Xlib − C Language X Interface

Xlib − C LibraryX11, Release 6.7 DRAFTOccludePaddingAwindow isoccluded if some other window occludes it. Window Aoccludes window Bifboth are mapped, if A is higher in the global stacking order, and if the rectangle defined bythe outside edges of A intersects the rectangle defined by the outside edges of B. Note thedistinction between occludes and obscures. Also note that window borders are included inthe calculation and that InputOnly windows never obscure other windows but can occludeother windows.Some padding bytes are inserted in the data stream to maintain alignment of the protocolrequests on natural boundaries. This increases ease of portability to some machine architectures.Parent windowIf C is a child of P, then P is the parent of C.Passive grabPixel valuePixmapPlaneGrabbing a key or button is a passive grab. The grab activates when the key or button isactually pressed.Apixel is an N-bit value, where N is the number of bit planes used in a particular windowor pixmap (that is, is the depth of the window orpixmap). A pixel in a window indexes acolormap to derive an actual color to be displayed.Apixmap is a three-dimensional array of bits. Apixmap is normally thought of as a twodimensionalarray of pixels, where each pixel can be a value from 0 to 2 N −1, and where Nis the depth (z axis) of the pixmap. Apixmap can also be thought of as a stack of Nbitmaps. A pixmap can only be used on the screen that it was created in.When a pixmap or window isthought of as a stack of bitmaps, each bitmap is called aplane or bit plane.Plane maskPointerGraphics operations can be restricted to only affect a subset of bit planes of a destination.Aplane mask is a bit mask describing which planes are to be modified. The plane mask isstored in a graphics context.The pointer is the pointing device currently attached to the cursor and tracked on thescreens.Pointer grabbingAclient can actively grab control of the pointer. Then button and motion events will besent to that client rather than the client the events would normally have been sent to.Pointing deviceApointing device is typically a mouse, tablet, or some other device with effective dimensionalmotion. The core protocol defines only one visible cursor, which tracks whateverpointing device is attached as the pointer.482