1.1 Basic elements and data structures

1.1.6 Multiple root viewports

Under CLX, you can create and use more than one root viewport at a time. Each root viewport has its own viewport hierarchy, and the parent of any root viewport isnil. The root viewport that is created when you initialize the Window Tool Kit is known as the primary root viewport. The root viewport that you most recently created or the one that most recently contained the mouse is called the current root viewport. All input and output goes to the current root viewport by default.

You can create root viewports and delete existing root viewports at any time, except for the primary root viewport. The primary root viewport can only be created with the functioninitialize-windows, and it can only be deleted when you exit the Window Tool Kit with the function leave-window-system. You can use the functionmake-window to create other root viewports, and you can delete them with the functiondelete-root-viewport. In all other respects, root viewports are treated equally by the Window Tool Kit. You cannot move or reshape a root viewport, and you cannot modify the bits of a root viewport's bitmap. A root viewport cannot be used as an output stream.

Any positions that you specify as arguments to window constructor functions are relative to the parent window or to the screen if there is no parent.

The Window Tool Kit - 9 SEP 1996

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