Each manager view (class IlvManagerView) has its own transformer
to define the area of the manager that the view is displaying and
also to define the zoom level and rotation applied to objects.
You may retrieve the current transformer of
a view using the following method:
IlvTransformer getTransformer()
To modify the transformer associated with a
view, use the following methods:
void setTransformer(IlvTransformer t)
void addTransformer(IlvTransformer t)
void translate(float deltax, float deltay, boolean redraw)
void zoom(IlvPoint, double, double, boolean)
void fitTransformerToContent()
void ensureVisible(IlvPoint p)
void ensureVisible(IlvRect rect)
To avoid distorting the image when it is
zoomed in or out, you can specify that the vertical and horizontal
aspect ratio remain the same by using the following methods:
boolean isKeepingAspectRatio()
void setKeepingAspectRatio(boolean set)
When the
KeepingAspectRatio
property is on, the view ensures that the horizontal and vertical
scaling are always the same, whatever transformer you set in the
view.
Example: Zooming a view
The following code zooms a view in by a
scale factor of 2:
managerView.zoom(point, 2.0, 2.0, true);
The
point
given as an argument keeps its position after the zoom. The last
parameter forces the redrawing of the view.
Transformer listeners
When the transformer of a view changes, the view fires a TransformerChangedEvent event. A class must
implement the
TransformerListener
interface to be notified that the transformer of the view has
changed, and must register itself using the addTransformerListener method of IlvManagerView. You can also specify that
the listener no longer be notified of such events using the removeTransformerListener method.
When the transformer of a view changes, the view calls the
transformerChanged
method of all listeners.
void transformerChanged(TransformerChangedEvent event)
This method is called with an instance of the class TransformerChangedEvent as a parameter. The
event
parameter can be used to retrieve the old and the new value of
the transformer.