API Programming: What’s behind the PB GUI objects

For Windows, this question is quickly answered: HWND. Pretty much everything is of this basic “window”-type and most API commands that deal with windows can be used on most GUI objects. You can also find many code examples on the forums that deal with a lot of common API tasks. The situation is different for Linux and OSX. Here, different Gadgets may have different underlying objects and so it is not entirely clear what functions can be used. There are also a lot less examples around for these systems. Of course when developing programs that run on multiple OS, you will need solutions for all of them.

To help this situation a bit, i have compiled a list of what are the underlying objects behind the PB gadgets and other GUI objects. You can get access to these using functions such as GadgetID(), WindowID(), etc.


This information is internal stuff. While many of these things haven’t changed in many years, it is still possible that we decide to change something in the future. Also some Gadgets are heavily modified for PB with custom subclasses or callbacks which also may change in the future and break your code. So as usual: Feel free to use this information, but if it breaks, its not our problem.

So here it goes:
Windows Linux OSX
WindowID() HWND GtkWindow WindowRef
MenuID() HMENU GtkMenuBar / GtkMenu MenuRef
StatusBarID() HWND GtkHBox ControlRef (UserPane)
ToolBarID() HWND GtkToolbar HIToolbarRef
FontID() HFONT PangoFontDescription PB internal pointer
ImageID() HBITMAP GdkPixbuf CGImageRef
GadgetID() HWND GtkWidget ControlRef
ButtonGadget “Button” GtkButton / GtkToggleButton PushButton / BevelButton
ButtonImageGadget “Button” GtkButton / GtkToggleButton PushButton / BevekButton
CalendarGadget “SysMonthCal32” GtkCalendar HIView
CheckBoxGadget “Button” GtkCheckButton CheckBox
ComboBoxGadget “ComboBox” / WC_COMBOBOXEX GtkComboBox / GtkComboBoxEntry PopupButton / HIComboBox
ContainerGadget custom class GtkFixed UserPane
DateGadget DATETIMEPICK_CLASS GtkEntry UserPane
EditorGadget RICHEDIT_CLASS GtkTextView UserPane (rendering a TNXObject)
ExplorerComboGadget WC_COMBOBOXEX GekComboBoxEntry HIComboBox
ExplorerListGadget WC_LISTVIEW GtkTreeView DataBrowser
ExplorerTreeGadget WC_TREEVIEW GtkTreeView DataBrowser
Frame3DGadget “Button” / “Static” GtkFrame GroupBox / UserPane / Separator
HyperLinkGadget “Static” GtkButton UserPane
IPAddressGadget WC_IPADDRESS GtkEntry EditUnicodeText
ImageGadget “Static” GtkImage UserPane
ListIconGadget WC_LISTVIEW GtkTreeView DataBrowser
ListIconGadget “ListBox” GtkTreeView DataBrowser
OptionGadget “Button” GtkRadioButton RadioButton
PanelGadget “SysTabControl32” GtkNotebook Tabs
ProgressBarGadget PROGRESS_CLASS GtkProgressBar ProgressBar
ScrollAreaGadget custom class GtkScrolledWindow UserPane
ScrollBarGadget “SCROLLBAR” GtkVScrollBar / GtkHScrollBar ScrollBar
ShortcutGadget HOTKEY_CLASS GtkEntry EditUnicodeText
SpinGadget UPDOWN_CLASS + “Edit” GtkHBox containing others UserPane containing others
SplitterGadget custom class GtkVPaned / GtkHPaned UserPane
StringGadget “Edit” GtkEntry EditUnicodeText
TextGadget “Static” GtkLabel StaticText
TrackBarGadget TRACKBAR_CLASS GtkVScale / GtkHScale Slider
TreeGadget WC_TREEVIEW GtkTreeView DataBrowser
WebGadget custom class + ActiveX control GtkMozEmbed HIWebView
  • Gadgets all have the same basic type noted in the GadgetID() row. However, Gadgets are devided into “window classes” on Windows, or subclasses of the general GtkWidget on Linux.
  • For Gadgets on Windows: If the entry is noted in “” then this is the class name, if it is not then this is the symbolic constant for the class name. You’ll have to look up the text value in the appropriate header files.
  • On OSX, there are no classes for the controls, its all a ControlRef. The names i noted here are derived from the control creation functions (ie CreateTabsControl()). If you are looking for information, you should start there.
  • Gadgets may have multiple classes depending on the flags on creation.
  • On Linux, many gadgets are placed inside their own container to add a frame or catch events. (GtkFrame, GtkEventBox). The GadgetID() command returns the real gadget in this case, not the container.
  • On OSX, the UserPane controls are drawn by PB itself, so you don’t have much ways to modify them other than the PB commands.

Thats it. I hope this information is useful to some people, and hopefully we will see some more cross-platform API examples on the forum in the future 🙂

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