Docs/readme canvas limitation

README.md

@@ -108,7 +108,7 @@ Use `.json` (File → Save Design) to save your work. It preserves every object
 ## Limitations
 
 - ZPL import covers the most common commands but not the full ZPL II command set. Labels using printer-stored images, downloaded graphics, or printer-specific extensions may not import completely.
-- The canvas is a design preview, not a pixel-perfect simulation: fonts and exact rendering may differ from what the printer produces. Shapes, spacing, and positions should match. For an accurate render, use the **Preview** in the bottom-right panel (powered by Labelary).
+- The canvas is a design preview, not a pixel-perfect simulation. Shapes, spacing, and positions match the print; text approximates Zebra's built-in font to within a few dots, but exact letterforms and anti-aliasing differ. For a faithful render, use the **Preview** in the bottom-right panel (powered by Labelary).
 - Label preview requires a connection to `api.labelary.com`.
 - The Labelary preview doesn't render every ZPL feature. Some less common elements (e.g. Codablock F barcodes) may be missing or wrong in the preview even when the actual print is fine.
 - The Labelary preview shows only the current page; the printed/exported ZPL still contains every page.

src/components/Canvas/KonvaObject.tsx

@@ -17,7 +17,9 @@ type Props = KonvaObjectProps;
  * Selection outline drawn as a separate (non-listening) overlay so the
  * underlying shape can keep its own stroke / fill / globalCompositeOperation
  * without compromise. Sits at local (0, 0) inside the parent Group so it
- * follows drag translations together with the body.
+ * follows drag translations together with the body. Tracing the declared
+ * bbox (not the inset body) means a thick outline shape gets a marker on
+ * its outer pixel, matching the user's mental model of selection.
  */
 function SelectionOverlay({
   width,
@@ -48,6 +50,31 @@ function SelectionOverlay({
   );
 }
 
+/** Ellipse-shaped counterpart of `SelectionOverlay` for ^GE / ^GC bodies. */
+function EllipseSelectionOverlay({
+  rx,
+  ry,
+  color,
+}: {
+  rx: number;
+  ry: number;
+  color: string;
+}) {
+  return (
+    <Ellipse
+      x={rx}
+      y={ry}
+      radiusX={rx}
+      radiusY={ry}
+      stroke={color}
+      strokeWidth={1.5}
+      strokeScaleEnabled={false}
+      fill="transparent"
+      listening={false}
+    />
+  );
+}
+
 const BARCODE_TYPES = new Set([
   "code128",
   "code39",
@@ -93,21 +120,19 @@ export function KonvaObject(props_: Props) {
  *
  * Convention for adding a new shape type:
  *
- *  1. `id={obj.id}` sits on the **outermost render node**. Single-node
- *     shapes (e.g. plain Text, Ellipse, Circle) put it on that shape;
- *     multi-node shapes (Text+reverse, Box, Image, Line) wrap their
- *     parts in a `<Group>` and put the id there. Stage-level lookups
- *     (`stage.findOne(#id)`, snap, alt+click cycle) all walk up to the
- *     id'd ancestor, so this stays consistent.
+ *  1. `id={obj.id}` sits on the **outermost render node**. Plain Text
+ *     puts it directly on the Text node; every other shape wraps body
+ *     plus selection overlay in a `<Group>` and puts the id there.
+ *     Stage-level lookups (`stage.findOne(#id)`, snap, alt+click cycle)
+ *     all walk up to the id'd ancestor, so this stays consistent.
  *
- *  2. Selection visuals: a single shape can put its own selection stroke
- *     on itself (`stroke={isSelected ? colors.selection : ...}`). A
- *     shape whose body uses `globalCompositeOperation: "difference"`
- *     for ZPL `^LRY` (currently Box and Line) needs an extra
- *     `<SelectionOverlay>` Rect drawn with normal blending, so the
- *     selection stroke isn't itself blended into a wrong colour. The
- *     overlay sits inside the same Group as the body so drag
- *     translations move both together.
+ *  2. Selection visuals: shapes draw a dedicated overlay component
+ *     (`SelectionOverlay` for rectangular bodies, `EllipseSelectionOverlay`
+ *     for ^GE / ^GC) that traces the declared outer bbox. Decoupling the
+ *     marker from the body means a thick outline (or a ^LRY difference-
+ *     blended body) keeps a clean blue marker on its outer pixel rather
+ *     than re-tracing the body's stroke. The overlay sits inside the same
+ *     Group as the body so drag translations move both together.
  */
 function KonvaObjectInner({
   obj,
@@ -368,14 +393,16 @@ function KonvaObjectInner({
 
