Manager Views

2D Graphics > Managers > Basic Manager Features > Manager Views

Manager Views

Attaching multiple views to a manager allows your program to display graphic objects simultaneously in various configurations. This is illustrated in Figure 1.2.

Figure 1.2 Multiple Views Bound To a Manager

The following IlvManager member functions handle the binding of views to a manager:

addView - Attaches a view to the manager. All events are then handled by the hierarchy of interactors in place in the manager.

removeView - Removes a view from the manager view list. The view is no longer handled by the manager.

IlvManager::getViews - Returns an array of pointers to all the views currently connected to the manager.

The following aspects of manager views are described in this section:

View Transformations

Double-buffering

View Transformations

Use the following IlvManager member functions to modify the transformer associated with the view (except for IlvManager::fitToContents, which modifies the size of the view):

IlvManager::setTransformer

IlvManager::addTransformer

IlvManager::translateView

IlvManager::zoomView

IlvManager::rotateView

IlvManager::fitToContents

IlvManager::fitTransformerToContents

IlvManager::ensureVisible

Example: Zooming a View

This accelerator zooms a view using a scaling factor of two:

static void

ZoomView(IlvManager* manager, IlvView* view, IlvEvent& event, IlAny)

{

IlvPoint pt(event.x(), event.y());

manager->zoomView(view, pt, IlvFloat(2), IlvFloat(2), IlTrue);

}

The point given in the zoomView argument keeps its position after the zoom. The last parameter forces the redrawing of the view.

Double-buffering

The double-buffering member functions can be used to prevent the screen from flickering when many objects are manipulated. For each manager view, this feature requires the allocation of a hidden bitmap the size of the view. Depending on the number of views and the color model, double-buffering may consume a large amount of memory.

The member functions that handle double-buffering are:

IlvManager::isDoubleBuffering

IlvManager::setDoubleBuffering

setBackground

Note: You must use the setBackground member function to change the background color of a view in double-buffering mode.

Example

This function switches the double-buffering mode of the given view:

static void

ToggleDoubleBuffering(IlvManager* manager, IlvView* view)

{

manager->setDoubleBuffering(view,

!manager->isDoubleBuffering(view));

}

Version 6.0