feat: add envelope editor

apps/remix/app/components/general/envelope-editor/envelope-editor-page-preview-renderer.tsx

@@ -0,0 +1,176 @@
+import { useEffect, useMemo, useRef } from 'react';
+
+import Konva from 'konva';
+import type { Layer } from 'konva/lib/Layer';
+import type { RenderParameters } from 'pdfjs-dist/types/src/display/api';
+import { usePageContext } from 'react-pdf';
+
+import type { TLocalField } from '@documenso/lib/client-only/hooks/use-editor-fields';
+import { useCurrentEnvelopeEditor } from '@documenso/lib/client-only/providers/envelope-editor-provider';
+import { useCurrentEnvelopeRender } from '@documenso/lib/client-only/providers/envelope-render-provider';
+import { renderField } from '@documenso/lib/universal/field-renderer/render-field';
+
+export default function EnvelopeEditorPagePreviewRenderer() {
+  const pageContext = usePageContext();
+
+  if (!pageContext) {
+    throw new Error('Unable to find Page context.');
+  }
+
+  const { _className, page, rotate, scale } = pageContext;
+
+  if (!page) {
+    throw new Error('Attempted to render page canvas, but no page was specified.');
+  }
+
+  const { editorFields, getRecipientColorKey } = useCurrentEnvelopeEditor();
+  const { currentEnvelopeItem } = useCurrentEnvelopeRender();
+
+  const canvasElement = useRef<HTMLCanvasElement>(null);
+  const konvaContainer = useRef<HTMLDivElement>(null);
+
+  const stage = useRef<Konva.Stage | null>(null);
+  const pageLayer = useRef<Layer | null>(null);
+
+  const viewport = useMemo(
+    () => page.getViewport({ scale, rotation: rotate }),
+    [page, rotate, scale],
+  );
+
+  const localPageFields = useMemo(
+    () =>
+      editorFields.localFields.filter(
+        (field) =>
+          field.page === pageContext.pageNumber && field.envelopeItemId === currentEnvelopeItem?.id,
+      ),
+    [editorFields.localFields, pageContext.pageNumber],
+  );
+
+  // Custom renderer from Konva examples.
+  useEffect(
+    function drawPageOnCanvas() {
+      if (!page) {
+        return;
+      }
+
+      const { current: canvas } = canvasElement;
+      const { current: container } = konvaContainer;
+
+      if (!canvas || !container) {
+        return;
+      }
+
+      const renderContext: RenderParameters = {
+        // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+        canvasContext: canvas.getContext('2d', { alpha: false }) as CanvasRenderingContext2D,
+        viewport,
+      };
+
+      const cancellable = page.render(renderContext);
+      const runningTask = cancellable;
+
+      cancellable.promise.catch(() => {
+        // Intentionally empty
+      });
+
+      void cancellable.promise.then(() => {
+        createPageCanvas(container);
+      });
+
+      return () => {
+        runningTask.cancel();
+      };
+    },
+    [page, viewport],
+  );
+
+  const renderFieldOnLayer = (field: TLocalField) => {
+    if (!pageLayer.current) {
+      console.error('Layer not loaded yet');
+      return;
+    }
+
+    renderField({
+      pageLayer: pageLayer.current,
+      field: {
+        renderId: field.formId,
+        ...field,
+        customText: '',
+        inserted: false,
+        fieldMeta: field.fieldMeta,
+      },
+      pageWidth: viewport.width,
+      pageHeight: viewport.height,
+      color: getRecipientColorKey(field.recipientId),
+      editable: false,
+      mode: 'export',
+    });
+  };
+
+  /**
+   * Create the initial Konva page canvas and initialize all fields and interactions.
+   */
+  const createPageCanvas = (container: HTMLDivElement) => {
+    stage.current = new Konva.Stage({
+      container,
+      width: viewport.width,
+      height: viewport.height,
+    });
+
+    // Create the main layer for interactive elements.
+    pageLayer.current = new Konva.Layer();
+    stage.current?.add(pageLayer.current);
+
+    // Render the fields.
+    for (const field of localPageFields) {
+      renderFieldOnLayer(field);
+    }
+
+    pageLayer.current.batchDraw();
+  };
+
+  /**
+   * Render fields when they are added or removed from the localFields.
+   */
+  useEffect(() => {
+    if (!pageLayer.current || !stage.current) {
+      return;
+    }
+
+    // If doesn't exist in localFields, destroy it since it's been deleted.
+    pageLayer.current.find('Group').forEach((group) => {
+      if (
+        group.name() === 'field-group' &&
+        !localPageFields.some((field) => field.formId === group.id())
+      ) {
+        console.log('Field removed, removing from canvas');
+        group.destroy();
+      }
+    });
+
+    // If it exists, rerender.
+    localPageFields.forEach((field) => {
+      console.log('Field created/updated, rendering on canvas');
+      renderFieldOnLayer(field);
+    });
+
+    pageLayer.current.batchDraw();
+  }, [localPageFields]);
+
+  if (!currentEnvelopeItem) {
+    return null;
+  }
+
+  return (
+    <div className="relative" key={`${currentEnvelopeItem.id}-renderer-${pageContext.pageNumber}`}>
+      <div className="konva-container absolute inset-0 z-10" ref={konvaContainer}></div>
+
+      <canvas
+        className={`${_className}__canvas z-0`}
+        height={viewport.height}
+        ref={canvasElement}
+        width={viewport.width}
+      />
+    </div>
+  );
+}