   if (obj.type === "ellipse") {
     const p = obj.props;
-    const rx = dotsToPx(p.width, scale, dpmm) / 2;
-    const ry = dotsToPx(p.height, scale, dpmm) / 2;
+    const w = dotsToPx(p.width, scale, dpmm);
+    const h = dotsToPx(p.height, scale, dpmm);
+    const rx = w / 2;
+    const ry = h / 2;
     const stroke = p.color === "B" ? "#000000" : "#cccccc";
     const strokeWidth = Math.max(dotsToPx(p.thickness, scale, dpmm), 0.5);
     // Option-A geometry — same outlineInset() definition as the box
     // path so the firmware's clamp-to-solid rule stays consistent
     // across shapes; only the centred-stroke placement differs.
-    const insetGeom = outlineInset(rx * 2, ry * 2, strokeWidth, p.filled);
+    const insetGeom = outlineInset(w, h, strokeWidth, p.filled);
     const renderFilled = insetGeom.renderFilled;
     const insetRx = insetGeom.width / 2;
     const insetRy = insetGeom.height / 2;
@@ -384,47 +411,44 @@ function KonvaObjectInner({
         ? "#000000"
         : "#ffffff"
       : "transparent";
+    // Group-at-top-left wrapper mirrors the box path: keeps the body's
+    // own stroke + thickness while a separate EllipseSelectionOverlay
+    // traces the outer bbox in the selection colour.
     return (
-      <Ellipse
+      <Group
         id={obj.id}
-        x={x + rx}
-        y={y + ry}
-        radiusX={insetRx}
-        radiusY={insetRy}
-        stroke={isSelected ? colors.selection : stroke}
-        strokeWidth={
-          isSelected
-            ? Math.max(strokeWidth, 1.5)
-            : renderFilled
-              ? 0
-              : strokeWidth
-        }
-        strokeScaleEnabled={false}
-        fill={fill}
+        x={x}
+        y={y}
         draggable={!obj.locked}
         {...selectionHandlers(onSelect)}
-        onDragMove={(e) => {
-          // Center-anchored: snap the top-left corner, then re-add radius
-          const snapped = snapPos(e.target.x() - rx, e.target.y() - ry);
-          e.target.position({ x: snapped.x + rx, y: snapped.y + ry });
-        }}
-        onDragEnd={(e) => {
-          onChange({
-            x: pxToDots(e.target.x() - rx - offsetX, scale, dpmm),
-            y: pxToDots(e.target.y() - ry - offsetY, scale, dpmm),
-          });
-        }}
-      />
+        onDragMove={handleDragMove}
+        onDragEnd={handleDragEnd}
+      >
+        <Ellipse
+          x={rx}
+          y={ry}
+          radiusX={insetRx}
+          radiusY={insetRy}
+          stroke={stroke}
+          strokeWidth={renderFilled ? 0 : strokeWidth}
+          strokeScaleEnabled={false}
+          fill={fill}
+        />
+        {isSelected && (
+          <EllipseSelectionOverlay rx={rx} ry={ry} color={colors.selection} />
+        )}
+      </Group>
     );
   }
 
