feat: resizable side panels, audio layer fixes

- Add horizontal resize handles for browser and properties panels with localStorage persistence
- Support hide/show toggles for each side panel
- Fix audio layers not being interactive on canvas (hasControls, hasBorders, evented flags)
- Convert hardcoded panel widths to CSS variables for responsive layout
- Support narrower windows by shrinking panels while preserving minimum canvas width
- Ensure old projects with audio layers don't show phantom control boxes at 0,0

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/index.html

@@ -311,6 +311,12 @@
 						<img src="assets/loading-video.svg" id="load-video" class="load-media">
             <canvas id="canvas"></canvas>
         </div>
+        <div id="browser-handle" class="panel-handle noselect" title="Drag to resize">
+            <div class="panel-toggle" id="browser-toggle"></div>
+        </div>
+        <div id="properties-handle" class="panel-handle noselect" title="Drag to resize">
+            <div class="panel-toggle" id="properties-toggle"></div>
+        </div>
         <div id="timeline-handle"></div>
         <div id="bottom-area" class="noselect">
             <div id="keyframe-properties">

src/js/database.js

@@ -53,6 +53,8 @@ function checkDB() {
           'cornerRadius',
           'selectable',
           'hasControls',
+          'hasBorders',
+          'evented',
           'subTargetCheck',
           'id',
           'hoverCursor',
@@ -230,6 +232,8 @@ async function autoSave() {
       'cornerRadius',
       'selectable',
       'hasControls',
+      'hasBorders',
+      'evented',
       'subTargetCheck',
       'id',
       'hoverCursor',
@@ -348,6 +352,13 @@ function loadProject() {
             });
             replaceSource(canvas.getItemById(object.id), canvas);
           } else {
+            // Projects saved before audio layers were flagged still carry
+            // controls / borders, which show up as a phantom box at 0,0.
+            canvas.getItemById(object.id).set({
+              hasControls: false,
+              hasBorders: false,
+              evented: false,
+            });
             renderProp('volume', canvas.getItemById(object.id));
           }
         });

src/js/functions.js

@@ -4381,6 +4381,11 @@ function newAudioLayer(src) {
       duration: audio.duration * 1000,
       opacity: 0,
       selectable: false,
+      // Audio layers are invisible placeholders. Selecting them (from the
+      // layer list) must not paint controls / a bounding box on the canvas.
+      hasControls: false,
+      hasBorders: false,
+      evented: false,
       volume: 0.5,
       assetType: 'audio',
       shadow: {
@@ -5367,6 +5372,10 @@ function resetHeight() {
     'calc(100% - ' + (top + 97) + 'px)'
   );
   $('#properties').css('height', 'calc(100% - ' + (top + 97) + 'px)');
+  $('.panel-handle').css(
+    'height',
+    'calc(100% - ' + (top + 97) + 'px)'
+  );
   $('#timeline-handle').css('bottom', top + 95);
   resizeCanvas();
 }
@@ -5399,6 +5408,208 @@ $(document).on('pointerdown', '#timeline-handle', dragTimeline);
 
 oldtimelinepos = $(window).height() - 92 - $('#timearea').height();
 
