fix background drag-scroll dying after card move; delegate to document, body marker; v1.1

autoscroll variable speed v1.0
auto-scroll on drag
2026-07-06 07:52:21 -03:00 · 2026-07-01 10:46:10 -03:00 · 2026-07-01 10:45:07 -03:00 · 2026-07-01 10:30:07 -03:00
9 changed files with 210 additions and 20 deletions
--- a/Asset/css/tweak-drag.css
+++ b/Asset/css/tweak-drag.css
@@ -6,16 +6,17 @@
 * --td-column-gap value, so it is not in this static stylesheet.
 *
 * Below: click-and-drag horizontal scrolling (added by Asset/js/drag-scroll.js when the
- * "Drag the board background to scroll" setting is enabled). The .td-drag-scroll class is
- * set on #board-container by the script, so these rules are inert when disabled. A grab
+ * "Drag the board background to scroll" setting is enabled). The .td-drag-scroll marker is
+ * set on <body> by the script (not on #board-container, which Kanboard replaces on every
+ * card move), so these rules are inert when disabled and survive board rebuilds. A grab
 * cursor advertises the empty background; cards keep the normal cursor since pressing them
 * does a card drag, not a pan.
 */
-#board-container.td-drag-scroll {
+body.td-drag-scroll #board-container {
    cursor: grab;
 }

-#board-container.td-drag-scroll .task-board {
+body.td-drag-scroll #board-container .task-board {
    cursor: default;
 }

