X Window Programming from Scratch

Chapter 9. Object Bounds Checking

In this chapter

• Point-Array–Based Object Bounds

• Arc Object Bounds

• Employing Object Bounds

• Next Steps

Every object of the Graphics Editor application has an associated size, position, width, and height. This chapter discusses methods of using the descriptive information available to the editor objects for determining whether an X ButtonPress Event occurred within the bounds of the object. This test is necessary to support the function of selection on the objects, making them eligible for manipulation and insuring proper object control.

The list of objects created by the Graphics Editor includes LatexLine, PolyLine, Box, Arrow, Arc, and Text.

Calculating the bounds of an object is dependent on the geometric shape represented ...