On the theory of moveable objects

On the theory of moveable objects 1 (30) Sergey Andreyev On the theory of moveable objects Abstract. User-driven applications belong to the new type of programs, in which users get the full control of WHAT, WHEN, and HOW must appear on the screen. Such programs can exist only if the screen view is organized not according with the predetermined scenario, written by the developers, but if any screen object can be moved, resized, and reconfigured by any user at any moment. This article describes the algorithm, by which an object of an arbitrary shape can be turned into moveable and resizable. It also explains some rules of such design and the technique, which can be useful in many cases. Both the individual movements of objects and their synchronous movements are analysed. After discussing the individually moveable controls, different types of groups are analysed and the arbitrary grouping of controls is considered. Content Content ................................................................................................1 Introduction .........................................................................................1 Algorithm ............................................................................................4 Safe and unsafe moving and resizing................................................ 7 The simplest case – single node covers ............................................ 7 Into the realm of covers.......................................................................9 Resizing of rectangles....................................................................... 9 Resizing of polygons and a bit of reconfiguring............................. 11 N-node covers................................................................................. 15 Transparent nodes........................................................................... 16 Rotation .......................................................................................... 18 Separately and together......................................................................20 And controls also...............................................................................23 Individually moved controls ........................................................... 23 Groups of controls .......................................................................... 24 Arbitrary grouping.......................................................................... 26 Summary............................................................................................27 Cover summary............................................................................... 27 Moving / resizing summary ............................................................ 28 Conclusion.........................................................................................29 Programs and documents...................................................................30 Introduction Moving of the screen objects is an extremely important thing, so the efforts in this direction were already made years ago. Any reader of this article can remember the programs, in which he saw the moveable objects. But the expression moving of the screen objects can mean absolutely different things, so let’s make the purpose of my research and the results, which are described here, absolutely clear. When a screen object is moved regardless of the users’ actions or as the result of his pressing the keyboard, but the reaction on each click is totally predetermined at the stage of the program development, then it is an animation. The moving, which is absolutely predicted and fixed in the code of a program by its developer, is not the purpose of this work. There are also movements, which are not predefined, but are not the real movements, though they can look like movements as a result of simple programmers’ tricks (or knowledge, if you look at it from slightly different angle). For example, in several programs (the well known Paint is one of them) you can select a rectangular area by pressing the mouse at one point and dragging the mouse across the screen without releasing; while the mouse is moving, the dashed line moves across the screen. Even with the much slower computers, than we have now, this trick was easy to implement by using the XOR operation for drawing; it is not the moving of an object. By moving of the screen objects I mean the process, when user selects an object and moves it across the screen according with his own wish. The main difference from the previously mentioned cases is that such moving can’t be predicted by the developer, because it is decided by the user only at the time, when the application is running. The real moving of some objects was introduced in some of the older programs, but in each case it was especially done for one or another particular class of objects. My opinion that for a specific class of obj

…(Full text truncated)…

This content is AI-processed based on ArXiv data.