+// Side panels: horizontal resize and hide/show
+// The widths live as CSS variables on :root - every panel rule is a calc() of
+// them, so moving a handle only has to write one number.
+const RAIL_WIDTH = 76;
+const BROWSER_MIN_WIDTH = 210;
+const BROWSER_MAX_WIDTH = 640;
+const PROPS_MIN_WIDTH = 300;
+const PROPS_MAX_WIDTH = 640;
+// Canvas width kept free while dragging, whatever the window size
+const CANVAS_MIN_WIDTH = 240;
+const PANEL_LAYOUT_KEY = 'motionity-panel-layout';
+
+var browserwidth = 299;
+var propswidth = 300;
+var propshidden = false;
+// Tool to reopen the library with, set when it gets collapsed
+var lasttool = $('.tool-active').attr('id') || 'shape-tool';
+
+function clampWidth(value, min, max) {
+  return Math.max(min, Math.min(max, value));
+}
+
+function browserHidden() {
+  return $('#browser').hasClass('collapsed');
+}
+
+function applyPanelWidths() {
+  const root = document.documentElement.style;
+  const hidden = browserHidden();
+  var browser = hidden ? 0 : browserwidth;
+  var properties = propshidden ? 0 : propswidth;
+  // Shrink to fit rather than squeeze the canvas out of a narrow window. The
+  // stored widths are left alone, so the panels grow back on a wider one.
+  var over =
+    RAIL_WIDTH +
+    browser +
+    properties +
+    CANVAS_MIN_WIDTH -
+    $(window).width();
+  if (over > 0 && properties > PROPS_MIN_WIDTH) {
+    const cut = Math.min(over, properties - PROPS_MIN_WIDTH);
+    properties -= cut;
+    over -= cut;
+  }
+  if (over > 0 && browser > BROWSER_MIN_WIDTH) {
+    browser -= Math.min(over, browser - BROWSER_MIN_WIDTH);
+  }
+  root.setProperty('--browser-w', browser + 'px');
+  root.setProperty('--props-w', properties + 'px');
+  // The layer list and the timeline keep their column width while the library
+  // is hidden, otherwise layer names would get squashed into the tool rail.
+  if (!hidden) {
+    root.setProperty('--layers-w', RAIL_WIDTH + browser + 'px');
+  }
+  $('#browser-handle').toggleClass('panel-hidden', hidden);
+  $('#properties-handle').toggleClass('panel-hidden', propshidden);
+  $('#properties').toggleClass('collapsed', propshidden);
+  $('#browser-toggle').attr(
+    'title',
+    hidden ? 'Show the library' : 'Hide the library'
+  );
+  $('#properties-toggle').attr(
+    'title',
+    propshidden ? 'Show the properties' : 'Hide the properties'
+  );
+}
+
+function savePanelLayout() {
+  try {
+    localStorage.setItem(
+      PANEL_LAYOUT_KEY,
+      JSON.stringify({
+        browser: browserwidth,
+        properties: propswidth,
+        propertieshidden: propshidden,
+      })
+    );
+  } catch (err) {
+    // Private browsing or a full quota - the layout just won't persist
+  }
+}
+
+function restorePanelLayout() {
+  var stored;
+  try {
+    stored = JSON.parse(localStorage.getItem(PANEL_LAYOUT_KEY));
+  } catch (err) {
+    stored = null;
+  }
+  if (stored) {
+    if (typeof stored.browser == 'number') {
+      browserwidth = clampWidth(
+        stored.browser,
+        BROWSER_MIN_WIDTH,
+        BROWSER_MAX_WIDTH
+      );
+    }
+    if (typeof stored.properties == 'number') {
+      propswidth = clampWidth(
+        stored.properties,
+        PROPS_MIN_WIDTH,
+        PROPS_MAX_WIDTH
+      );
+    }
+    propshidden = stored.propertieshidden === true;
+  }
+  applyPanelWidths();
+}
+
+// Dragging a side panel border
+function dragPanel(e) {
+  if (e.which == 3 || modalOpen() || $(this).hasClass('panel-hidden')) {
+    return false;
+  }
+  e.preventDefault();
+  const handle = $(this);
+  const isbrowser = handle.attr('id') == 'browser-handle';
+  const startx = e.pageX;
+  const startwidth = isbrowser ? browserwidth : propswidth;
+  // Suppress text selection for the duration of the drag only
+  const previousSelectStart = document.onselectstart;
+  document.onselectstart = function () {
+    return false;
+  };
+  handle.addClass('handle-dragging');
+
+  function draggingPanelBorder(ev) {
+    // The properties panel is anchored to the right, so its width grows the
+    // other way round
+    const delta = isbrowser ? ev.pageX - startx : startx - ev.pageX;
+    const otherwidth = isbrowser
+      ? propshidden
+        ? 0
+        : propswidth
+      : browserHidden()
+      ? 0
+      : browserwidth;
+    const room =
+      $(window).width() - RAIL_WIDTH - CANVAS_MIN_WIDTH - otherwidth;
+    if (isbrowser) {
+      browserwidth = clampWidth(
+        startwidth + delta,
+        BROWSER_MIN_WIDTH,
+        Math.min(BROWSER_MAX_WIDTH, room)
+      );
+    } else {
+      propswidth = clampWidth(
+        startwidth + delta,
+        PROPS_MIN_WIDTH,
+        Math.min(PROPS_MAX_WIDTH, room)
+      );
+    }
+    applyPanelWidths();
+    resizeCanvas();
+  }
+  function releasedPanelBorder() {
+    document.onselectstart = previousSelectStart || null;
+    handle.removeClass('handle-dragging');
+    savePanelLayout();
+  }
+  bindPointerDrag(e, this, draggingPanelBorder, releasedPanelBorder);
+}
+$(document).on('pointerdown', '.panel-handle', dragPanel);
+
+// Keep a click on a hide/show button from starting a resize drag
+$(document).on('pointerdown', '.panel-toggle', function (e) {
+  e.stopPropagation();
+});
+
+$(document).on('click', '#browser-toggle', function (e) {
+  e.stopPropagation();
+  if (browserHidden()) {
+    // Reopening goes through the tool click so the rail icons stay in sync
+    $('#' + lasttool).trigger('click');
+  } else {
+    collapsePanel();
+  }
+});
+
+$(document).on('click', '#properties-toggle', function (e) {
+  e.stopPropagation();
+  propshidden = !propshidden;
+  applyPanelWidths();
+  savePanelLayout();
+  resizeCanvas();
+});
+
+// Re-fits the panels after the window itself changed size. Runs after the
+// resizeCanvas listener registered at the top of this file, so the canvas is
+// measured again once the new widths are in.
+window.addEventListener(
+  'resize',
+  function () {
+    applyPanelWidths();
+    resizeCanvas();
+  },
+  false
+);
+
+restorePanelLayout();
+resizeCanvas();
+
 // Sync scrolling (vertical)
 function syncScroll(el1, el2) {
   var $el1 = $(el1);