@@ -24,3 +25,17 @@
    cursor: grabbing !important;
    user-select: none !important;
 }
+
+/*
+ * Enlarge the mobile card drag handle so it is a usable touch target.
+ * Kanboard reveals the .task-board-sort-handle (a FontAwesome fa-arrows-alt glyph) only
+ * on mobile (isMobile.any) and restricts card dragging to it; by default the glyph is
+ * tiny and hard to grab with a finger. FontAwesome icons are sized by font-size, so this
+ * is a pure font-size bump; it is inert on desktop where the handle stays display:none.
+ * Size comes from the --td-handle-size variable (Settings -> Tweak Drag), injected in the
+ * page head; falls back to 20px.
+ */
+.task-board-sort-handle,
+.task-board-sort-handle i {
+    font-size: var(--td-handle-size, 20px);
+}
--- a/Asset/js/drag-autoscroll.js
+++ b/Asset/js/drag-autoscroll.js
@@ -0,0 +1,119 @@
+/*
+ * TweakDrag -- auto-scroll the board while dragging a card near a screen edge.
+ *
+ * Kanboard drags cards with jQuery UI sortable. The board does not scroll during a drag
+ * (jQuery UI's autoscroll is unreliable horizontally, and on touch the bundled Touch Punch
+ * shim suppresses native scrolling while a card is held), so you can only drop onto columns
+ * already on screen. This scrolls #board-container while a card drag is active and the
+ * pointer nears the left/right edge, with a smooth continuous speed that grows toward the
+ * edge -- so you can drag a card to the edge and roll the board to a far column.
+ *
+ * It only acts during an active card drag near an edge, so it is harmless when idle. Works
+ * on desktop (mouse) and mobile (touch, via Touch Punch). No core changes.
+ */
+(function () {
+    "use strict";
+
+    var EDGE_ZONE = 50; // px from the board edge where auto-scroll begins
+    var MAX_SPEED = 22; // px per animation frame at the very edge
+    var EASE = 1;       // 1 = linear ramp, 2 = gentle-then-fast
+
+    var jq = window.jQuery;
+    if (!jq) {
+        return;
+    }
+
+    var container = null;
+    var dragging = false;
+    var rafId = 0;
+    var lastX = 0;
+    var lastY = 0;
+
+    function onMove(e) {
+        if (e.touches && e.touches.length) {
+            lastX = e.touches[0].clientX;
+            lastY = e.touches[0].clientY;
+        } else {
+            lastX = e.clientX;
+            lastY = e.clientY;
+        }
+    }
+
+    // Distance is px from the edge; returns 0 at the zone border up to MAX_SPEED at the edge.
+    function speedFor(distance) {
+        var p = (EDGE_ZONE - distance) / EDGE_ZONE;
+        if (p <= 0) {
+            return 0;
+        }
+        if (p > 1) {
+            p = 1;
+        }
+        if (EASE !== 1) {
+            p = Math.pow(p, EASE);
+        }
+        return MAX_SPEED * p;
+    }
+
+    function step() {
+        if (!dragging || !container) {
+            return;
+        }
+
+        var rect = container.getBoundingClientRect();
+        var dLeft = lastX - rect.left;
+        var dRight = rect.right - lastX;
+        var speed = 0;
+
+        if (dLeft < EDGE_ZONE) {
+            speed = -speedFor(dLeft);
+        } else if (dRight < EDGE_ZONE) {
+            speed = speedFor(dRight);
+        }
+
+        if (speed !== 0) {
+            var before = container.scrollLeft;
+            container.scrollLeft = before + speed;
+
+            // Only when the board actually moved: nudge jQuery UI to recompute drop
+            // positions so the placeholder follows onto the newly revealed column.
+            if (container.scrollLeft !== before) {
+                document.dispatchEvent(new MouseEvent("mousemove", {
+                    clientX: lastX,
+                    clientY: lastY,
+                    bubbles: true
+                }));
+            }
+        }
+
+        rafId = window.requestAnimationFrame(step);
+    }
+
+    function startLoop() {
+        container = document.getElementById("board-container");
+        if (!container) {
+            return;
+        }
+        dragging = true;
+        if (!rafId) {
+            rafId = window.requestAnimationFrame(step);
+        }
+    }
+
+    function stopLoop() {
+        dragging = false;
+        if (rafId) {
+            window.cancelAnimationFrame(rafId);
+            rafId = 0;
+        }
+    }
+
+    // Track the pointer at all times (cheap; only used while dragging).
+    document.addEventListener("mousemove", onMove, true);
+    document.addEventListener("touchmove", onMove, true);
+    document.addEventListener("pointermove", onMove, true);
+
+    // A card drag started / stopped. jQuery UI sortable fires these (on touch too, via
+    // Touch Punch); delegated on the document so board redraws need no rebinding.
+    jq(document).on("sortstart", startLoop);
+    jq(document).on("sortstop", stopLoop);
+})();
--- a/Asset/js/drag-scroll.js
+++ b/Asset/js/drag-scroll.js
@@ -6,6 +6,13 @@
 * pressing a task card, a drag handle, or any interactive control is ignored, so this
 * never interferes with Kanboard's own card and column drag-and-drop.
 *
+ * Resilience note: after a card drag Kanboard rebuilds the board with
+ * `$("#board-container").replaceWith(data)` (BoardDragAndDrop.refresh), destroying the
+ * element. So we must NOT bind to #board-container directly: we listen on `document` and
+ * re-resolve the container on each press, and the grab-cursor marker lives on <body>
+ * (which is never replaced). Previously the mousedown listener and the cursor class were
+ * on the container, so background dragging stopped working after every card move.
+ *
 * Loaded only when the "Drag the board background to scroll" setting is enabled.
 */
 (function () {
@@ -21,34 +28,40 @@
    }

    function init() {
-        var container = document.getElementById("board-container");
-
-        if (!container || container.getAttribute("data-td-drag") === "1") {
+        if (!document.getElementById("board-container") || document.body.getAttribute("data-td-drag") === "1") {
            return;
        }

-        container.setAttribute("data-td-drag", "1");
-        container.classList.add("td-drag-scroll");
+        // Marker on <body> (stable) enables the grab cursor via CSS, surviving board rebuilds.
+        document.body.setAttribute("data-td-drag", "1");
+        document.body.classList.add("td-drag-scroll");

        var dragging = false;
+        var container = null;
        var startX = 0;
        var startScrollLeft = 0;

-        container.addEventListener("mousedown", function (e) {
-            // Left button only, and only on empty board background.
-            if (e.button !== 0 || isIgnored(e.target)) {
+        document.addEventListener("mousedown", function (e) {
+            if (e.button !== 0) {
                return;
            }

