LCL class hierarchy

Exception
- EDBEditError Exception class raised for an error in a masked edit control.
  - EInvalidEditMask Exception type raised for an invalid mask value in an edit mask.
- EGraphicException Base exception type for an error in a graphic operation.
  - EInvalidGraphic EInvalidGraphic - exception handler for an invalid graphic.
  - EInvalidGraphicOperation EInvalidGraphicOperation - exception handler for invalid graphic operation.
- EGridException Exception raised when an error has occurred in a Grid class.
- EHelpSystemException Exception raised for Help system errors.
- EInterfaceException Base class for exceptions raised in the LCL interface.
  - EInterfaceCritical Exception raised in the LCL interface.
  - EInterfaceError Exception raised in the LCL interface.
  - EInterfaceWarning Exception raised in the LCL interface.
- EInvalidDate Exception raised for an invalid date in the calendar control.
- EInvalidGridOperation Exception raised for an invalid grid operation.
- EInvalidUtf8 Ancestor for UTF-8 exceptions.
  - EInvalidCodePoint Exception raised when an error occurs while setting a UTF-8 Code Point in a String.
- ELayoutException Exception raised when a loop is detected when adjusting the size for controls.
- EMenuError Exception raised when an error occurs while accessing a menu item.
- EPrinter Exception raised for errors in TPrinter methods.
- EScrollBar Exception class raised in .
- EShellCtrl Exception raised for errors occurring in shell controls.
  - EInvalidPath Exception raised for an invalid path in shell controls.
- ETreeNodeError Exception type raised for an error retrieving a tree node.
  - ETreeViewError Exception type raised for errors in a tree view.
TAbstractObjectReader
- TLRSObjectReader Reader for resource streams.
TAbstractObjectWriter
- TLRSObjectWriter Object writer for Lazarus Resource Streams.
TActionListEnumerator
TArrayNode
TArrayNodesTree
TAvlTreeNodeEnumerator
- TLazAccessibleObjectEnumerator Implements an enumerator for a list of TLazAccessibleObject instances.
TBasicAction
- TContainedAction Implements an Action class which has a category and parent action list.
  - TCustomAction TCustomAction is the ancestor class for TAction.
    - TAction TAction is the basic action object used in the LCL.
      - TDataSetAction TDataSetAction is the base class for all other standard TDataSet actions.
        TDataSetCancel TDataSetCancel cancels the current edit mode for a DataSet.
        TDataSetDelete TDataSetDelete deletes the current record in the DataSet.
        TDataSetEdit TDataSetEdit edits the current record in the DataSet.
        TDataSetFirst TDataSetFirst moves to first record in the DataSet.
        TDataSetInsert TDataSetInsert inserts (appends) a new record into the DataSet.
        TDataSetLast TDataSetLast moves to last record in the DataSet.
        TDataSetNext TDataSetNext moves to next record in the DataSet.
        TDataSetPost TDataSetPost posts changes for the current record to the DataSet.
        TDataSetPrior TDataSetPrior moves to previous record in the DataSet.
        TDataSetRefresh TDataSetRefresh refreshes the DataSet.
      - TEditAction The base class for standard editing actions applied to an edit control.
        TEditCopy Editing action used to copy the selected value in a control to the clipboard.
        TEditCut Editing action used to cut the selected value in a control to the clipboard.
        TEditDelete Editing action used to remove the current selection in the specified control.
        TEditPaste Editing action used to paste values from the clipboard into the specified control.
        TEditSelectAll Editing action used to select all of the content in the value for the specified control.
        TEditUndo Editing action used to Undo the previous change to the value for the specified control.
      - THelpAction The base class for standard help actions.
        THelpContents Help action used to display a Table of Contents for the HelpContext.
        THelpContextAction Help action used to get help for a specific help context.
        THelpOnHelp Help action used to display the Help on Help topic, or "How to Get Help".
        THelpTopicSearch Help action used to search for a help topic.
    - TCommonDialogAction Dialog action used to create, configure, display, and execute a dialog form.
      - TColorSelect TColorSelect - standard action for opening a Color Selection dialog.
      - TFileAction TFileAction - base class for providing actions associated with various file dialogs and menu options.
        TFileOpen TFileOpen - standard action (including opening a dialog) associated with the File Open menu option.
        TFileOpenWith TFileOpenWith - standard action (including opening a dialog) associated with the File Open With menu option.
        TFileSaveAs TFileSaveAs - standard action (including opening a dialog) associated with the File Save As menu option.
      - TFontEdit TFontEdit - standard action for opening a Font Edit dialog.
      - TSearchAction TSearchAction - base class for the actions associated with the various Search menu options.
        TSearchFind TSearchFind - the action associated with a Search and Find dialog (as opposed to search and replace).
        TSearchFindFirst TSearchFindFirst - Search action to find the first match.
        TSearchReplace TSearchReplace - action associated with the Search and Replace menu option and dialogs.
    - TCustomHintAction Represents a standard action used to get a Hint value.
      - THintAction THintAction - standard action for dealing with requests for a Hint.
    - TFileExit TFileExit - standard action (closing file and terminating application) associated with the File Exit menu option.
    - TSearchFindNext TSearchFindNext - search action to find the next match.
