15 files changed, 607 insertions, 385 deletions

diff --git a/subprojects/frontend/config/graphvizUMDVitePlugin.ts b/subprojects/frontend/config/graphvizUMDVitePlugin.ts
index 7a42560b..9c60a84e 100644
--- a/subprojects/frontend/config/graphvizUMDVitePlugin.ts
+++ b/subprojects/frontend/config/graphvizUMDVitePlugin.ts
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
 import { readFile } from 'node:fs/promises';
 import path from 'node:path';
 
diff --git a/subprojects/frontend/index.html b/subprojects/frontend/index.html
index 1bf3472e..f4b46da2 100644
--- a/subprojects/frontend/index.html
+++ b/subprojects/frontend/index.html
@@ -18,7 +18,7 @@
     <meta name="theme-color" media="(prefers-color-scheme:light)" content="#f5f5f5">
     <meta name="theme-color" media="(prefers-color-scheme:dark)" content="#21252b">
     <style>
-      @import '@fontsource-variable/inter/wght.css';
+      @import '@fontsource-variable/open-sans/wdth.css';
       @import '@fontsource-variable/jetbrains-mono/wght.css';
       @import '@fontsource-variable/jetbrains-mono/wght-italic.css';
     </style>
diff --git a/subprojects/frontend/package.json b/subprojects/frontend/package.json
index 97f6baf6..3ebb1542 100644
--- a/subprojects/frontend/package.json
+++ b/subprojects/frontend/package.json
@@ -37,8 +37,8 @@
     "@codemirror/view": "^6.16.0",
     "@emotion/react": "^11.11.1",
     "@emotion/styled": "^11.11.0",
-    "@fontsource-variable/inter": "^5.0.8",
     "@fontsource-variable/jetbrains-mono": "^5.0.9",
+    "@fontsource-variable/open-sans": "^5.0.9",
     "@hpcc-js/wasm": "^2.13.1",
     "@lezer/common": "^1.0.3",
     "@lezer/highlight": "^1.1.6",
@@ -53,7 +53,6 @@
     "d3-selection": "^3.0.0",
     "d3-zoom": "patch:d3-zoom@npm%3A3.0.0#~/.yarn/patches/d3-zoom-npm-3.0.0-18f706a421.patch",
     "escape-string-regexp": "^5.0.0",
-    "json-stringify-pretty-compact": "^4.0.0",
     "lodash-es": "^4.17.21",
     "loglevel": "^1.8.1",
     "loglevel-plugin-prefix": "^0.8.4",
diff --git a/subprojects/frontend/src/TopBar.tsx b/subprojects/frontend/src/TopBar.tsx
index f2542b14..c722c203 100644
--- a/subprojects/frontend/src/TopBar.tsx
+++ b/subprojects/frontend/src/TopBar.tsx
@@ -124,7 +124,16 @@ export default observer(function TopBar(): JSX.Element {
                 href="https://www.mcgill.ca/ece/daniel-varro"
                 target="_blank"
               >
-                McGill ECE
+                M<span style={{ textTransform: 'none' }}>c</span>Gill ECE
+              </Button>
+              <Button
+                aria-label="Linkönping University, Department of Computer and Information Science"
+                className="rounded"
+                color="inherit"
+                href="https://liu.se/en/employee/danva91"
+                target="_blank"
+              >
+                L<span style={{ textTransform: 'none' }}>i</span>U IDA
               </Button>
               <Button
                 aria-label="2022 Amazon Research Awards recipent"
diff --git a/subprojects/frontend/src/editor/EditorTheme.ts b/subprojects/frontend/src/editor/EditorTheme.ts
index dd551a52..4508273b 100644
--- a/subprojects/frontend/src/editor/EditorTheme.ts
+++ b/subprojects/frontend/src/editor/EditorTheme.ts
@@ -56,8 +56,9 @@ export default styled('div', {
     '.cm-activeLineGutter': {
       background: 'transparent',
     },
-    '.cm-cursor, .cm-cursor-primary': {
+    '.cm-cursor, .cm-dropCursor, .cm-cursor-primary': {
       borderLeft: `2px solid ${theme.palette.info.main}`,
+      marginLeft: -1,
     },
     '.cm-selectionBackground': {
       background: theme.palette.highlight.selection,
diff --git a/subprojects/frontend/src/graph/DotGraphVisualizer.tsx b/subprojects/frontend/src/graph/DotGraphVisualizer.tsx
new file mode 100644
index 00000000..7c25488a
--- /dev/null
+++ b/subprojects/frontend/src/graph/DotGraphVisualizer.tsx
@@ -0,0 +1,142 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+import * as d3 from 'd3';
