feat: update document flow

- Fixed z-index when dragging pre-existing fields
- Refactored document flow
- Added button spinner
- Added animation for document flow slider
- Updated drag and drop fields
- Updated document flow so it adjusts to the height of the PDF
- Updated claim plan dialog

packages/lib/client-only/hooks/use-document-element.ts

@@ -0,0 +1,93 @@
+'use client';
+
+import { useCallback } from 'react';
+
+import { getBoundingClientRect } from '@documenso/lib/client-only/get-bounding-client-rect';
+
+export const useDocumentElement = () => {
+  /**
+   * Given a mouse event, find the nearest element found by the provided selector.
+   */
+  const getPage = (event: MouseEvent, pageSelector: string) => {
+    if (!(event.target instanceof HTMLElement)) {
+      return null;
+    }
+
+    const target = event.target;
+
+    const $page =
+      target.closest<HTMLElement>(pageSelector) ?? target.querySelector<HTMLElement>(pageSelector);
+
+    if (!$page) {
+      return null;
+    }
+
+    return $page;
+  };
+
+  /**
+   * Provided a page and a field, calculate the position of the field
+   * as a percentage of the page width and height.
+   */
+  const getFieldPosition = (page: HTMLElement, field: HTMLElement) => {
+    const {
+      top: pageTop,
+      left: pageLeft,
+      height: pageHeight,
+      width: pageWidth,
+    } = getBoundingClientRect(page);
+
+    const {
+      top: fieldTop,
+      left: fieldLeft,
+      height: fieldHeight,
+      width: fieldWidth,
+    } = getBoundingClientRect(field);
+
+    return {
+      x: ((fieldLeft - pageLeft) / pageWidth) * 100,
+      y: ((fieldTop - pageTop) / pageHeight) * 100,
+      width: (fieldWidth / pageWidth) * 100,
+      height: (fieldHeight / pageHeight) * 100,
+    };
+  };
+
+  /**
+   * Given a mouse event, determine if the mouse is within the bounds of the
+   * nearest element found by the provided selector.
+   *
+   * @param mouseWidth The artifical width of the mouse.
+   * @param mouseHeight The artifical height of the mouse.
+   */
+  const isWithinPageBounds = useCallback(
+    (event: MouseEvent, pageSelector: string, mouseWidth = 0, mouseHeight = 0) => {
+      const $page = getPage(event, pageSelector);
+
+      if (!$page) {
+        return false;
+      }
+
+      const { top, left, height, width } = $page.getBoundingClientRect();
+
+      const halfMouseWidth = mouseWidth / 2;
+      const halfMouseHeight = mouseHeight / 2;
+
+      if (event.clientY > top + height - halfMouseHeight || event.clientY < top + halfMouseHeight) {
+        return false;
+      }
+
+      if (event.clientX > left + width - halfMouseWidth || event.clientX < left + halfMouseWidth) {
+        return false;
+      }
+
+      return true;
+    },
+    [],
+  );
+
+  return {
+    getPage,
+    getFieldPosition,
+    isWithinPageBounds,
+  };
+};