TBasicActionLink
- TActionLink A link between an action and a client class.
  - TControlActionLink Links an Action to a control.
    - TSpeedButtonActionLink Links a TSpeedButton with a TAction instance.
    - TToolButtonActionLink TToolButtonActionLink - links a ToolButton on the ToolBar to an Action on an ActionList.
  - TMenuActionLink TMenuActionLink: defines the link between a selected menu item and its corresponding action.
TBookmarkedRecordEnumerator
TBookmarkList
TCDColorPalette
TCDControlStateEx
- TCDButtonStateEx
- TCDCTabControlStateEx
- TCDEditStateEx
- TCDListBoxStateEx
  - TCDCheckListBoxStateEx
- TCDListViewStateEx
- TCDPanelStateEx
- TCDPositionedCStateEx
  - TCDSpinStateEx
- TCDProgressBarStateEx
- TCDStatusBarStateEx
- TCDToolBarStateEx
TCDDrawer
- TCDDrawerCommon Provides a minimal implementation of a drawer for custom-drawn controls common to its derived classes.
TCDListItems
TCDToolBarItem
TCheckComboItemState
TCollection
- TCoolBands Implements a collection for TCoolBand items.
- TDialogButtons Collection used to store TDialogButton instances.
- TGridColumns Collection used to store column definitions for a grid control.
  - TDBGridColumns Implements a collection for columns in a database-aware grid.
- THeaderSections Implements a collection for sections in a TCustomHeaderControl control.
- TLCLCollection
- TListColumns A collection for TListColumn instances defined for a multi-column list view control.
  - TShellListColumns Collection type used to store column definitions in a shell list view control.
- TStatusPanels A collection of panels displayed on a status bar control.
TCollectionItem
- TCoolBand Implements a band displayed on the TCoolBar control.
- TDialogButton Implements a standard dialog button.
- TFlowPanelControl Implements a collection item for the TFlowPanelControlList collection.
- TGridColumn Implements a column definition used for tabular data in TCustomGrid.
  - TColumn Implements a display column for the TDBGrid control.
- THeaderSection Implements a section displayed on a TCustomHeaderControl / THeaderControl instance.
- TListColumn Represents an individual column in a multi-column list control.
  - TShellListColumn Defines a column displayed on a shell list view control.
- TListControlItem Implements a collection item added to a list control.
  - TComboExItem Implements an extended item used in TComboEx.
- TStatusPanel Implements a panel displayed in TStatusBar.
- TStoredValue A key/value pair representing a property value, with added Save/Restore features.
- TTaskDialogBaseButtonItem Defines the base class for a custom button displayed on a Task dialog.
  - TTaskDialogButtonItem Implements a button definition used for a button in TCustomTaskDialog.
  - TTaskDialogRadioButtonItem Implements a radio button displayed on a Task dialog.
TComponent
- TCustomLazComponentQueue A queue to stream components, used for multi-threading or network.
  - TLazComponentQueue Publishes property from the ancestor class.
- TCustomPropertyStorage Defines a container used to Save and Restore property values.
  - TControlPropertyStorage Implements the abstract ancestor class used to get the property list for a control.
    - TFormPropertyStorage TFormPropertyStorage - class for storage of a Form's properties.
      - TCustomIniPropStorage Implements the base class for storage of form session properties in an INI file.
        TIniPropStorage Implements a class used to store session properties in an INI file.
      - TCustomJSONPropStorage Implements the base class used to store session properties to a file in JSON format.
        TJSONPropStorage Implements the final class for the JSON Form Session Properties storage.
      - TCustomXMLPropStorage Implements the base class for XML storage of Form Session properties.
        TXMLPropStorage Implements a class for XML storage of Form Session properties.
- TCustomTimer Defines the base class for TTimer.
  - TCustomIdleTimer Implements the base class for TIdleTimer.
    - TIdleTimer Implements a timer to measure idle time between processes.
  - TTimer TTimer is an elapsed timer useful in many applications.
- TDBLookup TDBLookup - used as source of data by TDBLookupListBox or TDBLookupComboBox, to find data from a lookup table.
- TDragManager The abstract base class used to manage dragging of controls (for drop or dock operations).
- THelpDatabase Provides support for integrating a collection of related help topics with a table of contents.
  - THTMLHelpDatabase Provides support for context-sensitive help using HTML help files.
- THelpViewer Base class for help viewers used in the LCL help system.
  - THTMLBrowserHelpViewer Implements a browser/viewer for HTML help topics.
- TLCLComponent The base class for LCL components which have an associated widget.
  - TApplicationProperties A component that provides access to the properties for the current application.
  - TCommonDialog The base type from which other dialogs are derived.
    - TColorDialog Implements a dialog used to select a TColor value.
    - TCustomPrintDialog Implements the base class for TPrintDialog.
    - TCustomPrinterSetupDialog Base class for TPrinterSetupDialog and TPageSetupDialog.
    - TExtCommonDialog The common base class for custom drawn dialogs (Calculator and Calendar).
      - TCalculatorDialog Implements a pop-up calculator dialog used to perform simple calculations and return the value.
      - TCalendarDialog TCalendarDialog - a popup calendar dialog that allows a date to be selected and returned to the main program.