+import { type Graphviz, graphviz } from 'd3-graphviz';
+import type { BaseType, Selection } from 'd3-selection';
+import { reaction, type IReactionDisposer } from 'mobx';
+import { useCallback, useRef } from 'react';
+
+import { useRootStore } from '../RootStoreProvider';
+import type { SemanticsSuccessResult } from '../xtext/xtextServiceResults';
+
+import GraphTheme from './GraphTheme';
+import postProcessSvg from './postProcessSVG';
+
+function toGraphviz(
+  semantics: SemanticsSuccessResult | undefined,
+): string | undefined {
+  if (semantics === undefined) {
+    return undefined;
+  }
+  const lines = [
+    'digraph {',
+    'graph [bgcolor=transparent];',
+    `node [fontsize=12, shape=plain, fontname="OpenSans"];`,
+    'edge [fontsize=10.5, color=black, fontname="OpenSans"];',
+  ];
+  const nodeIds = semantics.nodes.map((name, i) => name ?? `n${i}`);
+  lines.push(
+    ...nodeIds.map(
+      (id, i) =>
+        `n${i} [id="${id}", label=<<table border="1" cellborder="0" cellspacing="0" cellpadding="4.5" style="rounded" bgcolor="green"><tr><td>${id}</td></tr><hr/><tr><td bgcolor="white">node</td></tr></table>>];`,
+    ),
+  );
+  Object.keys(semantics.partialInterpretation).forEach((relation) => {
+    if (relation === 'builtin::equals' || relation === 'builtin::contains') {
+      return;
+    }
+    const tuples = semantics.partialInterpretation[relation];
+    if (tuples === undefined) {
+      return;
+    }
+    const first = tuples[0];
+    if (first === undefined || first.length !== 3) {
+      return;
+    }
+    const nameFragments = relation.split('::');
+    const simpleName = nameFragments[nameFragments.length - 1] ?? relation;
+    lines.push(
+      ...tuples.map(([from, to, value]) => {
+        if (
+          typeof from !== 'number' ||
+          typeof to !== 'number' ||
+          typeof value !== 'string'
+        ) {
+          return '';
+        }
+        const isUnknown = value === 'UNKNOWN';
+        return `n${from} -> n${to} [
+            id="${nodeIds[from]},${nodeIds[to]},${relation}",
+            xlabel="${simpleName}",
+            style="${isUnknown ? 'dashed' : 'solid'}",
+            class="edge-${value}"
+          ];`;
+      }),
+    );
+  });
+  lines.push('}');
+  return lines.join('\n');
+}
+
+export default function DotGraphVisualizer(): JSX.Element {
+  const { editorStore } = useRootStore();
+  const disposerRef = useRef<IReactionDisposer | undefined>();
+  const graphvizRef = useRef<
+    Graphviz<BaseType, unknown, null, undefined> | undefined
+  >();
+
+  const setElement = useCallback(
+    (element: HTMLDivElement | null) => {
+      if (disposerRef.current !== undefined) {
+        disposerRef.current();
+        disposerRef.current = undefined;
+      }
+      if (graphvizRef.current !== undefined) {
+        // `@types/d3-graphviz` does not contain the signature for the `destroy` method.
+        (graphvizRef.current as unknown as { destroy(): void }).destroy();
+        graphvizRef.current = undefined;
+      }
+      if (element !== null) {
+        element.replaceChildren();
+        const renderer = graphviz(element) as Graphviz<
+          BaseType,
+          unknown,
+          null,
+          undefined
+        >;
+        renderer.keyMode('id');
+        renderer.zoom(false);
+        renderer.tweenPrecision('5%');
+        renderer.tweenShapes(false);
+        renderer.convertEqualSidedPolygons(false);
+        const transition = () =>
+          d3.transition().duration(300).ease(d3.easeCubic);
+        /* eslint-disable-next-line @typescript-eslint/no-unsafe-argument,
+          @typescript-eslint/no-explicit-any --
+          Workaround for error in `@types/d3-graphviz`.
+        */
+        renderer.transition(transition as any);
+        renderer.on(
+          'postProcessSVG',
+          // @ts-expect-error Custom `d3-graphviz` hook not covered by typings.