   if (obj.type === "circle") {
     const p = obj.props;
-    const r = dotsToPx(p.diameter, scale, dpmm) / 2;
+    const d = dotsToPx(p.diameter, scale, dpmm);
+    const r = d / 2;
     const stroke = p.color === "B" ? "#000000" : "#cccccc";
     const strokeWidth = Math.max(dotsToPx(p.thickness, scale, dpmm), 0.5);
     // Option-A geometry — same outlineInset() definition as box/ellipse.
-    const insetGeom = outlineInset(r * 2, r * 2, strokeWidth, p.filled);
+    const insetGeom = outlineInset(d, d, strokeWidth, p.filled);
     const renderFilled = insetGeom.renderFilled;
     const insetR = insetGeom.width / 2;
     const fill = renderFilled
@@ -433,34 +457,28 @@ function KonvaObjectInner({
         : "#ffffff"
       : "transparent";
     return (
-      <Circle
+      <Group
         id={obj.id}
-        x={x + r}
-        y={y + r}
-        radius={insetR}
-        stroke={isSelected ? colors.selection : stroke}
-        strokeWidth={
-          isSelected
-            ? Math.max(strokeWidth, 1.5)
-            : renderFilled
-              ? 0
-              : strokeWidth
-        }
-        strokeScaleEnabled={false}
-        fill={fill}
+        x={x}
+        y={y}
         draggable={!obj.locked}
         {...selectionHandlers(onSelect)}
-        onDragMove={(e) => {
-          const snapped = snapPos(e.target.x() - r, e.target.y() - r);
-          e.target.position({ x: snapped.x + r, y: snapped.y + r });
-        }}
-        onDragEnd={(e) => {
-          onChange({
-            x: pxToDots(e.target.x() - r - offsetX, scale, dpmm),
-            y: pxToDots(e.target.y() - r - offsetY, scale, dpmm),
-          });
-        }}
-      />
+        onDragMove={handleDragMove}
+        onDragEnd={handleDragEnd}
+      >
+        <Circle
+          x={r}
+          y={r}
+          radius={insetR}
+          stroke={stroke}
+          strokeWidth={renderFilled ? 0 : strokeWidth}
+          strokeScaleEnabled={false}
+          fill={fill}
+        />
+        {isSelected && (
+          <EllipseSelectionOverlay rx={r} ry={r} color={colors.selection} />
+        )}
+      </Group>
     );
   }
 

src/components/Canvas/hooks/useKonvaTransformer.ts

@@ -9,7 +9,6 @@ import { findObjectById, isGroup } from "../../../types/Group";
 import {
   applyHeightSnap,
   pinInactiveEdges,
-  transformNodeTopLeft,
   positionDidMove,
   forceSquareBox,
   type BoundingBox,
@@ -303,7 +302,6 @@ export function useKonvaTransformer({
     }
     const sx = node.scaleX();
     const sy = node.scaleY();
-    const nodeWidth = node.width();
     const nodeHeight = node.height();
     node.scaleX(1);
     node.scaleY(1);
@@ -312,18 +310,8 @@ export function useKonvaTransformer({
       cleanupTransformState();
       return;
     }
-    const isCenterAnchored = ObjectRegistry[obj.type]?.nodeOrigin === "center";
-    const topLeft = transformNodeTopLeft(
-      node.x(),
-      node.y(),
-      nodeWidth,
-      nodeHeight,
-      sx,
-      sy,
-      isCenterAnchored,
-    );
-    const renderedXDots = pxToDots(topLeft.x - objectsOffsetX, scale, dpmm);
-    const renderedYDots = pxToDots(topLeft.y - labelOffsetY, scale, dpmm);
+    const renderedXDots = pxToDots(node.x() - objectsOffsetX, scale, dpmm);
+    const renderedYDots = pxToDots(node.y() - labelOffsetY, scale, dpmm);
     // For FT-anchored 1D barcodes, model.y is the bar baseline — needs the
     // post-resize bar height to convert from the bbox top back. Pipe the
     // scaled height through the same snap() commitBarcodeWidthHeight-

src/components/Canvas/transformerGeometry.test.ts

@@ -3,7 +3,6 @@ import {
   snapBoxHeight,
   pinBottomEdge,
   isTopAnchorResize,
-  transformNodeTopLeft,
   positionDidMove,
   forceSquareBox,
   applyHeightSnap,
@@ -62,29 +61,6 @@ describe("isTopAnchorResize", () => {
   });
 });
 
