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# OnVisibleDocumentAreaChange Method of the IImageViewerEvents Interface

> OnVisibleDocumentAreaChange method of the IImageViewerEvents Interface in ABBYY FineReader Engine Visual Components on Windows — This method is implemented on the client-side.

This method is implemented on the client-side. It is called by ABBYY FineReader Engine after the visible document area has been changed in [Image Viewer](/fine-reader/engine/visual-components-reference/imageviewer).

The method delivers to the client the coordinates of the new visible area.

## Syntax

### C++

```cpp theme={null}
HRESULT OnVisibleDocumentAreaChange( IFRRectangle* Value );
```

### C\#

```csharp theme={null}
void OnVisibleDocumentAreaChange( IFRRectangle Value );
```

### Visual Basic .NET

```vb theme={null}
Sub OnVisibleDocumentAreaChange(Value As IFRRectangle)
```

## Parameters

Value

\[in] Refers to the [FRRectangle](/fine-reader/engine/api-reference/supplementary-objects-and-methods/frrectangle) object which contains the coordinates of the visible document area in pixels. The coordinates are relative to the document image.

## Return values

This method has no specific return values. It returns the [standard return values of ABBYY FineReader Engine functions](/fine-reader/engine/api-reference/return-codes).

## Remarks

The client implementation of this method must assure that all exceptions thrown inside the method are caught and handled and no exceptions are propagated outside the method. Propagation of an exception outside the method may lead to unpredictable results (such as program termination).

## See also

[IImageViewerEvents](/fine-reader/engine/visual-components-reference/iimageviewerevents)