+          (
+            svgSelection: Selection<SVGSVGElement, unknown, BaseType, unknown>,
+          ) => {
+            const svg = svgSelection.node();
+            if (svg !== null) {
+              postProcessSvg(svg);
+            }
+          },
+        );
+        disposerRef.current = reaction(
+          () => editorStore?.semantics,
+          (semantics) => {
+            const str = toGraphviz(semantics);
+            if (str !== undefined) {
+              renderer.renderDot(str);
+            }
+          },
+          { fireImmediately: true },
+        );
+        graphvizRef.current = renderer;
+      }
+    },
+    [editorStore],
+  );
+
+  return <GraphTheme ref={setElement} />;
+}
diff --git a/subprojects/frontend/src/graph/GraphArea.tsx b/subprojects/frontend/src/graph/GraphArea.tsx
index 6ca3bc87..32147d92 100644
--- a/subprojects/frontend/src/graph/GraphArea.tsx
+++ b/subprojects/frontend/src/graph/GraphArea.tsx
@@ -1,384 +1,16 @@
 /*
- * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
  *
  * SPDX-License-Identifier: EPL-2.0
  */
 
-import AddIcon from '@mui/icons-material/Add';
-import CropFreeIcon from '@mui/icons-material/CropFree';
-import RemoveIcon from '@mui/icons-material/Remove';
-import Box from '@mui/material/Box';
-import IconButton from '@mui/material/IconButton';
-import Stack from '@mui/material/Stack';
-import { useTheme } from '@mui/material/styles';
-import { CSSProperties } from '@mui/material/styles/createTypography';
-import * as d3 from 'd3';
-import { type Graphviz, graphviz } from 'd3-graphviz';
-import type { BaseType, Selection } from 'd3-selection';
-import { zoom as d3Zoom } from 'd3-zoom';
-import { reaction, type IReactionDisposer } from 'mobx';
-import { useCallback, useRef, useState } from 'react';
-
-import { useRootStore } from '../RootStoreProvider';
-import type { SemanticsSuccessResult } from '../xtext/xtextServiceResults';
-
-function toGraphviz(
-  semantics: SemanticsSuccessResult | undefined,
-): string | undefined {
-  if (semantics === undefined) {
-    return undefined;
-  }
-  const lines = [
-    'digraph {',
-    'graph [bgcolor=transparent];',
-    'node [fontsize=16, shape=plain];',
-    'edge [fontsize=12, color=black];',
-  ];
-  const nodeIds = semantics.nodes.map((name, i) => name ?? `n${i}`);
-  lines.push(
-    ...nodeIds.map(
-      (id, i) =>
-        `n${i} [id="${id}", label=<<table border="1" cellborder="0" cellspacing="0" cellpadding="4" style="rounded" bgcolor="green"><tr><td>${id}</td></tr><hr/><tr><td bgcolor="white">node</td></tr></table>>];`,
-    ),
-  );
-  Object.keys(semantics.partialInterpretation).forEach((relation) => {
-    if (relation === 'builtin::equals' || relation === 'builtin::contains') {
-      return;
-    }
-    const tuples = semantics.partialInterpretation[relation];
-    if (tuples === undefined) {
-      return;
-    }
-    const first = tuples[0];
-    if (first === undefined || first.length !== 3) {
-      return;
-    }
-    const nameFragments = relation.split('::');
-    const simpleName = nameFragments[nameFragments.length - 1] ?? relation;
-    lines.push(
-      ...tuples.map(([from, to, value]) => {
-        if (
-          typeof from !== 'number' ||
-          typeof to !== 'number' ||
-          typeof value !== 'string'
-        ) {
-          return '';
-        }
-        const isUnknown = value === 'UNKNOWN';
-        return `n${from} -> n${to} [
-            id="${nodeIds[from]},${nodeIds[to]},${relation}",
-            xlabel="${simpleName}",
-            style="${isUnknown ? 'dashed' : 'solid'}",
-            class="edge-${value}"
-          ];`;
-      }),
-    );
-  });
-  lines.push('}');
-  return lines.join('\n');
-}
-
-interface Transform {
-  x: number;
-  y: number;
-  k: number;
-}
+import DotGraphVisualizer from './DotGraphVisualizer';
+import ZoomCanvas from './ZoomCanvas';
 
 export default function GraphArea(): JSX.Element {
-  const { editorStore } = useRootStore();
-  const theme = useTheme();
-  const disposerRef = useRef<IReactionDisposer | undefined>();
-  const graphvizRef = useRef<
-    Graphviz<BaseType, unknown, null, undefined> | undefined
-  >();
-  const canvasRef = useRef<HTMLDivElement | undefined>();
-  const elementRef = useRef<HTMLDivElement | undefined>();
-  const zoomRef = useRef<
-    d3.ZoomBehavior<HTMLDivElement, unknown> | undefined
-  >();
-  const [zoom, setZoom] = useState<Transform>({ x: 0, y: 0, k: 1 });
-
-  const setCanvas = useCallback((element: HTMLDivElement | null) => {
-    canvasRef.current = element ?? undefined;
-    if (element === null) {
-      return;
-    }
-    const zoomBehavior = d3Zoom<HTMLDivElement, unknown>();
-    // `@types/d3-zoom` does not contain the `center` function, because it is
-    // only available as a pull request for `d3-zoom`.
-    (
-      zoomBehavior as unknown as {
-        center(callback: (event: MouseEvent) => [number, number]): unknown;
-      }
-    ).center((event: MouseEvent | Touch) => {
-      const { width, height } = element.getBoundingClientRect();
-      const [x, y] = d3.pointer(event, element);
-      return [x - width / 2, y - height / 2];
-    });
-    // Custom `centroid` method added via patch.
-    (
-      zoomBehavior as unknown as {
-        centroid(centroid: [number, number]): unknown;
-      }
-    ).centroid([0, 0]);
-    zoomBehavior.on('zoom', (event: d3.D3ZoomEvent<HTMLDivElement, unknown>) =>
-      setZoom(event.transform),
-    );
-    d3.select(element).call(zoomBehavior);
-    zoomRef.current = zoomBehavior;
-  }, []);
-
-  const setElement = useCallback(
-    (element: HTMLDivElement | null) => {
-      elementRef.current = element ?? undefined;
-      if (disposerRef.current !== undefined) {
-        disposerRef.current();
-        disposerRef.current = undefined;
-      }
-      if (graphvizRef.current !== undefined) {
-        // `@types/d3-graphviz` does not contain the signature for the `destroy` method.
