => {
-  if (checking !== null) {
-    const range = document.getSelection().getRangeAt(0)
-    const treeWalker = document.createTreeWalker(
-      range.commonAncestorContainer,
-      NodeFilter.SHOW_ELEMENT,
-  { acceptNode: (node) => node.nodeName.toLowerCase() === 'input' ? NodeFilter.FILTER_ACCEPT : NodeFilter.FILTER_SKIP }
-    )
-    while (currentNode = treeWalker.nextNode()) {
-      if (range.intersectsNode(currentNode)) currentNode.checked = checking;
-    }
-  }
-});
-
-document.addEventListener('pointerup', () => {
-  if (checking !== null) {
-    checking = null
-    document.getSelection().empty()
-  }
-})
-</script>
 
 <header>
 <h1>Soli-Bus-Fahrten von Berlin nach Lützerath</h1>
@@ -296,6 +265,7 @@ Zur groben Einordnung: Eine Fahrt dauert rund 9 Stunden und kostet pro Person mi
 
 <h2>Termine</h2>
 <p>Bitte markier alle Tage im Kalender, an denen du mit dem Soli-Bus nach Lützerath fahren könntest (also nur die Hinfahrt). </p>
+<div id=months>
 <?php
 
 $start = (new DateTimeImmutable())->setTimestamp(mktime(0, 0, 0, $START_DATE[1], $START_DATE[2], $START_DATE[0]));
@@ -306,6 +276,95 @@ $month_end = (new DateTimeImmutable())->setTimestamp(strtotime("first day of nex
 print_month($month_end);
 
 ?>
+</div>
+<script>
+(function() {
+  "use strict"
+
+  const months = document.getElementById('months')
+  let selecting = null // { origin, className, range }
+  let is_select = false
+
+  months.addEventListener("pointerdown", event => {
+    selecting = null
+    is_select = false
+    for (const elem of document.querySelectorAll(".selecting, .unselecting")) {
+      elem.className = ""
+    }
+
+    if (event.buttons !== 1) return
+    let target = event.target
+    if (target.nodeType == 3) target = target.parentNode
+    if (target.tagName !== "LABEL") return
+
+    event.preventDefault()
+
+    const className = target.className = document.getElementById(target.htmlFor).checked ? "unselecting" : "selecting"
+    selecting = {
+      origin: target,
+      className,
+      range: [ target ]
+    }
+  })
+
+  months.addEventListener('pointermove', event => {
+    if (selecting === null) return
+    event.preventDefault()
+    is_select = true
+
+    const range = document.createRange()
+    range.selectNode(selecting.origin)
+    if (range.comparePoint(event.target, 0) > 0) range.setEndAfter(event.target)
+    else range.setStartBefore(event.target)
+
+    const treeWalker = document.createTreeWalker(
+      range.commonAncestorContainer,
+      NodeFilter.SHOW_ELEMENT,
+      { acceptNode: (node) => node.nodeName.toLowerCase() === 'label' ? NodeFilter.FILTER_ACCEPT : NodeFilter.FILTER_SKIP }
+    )
+
+    const new_range = []
+    let currentNode
+    while (currentNode = treeWalker.nextNode()) {
+      if (range.intersectsNode(currentNode)) {
+        new_range.push(currentNode)
+        const idx = selecting.range.indexOf(currentNode)
+        if (idx !== -1) selecting.range.splice(idx, 1)
+        else currentNode.className = selecting.className
+      }
+    }
+    for (const elem of selecting.range) {
+      elem.className = ""
+    }
+    selecting.range = new_range
+  })
+
+  document.addEventListener('pointercancel', event => {
+    if (selecting === null) return
+    for (const elem of selecting.range) {
+      elem.className = ""
+    }
+    selecting = null
+    is_select = false
+  })
+
+  document.addEventListener('pointerup', event => {
+    if (selecting === null) return
+    event.preventDefault()
+    for (const elem of selecting.range) {
+      if (is_select) document.getElementById(elem.htmlFor).checked = selecting.className == "selecting"
+      elem.className = ""
+    }
+    selecting = null
+  })
+  months.addEventListener('click', event => {
+    if (is_select) {
+      event.preventDefault()
+      is_select = false
+    }
+  })
+})()
+</script>
 <h3>Tag X</h3>
 <label><input type=checkbox name=tagx>Ich möchte im Fall eines Räumungsversuchs mit dem Solibus nach Lützerath fahren.</label>
 <h2>Kontaktmöglichkeiten</h2>