    - TFileDialog TFileDialog allows selection of a file from the current directory.
      - TOpenDialog Implements a File / Open dialog used to select one or more files on the local file system.
        TLazOpenDialog Implements a Lazarus file open dialog.
        TLazSaveDialog Implements a Lazarus File Save dialog.
        TLazSelectDirectoryDialog Implements a Lazarus directory selection dialog.
        TPreviewFileDialog TPreviewFileDialog - a dialog that allows the contents of a file to be inspected before opening the file.
        TOpenPictureDialog TOpenPictureDialog - a preview dialog that shows a preview of a picture before opening the file.
        TSavePictureDialog TSavePictureDialog - a dialog for saving the picture in the current buffer to a file.
        TSaveDialog TSaveDialog - Dialog for saving the current buffer to a file.
        TSelectDirectoryDialog Implements a select directory dialog.
    - TFindDialog TFindDialog - a dialog used for finding text within the current editor or text buffer.
      - TReplaceDialog Implements a find and replace dialog.
    - TFontDialog Dialog used to select a font typeface and size.
  - TControl The base class for visible controls.
    - TGraphicControl TGraphicControl is the base class for all lightweight controls.
      - TBevel A bevel placed around the edge of buttons and other components.
      - TCustomImage Implements the base class for TImage.
        TDBImage TDBImage - a data-aware Image box to display a single image from a dataset.
        TImage Implements a graphic image placed on a form, and usually loaded from a picture file.
      - TCustomLabel Control used to show static text optionally using multiple lines.
        TBoundLabel Implements a label bound to another control.
        TDBText Displays a string value stored in a dataset field.
        TLabel Control used to display static text, possibly in multiple lines and rotated by an arbitrary angle.
      - TCustomShape Defines a shaped control with an arbitrary geometric shape.
        TShape Implements a shaped control with an arbitrary geometric shape.
      - TCustomSpeedButton The ancestor for the TSpeedButton class.
        TColorButton TColorButton - a SpeedButton designed to be used with the Color dialog, allowing a color to be selected for text or graphics.
        TSpeedButton A Button used to represent states (checked or unchecked).
        TDBNavButton TDBNavButton implements a SpeedButton displayed on a TDBNavigator control.
        TEditSpeedButton Implements a speed button used in TCustomEditButton.
      - TIndustrialBase Implements the base class for a control with an anti-aliasing setting.
        TArrow TArrow - an arrow symbol widely used in forms.
      - TPaintBox Implements a control with a rectangular drawing area using a given Font and Color.
      - TToolButton TToolButton is a button control used in a TToolBar object.
    - TWinControl Implements a windowed control which can contain other child controls.
      - TButtonControl Specifies a base class for button controls.
        TCustomButton The base class for a push button control.
        TButton Implements a push button control.
        TButtonCellEditor The editor used for button-style cells in a grid.
        TCustomBitBtn TCustomBitBtn - the ancestor class for TBitBtn.
        TBitBtn A button with a small image attached.
        TDBNavFocusableButton Implements a button used on a database navigator control.
        TPanelBitBtn Implements the buttons displayed for TButtonPanel.
        TCustomCheckBox The base class for a check box component.
        TCheckBox A label with a box which can contain a check mark.
        TDBCheckBox Implements a data-aware check box control.
        TRadioButton Implement a radio button control.
        TToggleBox A labelled box capable of being checked or unchecked.
      - TCustomCalendar Implements the base class for TCalendar.
        TCalendar TCalendar allows selection of a date from a calendar display.
        TDBCalendar TDBCalendar - a data-aware version of TCalendar, for selecting a date to store in a database field.
      - TCustomComboBox The base class for combo-box components.
        TComboBox Implements a control with an edit box and a drop-down list allowing one of several options to be chosen.
        TCustomCheckCombo Base class for a combo-box which displays check boxes for Items in the control.
        TCheckComboBox Combo-box control which displays check boxes for the items in the control.
        TCustomColorBox The base class for TColorBox.
        TColorBox Implements combo-box control used to select a color name or value.
        TCustomComboBoxEx Implements the base class for an extended/enhanced combo-box.
        TComboBoxEx Implements an extended combo-box component.
        TCustomDBComboBox TCustomDBComboBox is a data-aware combo-box for displaying information from a database.
        TDBComboBox TDBComboBox is a data-aware version of TComboBox which allows selection of a value from a list of entries into a database field.
        TDBLookupComboBox TDBLookupComboBox is a data-aware combo-box for examining a lookup table in a database.
        TCustomFilterComboBox Specifies a combo-box used to select a file filter.
        TFilterComboBox Implements a combo-box used to select a file filter.
        TPickListCellEditor Implements a cell editor control which displays a pick list.
      - TCustomControl The base class for windowed controls which paint themselves.
        TCDControl
        TCDButtonControl
        TCDButton
        TCDToggleBox
        TCDCheckBox
        TCDRadioButton
        TCDCustomTabControl
        TCDPageControl
        TCDTabControl
        TCDEdit
        TCDComboBox
        TCDSpinEdit
        TCDGroupBox
        TCDListBox
        TCDCheckListBox
        TCDPanel
        TCDPositionedControl
        TCDScrollBar
        TCDTrackBar
        TCDProgressBar
        TCDScrollableControl
        TCDListView
        TCDStaticText
        TCDStatusBar
        TCDToolBar
        TCDTabSheet
        TCompositeCellEditor Implements a composite cell editor with combines one or more of the predefined cell editors types.