-        (graphvizRef.current as unknown as { destroy(): void }).destroy();
-        graphvizRef.current = undefined;
-      }
-      if (element !== null) {
-        element.replaceChildren();
-        const renderer = graphviz(element) as Graphviz<
-          BaseType,
-          unknown,
-          null,
-          undefined
-        >;
-        renderer.keyMode('id');
-        renderer.zoom(false);
-        renderer.tweenPrecision('5%');
-        renderer.tweenShapes(false);
-        renderer.convertEqualSidedPolygons(false);
-        const transition = () =>
-          d3.transition().duration(300).ease(d3.easeCubic);
-        /* eslint-disable-next-line @typescript-eslint/no-unsafe-argument,
-          @typescript-eslint/no-explicit-any --
-          Workaround for error in `@types/d3-graphviz`.
-        */
-        renderer.transition(transition as any);
-        renderer.on(
-          'postProcessSVG',
-          // @ts-expect-error Custom `d3-graphviz` hook not covered by typings.
-          (
-            svgSelection: Selection<SVGSVGElement, unknown, BaseType, unknown>,
-          ) => {
-            svgSelection.selectAll('title').remove();
-            const svg = svgSelection.node();
-            if (svg === null) {
-              return;
-            }
-            svg.querySelectorAll('.node').forEach((node) => {
-              node.querySelectorAll('path').forEach((path) => {
-                const d = path.getAttribute('d') ?? '';
-                const points = d.split(/[A-Z ]/);
-                points.shift();
-                const x = points.map((p) => {
-                  return Number(p.split(',')[0] ?? 0);
-                });
-                const y = points.map((p) => {
-                  return Number(p.split(',')[1] ?? 0);
-                });
-                const xmin = Math.min.apply(null, x);
-                const xmax = Math.max.apply(null, x);
-                const ymin = Math.min.apply(null, y);
-                const ymax = Math.max.apply(null, y);
-                const rect = document.createElementNS(
-                  'http://www.w3.org/2000/svg',
-                  'rect',
-                );
-                rect.setAttribute('fill', path.getAttribute('fill') ?? '');
-                rect.setAttribute('stroke', path.getAttribute('stroke') ?? '');
-                rect.setAttribute('x', String(xmin));
-                rect.setAttribute('y', String(ymin));
-                rect.setAttribute('width', String(xmax - xmin));
-                rect.setAttribute('height', String(ymax - ymin));
-                rect.setAttribute('height', String(ymax - ymin));
-                rect.setAttribute('rx', '8');
-                rect.setAttribute('ry', '8');
-                node.replaceChild(rect, path);
-              });
-            });
-          },
-        );
-        disposerRef.current = reaction(
-          () => editorStore?.semantics,
-          (semantics) => {
-            const str = toGraphviz(semantics);
-            if (str !== undefined) {
-              renderer.renderDot(str);
-            }
-          },
-          { fireImmediately: true },
-        );
-        graphvizRef.current = renderer;
-      }
-    },
-    [editorStore],
-  );
-
-  const changeZoom = useCallback((event: React.MouseEvent, factor: number) => {
-    if (canvasRef.current === undefined || zoomRef.current === undefined) {
-      return;
-    }
-    const selection = d3.select(canvasRef.current);
-    const zoomTransition = selection.transition().duration(250);
-    const center: [number, number] = [0, 0];
-    zoomRef.current.scaleBy(zoomTransition, factor, center);
-    event.preventDefault();
-    event.stopPropagation();
-  }, []);
-
-  const fitZoom = useCallback((event: React.MouseEvent) => {
-    if (
-      canvasRef.current === undefined ||
-      zoomRef.current === undefined ||
-      elementRef.current === undefined
-    ) {
-      return;
-    }
-    const { width: canvasWidth, height: canvasHeight } =
-      canvasRef.current.getBoundingClientRect();
-    const { width: scaledWidth, height: scaledHeight } =
-      elementRef.current.getBoundingClientRect();
-    const currentFactor = d3.zoomTransform(canvasRef.current).k;
-    const width = scaledWidth / currentFactor;
-    const height = scaledHeight / currentFactor;
-    if (width > 0 && height > 0) {
-      const factor = Math.min(
-        1.0,
-        (canvasWidth - 64) / width,
-        (canvasHeight - 64) / height,
-      );
-      const selection = d3.select(canvasRef.current);
-      const zoomTransition = selection.transition().duration(250);
-      zoomRef.current.transform(zoomTransition, d3.zoomIdentity.scale(factor));
-    }
-    event.preventDefault();
-    event.stopPropagation();
-  }, []);
-
   return (
-    <Box
-      sx={{
-        width: '100%',
-        height: '100%',
