OrganonTweaks: swallow post-drag click so a held press (>100ms) never opens the card; v1.2

Asset/js/click-guard.js

@@ -0,0 +1,35 @@
+/*
+ * OrganonTweaks -- only open a card on a quick click.
+ *
+ * A real click is a quick press-release; a drag is a press, some movement, and a release
+ * much later. When you drop a card, jQuery UI can leak a trailing "click" on it, and
+ * Kanboard opens the card -- an unwanted side effect of the drag.
+ *
+ * We simply time the press on a card: record the moment of mousedown / touchstart, and on
+ * the click that follows, if more than THRESHOLD ms elapsed the press was a drag (held),
+ * not a click, so we swallow the click in the capture phase before Kanboard's open handler
+ * runs. A normal click is well under the threshold and opens the card as usual.
+ */
+(function () {
+    "use strict";
+
+    var THRESHOLD = 100; // ms; a press on a card held longer than this is a drag, not a click
+    var pressStart = 0;
+
+    function onDown(e) {
+        pressStart = (e.target && e.target.closest && e.target.closest(".task-board")) ? Date.now() : 0;
+    }
+
+    document.addEventListener("mousedown", onDown, true);
+    document.addEventListener("touchstart", onDown, true);
+
+    document.addEventListener("click", function (e) {
+        if (pressStart &&
+            e.target && e.target.closest && e.target.closest(".task-board") &&
+            (Date.now() - pressStart) > THRESHOLD) {
+            e.stopImmediatePropagation();
+            e.preventDefault();
+        }
+        pressStart = 0;
+    }, true);
+})();