|Navigation: Language Reference > 9 - Window and Report Attributes > Window and Report Attributes >====== SCROLL (set scrolling control) ======|
The SCROLL attribute (PROP:SCROLL) specifies a control that moves with the window when the WINDOW scrolls. This allows “virtual” windows larger than the physical video display.
The presence of the SCROLL attribute means that the control stays fixed at a position in the window relative to the top left corner of the virtual window, whether that position is currently in view or not. This means that the control appears to move as the window scrolls.
If the SCROLL attribute is omitted, the control stays fixed at a position in the window relative to the top left corner of the currently visible portion of the window. This means that the control appears to stay in the same position on screen while the rest of the window scrolls, which is useful for controls which should stay visible to the user at all times (such as Ok or Cancel buttons).
Mixing controls with and without the SCROLL attribute on the same WINDOW can result in multiple controls appearing to occupy the same screen position. This occurs because the controls with SCROLL move and the controls without SCROLL do not. This condition is temporary and scrolling the window further will correct the situation. The situation can be avoided entirely by careful placement of controls in the window. For example, you can place all controls without SCROLL at the bottom of the window then place all controls with SCROLL above them extending to the right and left. This would create a window that is designed to scroll horizontally (the WINDOW should have the HSCROLL attribute and not the VSCROLL or HVSCROLL attributes).