Windows USER - Functionality and Role

Functionality and Role

Windows USER provides a large part of the core user experience for Microsoft Windows. Historically, USER was responsible for:

• Causing windows to be drawn
• Obscuring overlapping windows behind others
• Window size and positioning
• Providing all the standard window management controls (such as close boxes or title bars)
• Providing the standard Windows menu bar
• Providing of standard controls (such as button, List box or Edit Box)
• Providing dialog box management (short-cut keys, tab key processing)
• Processing all user input from the mouse and keyboard
• The desktop background image
• Drawing all standard visual elements
• Inter-process communication using Dynamic Data Exchange
• Mouse pointer cursor display and management
• Data transfer (Clipboard)

Gradually, as Windows has become larger and better factored, Windows USER has cooperated with other components to provide this functionality:

• Controls: Starting with Windows 95, new controls were placed into a separate common controls component. Starting with Windows XP, new implementations of the standard controls were also moved to that same component.

• Windows Management experience: Starting with Windows Vista, drawing standard window management was moved from Windows USER to the Desktop Window Manager.

• Standard Visuals: Starting with Windows XP, visual elements are drawn by the Theming component.

• Inter-program communication: Starting with Windows 3.1, Object Linking and Embedding replaced Dynamic Data Exchange as the recommended model for inter program communication.

• Menu bar: Starting in Windows 7, the Ribbon interface is a recommended replacement for the menu bar and context menus. It is provided by the UIRibbon component.