TCalloutRectangle = class(TRectangle)
class PASCALIMPLEMENTATION TCalloutRectangle : public TRectangle
A rectangle with a triangular "peak" on one of four sides, used primarily to render a TCalloutPanel.
Because TCalloutRectangle inherits from TRectangle, TCalloutRectangle provides all the properties (Corners, CornerType, Sides, XRadius, YRadius, and others) and methods to define the shape of the rectangle itself.
A call-out often takes the form of a pull-quote, in which a particular snippet of text in a document is duplicated to attract attention: in a larger size, with a different typeface, in a colored box, with stylized quote marks, and so on. With illustrations, boxed text will refer to different elements of interest, and each box will be drawn with extra lines that point to its element.
TCalloutRectangle is a rectangle with an isosceles triangle on one of its four sides, used to point at something else. The triangle is included in the bounding rectangle of the object: the longer its length, the shorter the rectangle shape will be, and vice versa. Keeping the rectangle the same size while changing the length of the triangle requires changing the height or width of the object, depending on which side the triangle appears.