        TCustomAbstractGroupedEdit Implements a grouped edit control.
        TAbstractGroupedEdit Implements a grouped edit control.
        TCustomEditButton TCustomEditButton - base class for TEditButton, an Edit Box with attached Speed Button.
        TCalcEdit Implements an numeric edit control with a button to display a calculator dialog.
        TCustomControlFilterEdit Base class for edit controls which filter data in an associated control like TListbox or TTreeview.
        TDateEdit Implements a control with an edit box for a date value and an attached speed button to display a date selection (calendar) dialog.
        TDBDateEdit TDBDateEdit implements a data-aware editing control for a date field in a dataset.
        TDirectoryEdit TDirectoryEdit - an EditBox to hold a directory name, with an attached SpeedButton that summons a Directory Open dialog.
        TEditButton Implements a grouped edit control with both an Edit and a Button.
        TFileNameEdit TFileNameEdit - an EditBox to hold a filename, with an attached SpeedButton that summons a File Open dialog.
        TTimeEdit Implements a control used to edit time values.
        TCustomGrid Implements the base class for grid controls.
        TCustomDBGrid TCustomDBGrid is the base class for TDBGrid.
        TDBGrid Data-aware grid control used to display and edit rows and columns in a dataset.
        TCustomDrawGrid The base class for a custom-drawn grid control.
        TCustomStringGrid The base class for TStringGrid.
        TStringGrid Implements a grid specialized for textual content.
        TValueListEditor A visual grid control for editing Key-Value pairs.
        TDrawGrid Implements a custom-drawn grid control.
        TCustomHeaderControl TCustomHeaderControl - base class for THeaderControl, a header strip of user-designed sections which allow selection of pages or actions.
        THeaderControl THeaderControl, a header strip of user-designed sections which allow selection of pages or actions.
        TCustomPanel The base class for a general container which can hold other objects. It has a customizable border and a central text.
        TCustomButtonPanel Defines the base class for TButtonPanel.
        TButtonPanel Implements a panel with Bitmap Button instances.
        TCustomControlBar Implements a panel used to maintain and manage tool bars and tool buttons on a form.
        TControlBar Implements a panel used to maintain and manage tool bars and tool buttons.
        TCustomFlowPanel The base class for TFlowPanel.
        TFlowPanel Implements a panel with flowed layout for its controls.
        TDBCustomNavigator TDBCustomNavigator is the base class for TDBNavigator, a tool for navigating through the records of a dataset.
        TDBNavigator TDBNavigator - a data-aware Button-Bar to facilitate navigating between records of a dataset.
        TPanel Implements a general purpose container which can hold other components.
        TCalculatorPanel Implements a panel used for buttons and the value display in a calculator form.
        TCustomSplitter TCustomSplitter is the base type for TSplitter.
        TLazDockSplitter TLazDockSplitter - a splitter used with Lazarus docking components.
        TSplitter TSplitter is a vertical or horizontal bar placed on a panel or form to separate sub-panels functionally.
        TCustomTreeView The base class for TTreeView.
        TCustomShellTreeView The base class for a tree view control used to display files, directories and other objects (such as devices) from the local file system.
        TShellTreeView Implements a tree view control to display the files, directories and other objects (such as devices) from the local file system.
        TTreeView TTreeView is a control that displays a hierarchical list of items.
        TCustomUpDown TCustomUpDown - base class for TUpDown - a pair of arrow-like buttons which are used to increment or decrement some controlled variable; often attached to a scroll-bar but can also control a digital numeric display.
        TUpDown TUpDown - a pair of arrow-like buttons which are used to increment or decrement some controlled variable; often attached to a scroll-bar but can also control a digital numeric display.
        TNotebook TNotebook is a container for a group of related pages.
        TNotifierXButton Implements the button for TNotifierForm.
        TPage TPage: One of the pages in a tabbed Notebook.
        TScrollingWinControl Implements a windowed control with scroll bars.
        TCustomDesignControl Provides a designer surface for scaling and layout of its child controls.
        TCustomForm The base type for TForm classes.
        TCustomDockForm A floating DockSite used to make TControls float.
        TForm Implements a form used in an LCL application.
        TCalculatorForm Implements the form used to display a calculator for a TCalculatorDialog instance.
        TCalendarPopupForm Implements a non-modal pop-up form used to select a date from a TCalendar control.
        TCustomCopyToClipboardDialog Base class for a dialog form used during copy to clipboard operations.
        TFindDialogForm TForm descendant which implements a find text dialog.
        TLazarusFileDialogForm Implements the form displayed for TLazOpenDialog descendants.
        TLazMessageDialog
        TLCLTaskDialog Implements an emulated (non-native) task dialog form.
        TLoginDialog Implements a database login dialog form.
        TReplaceDialogForm Form displayed when a TReplaceDialog instance is executed.
        TTimePopupForm Implements a form displayed to capture a time value.