-        position: 'relative',
-        overflow: 'hidden',
-      }}
-    >
-      <Box
-        sx={{
-          position: 'absolute',
-          overflow: 'hidden',
-          top: 0,
-          left: 0,
-          right: 0,
-          bottom: 0,
-        }}
-        ref={setCanvas}
-      >
-        <Box
-          sx={{
-            position: 'absolute',
-            top: '50%',
-            left: '50%',
-            transform: `
-              translate(${zoom.x}px, ${zoom.y}px)
-              scale(${zoom.k})
-              translate(-50%, -50%)
-            `,
-            transformOrigin: '0 0',
-            '& svg': {
-              userSelect: 'none',
-              '& .node': {
-                '& text': {
-                  ...(theme.typography.body2 as Omit<
-                    CSSProperties,
-                    '@font-face'
-                  >),
-                  fill: theme.palette.text.primary,
-                },
-                '& [stroke="black"]': {
-                  stroke: theme.palette.text.primary,
-                },
-                '& [fill="green"]': {
-                  fill:
-                    theme.palette.mode === 'dark'
-                      ? theme.palette.primary.dark
-                      : theme.palette.primary.light,
-                },
-                '& [fill="white"]': {
-                  fill: theme.palette.background.default,
-                  stroke: theme.palette.background.default,
-                },
-              },
-              '& .edge': {
-                '& text': {
-                  ...(theme.typography.caption as Omit<
-                    CSSProperties,
-                    '@font-face'
-                  >),
-                  fill: theme.palette.text.primary,
-                },
-                '& [stroke="black"]': {
-                  stroke: theme.palette.text.primary,
-                },
-                '& [fill="black"]': {
-                  fill: theme.palette.text.primary,
-                },
-              },
-              '& .edge-UNKNOWN': {
-                '& text': {
-                  fill: theme.palette.text.secondary,
-                },
-                '& [stroke="black"]': {
-                  stroke: theme.palette.text.secondary,
-                },
-                '& [fill="black"]': {
-                  fill: theme.palette.text.secondary,
-                },
-              },
-              '& .edge-ERROR': {
-                '& text': {
-                  fill: theme.palette.error.main,
-                },
-                '& [stroke="black"]': {
-                  stroke: theme.palette.error.main,
-                },
-                '& [fill="black"]': {
-                  fill: theme.palette.error.main,
-                },
-              },
-            },
-          }}
-          ref={setElement}
-        />
-      </Box>
-      <Stack
-        direction="column"
-        p={1}
-        sx={{ position: 'absolute', bottom: 0, right: 0 }}
-      >
-        <IconButton
-          aria-label="Zoom in"
-          onClick={(event) => changeZoom(event, 2)}
-        >
-          <AddIcon fontSize="small" />
-        </IconButton>
-        <IconButton
-          aria-label="Zoom out"
-          onClick={(event) => changeZoom(event, 0.5)}
-        >
-          <RemoveIcon fontSize="small" />
-        </IconButton>
-        <IconButton aria-label="Fit screen" onClick={fitZoom}>
-          <CropFreeIcon fontSize="small" />
-        </IconButton>
-      </Stack>
-    </Box>
+    <ZoomCanvas>
+      <DotGraphVisualizer />
+    </ZoomCanvas>
   );
 }
diff --git a/subprojects/frontend/src/graph/GraphPane.tsx b/subprojects/frontend/src/graph/GraphPane.tsx
index f04b9931..c2ef8927 100644
--- a/subprojects/frontend/src/graph/GraphPane.tsx
+++ b/subprojects/frontend/src/graph/GraphPane.tsx
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
  *
  * SPDX-License-Identifier: EPL-2.0
  */
diff --git a/subprojects/frontend/src/graph/GraphTheme.tsx b/subprojects/frontend/src/graph/GraphTheme.tsx
new file mode 100644
index 00000000..41ba6ba5
--- /dev/null
+++ b/subprojects/frontend/src/graph/GraphTheme.tsx
@@ -0,0 +1,64 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+import { styled, type CSSObject } from '@mui/material/styles';
+
+function createEdgeColor(suffix: string, color: string): CSSObject {
+  return {
+    [`& .edge-${suffix}`]: {
+      '& text': {
+        fill: color,
+      },
+      '& [stroke="black"]': {
+        stroke: color,
+      },
+      '& [fill="black"]': {
+        fill: color,
+      },
+    },
+  };
+}
+
+export default styled('div', {
+  name: 'GraphTheme',
+})(({ theme }) => ({
+  '& svg': {
+    userSelect: 'none',
+    '& .node': {
+      '& text': {
+        fontFamily: theme.typography.fontFamily,
+        fill: theme.palette.text.primary,
+      },