src/js/ui.js

@@ -1219,12 +1219,13 @@ $(document).on(
 
 // Switch tool
 function switchTool(e) {
-  $('#browser').removeClass('collapsed');
-  $('#canvas-area').removeClass('canvas-full');
   if ($(this).attr('id') == 'more-tool') {
     showMore();
     return false;
   }
+  $('#browser').removeClass('collapsed');
+  $('#behind-browser').removeClass('collapsed');
+  applyPanelWidths();
   resizeCanvas();
   var act = $('.tool-active');
   if (act.attr('id') == 'image-tool') {
@@ -1292,6 +1293,10 @@ function dragObject(e) {
   if (e.which == 3) {
     return false;
   }
+  // Measure before the clone leaves the panel - panel items are sized in
+  // percentages of a resizable panel, so a clone parented to <body> would
+  // report the body width instead.
+  var sourcewidth = $(this).width();
   var drag = $(this).clone();
   drag.css({
     background: 'transparent',
@@ -1304,7 +1309,7 @@ function dragObject(e) {
     zIndex: 9999999,
     left: $(this).offset().left,
     top: $(this).offset().top,
-    width: canvas.getZoom() * drag.width(),
+    width: canvas.getZoom() * sourcewidth,
     pointerEvents: 'none',
     opacity: 0,
   });
@@ -1619,10 +1624,13 @@ $(document).on(
 
 // Collapse library
 function collapsePanel() {
+  var act = $('.tool-active');
+  if (act.length > 0) {
+    // Remembered so the handle button can reopen the same tab
+    lasttool = act.attr('id');
+  }
   $('#browser').addClass('collapsed');
   $('#behind-browser').addClass('collapsed');
-  $('#canvas-area').addClass('canvas-full');
-  var act = $('.tool-active');
   if (act.attr('id') == 'image-tool') {
     act.find('img').attr('src', 'assets/image.svg');
   } else if (act.attr('id') == 'text-tool') {
@@ -1637,6 +1645,7 @@ function collapsePanel() {
     act.find('img').attr('src', 'assets/uploads.svg');
   }
   $('.tool-active').removeClass('tool-active');
+  applyPanelWidths();
   resizeCanvas();
 }
 $(document).on('click', '#collapse', collapsePanel);

