Merge pull request #11935 from Budibase/grid-mobile-scrolling

Grid mobile scrolling support

packages/frontend-core/src/components/grid/layout/GridBody.svelte

@@ -35,7 +35,7 @@
 </script>
 
 <div bind:this={body} class="grid-body">
-  <GridScrollWrapper scrollHorizontally scrollVertically wheelInteractive>
+  <GridScrollWrapper scrollHorizontally scrollVertically attachHandlers>
     {#each $renderedRows as row, idx}
       <GridRow
         {row}

packages/frontend-core/src/components/grid/layout/GridScrollWrapper.svelte

@@ -17,7 +17,11 @@
 
   export let scrollVertically = false
   export let scrollHorizontally = false
-  export let wheelInteractive = false
+  export let attachHandlers = false
+
+  // Used for tracking touch events
+  let initialTouchX
+  let initialTouchY
 
   $: style = generateStyle($scroll, $rowHeight, $hiddenColumnsWidth)
 
@@ -27,17 +31,47 @@
     return `transform: translate3d(${offsetX}px, ${offsetY}px, 0);`
   }
 
-  // Handles a wheel even and updates the scroll offsets
+  // Handles a mouse wheel event and updates scroll state
   const handleWheel = e => {
     e.preventDefault()
-    debouncedHandleWheel(e.deltaX, e.deltaY, e.clientY)
+    updateScroll(e.deltaX, e.deltaY, e.clientY)
 
     // If a context menu was visible, hide it
     if ($menu.visible) {
       menu.actions.close()
     }
   }
-  const debouncedHandleWheel = domDebounce((deltaX, deltaY, clientY) => {
+
+  // Handles touch start events
+  const handleTouchStart = e => {
+    if (!e.touches?.[0]) return
+    initialTouchX = e.touches[0].clientX
+    initialTouchY = e.touches[0].clientY
+  }
+
+  // Handles touch move events and updates scroll state
+  const handleTouchMove = e => {
+    if (!e.touches?.[0]) return
+    e.preventDefault()
+
+    // Compute delta from previous event, and update scroll
+    const deltaX = initialTouchX - e.touches[0].clientX
+    const deltaY = initialTouchY - e.touches[0].clientY
+    updateScroll(deltaX, deltaY)
+
+    // Store position to reference in next event
+    initialTouchX = e.touches[0].clientX
+    initialTouchY = e.touches[0].clientY
+
+    // If a context menu was visible, hide it
+    if ($menu.visible) {
+      menu.actions.close()
+    }
+  }
+
+  // Updates the scroll offset by a certain delta, and ensure scrolling
+  // stays within sensible bounds. Debounced for performance.
+  const updateScroll = domDebounce((deltaX, deltaY, clientY) => {
     const { top, left } = $scroll
 
     // Calculate new scroll top
@@ -55,15 +89,19 @@
     })
 
     // Hover row under cursor
-    const y = clientY - $bounds.top + (newScrollTop % $rowHeight)
-    const hoveredRow = $renderedRows[Math.floor(y / $rowHeight)]
-    hoveredRowId.set(hoveredRow?._id)
+    if (clientY != null) {
+      const y = clientY - $bounds.top + (newScrollTop % $rowHeight)
+      const hoveredRow = $renderedRows[Math.floor(y / $rowHeight)]
+      hoveredRowId.set(hoveredRow?._id)
+    }
   })
 </script>
 