+      '& [stroke="black"]': {
+        stroke: theme.palette.text.primary,
+      },
+      '& [fill="green"]': {
+        fill:
+          theme.palette.mode === 'dark'
+            ? theme.palette.primary.dark
+            : theme.palette.primary.light,
+      },
+      '& [fill="white"]': {
+        fill: theme.palette.background.default,
+        stroke: theme.palette.background.default,
+      },
+    },
+    '& .edge': {
+      '& text': {
+        fontFamily: theme.typography.fontFamily,
+        fill: theme.palette.text.primary,
+      },
+      '& [stroke="black"]': {
+        stroke: theme.palette.text.primary,
+      },
+      '& [fill="black"]': {
+        fill: theme.palette.text.primary,
+      },
+    },
+    ...createEdgeColor('UNKNOWN', theme.palette.text.secondary),
+    ...createEdgeColor('ERROR', theme.palette.error.main),
+  },
+}));
diff --git a/subprojects/frontend/src/graph/ZoomButtons.tsx b/subprojects/frontend/src/graph/ZoomButtons.tsx
new file mode 100644
index 00000000..72f54774
--- /dev/null
+++ b/subprojects/frontend/src/graph/ZoomButtons.tsx
@@ -0,0 +1,43 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+import AddIcon from '@mui/icons-material/Add';
+import CropFreeIcon from '@mui/icons-material/CropFree';
+import RemoveIcon from '@mui/icons-material/Remove';
+import IconButton from '@mui/material/IconButton';
+import Stack from '@mui/material/Stack';
+
+export default function ZoomButtons({
+  changeZoom,
+  fitZoom,
+}: {
+  changeZoom: (event: React.MouseEvent, factor: number) => void;
+  fitZoom: (event: React.MouseEvent) => void;
+}): JSX.Element {
+  return (
+    <Stack
+      direction="column"
+      p={1}
+      sx={{ position: 'absolute', bottom: 0, right: 0 }}
+    >
+      <IconButton
+        aria-label="Zoom in"
+        onClick={(event) => changeZoom(event, 2)}
+      >
+        <AddIcon fontSize="small" />
+      </IconButton>
+      <IconButton
+        aria-label="Zoom out"
+        onClick={(event) => changeZoom(event, 0.5)}
+      >
+        <RemoveIcon fontSize="small" />
+      </IconButton>
+      <IconButton aria-label="Fit screen" onClick={fitZoom}>
+        <CropFreeIcon fontSize="small" />
+      </IconButton>
+    </Stack>
+  );
+}
diff --git a/subprojects/frontend/src/graph/ZoomCanvas.tsx b/subprojects/frontend/src/graph/ZoomCanvas.tsx
new file mode 100644
index 00000000..eb3e9285
--- /dev/null
+++ b/subprojects/frontend/src/graph/ZoomCanvas.tsx
@@ -0,0 +1,177 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+import Box from '@mui/material/Box';
+import * as d3 from 'd3';
+import { zoom as d3Zoom } from 'd3-zoom';
+import React, { useCallback, useRef, useState } from 'react';
+
+import ZoomButtons from './ZoomButtons';
+
+declare module 'd3-zoom' {
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars -- Redeclaring type parameters.
+  interface ZoomBehavior<ZoomRefElement extends Element, Datum> {
+    // `@types/d3-zoom` does not contain the `center` function, because it is
+    // only available as a pull request for `d3-zoom`.
+    center(callback: (event: MouseEvent | Touch) => [number, number]): this;
+
+    // Custom `centroid` method added via patch.
+    centroid(centroid: [number, number]): this;
+  }
+}
+
+interface Transform {
+  x: number;
+  y: number;
+  k: number;
+}
+
+export default function ZoomCanvas({
+  children,
+  fitPadding,
+  transitionTime,
+}: {
+  children?: React.ReactNode;
+  fitPadding?: number;
+  transitionTime?: number;
+}): JSX.Element {
+  const canvasRef = useRef<HTMLDivElement | undefined>();
+  const elementRef = useRef<HTMLDivElement | undefined>();
+  const zoomRef = useRef<
+    d3.ZoomBehavior<HTMLDivElement, unknown> | undefined
+  >();
+  const fitPaddingOrDefault = fitPadding ?? ZoomCanvas.defaultProps.fitPadding;
+  const transitionTimeOrDefault =
+    transitionTime ?? ZoomCanvas.defaultProps.transitionTime;
+
+  const [zoom, setZoom] = useState<Transform>({ x: 0, y: 0, k: 1 });
+
+  const setCanvas = useCallback(
+    (canvas: HTMLDivElement | null) => {
+      canvasRef.current = canvas ?? undefined;
+      if (canvas === null) {
+        return;
+      }
+      const zoomBehavior = d3Zoom<HTMLDivElement, unknown>()
+        .duration(transitionTimeOrDefault)
+        .center((event) => {
+          const { width, height } = canvas.getBoundingClientRect();
+          const [x, y] = d3.pointer(event, canvas);
+          return [x - width / 2, y - height / 2];
+        })
+        .centroid([0, 0]);
+      zoomBehavior.on(
+        'zoom',
+        (event: d3.D3ZoomEvent<HTMLDivElement, unknown>) =>
+          setZoom(event.transform),
+      );
+      d3.select(canvas).call(zoomBehavior);
+      zoomRef.current = zoomBehavior;
+    },
+    [transitionTimeOrDefault],
+  );
+
+  const makeTransition = useCallback(
+    (element: HTMLDivElement) =>