src/styles.css

@@ -7,6 +7,14 @@
   --input-color: #22233e;
   --accent-color: #166ef1;
   --button-hover: #262746;
+  /* Panel geometry. Every rule that used to hardcode 76/299/300/375 derives
+     from these so the resize handles only have to move one number each.
+     --layers-w tracks --rail-w + --browser-w while the library panel is
+     visible, but stays put when it is hidden so the layer names keep room. */
+  --rail-w: 76px;
+  --browser-w: 299px;
+  --props-w: 300px;
+  --layers-w: 375px;
 }
 /*
 :root {
@@ -41,7 +49,7 @@ body {
   font-size: 14px;
   font-weight: 600;
   background: var(--panel-back);
-  width: 76px;
+  width: var(--rail-w);
   border-right: 1px solid var(--panel-stroke);
   box-sizing: border-box;
 }
@@ -244,7 +252,7 @@ body {
 #toolbar {
   position: absolute;
   height: calc(100% - 340px);
-  width: 76px;
+  width: var(--rail-w);
   background-color: var(--panel-back);
   border-right: 1px solid var(--panel-stroke);
   left: 0px;
@@ -308,8 +316,8 @@ body {
 #behind-browser {
   position: absolute;
   height: 100%;
-  width: 299px;
+  width: var(--browser-w);
-  left: 76px;
+  left: var(--rail-w);
   background: var(--panel-back);
   border-right: 1px solid var(--panel-stroke);
   z-index: 1;
@@ -318,10 +326,10 @@ body {
 #browser {
   position: absolute;
   height: calc(100% - 450px);
-  width: 299px;
+  width: var(--browser-w);
   background-color: var(--panel-back);
   border-right: 1px solid var(--panel-stroke);
-  left: 76px;
+  left: var(--rail-w);
   top: 110px;
   box-sizing: border-box;
   z-index: 999999;
@@ -333,7 +341,7 @@ body {
   display: none !important;
 }
 #browser-container {
-  width: 260px;
+  width: calc(var(--browser-w) - 39px);
   margin-left: auto;
   margin-right: auto;
   height: 100%;
@@ -359,7 +367,7 @@ body {
 }
 .image-grid-item,
 .video-grid-item {
-  width: 120px;
+  width: 100%;
   margin-bottom: 15px;
   position: relative;
 }
@@ -388,7 +396,7 @@ body {
   text-align: right;
   text-decoration: none;
   text-shadow: 0px 1px 5px #000000;
-  width: 110px;
+  width: calc(100% - 10px);
   white-space: nowrap;
   overflow: hidden;
   text-overflow: ellipsis;
@@ -436,7 +444,9 @@ body {
   grid-gap: 15px;
   width: 100%;
   grid-auto-columns: auto;
-  grid-template-columns: 52px 52px 52px 52px;
+  /* Column count follows the panel width so the grid reflows when the library
+     is resized instead of overflowing a fixed four-column track. */
+  grid-template-columns: repeat(auto-fill, minmax(52px, 1fr));
   overflow: hidden;
 }
 .scroll-row:before {
@@ -461,7 +471,7 @@ body {
 #search-fixed {
   position: fixed;
   top: 0px;
-  width: 279px;
+  width: calc(var(--browser-w) - 20px);
   padding-left: 19px;
   margin-left: -19px;
   z-index: 999999;
@@ -776,12 +786,13 @@ body {
   position: absolute;
   right: 0px;
   top: 0px;
-  width: 300px;
+  width: var(--props-w);
   height: calc(100% - 340px);
   background-color: var(--panel-back);
   border-left: 1px solid var(--panel-stroke);
   z-index: 999;
   overflow-y: overlay;
+  overflow-x: hidden;
 }
 #properties-overlay {
   width: 100%;
@@ -830,9 +841,12 @@ hr {
   background-color: var(--panel-stroke);
   margin-bottom: 20px;
 }
+#properties hr {
+  width: calc(var(--props-w) - 40px);
+}
 /* Property sections */
 .panel-section {
-  width: 260px;
+  width: calc(var(--props-w) - 40px);
   margin-left: auto;
   margin-right: auto;
 }
@@ -869,8 +883,17 @@ th {
   width: 189px;
   display: flex;
   align-items: center;
+  /* Keeps the inputs against the right edge once the column can be wider
+     than its contents */
+  justify-content: flex-end;
   margin-left: auto;
 }
+/* Inside the properties panel the value column follows the panel width, so
+   dropdowns and sliders grow when the panel is widened. 111px is the label
+   column plus the panel gutters. The filters popup keeps the fixed width. */
+#properties .value-col {
+  width: calc(var(--props-w) - 111px);
+}
 /* Dropdows */
 .nice-select,
 .list,
@@ -1550,16 +1573,12 @@ label span {
 #canvas-area {
   position: absolute;
   top: 0px;
-  left: 375px;
