A birdcage (or bird cage) is a cage designed to house birds as pets. Antique (or antique-style) birdcages are often popular as collectors' items or as household decor but most are not suitable for housing live birds, being too small, or of unsafe materials or construction.ood quality cages designed for pet birds are more suitable. Most parrot cages are made or wrought iron and painted with a non-toxic paint referred to as powder-coating. However, the newest trend in the market is cages made of solid stainless steel.
A viewport is a 2D rectangle that defines the size of the rendering surface onto which a 3D scene is projected.
Remarks. A ScrollViewer enables content to be displayed in a smaller area than its actual size. When the content of the ScrollViewer is not entirely visible, the ScrollViewer displays scrollbars that the user can use to move the content areas that is visible. The area that includes all of the content of the ScrollViewer is the extent. The visible area of the content is the viewport. Physical scrolling is used to scroll content by a predetermined physical increment, typically by a value that is declared in pixels.