## CGAL::Custom_zoom_layer

#include <CGAL/IO/Custom_zoom_layer.h>

### Inherits From

Custom_zoom_layer

### Creation

Custom_zoom_layer zoom_layer ( QObject* parent = 0, const char* name = 0);
| parent is the parent widget and name is the name you give to this layer.

The standard toolbar already provide zooming functionality, but this layer comes to complete the latest. When this layer is attached and active, zooming functionality could be used anytime. To zoom in x2 you must press the + key on your keyboard. To zoom out x2 you must press the - key on your keyboard. You can also use the mouse to zoom to a region defined by one rectangle. To define the rectangle you must press Ctrl+LeftMouseButton for the first corner of the rectangle, you may release, then move, then press Ctrl+LeftMouseButton once again to define the second corner.