        THintWindow The pop-up box containing helpful information that appears when the mouse pointer hovers over an object.
        THintWindowRendered For a rendered hint with a child control added by an external provider.
        TNotifierForm Implements the form used for TPopupNotifier.
        TLazDockForm TLazDockForm - the default DockSite for a TLazDockTree and for TCustomAnchoredDockManager.
        TCustomFrame The base type for TFrame.
        TFrame Frames can be designed like Forms and used like custom controls, without much coding or installation in the IDE.
        TScrollBox Implements a windowed control with scroll bars.
        TToolWindow Implements a control which can paint its client area with borders.
        TCustomCoolBar Defines a Rebar-like control with resizable bands.
        TCoolBar Implements a Rebar-like control with resizable bands.
        TToolBar Implements an application tool bar with buttons or other visual controls.
      - TCustomEdit The base class for controls presenting editable text.
        TCustomFloatSpinEdit The base class for a spin edit control using a floating point value.
        TCustomSpinEdit The base class for an integer-based spin edit control.
        TSpinEdit Implements an integer-based spin edit control.
        TFloatSpinEdit Implements a spin edit control using a floating point value.
        TCustomLabeledEdit Defines an edit control with a label bound to the control.
        TLabeledEdit Implements an edit control with a label bound to the control.
        TCustomListViewEditor Provides multi-platform editing capabilities for a list view control.
        TCustomMaskEdit The base class for TMaskEdit.
        TDBEdit TDBEdit - a data-aware edit box for processing a single text-string from a dataset.
        TGEEdit Implements the edit control used in TCustomAbstractGroupedEdit.
        TEbEdit Implements the embedded edit control used in TCustomEditButton.
        TMaskEdit TMaskEdit is an Edit box with characters masked out to avoid unauthorized reading.
        TStringCellEditor Implements the default editor for cells in TCustomGrid.
        TCustomMemo The base class for multi-line text controls.
        TDBMemo TDBMemo is a data-aware Memo box to process the multi-line text of a single field in a dataset.
        TMemo Control used to display and edit multi-line text.
        TEdit Implements an edit control with a single line of text.
      - TCustomGroupBox The base class for TGroupBox, TRadioGroup and TCheckGroup.
        TCustomCheckGroup TCustomCheckGroup is the base type for TCheckGroup.
        TCheckGroup TCheckGroup is a group of Check Boxes physically and logically grouped together on a form.
        TCustomRadioGroup TCustomRadioGroup is the base type for TRadioGroup.
        TDBRadioGroup TDBRadioGroup is a data-aware version of TRadioGroup, providing a series of mutually exclusive buttons to select an entry to insert into a database field.
        TRadioGroup TRadioGroup is a group of related but mutually exclusive radio buttons, requiring the user to select one of a set of alternatives.
        TDBGroupBox TDBGroupBox is a data-aware version of TGroupBox, allowing a number of data-aware objects to be grouped together on a form.
        TGroupBox A container that allows a number of objects to be grouped physically and conceptually on a form.
      - TCustomListBox The base class for TListBox.
        TCustomCheckListBox The base class for TCheckListBox, a list box with check box items.
        TCheckListBox TCheckListBox implements a list box with check boxes for its items.
        TCustomColorListBox Implements the base class for TColorListBox.
        TColorListBox Implements a list box control used to display and select color names and values.
        TCustomDBListBox Specifies a data-aware listbox control.
        TDBListBox Implements a data-aware version of TListBox.
        TDBLookupListBox Implements a data-aware listbox control with database lookup capabilities.
        TCustomFileListBox Implements the base class for a file selection list box.
        TFileListBox Implements a file selection list box control.
        TListBox Control which displays a scrollable list of values.
      - TCustomListView TCustomListView is the base class for TListView.
        TCustomShellListView The base class that defines a list view control to display files or directories found on the local file system.
        TShellListView Implements a list view control to display files or directories found on the local file system.
        TListView TListView - a window showing a list of Items which may or may not have associated icons.
      - TCustomPage The base class for TTabSheet.
        TLazDockPage TLazDockPage - an entity similar to a TLazDockForm, but forming a page in a notebook of TLazDockPages.
        TTabSheet An individual page used in TPageControl.
      - TCustomPairSplitter Defines the base class for the TPairSplitter component.
        TPairSplitter Implements the TPairSplitter component.
      - TCustomProgressBar Implements the base class for progress bar controls.
        TProgressBar TProgress Bar - a bar that depicts what proportion of a process has been completed.
      - TCustomRubberBand Base class which implements a rubber-band selection.
        TRubberBand Implements a rubber-band selection.
      - TCustomScrollBar The base class for TScrollBar.
        TScrollBar A control that allows the user to scroll the content in an associated control by moving a slider.
      - TCustomStaticText The base class for TStaticText.
        TStaticText Control used to display a text value which does not change.
      - TCustomTabControl Implements the base class for tabbed controls in the LCL.
        TLazDockPages TLazDockPages a notebook in which each page is a TLazDockPage.
        TPageControl Implements a multi-page component with a series of tabs.
        TNoteBookStringsTabControl Implements the tabbed page control used in TNoteBookStringsTabControl.
        TTabControl TTabControl - a series of Tabs along the edge of a display area; selection of a Tab governs the contents of the DisplayRect.