+  left: calc(var(--rail-w) + var(--browser-w));
   height: calc(100% - 342px);
-  width: calc(100% - 675px);
+  width: calc(100% - var(--rail-w) - var(--browser-w) - var(--props-w));
   box-sizing: border-box;
   overflow: hidden;
 }
-.canvas-full {
-  left: 76px !important;
-  width: calc(100% - 376px) !important;
-}
 .canvas-container {
   left: 0px;
   top: 0px;
@@ -1614,7 +1633,7 @@ canvas {
 #layer-list {
   position: absolute;
   height: 245px;
-  width: 375px;
+  width: var(--layers-w);
   left: 0px;
   bottom: 60px;
   background-color: var(--panel-back);
@@ -1816,7 +1835,7 @@ layer:nth-child(even) .properties {
   color: var(--secondary-text-color);
   line-height: 40px;
   height: 40px;
-  width: 375px;
+  width: var(--layers-w);
   position: fixed;
   margin-top: -35px;
   background-color: var(--panel-back);
@@ -1840,10 +1859,10 @@ layer:nth-child(even) .properties {
 #timearea {
   position: absolute;
   bottom: 60px;
-  left: 375px;
+  left: var(--layers-w);
   height: 245px;
   background-color: var(--main-back);
-  width: calc(100% - 375px);
+  width: calc(100% - var(--layers-w));
   border-top: 1px solid var(--panel-stroke);
   z-index: 999;
 }
@@ -1858,10 +1877,108 @@ layer:nth-child(even) .properties {
   cursor: ns-resize;
   background-color: var(--panel-stroke);
 }
+/* Side panel resize handles. Each one straddles the border between a side
+   panel and the canvas, and carries the hide/show button for that panel.
+   Their height is kept in sync with the panels by resetHeight(). */
+.panel-handle {
+  position: absolute;
+  top: 0px;
+  height: calc(100% - 340px);
+  width: 7px;
+  z-index: 9999999;
+  box-sizing: border-box;
+  touch-action: none;
+  -webkit-user-drag: none;
+  -webkit-user-select: none;
+  user-select: none;
+}
+#browser-handle {
+  left: calc(var(--rail-w) + var(--browser-w) - 3px);
+}
+#properties-handle {
+  right: calc(var(--props-w) - 3px);
+}
+#properties-handle.panel-hidden {
+  right: 0px;
+}
+.panel-handle:not(.panel-hidden):hover,
+.panel-handle.handle-dragging {
+  cursor: ew-resize;
+}
+.panel-handle:before {
+  content: "";
+  position: absolute;
+  left: 2px;
+  top: 0px;
+  width: 2px;
+  height: 100%;
+  background-color: var(--accent-color);
+  opacity: 0;
+}
+.panel-handle:not(.panel-hidden):hover:before,
+.panel-handle.handle-dragging:before {
+  opacity: 1;
+}
+.panel-toggle {
+  position: absolute;
+  top: 50%;
+  margin-top: -18px;
+  width: 18px;
+  height: 36px;
+  background-color: var(--input-color);
+  border: 1px solid var(--panel-stroke);
+  box-sizing: border-box;
+  /* Always on screen, dimmed. Revealing it on hover meant having to find the
+     3px resize line first, then travel onto the button. */
+  opacity: 0.4;
+}
+.panel-toggle:hover {
+  cursor: pointer;
+  background-color: var(--button-hover);
+}
+.panel-toggle:hover,
+.panel-handle:hover .panel-toggle,
+.panel-handle.handle-dragging .panel-toggle,
+.panel-handle.panel-hidden .panel-toggle {
+  opacity: 1;
+}
+/* Chevron, pointing at the edge the panel would collapse towards */
+.panel-toggle:after {
+  content: "";
+  position: absolute;
+  width: 5px;
+  height: 5px;
+  top: 50%;
+  left: 50%;
+  border-left: 1.5px solid var(--secondary-text-color);
+  border-bottom: 1.5px solid var(--secondary-text-color);
+}
+#browser-handle .panel-toggle {
+  left: 5px;
+  border-radius: 0px 4px 4px 0px;
+}
+#properties-handle .panel-toggle {
+  right: 5px;
+  border-radius: 4px 0px 0px 4px;
+}
+#properties-handle.panel-hidden .panel-toggle {
+  right: 4px;
+}
+#browser-handle .panel-toggle:after,
+#properties-handle.panel-hidden .panel-toggle:after {
+  margin: -4px 0px 0px -2px;
+  transform: rotate(45deg);
+}
+#properties-handle .panel-toggle:after,
+#browser-handle.panel-hidden .panel-toggle:after {
+  margin: -4px 0px 0px -5px;
+  transform: rotate(-135deg);
+}
 #seekarea {
   height: 100%;
   z-index: 99999;
-  width: calc(100% - 375px);
+  /* Fixed positioning - the percentage is the viewport, not #timearea. */
+  width: calc(100% - var(--layers-w));
   overflow-x: auto;
   overflow-y: hidden;
   position: fixed;