+            // Re-resolve the current container and only act on its empty background.
+            var c = document.getElementById("board-container");
+            if (!c || !c.contains(e.target) || isIgnored(e.target)) {
+                return;
+            }
+
+            container = c;
            dragging = true;
            startX = e.clientX;
-            startScrollLeft = container.scrollLeft;
-            container.classList.add("td-grabbing");
+            startScrollLeft = c.scrollLeft;
+            document.body.classList.add("td-grabbing");
            e.preventDefault();
        });

        document.addEventListener("mousemove", function (e) {
-            if (!dragging) {
+            if (!dragging || !container) {
                return;
            }
            container.scrollLeft = startScrollLeft - (e.clientX - startX);
@@ -60,7 +73,8 @@
                return;
            }
            dragging = false;
-            container.classList.remove("td-grabbing");
+            container = null;
+            document.body.classList.remove("td-grabbing");
        }

        document.addEventListener("mouseup", stop);
--- a/Controller/ConfigController.php
+++ b/Controller/ConfigController.php
@@ -13,11 +13,16 @@ class ConfigController extends BaseController
    const MIN_GAP_SIZE = 0;
    const MAX_GAP_SIZE = 200;

+    const DEFAULT_HANDLE_SIZE = 20;
+    const MIN_HANDLE_SIZE = 8;
+    const MAX_HANDLE_SIZE = 200;
+
    public function show()
    {
        $gapSize = (int) $this->configModel->get('tweakdrag_column_gap_size', self::DEFAULT_GAP_SIZE);
        $columnGap = (int) $this->configModel->get('tweakdrag_column_gap', 1);
        $dragScroll = (int) $this->configModel->get('tweakdrag_drag_scroll', 1);
+        $handleSize = (int) $this->configModel->get('tweakdrag_handle_size', self::DEFAULT_HANDLE_SIZE);

        $this->response->html($this->helper->layout->config('tweakDrag:config/show', array(
            'title' => t('Settings').' &gt; '.t('Tweak Drag'),
@@ -25,6 +30,7 @@ class ConfigController extends BaseController
                'tweakdrag_column_gap_size' => $gapSize,
                'tweakdrag_column_gap' => $columnGap,
                'tweakdrag_drag_scroll' => $dragScroll,
+                'tweakdrag_handle_size' => $handleSize,
            ),
            'errors' => array(),
        )));
@@ -40,10 +46,14 @@ class ConfigController extends BaseController
        $columnGap = isset($values['tweakdrag_column_gap']) ? 1 : 0;
        $dragScroll = isset($values['tweakdrag_drag_scroll']) ? 1 : 0;

+        $handleSize = isset($values['tweakdrag_handle_size']) ? (int) $values['tweakdrag_handle_size'] : self::DEFAULT_HANDLE_SIZE;
+        $handleSize = max(self::MIN_HANDLE_SIZE, min(self::MAX_HANDLE_SIZE, $handleSize));
+
        if ($this->configModel->save(array(
            'tweakdrag_column_gap_size' => $gapSize,
            'tweakdrag_column_gap' => $columnGap,
            'tweakdrag_drag_scroll' => $dragScroll,
+            'tweakdrag_handle_size' => $handleSize,
        ))) {
            $this->flash->success(t('Settings saved successfully.'));
        } else {
--- a/Plugin.php
+++ b/Plugin.php
@@ -25,6 +25,12 @@ class Plugin extends Base
                'template' => 'plugins/TweakDrag/Asset/js/drag-scroll.js',
            ));
        }
+
+        // Auto-scroll the board while dragging a card near a screen edge. Always loaded;
+        // it only acts during an active card drag.
+        $this->hook->on('template:layout:js', array(
+            'template' => 'plugins/TweakDrag/Asset/js/drag-autoscroll.js',
+        ));
    }

    public function getPluginName()
@@ -44,7 +50,7 @@ class Plugin extends Base

    public function getPluginVersion()
    {
-        return '0.2.0';
+        return '1.1.0';
    }

    public function getPluginHomepage()
--- a/README.md
+++ b/README.md
@@ -1,12 +1,16 @@
 # TweakDrag -- board drag, touch and column-gap tweaks

-A Kanboard plugin that groups board dragging and spacing tweaks. This first version
-provides two options, both configurable under "Settings -> Tweak Drag":
+A Kanboard plugin that groups board dragging and spacing tweaks, configurable under
+"Settings -> Tweak Drag":

 - **Drag the board background to scroll** (desktop) -- click and drag on the empty board
  background to scroll the columns sideways, like the Trello board canvas.
 - **Widen the gap between columns** -- spread the columns further apart, easier to tell
  apart and to touch.
+- **Mobile drag handle size** -- enlarge the card drag handle Kanboard shows on mobile so
+  it is easy to grab with a finger.
+- **Drag auto-scroll** -- while dragging a card, the board scrolls when the pointer nears a
+  screen edge, so you can reach a column that is off screen (desktop and mobile).