      - TCustomTrackBar TCustomTrackBar - the base class for TTrackBar.
        TTrackBar TTrackBar: a device which allows the user to determine the value of a variable using a quasi-analog slider.
      - TPairSplitterSide Implements the child controls used in the TPairSplitter component.
      - TPreviewFileControl TPreviewFileControl - a windowed control allowing the contents of a file to be previewed before opening.
      - TStatusBar Displays a panel along the bottom of a form with current status information.
  - TCustomActionList TCustomActionList - the ancestor class for TActionList.
    - TActionList TActionList - The basic actions list class.
  - TCustomImageList The base class for TImageList.
    - TDragImageList A multi-resolution list of Images used during Drag operations.
      - TImageList Implements a multi-resolution container for images used in an application.
    - TLCLGlyphs Represents glyphs for buttons or icons used in LCL controls.
      - TDialogImageList Implements a multi-resolution image list used for a dialog icon loaded from a resource file.
  - TCustomTaskDialog Defines a configurable, modal task dialog at run-time.
    - TTaskDialog Implements a configurable modal task dialog.
  - TCustomTrayIcon Defines the base class for a multi-platform system tray icon component.
    - TTrayIcon Implements a multi-platform system tray component.
  - TLCLReferenceComponent Base class for all components having an associated widget with a handle.
    - TCustomImageListResolution Implements an image resolution (or size) used in TCustomImageList.
      - TDragImageListResolution Implements an image list resolution with features used in Drag and Drop operations.
  - TMenu TMenu - a menu appearing in a form. Base class for TMainMenu or TPopupMenu.
    - TMainMenu TMainMenu - the Main Menu that appears at the top of most windows.
    - TPopupMenu Implements a menu panel that pops up on the screen when the right mouse button is clicked.
  - TMenuItem Represents a menu item displayed in a menu.
  - TScreen Provides information about screen displays in an application.
- TPopupNotifier Implements a pop-up notification component.
TConfigStorage
- TXMLConfigStorage Implements a configuration storage mechanism using XML-tagged content.
TCtrlBand
TCustomApplication
- TApplication Application management and configuration for a GUI application.
TCustomImageListResolutionEnumerator
TCustomMemoryStream
- TLazarusResourceStream Helper class for streaming resources (read only).
TDatalink
- TComponentDataLink Maintains an association between a component and a dataset.
- TDBNavDataLink TDBNavDataLink - provides a link between a Database Navigator and a DataSet.
- TFieldDataLink Maintains an association between a control, an action, and a field in a linked dataset.
TDebugLCLItemInfo
TDebugLCLItems
TDockZone
- TLazDockZone TLazDockZone - a zone for docking in a Lazarus form.
TDragObject
- TDragControlObject A drag object for dragging a control.
  - TDragControlObjectEx A drag object for dragging a control.
- TDragDockObject A drag object for drag-dock.
  - TDragDockObjectEx A drag object for docking that is automatically destroyed after use.
- TDragObjectEx Extends TDragObject to automatically free itself in the DragManager.
TFPCustomBrush
- TBrush The Brush to be used to Paint on the current Canvas.
TFPCustomCanvas
- TCanvas Implements a drawing surface for a visual control or bitmap image.
  - TControlCanvas Base class which provides a canvas property used in graphic controls.
  - TPrinterCanvas Implements a canvas used for TPrinter device output.
    - TFilePrinterCanvas Defines a printer canvas with an associated file for its output.
      - TPostScriptPrinterCanvas
        TPostScriptCanvas
TFPCustomFont
- TFont Represents a font used to draw text in an application.
  - TControlFont
TFPCustomImage
- TLazIntfImage Represents a graphical image.
- TLazIntfImageMask TLazIntfImageMask - applying a mask at the Raw Image level.
TFPCustomImageReader
- TLazReaderDIB
  - TLazReaderBMP TLazReaderBMP - This is an improved FPImage reader for bmp images.
  - TLazReaderIconDIB Implements an image reader for a single DIB in an icon file.
- TLazReaderIcnsPart
- TLazReaderXPM TLazReaderXPM - this is a FPImage reader for xpm images.
TFPCustomImageWriter
- TLazWriterXPM TLazWriterXPM is a FPImage writer for xpm images.
TFPCustomInterpolation
- TFPSharpInterpolation Implements a very sharp and square interpolation.
TFPCustomPen
- TPen Represents a pen used to draw on a canvas.
TFPCustomRegion
- TLazRegion Represents a custom region in the Lazarus LCL.
  - TLazRegionWithChilds Implement a region which can have other regions as children.
TFPGObjectList
- TCtrlBands Container used to store TCtrlBand instances.
TFPImageCanvas
- TLazCanvas Implements a canvas which masks differences between FCL and LCL canvas classes.
TFPPalette
- TLazAVLPalette Descendant of TFPPalette which uses an AVL tree for speed up.
TFPReaderPNG
- TLazReaderPNG
TFPReaderTiff
- TLazReaderTiff Extends the FCL TIFF image reader to support the ILazImageReader interface.
TFPWriterBMP
- TLazWriterBMP
TFPWriterPNG
- TLazWriterPNG
TFPWriterTiff
- TLazWriterTiff Extends the FCL TIFF image writer to support the ILazImageWriter interface.
