GUI Vocabulary Section

  1. The Desktop
  2. Widgets
  3. Panels
  4. Windows
  5. Frames
  6. Dialogs
  7. Layout Managers
  8. Renderers

All of the types of components described in this section are implemented completely in python in PyUI. As such, they can all be sub-classed by user code to be extended and have their functionality customized by python code.

The Desktop
In any PyUI application there is single space in which everything is drawn. This is known as the desktop. It is a rectangular two-dimensional plane that hosts all the other user interface components. In most renderers, the desktop is opaque - it has a background that can contain an image, a fill color or a view into 3D world. There is a single desktop object. It can be retrieved by calling pyui.desktop.getDesktop().

Widgets are GUI objects that are interactive and provide functionality. This include list boxes, edit boxes, scroll bars, buttons and labels. There many kinds of widgets all derived from the pyui.widgets.Base class. Widgets can be contained in other Widgets.

Panels are a special type of widgets that is designed to contain other widgets. Widgets within a panel are placed procedurally by "layout managers". There are special types of panels such as the TabbedPanel and SplitterPanel for more direct control over the layout of widgets within the panel.

Windows higher level objects that are containers of widgets. They are managed by the desktop and so can overlap each other but are still drawn in the correct order. Each Window contains a default Panel which in turn contains widgets and other Panels. Most user code will use Frames rather than Windows.

Frames are a special type of Window that has a title bar, a frame border and functionality for resizing and moving. Frames still have a default Panel within them, but it is enclosed within the title bar and frame border.

Dialogs are special types of Frames that provide specific functionality. For example, there is a ConsoleDialog which is an interactive python console - it allows text to be entered and executed as python code, then displays the resulting output in a scrolling area. Dialogs may be "modal" - they may require that the user interact with them before any other UI interactions can take place. The StdDialog is an example of a modal dialog.

Layout Managers
Layout Managers are objects that control the placement of widgets within Panels. There are a number of built-in Layout Managers such as the GridLayoutManager and BorderLayoutManager that do common types of widget placement.

Renderers are the back-end to the widget construction front-end. They are responsible for actually drawing the rectangles, images, text and lines on the screen; and handling user input and mapping it into PyUI events.

(C) Sean Riley 2002