+      d3.select(element).transition().duration(transitionTimeOrDefault),
+    [transitionTimeOrDefault],
+  );
+
+  const changeZoom = useCallback(
+    (event: React.MouseEvent, factor: number) => {
+      if (canvasRef.current === undefined || zoomRef.current === undefined) {
+        return;
+      }
+      const zoomTransition = makeTransition(canvasRef.current);
+      const center: [number, number] = [0, 0];
+      zoomRef.current.scaleBy(zoomTransition, factor, center);
+      event.preventDefault();
+      event.stopPropagation();
+    },
+    [makeTransition],
+  );
+
+  const fitZoom = useCallback(
+    (event: React.MouseEvent) => {
+      if (
+        canvasRef.current === undefined ||
+        zoomRef.current === undefined ||
+        elementRef.current === undefined
+      ) {
+        return;
+      }
+      const { width: canvasWidth, height: canvasHeight } =
+        canvasRef.current.getBoundingClientRect();
+      const { width: scaledWidth, height: scaledHeight } =
+        elementRef.current.getBoundingClientRect();
+      const currentFactor = d3.zoomTransform(canvasRef.current).k;
+      const width = scaledWidth / currentFactor;
+      const height = scaledHeight / currentFactor;
+      if (width > 0 && height > 0) {
+        const factor = Math.min(
+          1.0,
+          (canvasWidth - fitPaddingOrDefault) / width,
+          (canvasHeight - fitPaddingOrDefault) / height,
+        );
+        const zoomTransition = makeTransition(canvasRef.current);
+        zoomRef.current.transform(
+          zoomTransition,
+          d3.zoomIdentity.scale(factor),
+        );
+      }
+      event.preventDefault();
+      event.stopPropagation();
+    },
+    [fitPaddingOrDefault, makeTransition],
+  );
+
+  return (
+    <Box
+      sx={{
+        width: '100%',
+        height: '100%',
+        position: 'relative',
+        overflow: 'hidden',
+      }}
+    >
+      <Box
+        sx={{
+          position: 'absolute',
+          overflow: 'hidden',
+          top: 0,
+          left: 0,
+          right: 0,
+          bottom: 0,
+        }}
+        ref={setCanvas}
+      >
+        <Box
+          sx={{
+            position: 'absolute',
+            top: '50%',
+            left: '50%',
+            transform: `
+              translate(${zoom.x}px, ${zoom.y}px)
+              scale(${zoom.k})
+              translate(-50%, -50%)
+            `,
+            transformOrigin: '0 0',
+          }}
+          ref={elementRef}
+        >
+          {children}
+        </Box>
+      </Box>
+      <ZoomButtons changeZoom={changeZoom} fitZoom={fitZoom} />
+    </Box>
+  );
+}
+
+ZoomCanvas.defaultProps = {
+  children: undefined,
+  fitPadding: 64,
+  transitionTime: 250,
+};
diff --git a/subprojects/frontend/src/graph/parseBBox.ts b/subprojects/frontend/src/graph/parseBBox.ts
new file mode 100644
index 00000000..9806cbca
--- /dev/null
+++ b/subprojects/frontend/src/graph/parseBBox.ts
@@ -0,0 +1,68 @@
+/*
+ * Copyright 2017, Magnus Jacobsson
+ * Copyright 2023, The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: BSD-3-Clause AND EPL-2.0
+ *
+ * This file Incorporates patches from the Refinery authors.
+ *
+ * Redistribution and use is only permitted if neither
+ * the name of the copyright holder Magnus Jacobsson nor the names of other
+ * contributors to the d3-graphviz project are used to endorse or promote
+ * products derived from this software as per the 3rd clause of the
+ * 3-clause BSD license.
+ *
+ * See LICENSES/BSD-3-Clause.txt for more details.
+ */
+
+export interface BBox {
+  x: number;
+  y: number;
+  width: number;
+  height: number;
+}
+
+function parsePoints(points: string[]): BBox {
+  const x = points.map((p) => Number(p.split(',')[0] ?? 0));
+  const y = points.map((p) => Number(p.split(',')[1] ?? 0));
+  const xmin = Math.min.apply(null, x);
+  const xmax = Math.max.apply(null, x);
+  const ymin = Math.min.apply(null, y);
+  const ymax = Math.max.apply(null, y);
+  return {
+    x: xmin,
+    y: ymin,
+    width: xmax - xmin,
+    height: ymax - ymin,
+  };
+}
+
+/**
+ * Compute the bounding box of a polygon without adding it to the DOM.
+ *
+ * Copyed from
+ * https://github.com/magjac/d3-graphviz/blob/81ab523fe5189a90da2d9d9cc9015c7079eea780/src/element.js#L36-L53
+ *
+ * @param path The polygon to compute the bounding box of.
+ * @returns The computed bounding box.
+ */
+export function parsePolygonBBox(polygon: SVGPolygonElement): BBox {
+  const points = (polygon.getAttribute('points') ?? '').split(' ');
+  return parsePoints(points);
+}
+
+/**
+ * Compute the bounding box of a path without adding it to the DOM.
+ *
+ * Copyed from
+ * https://github.com/magjac/d3-graphviz/blob/81ab523fe5189a90da2d9d9cc9015c7079eea780/src/element.js#L56-L75
+ *
+ * @param path The path to compute the bounding box of.
+ * @returns The computed bounding box.
