Drag and drop operation is one of the key capabilities of any Graphical User Interface. The user can do quite complex operations simply by visually dragging and dropping objects from one location to another. It saves user from remembering and typing a lot of commands.

The result of a drag and drop operation may vary depending the type of source object and type of destination object. For example dragging a file and dropping on a folder may copy or move the file to the destination folder, dropping that file to a remote ftp location may upload that file using internet, dropping that file on a printer icon may print that file, dropping that file on the trash can may delete that file, and dropping that file on an executable may play or open or compute or manipulate that file.

Although a drag and drop operation prima facie seems to be a simple operation, it can become extremely complicated depending on the type of source objects dragged and the type of destination objects selected for dropping. There are many limitations of a conventional drag and drop operation. This article points out the difficulties of a drag and drop operation and illustrates the solutions disclosed by various inventions to overcome those difficulties.

Selecting an object or element is a fundamental operation in any graphic user interface. It is necessary to select an object before doing any operation (such as, dragging, copying, opening, deleting etc.) on that object. The GUI may provide features to select any single object or even multiple objects. The feature of selecting multiple objects can provides tremendous power to the GUI as the user can do complex operations on multiple objects in one go.

However, the process of selection is not as simple as it appears to the user of a GUI. The internal logic of a selection mechanism can be very complex in some situations. The article describes some fundamental difficulties associated with the selection mechanism, and illustrates the solutions provided by different inventions selected from US patent database.

Windows are used quite frequently in a GUI environment. The greatest advantage of using windows is that each window creates a virtual screen space. Hence, although the physical screen space is limited to a few inches, use of windows can create unlimited screen space to display innumerable items.

The use of windows facilitates the user to open and interact with multiple programs or documents simultaneously in different windows. Sometimes a single program may also open multiple windows to display various items. The user can resize the windows and move their location time to time as desired.

However, there are several concerns of a window relating to its size, appearance, positioning, color, visibility, resizability etc. For example, the window should have a minimum and a maximum size, dragging and resizing the window should be easy, one window should not be obscured by another window, windows should adjust their size and location in order to match with the changes in the resolution and display environment etc.

This article illustrates six patents from US Patent database solving problems relating to displaying and resizing of windows. The inventions include automatic resizing and relocating of windows, alternative modes of displaying windows to accommodate within the limited display area, combining both spatial and temporal methods to resize the window, locking and minimizing windows and making the windows invisible on specific situations.