Cropping PDF pages using JavaScript

1WebViewer(...)
2  .then(instance => {
3    const docViewer = instance.docViewer;
4    const rotation = instance.CoreControls.PageRotation;
5
6    docViewer.on('documentLoaded', async () => {
7      const doc = docViewer.getDocument();
8      const cropTop = 100, cropLeft = 0, cropRight = 0, cropBottom = 0;
9      const page1 = 1, page2 = 2, page3 = 3;
10
11      doc.getPageInfo(page1); // {width: 612, height: 792}
12
13      await doc.cropPages([page1], cropTop, cropBottom, cropLeft, cropRight)
14      doc.getPageInfo(page1); // {width: 612, height: 692}
15
16      await doc.rotatePages([page1], rotation.E_90);
17      docViewer.rotateCounterClockwise(page1);
18      doc.getPageInfo(page1); // {width: 692, height: 612}, width and height get swapped
19
20      // rotate the first page back so that it appears upright in the viewer
21      await doc.cropPages([page1], cropTop, cropBottom, cropLeft, cropRight);
22      doc.getPageInfo(page1); // {width: 692, height: 512}
23      // Even though the page appears upright, the document is rotated 90 degree clockwise
24      // So the left side of the document is cropped
25    });
26  });

1WebViewer(...)
2  .then(instance => {
3    const docViewer = instance.docViewer;
4    const rotation = instance.CoreControls.PageRotation;
5
6    docViewer.on('documentLoaded', async () => {
7      const doc = docViewer.getDocument();
8      const cropTop = 100, cropLeft = 0, cropRight = 0, cropBottom = 0;
9      const page1 = 1, page2 = 2, page3 = 3;
10
11      doc.getPageInfo(page1 - 1); // {width: 612, height: 792}
12
13      await doc.cropPages([page1], cropTop, cropBottom, cropLeft, cropRight)
14      doc.getPageInfo(page1); // {width: 612, height: 692}
15
16      await doc.rotatePages([page1], rotation.e_90);
17      docViewer.rotateCounterClockwise(page1);
18      doc.getPageInfo(page1 - 1); // {width: 692, height: 612}, width and height get swapped
19
20      // rotate the first page back so that it appears upright in the viewer
21      await doc.cropPages([page1], cropTop, cropBottom, cropLeft, cropRight);
22      doc.getPageInfo(page1 - 1); // {width: 692, height: 512}
23      // Even though the page appears upright, the document is rotated 90 degree clockwise
24      // So the left side of the document is cropped
25    });
26  });