-describe("transformNodeTopLeft", () => {
-  it("passes top-left-anchored nodes through unchanged", () => {
-    // Rect / Image / Text use their top-left as the Konva origin.
-    const result = transformNodeTopLeft(100, 50, 200, 100, 1.5, 1, false);
-    expect(result).toEqual({ x: 100, y: 50 });
-  });
-
-  it("subtracts half the visual size for center-anchored nodes (Ellipse)", () => {
-    // Ellipse with intrinsic size 100x80, scaled 2x in both axes.
-    // node.x()/y() are the center; visual radius = nodeSize * scale / 2.
-    const result = transformNodeTopLeft(200, 100, 100, 80, 2, 2, true);
-    expect(result).toEqual({ x: 100, y: 20 });
-  });
-
-  it("uses the captured (pre-reset) node size, not the post-reset one", () => {
-    // Even when scale is no longer 1 conceptually, the formula uses the
-    // intrinsic nodeWidth/nodeHeight times the scale to derive visual size.
-    const result = transformNodeTopLeft(150, 150, 50, 50, 4, 4, true);
-    expect(result.x).toBe(50); // 150 - (50 * 4) / 2 = 150 - 100
-    expect(result.y).toBe(50);
-  });
-});
-
 describe("positionDidMove", () => {
   it("returns false when the position matches within the tolerance", () => {
     expect(positionDidMove(100, 100)).toBe(false);

src/components/Canvas/transformerGeometry.ts

@@ -50,27 +50,6 @@ export function isTopAnchorResize(
   return Math.abs(newBox.y - oldBox.y) > thresholdPx;
 }
 
-/**
- * Translate a transformed Konva node's coordinate into the model's top-left
- * stage-pixel coordinate. Konva's Ellipse positions by its center; everything
- * else by top-left. The visual size after a Transformer drag is `nodeSize * s`
- * (full width / height): the node's intrinsic size is unchanged at this point,
- * so only the scale captured before reset reflects the post-drag dimensions.
- */
-export function transformNodeTopLeft(
-  nodeX: number,
-  nodeY: number,
-  nodeWidth: number,
-  nodeHeight: number,
-  sx: number,
-  sy: number,
-  isCenterAnchored: boolean,
-): { x: number; y: number } {
-  const dx = isCenterAnchored ? (nodeWidth * sx) / 2 : 0;
-  const dy = isCenterAnchored ? (nodeHeight * sy) / 2 : 0;
-  return { x: nodeX - dx, y: nodeY - dy };
-}
-
 /**
  * Phase 1 of resize: row-quantise the height for stacked-2D barcodes
  * (PDF417, MicroPDF417, Codablock) where a non-integer row count is

src/registry/circle.tsx

@@ -22,7 +22,6 @@ export const circle: ObjectTypeDefinition<CircleProps> = {
     color: 'B',
   },
   defaultSize: { width: 100, height: 100 },
-  nodeOrigin: 'center',
   uniformScale: true,
 
   // Force a uniform scale: take the smaller of the two axes so the resized

src/registry/ellipse.tsx

@@ -25,7 +25,6 @@ export const ellipse: ObjectTypeDefinition<EllipseProps> = {
     color: 'B',
   },
   defaultSize: { width: 150, height: 100 },
-  nodeOrigin: 'center',
 
   commitTransform: commitWidthHeightTransform,
 

src/types/ObjectType.ts

@@ -73,13 +73,6 @@ export interface ObjectTypeDefinition<P extends object = object> {
   group: ObjectGroup;
   defaultProps: P;
   defaultSize: { width: number; height: number };
-  /**
-   * Origin of the Konva node used to render this type. Defaults to 'top-left'.
-   * Set to 'center' for shapes whose Konva counterpart positions by their
-   * center (e.g. Ellipse), so the transformer can convert the node coordinate
-   * back to the model's top-left convention.
-   */
-  nodeOrigin?: 'center' | 'top-left';
   /**
    * True if the rendered height is fixed by the symbology spec rather than the
    * `height` prop (e.g. GS1 Databar Omnidirectional). The transformer disables