[MNT-25896] Introduce page rotation button in pdf viewer (#12241)

* [MNT-25896] Introduce page rotation button in pdf viewer

* [MNT-25896] CR fixes

lib/core/viewer/pdf/src/lib/components/pdf-viewer/pdf-viewer.component.html

@@ -106,6 +106,14 @@
             <mat-icon adf-icon="zoom_out" />
         </button>
 
+        <button id="viewer-rotate-page-button"
+                title="{{ 'ADF_VIEWER.ARIA.ROTATE' | translate }}"
+                attr.aria-label="{{ 'ADF_VIEWER.ARIA.ROTATE' | translate }}"
+                mat-icon-button
+                (click)="rotatePage()">
+            <mat-icon adf-icon="rotate_left" />
+        </button>
+
         <button id="viewer-scale-page-button"
                 role="button" aria-pressed="true"
                 title="{{ 'ADF_VIEWER.ARIA.FIT_PAGE' | translate }}"
@@ -114,6 +122,5 @@
                 (click)="pageFit()">
             <mat-icon adf-icon="zoom_out_map" />
         </button>
-
     </adf-toolbar>
 </div>

lib/core/viewer/pdf/src/lib/components/pdf-viewer/pdf-viewer.component.spec.ts

@@ -461,8 +461,10 @@ describe('Test PdfViewer - User interaction', () => {
     let component: PdfViewerComponent;
     let testingUtils: UnitTestingUtils;
     let pdfViewerSpy: jasmine.Spy;
+    let pageViewMock: { width: number; height: number; scale: number; rotation: number; update: jasmine.Spy };
 
     beforeEach(fakeAsync(() => {
+        pageViewMock = { width: 100, height: 100, scale: 1, rotation: 0, update: jasmine.createSpy() };
         pdfViewerSpy = jasmine.createSpy('PDFViewer').and.returnValue({
             setDocument: jasmine.createSpy().and.returnValue({
                 loadingTask: () => ({
@@ -479,7 +481,7 @@ describe('Test PdfViewer - User interaction', () => {
             update: jasmine.createSpy(),
             currentScaleValue: 1,
             _currentPageNumber: 1,
-            _pages: [{ width: 100, height: 100, scale: 1 }]
+            _pages: [pageViewMock]
         });
 
         TestBed.configureTestingModule({
@@ -617,6 +619,30 @@ describe('Test PdfViewer - User interaction', () => {
         }), 300);
     });
 
+    describe('Rotation', () => {
+        it('should rotate only the current page counter-clockwise by 90 degrees', () => {
+            testingUtils.clickByCSS('#viewer-rotate-page-button');
+
+            expect(pageViewMock.update).toHaveBeenCalledWith({ rotation: 270 });
+        });
+
+        it('should wrap rotation back to 0 after a full turn', () => {
+            pageViewMock.rotation = 90;
+
+            testingUtils.clickByCSS('#viewer-rotate-page-button');
+
+            expect(pageViewMock.update).toHaveBeenCalledWith({ rotation: 0 });
+        });
+
+        it('should recompute the document overflow after rotation', () => {
+            spyOn(component, 'setDocumentOverflow');
+
+            testingUtils.clickByCSS('#viewer-rotate-page-button');
+
+            expect(component.setDocumentOverflow).toHaveBeenCalled();
+        });
+    });
+
     describe('Resize interaction', () => {
         it('should resize event trigger setScaleUpdatePages', () => {
             spyOn(component, 'onResize');

lib/core/viewer/pdf/src/lib/components/pdf-viewer/pdf-viewer.component.ts

@@ -577,6 +577,24 @@ export class PdfViewerComponent implements OnChanges, OnDestroy {
         this.setScaleUpdatePages(newScale);
     }
 
+    /**
+     * Rotate the currently displayed page 90 degrees counter-clockwise.
+     *
+     * Only the current page is affected; every other page keeps its own rotation.
+     * The angle wraps around, so four consecutive calls return the page to its
+     * original orientation (0 → 270 → 180 → 90 → 0). The document overflow state
+     * is recomputed afterwards, since rotation swaps the page width and height.
+     */
+    rotatePage() {
+        if (this.pdfViewer) {
+            const pageView = this.pdfViewer._pages[this.pdfViewer._currentPageNumber - 1];
+            if (pageView) {
+                pageView.update({ rotation: (pageView.rotation + 270) % 360 });
+                this.setDocumentOverflow();
+            }
+        }
+    }
+
     /**
      * load the previous page
      */