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GtkBin
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GtkBox — Base class for box containers
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GtkButtonBox — Base class for GtkHButtonBox and GtkVButtonBox
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GtkContainer — Base class for widgets which contain other widgets
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GtkItem — Abstract base class for GtkMenuItem, GtkListItem and GtkTreeItem
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GtkMenuShell — A base class for menu objects
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GtkMisc — Base class for widgets with alignments and padding
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GtkObject — The base class of the GTK+ type hierarchy
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GtkPaned — Base class for widgets with two adjustable panes
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GtkRange — Base class for widgets which visualize an adjustment
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GtkScale — Base class for GtkHScale and GtkVScale
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GtkScrollbar — Base class for GtkHScrollbar and GtkVScrollbar
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GtkSeparator — Base class for GtkHSeparator and GtkVSeparator
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GtkWidget
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GtkIMContext — Base class for input method contexts