feat: add page translate function

src/api/PDFPage.ts

@@ -568,6 +568,31 @@ export default class PDFPage {
     this.node.wrapContentStreams(startRef, endRef);
   }
 
+  /**
+   * translate this page's content and annotations. In some scenarios, the annotations
+   * is following this text.If only the [translateContent] function is used, 
+   * the position of the annotations relative to the text will change,so you can use [translate] function .
+   * For example:
+   * ```js
+   * // Move the page's content and annotations from the lower-left corner of the page
+   * // to the top-right corner.
+   * page.translate(50, 50)
+   * ```
+   * @param x The new position on the x-axis for this page's content.
+   * @param y The new position on the y-axis for this page's content.
+   */
+  translate(x:number,y:number):void {
+    assertIs(x, 'x', ['number']);
+    assertIs(y, 'y', ['number']);
+    this.translateContent(x, y)
+    const annots = this.node.Annots()
+    if (!annots) return
+    for (let idx = 0; idx < annots.size(); idx++) {
+      const annot = annots.lookup(idx)
+      if (annot instanceof PDFDict) this.translateAnnot(annot,x,y)
+    }
+  }
+
   /**
    * Scale the size, content, and annotations of a page.
    *
@@ -1618,4 +1643,25 @@ export default class PDFPage {
       }
     }
   }
+  /**
+   * move annotations
+   * @param annot annot
+   * @param x The new position on the x-axis for this page's content.
+   * @param y The new position on the y-axis for this page's content.
+   */
+  private translateAnnot(annot: PDFDict, x: number, y: number) {
+    const selectors = ['RD', 'CL', 'Vertices', 'QuadPoints', 'L', 'Rect']
+      for (let idx = 0, len = selectors.length; idx < len; idx++) {
+        const list = annot.lookup(PDFName.of(selectors[idx]))
+        if (list instanceof PDFArray) list.translatePDFNumbers(x,y)
+      }
+
+      const inkLists = annot.lookup(PDFName.of('InkList'))
+      if (inkLists instanceof PDFArray) {
+        for (let idx = 0, len = inkLists.size(); idx < len; idx++) {
+          const arr = inkLists.lookup(idx)
+          if (arr instanceof PDFArray) arr.translatePDFNumbers(x,y)
+        }
+      }
+  }
 }

src/core/objects/PDFArray.ts

@@ -180,6 +180,15 @@ class PDFArray extends PDFObject {
       }
     }
   }
+
+  translatePDFNumbers(x: number, y: number): void {
+    for (let idx = 0,len = this.size(); idx < len; idx++) {
+      const el = this.lookup(idx)
+      if (el instanceof PDFNumber) {
+        this.set(idx, PDFNumber.of(el.asNumber() + (idx % 2 === 0 ? x : y)))
+      }
+    }
+  }
 }
 
 export default PDFArray;