TFreeTypeDrawer
- TIntfFreeTypeDrawer
TGridScroller
THelpNodeQuery
THelpNodeQueryList
THelpQueryItem
- TPascalHelpContextList Implements a list for Pascal help contexts.
THelpViewers
TIconImage
- TCursorImageImage Implements the image for a cursor, stored as an Icon.
TImageListCache
TItemPropList
TLazAccelerometer
TLazAccessibleObject
TLazCanvasState
TLazDevice
TLazDeviceMessage
TLazMessaging
TLazPositionInfo
TLazRegionPart
- TLazRegionEllipse Implements a region defined as an Ellipse.
- TLazRegionPolygon Represents a region defined as a series of vertices for a polygon.
- TLazRegionRect Implements a region defined by a TRect structure.
TList
- TIcnsList Implements a list used to maintain TIcnsIcon instances.
- TImageCacheItems Implements a container for cached image lists.
- TListWithEvent Implements a list with an event signalled when values are added or removed.
- TMenuItems Implements a list used to store TMenuItem instances with a given parent.
- TMonitorList A list of monitors available on the system.
- TPropertiesToSkip Implements a list used to store properties which are skipped during LCL streaming.
TListItemsEnumerator
TLResource
TMenuItemEnumerator
TMergedMenuItems
TMessageDispatcher
TMouse
TObject
- TAbstractTranslator Abstract base class for translators used in the LCL.
  - TUpdateTranslator Performs string translations for persistent objects.
    - TDefaultTranslator Performs string translations using a .mo file (Machine Object).
    - TPOTranslator Performs string translations using a .po (Portable Object) file.
- TButtonGlyph Represents an image that can be attached to a button.
- TChangeLink Performs notifications when images are added or deleted in TImageList.
- TCustomImageListResolutions Provides multiple image resolutions in TCustomImageList.
- TFileItem Provides information about a file or directory on the local file system for use in file sort comparison routines.
- THelpManager Defines a help manager used to display a help query or a table of contents.
  - THelpDatabases Implements support for accessing and maintaining registered help database classes in the help system.
- TIDesigner The abstract base class for visual Form designers.
- TLResourceList Container class used for Lazarus resource descriptions.
- TMonitor Provides information about a physical monitor.
- TPaperSize Size for a paper used on an attached printer device.
- TPostScript
- TPostScriptCanvas
- TPrinter TPrinter defines a printer object used in Lazarus applications.
- TPSObject
  - TPSPen
- TPSPattern
- TThemeServices Implements theme services for supported platforms.
- TWidgetSet Provides an application helper class (platform and drawing interface).
TOwnedCollection
- TFlowPanelControlList Implements a collection for TCustomFlowPanel collection items.
- TListControlItems Container for the items added to a list control.
  - TComboExItems Implements a collection for the items added to TCustomComboBoxEx.
- TStoredValues Implements a collection for TStoredValue collection items.
- TTaskDialogButtons Collection type used to access and maintain buttons defined for a Task dialog.
TPersistent
- TAnchorSide Specifies how the side of a control is anchored to other controls.
- TClipboard Represents the clipboard on platforms supported for the LCL.
- TControlBorderSpacing Describes the (minimum) spacing around a control.
- TControlChildSizing Provides settings to layout child-controls into a grid (table) layout.
- TControlScrollBar Scroll bar type used in TScrollingWinControl.
  - TMemoScrollbar A scrollbar for use in Memo controls.
- TDockManager The layout manager for a docksite.
  - TDockTree A tree of TDockZone instances where each docked window has one tree.
    - TLazDockTree Implements a docking manager using a simple layout.
- TGraphic Abstract base class used for images in supported image formats.
  - TRasterImage Base class for a number of graphic controls, including TCustomBitmap and TCustomIcon, which use a raster of dots to display graphic information.
    - TCustomBitmap TCustomBitmap - the base class for TBitmap.
      - TFPImageBitmap Implements a Bitmap using the FPImage reader and writer from the FCL.
        TBitmap Implements a FCL-compatible reader/writer for a Bitmap image.
        TGIFImage Implements an image using the GIF (Graphics Interchange Format) image format.
        TJPEGImage TJPEGImage - a class for handling images stored in JPEG (compressed) format.
        TPixmap Implements support for the XPM (Pixmap) image format.
        TPortableAnyMapGraphic Implements an image which supports for the Portable Any Map (PNM) graphic format.
        TPortableNetworkGraphic Implements support for the PNG image format.
        TTiffImage Implements support for the TIFF (Tag Image File Format) graphic format.
    - TCustomIcon TCustomIcon - base class for TIcon.
      - TCursorImage TCursorImage - an Icon to be used to represent a cursor.
      - TIcnsIcon Implements a macOS Icon Resource file.
      - TIcon Implements an icon image type; small images typically associated with applications, controls, etc.
- TGraphicsObject Primitive ancestor class, mainly for Delphi compatibility.
  - TRegion A defined area on a screen or canvas used to render a graphic image or text output.
- TGridColumnTitle Provides properties and methods need to represent a column title in a grid.