 <div
   class="outer"
-  on:wheel={wheelInteractive ? handleWheel : null}
+  on:wheel={attachHandlers ? handleWheel : null}
+  on:touchstart={attachHandlers ? handleTouchStart : null}
+  on:touchmove={attachHandlers ? handleTouchMove : null}
   on:click|self={() => ($focusedCellId = null)}
 >
   <div {style} class="inner">

packages/frontend-core/src/components/grid/layout/NewRow.svelte

@@ -205,7 +205,7 @@
       {/if}
     </div>
     <div class="normal-columns" transition:fade|local={{ duration: 130 }}>
-      <GridScrollWrapper scrollHorizontally wheelInteractive>
+      <GridScrollWrapper scrollHorizontally attachHandlers>
         <div class="row">
           {#each $renderedColumns as column, columnIdx}
             {@const cellId = `new-${column.name}`}

packages/frontend-core/src/components/grid/layout/StickyColumn.svelte

@@ -64,7 +64,7 @@
   </div>
 
   <div class="content" on:mouseleave={() => ($hoveredRowId = null)}>
-    <GridScrollWrapper scrollVertically wheelInteractive>
+    <GridScrollWrapper scrollVertically attachHandlers>
       {#each $renderedRows as row, idx}
         {@const rowSelected = !!$selectedRows[row._id]}
         {@const rowHovered = $hoveredRowId === row._id}

packages/frontend-core/src/components/grid/overlays/ScrollOverlay.svelte

@@ -53,18 +53,27 @@
     }
   }
 
+  const getLocation = e => {
+    return {
+      y: e.touches?.[0]?.clientY ?? e.clientY,
+      x: e.touches?.[0]?.clientX ?? e.clientX,
+    }
+  }
+
   // V scrollbar drag handlers
   const startVDragging = e => {
     e.preventDefault()
-    initialMouse = e.clientY
+    initialMouse = getLocation(e).y
     initialScroll = $scrollTop
     document.addEventListener("mousemove", moveVDragging)
+    document.addEventListener("touchmove", moveVDragging)
     document.addEventListener("mouseup", stopVDragging)
+    document.addEventListener("touchend", stopVDragging)
     isDraggingV = true
     closeMenu()
   }
   const moveVDragging = domDebounce(e => {
-    const delta = e.clientY - initialMouse
+    const delta = getLocation(e).y - initialMouse
     const weight = delta / availHeight
     const newScrollTop = initialScroll + weight * $maxScrollTop
     scroll.update(state => ({
@@ -74,22 +83,26 @@
   })
   const stopVDragging = () => {
     document.removeEventListener("mousemove", moveVDragging)
+    document.removeEventListener("touchmove", moveVDragging)
     document.removeEventListener("mouseup", stopVDragging)
+    document.removeEventListener("touchend", stopVDragging)
     isDraggingV = false
   }
 
   // H scrollbar drag handlers
   const startHDragging = e => {
     e.preventDefault()
-    initialMouse = e.clientX
+    initialMouse = getLocation(e).x
     initialScroll = $scrollLeft
     document.addEventListener("mousemove", moveHDragging)
+    document.addEventListener("touchmove", moveHDragging)
     document.addEventListener("mouseup", stopHDragging)
+    document.addEventListener("touchend", stopHDragging)
     isDraggingH = true
     closeMenu()
   }
   const moveHDragging = domDebounce(e => {
-    const delta = e.clientX - initialMouse
+    const delta = getLocation(e).x - initialMouse
     const weight = delta / availWidth
     const newScrollLeft = initialScroll + weight * $maxScrollLeft
     scroll.update(state => ({
@@ -99,7 +112,9 @@
   })
   const stopHDragging = () => {
     document.removeEventListener("mousemove", moveHDragging)
+    document.removeEventListener("touchmove", moveHDragging)
     document.removeEventListener("mouseup", stopHDragging)
+    document.removeEventListener("touchend", stopHDragging)
     isDraggingH = false
   }
 </script>
@@ -109,6 +124,7 @@
     class="v-scrollbar"
     style="--size:{ScrollBarSize}px; top:{barTop}px; height:{barHeight}px;"
     on:mousedown={startVDragging}
+    on:touchstart={startVDragging}
     class:dragging={isDraggingV}
   />
 {/if}
@@ -117,6 +133,7 @@
     class="h-scrollbar"
     style="--size:{ScrollBarSize}px; left:{barLeft}px; width:{barWidth}px;"
     on:mousedown={startHDragging}
+    on:touchstart={startHDragging}
     class:dragging={isDraggingH}
   />
 {/if}