+ */
+export function parsePathBBox(path: SVGPathElement): BBox {
+  const d = path.getAttribute('d') ?? '';
+  const points = d.split(/[A-Z ]/);
+  points.shift();
+  return parsePoints(points);
+}
diff --git a/subprojects/frontend/src/graph/postProcessSVG.ts b/subprojects/frontend/src/graph/postProcessSVG.ts
new file mode 100644
index 00000000..59cc15b9
--- /dev/null
+++ b/subprojects/frontend/src/graph/postProcessSVG.ts
@@ -0,0 +1,79 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+
+import { type BBox, parsePolygonBBox, parsePathBBox } from './parseBBox';
+
+const SVG_NS = 'http://www.w3.org/2000/svg';
+
+function clipCompartmentBackground(node: SVGGElement) {
+  // Background rectangle of the node created by the `<table bgcolor="green">`
+  // HTML element in dot. It was transformed into a rounded rect by `fixNodeBackground`.
+  const container = node.querySelector<SVGRectElement>('rect[fill="green"]');
+  // Background rectangle of the lower compartment created by the `<td bgcolor="white">`
+  // HTML element in dot. It was transformed into a rounded rect by `fixNodeBackground`.
+  // Since dot doesn't round the coners of `<td>` background,
+  // we have to clip it ourselves.
+  const compartment = node.querySelector<SVGPolygonElement>(
+    'polygon[fill="white"]',
+  );
+  if (container === null || compartment === null) {
+    return;
+  }
+  const copyOfContainer = container.cloneNode() as SVGRectElement;
+  const clipPath = document.createElementNS(SVG_NS, 'clipPath');
+  const clipId = `${node.id},,clip`;
+  clipPath.setAttribute('id', clipId);
+  clipPath.appendChild(copyOfContainer);
+  node.appendChild(clipPath);
+  compartment.setAttribute('clip-path', `url(#${clipId})`);
+}
+
+function createRect(
+  { x, y, width, height }: BBox,
+  original: SVGElement,
+): SVGRectElement {
+  const rect = document.createElementNS(SVG_NS, 'rect');
+  rect.setAttribute('fill', original.getAttribute('fill') ?? '');
+  rect.setAttribute('stroke', original.getAttribute('stroke') ?? '');
+  rect.setAttribute('x', String(x));
+  rect.setAttribute('y', String(y));
+  rect.setAttribute('width', String(width));
+  rect.setAttribute('height', String(height));
+  return rect;
+}
+
+function optimizeNodeShapes(node: SVGGElement) {
+  node.querySelectorAll('path').forEach((path) => {
+    const bbox = parsePathBBox(path);
+    const rect = createRect(bbox, path);
+    rect.setAttribute('rx', '12');
+    rect.setAttribute('ry', '12');
+    node.replaceChild(rect, path);
+  });
+  node.querySelectorAll('polygon').forEach((polygon) => {
+    const bbox = parsePolygonBBox(polygon);
+    if (bbox.height === 0) {
+      const polyline = document.createElementNS(SVG_NS, 'polyline');
+      polyline.setAttribute('stroke', polygon.getAttribute('stroke') ?? '');
+      polyline.setAttribute(
+        'points',
+        `${bbox.x},${bbox.y} ${bbox.x + bbox.width},${bbox.y}`,
+      );
+      node.replaceChild(polyline, polygon);
+    } else {
+      const rect = createRect(bbox, polygon);
+      node.replaceChild(rect, polygon);
+    }
+  });
+  clipCompartmentBackground(node);
+}
+
+export default function postProcessSvg(svg: SVGSVGElement) {
+  svg
+    .querySelectorAll<SVGTitleElement>('title')
+    .forEach((title) => title.parentNode?.removeChild(title));
+  svg.querySelectorAll<SVGGElement>('g.node').forEach(optimizeNodeShapes);
+}
diff --git a/subprojects/frontend/src/theme/ThemeProvider.tsx b/subprojects/frontend/src/theme/ThemeProvider.tsx
index 78146f25..90fea897 100644
--- a/subprojects/frontend/src/theme/ThemeProvider.tsx
+++ b/subprojects/frontend/src/theme/ThemeProvider.tsx
@@ -75,13 +75,15 @@ function createResponsiveTheme(
     ...options,
     typography: {
       fontFamily:
-        '"Inter Variable", "Inter", "Roboto", "Helvetica", "Arial", sans-serif',
-      fontWeightMedium: 600,
+        '"Open Sans Variable", "Open Sans", "Roboto", "Helvetica", "Arial", sans-serif',
+      fontWeightMedium: 500,
       fontWeightEditorNormal: 400,
       fontWeightEditorBold: 700,
       button: {
-        // 24px line height for 14px button text to fix browser rounding errors.
-        lineHeight: 1.714286,
+        fontWeight: 600,
+        fontVariationSettings: '"wdth" 87.5',
+        fontSize: '1rem',
+        lineHeight: 1.5,
       },
       editor: {
         fontFamily:
diff --git a/subprojects/frontend/vite.config.ts b/subprojects/frontend/vite.config.ts
index 5bda8071..82e432de 100644
--- a/subprojects/frontend/vite.config.ts
+++ b/subprojects/frontend/vite.config.ts
@@ -30,7 +30,7 @@ const { mode, isDevelopment, devModePlugins, serverOptions } =
 process.env['NODE_ENV'] ??= mode;
 
 const fontsGlob = [
-  'inter-latin-wght-normal-*.woff2',
+  'open-sans-latin-wdth-normal-*.woff2',
   'jetbrains-mono-latin-wght-{normal,italic}-*.woff2',
 ];