  - TColumnTitle TColumnTitle is a TGridColumnTitle descendant.
- THelpBasePathObject Stores the base file path for help databases.
- THelpBaseURLObject Stores the base URL for topics in help databases.
- THelpDBItem
  - THelpDBIClass
  - THelpDBIMessage
  - THelpDBISourceFile
    - THelpDBISourceDirectory
      - THelpDBISourceDirectories
- THelpNode .
- THelpQuery
  - THelpQueryClass
  - THelpQueryContext
  - THelpQueryDirective
  - THelpQueryKeyword
  - THelpQueryMessage
  - THelpQueryNode
  - THelpQuerySourcePosition
    - THelpQueryPascalContexts
  - THelpQueryTOC
- TIconOptions Contains text wrapping and icon layout settings for a list view control.
- TItemProp Represents items in the TValueListEditor control.
- TListItem Represents the items created in TCustomListView and descendants.
  - TOwnerDataListItem List item class used in a list view control when OwnerData (virtual) mode is enabled.
  - TShellListItem Implements the class used for list items maintained in TShelllListView.
- TListItems Implements a container for list items on a list view control.
  - TOwnerDataListItems Container for the items in a list view control when owner data (virtual) mode is enabled.
- TPicture Implements a container for TGraphic and descendent classes.
- TPropertyStorageLink Links a storage object to a property collection.
- TSizeConstraints Holds minimum and maximum values for the width or height of a control.
- TTaskDialogProgressBar Provides information about a progress bar displayed on a TTaskDialog instance.
- TTreeNode Implements a tree node displayed in a TTreeView control.
  - TShellTreeNode Represents tree nodes in TCustomShellTreeView / TShellTreeView.
- TTreeNodes Implements a container for TTreeNode instances.
- TWindowMagnetOptions Implements options which control magnetic window behavior in form instances.
TProcessUTF8
- TAsyncProcess Implements a process with asynchronous notifications for data and termination.
TPsUnicode
TReplaceDialog
TResourceCache
- TFontHandleCache TFontHandleCache - a resource cache for font handles.
- THandleResourceCache THandleResourceCache - a Resource Cache for Handles.
  - TBlockResourceCache TBlockResourceCache - a cache for Block resources.
    - TBrushHandleCache TBrushHandleCache - resource cache for Brush Handles.
- TPenHandleCache TPenHandleCache - Resource Cache for Pen Handles.
TResourceCacheDescriptor
- TBlockResourceCacheDescriptor TBlockResourceCacheDescriptor - descriptor for a Block Resource Cache.
- TFontHandleCacheDescriptor TFontHandleCacheDescriptor - descriptor for items in Font Handle Cache.
- TPenHandleCacheDescriptor Cache descriptor for Pen Handles.
TResourceCacheItem
TSharedImage
- TSharedRasterImage Implements a reference counted raster image that may be shared between controls.
  - TSharedCustomBitmap Implements the base class for a reference-counted shared image.
    - TSharedBitmap Defines a reference-counted shared Bitmap graphic.
    - TSharedGIFImage Implements a reference-counted shared GIF image.
    - TSharedJpegImage TSharedJpegImage - a reference counted shared image of type JPEG.
    - TSharedPixmap Implements a reference-counted shared Pixmap image type.
    - TSharedPortableAnyMapGraphic TSharedPortableAnyMapGraphic - a reference counted shared PNM.
    - TSharedPortableNetworkGraphic TSharedPortableNetworkGraphic - a reference counted PNG Image.
    - TSharedTiffImage Declares the shared image for the TTiffImage type.
  - TSharedIcon Implements a reference-counted shared Icon image type.
    - TSharedCursorImage Implements a reference-counted shared image used for cursors.
    - TSharedIcnsIcon Declares the shared icon for the TIcnsIcon type.
TStringList
- TShortCutList A list of shortcuts (accelerator keys) for actions in an action list.
- TValueListStrings Stores values and item definitions used in TValueListEditor.
TStrings
- TNBBasePages Ancestor for the TNBPages class.
  - TNBNoPages Re-implements an empty page container for TCustomTabControl controls.
  - TNBPages Implements a list of pages used in TCustomTabControl.
- TStringGridStrings Represents strings used as the cell values in TCustomStringGrid / TStringGrid.
- TTabControlStrings TTabControlStrings - the Strings that appear on the tabs of TTabControl.
  - TTabControlNoteBookStrings TTabControlNoteBookStrings - instance of TTabControlStrings for use with a TNoteBook.
- TUNBPages Represents page names and page class instances for a notebook.
TTaskDialogButtonsEnumerator
TToolBarEnumerator
TTreeNodeExpandedState
TTreeNodesEnumerator
TVirtualGrid
TWinControlActionLink
- TButtonActionLink Links a button control to a basic action.
TWinControlEnumerator
TWindowMagnetManager
TWSCustomImageListResolution
- TWSDragImageListResolution
  - TWSImageList
TWSLCLComponent
- TWSControl
  - TWSGraphicControl
  - TWSWinControl
    - TWSCustomControl
TWSObject
- TWSLazAccessibleObject
TXMLConfig
- TPropStorageXMLConfig Wrapper for the TXMLConfig class defined in the FCL XMLConf.pp unit.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.