 These options were originally part of the ShrinkVertically plugin and moved here so that
 drag/touch behaviour can grow on its own (planned: mobile drag-to-move cards, and a drag
@@ -23,6 +27,17 @@ movement threshold so ending a drag does not open the task) without bloating tha
  by the `--td-column-gap` CSS variable. This spreads the columns without shrinking the
  cards and keeps each column header aligned with its list. It also adds some spacing at
  the left and right edges of the board.
+- **Mobile drag handle size**: Kanboard already supports dragging cards on mobile, but only
+  via a small handle (a FontAwesome `fa-arrows-alt` glyph it reveals on touch devices) that
+  is hard to grab. FontAwesome icons are sized by `font-size`, so a single rule scales the
+  handle from the `--td-handle-size` CSS variable. It is inert on desktop, where Kanboard
+  keeps the handle hidden.
+- **Drag auto-scroll**: a script (`Asset/js/drag-autoscroll.js`) listens for jQuery UI
+  sortable's `sortstart`/`sortstop` (which also fire on touch via Kanboard's bundled Touch
+  Punch) and, while a card drag is active, scrolls `#board-container` when the pointer nears
+  its left/right edge. Speed ramps up smoothly toward the edge. After each scroll step it
+  dispatches a synthetic `mousemove` so jQuery UI moves the drop placeholder onto the newly
+  revealed column. It only acts during an active drag, so it is idle otherwise.

 ## Requirements

@@ -43,6 +58,8 @@ These settings are global (per Kanboard instance) and admin-only. Go to
 - **Widen the gap between columns** -- toggles the wider gap. Default: on.
 - **Drag the board background to scroll horizontally** -- toggles the Trello-style
  click-and-drag panning. Desktop (mouse) for now. Default: on.
+- **Mobile drag handle size in pixels** -- size of the mobile card drag handle
+  (`--td-handle-size`). No effect on desktop. Default: 20.

 ## License

--- a/Template/config/show.php
+++ b/Template/config/show.php
@@ -27,6 +27,14 @@
        </p>
    </fieldset>

+    <fieldset>
+        <?= $this->form->label(t('Mobile drag handle size in pixels'), 'tweakdrag_handle_size') ?>
+        <?= $this->form->number('tweakdrag_handle_size', $values, $errors) ?>
+        <p class="form-help">
+            <?= t('Size of the card drag handle that Kanboard shows on mobile, so it is easy to grab with a finger. No effect on desktop. Default: 20.') ?>
+        </p>
+    </fieldset>
+
    <div class="form-actions">
        <button type="submit" class="btn btn-blue"><?= t('Save') ?></button>
    </div>
--- a/Template/layout/variable.php
+++ b/Template/layout/variable.php
@@ -1,6 +1,7 @@
 <style type="text/css">
    :root {
        --td-column-gap: <?= (int) $this->app->config('tweakdrag_column_gap_size', 25) ?>px;
+        --td-handle-size: <?= (int) $this->app->config('tweakdrag_handle_size', 20) ?>px;
    }
 <?php if ((int) $this->app->config('tweakdrag_column_gap', 1) === 1): ?>
    #board { border-collapse: separate !important; border-spacing: var(--td-column-gap, 25px) 0 !important; }
--- a/2
+++ b/2
@@ -1 +1 @@
-TweakDrag v0.2
+TweakDrag v1.1
Author	SHA1	Message	Date
Ruben Carlo Benante	8760377927	fix background drag-scroll dying after card move; delegate to document, body marker; v1.1	2026-07-06 07:52:21 -03:00
Ruben Carlo Benante	7f9235dbdc	autoscroll variable speed v1.0	2026-07-01 10:46:10 -03:00
Ruben Carlo Benante	bb3ac1c946	auto-scroll on drag	2026-07-01 10:45:07 -03:00
Ruben Carlo Benante	924e287aee	drag for mobile - handle sizeable	2026-07-01 10:30:07 -03:00