Sometimes there is a need to be able to accommodate a very large number of visual elements on a form, so large that it will almost never be possible to see them all, even if the form is expanded to full screen. Sometimes it is also necessary to ensure the scrolling of a large work plane, such as a drawing box, the dimensions of which are large, and sometimes unknown in advance.

 

In the VCL, for the first time, the form itself has the ability to scroll through its content using standard scroll bars. But this feature is implemented so strangely that sometimes you just wonder when looking at applications developed in Delphi and running on another computer. For example, if the application itself was developed on a machine with completely different desktop font size settings, then even on a small form its elements begin to not fit (although if they had a normal font, everything would fit perfectly, and there would still be space). And that's when the scroll bars appear. Moreover, the developer did not even order such an opportunity, just the automatic inclusion of scroll bars for the VCL form is built in by default, and on his machine everything fit perfectly without them. He doesn't even know

 

The KOL form, in principle, does not have any scroll bars. But, if you wish, you can use a specially designed version of the TControl object for this purpose: a container, or a scrolling box. Its constructors:

 

NewScrollBox(Parent, edgestyle, bars) - creates a universal "scroll box" for scrolling some geometrically large object;

NewScrollBoxEx(Pafrent, edgestyle) - creates a scroll box that automatically scrolls child visuals (if any).

 

In general, this visual element no longer has any other specific properties. Otherwise, it can be considered a panel "with edges extending beyond the horizon". In MCK, the mirror for this object