TCustomComboBox

type TCustomComboBox = class(TWinControl)

protected

  class procedure WSRegisterClass; override;

Registers this component class with the current WidgetSet.

  function CanShowEmulatedTextHint; virtual;

Indicates whether an emulated TextHint can be displayed for the control.

  procedure CreateParams(); override;

Updates the specified creation parameters to include additional flags for the control.

  procedure InitializeWnd; override;

Synchronizes the control and its widgetset class instance when the handle is created.

  procedure DestroyWnd; override;

Destroys the handle for the control (and its children).

  procedure DoAutoCompleteSelect; virtual;

Selects an item in the control when auto-complete is enabled and activated by a key event.

  procedure DoEnter; override;

Updates the control when the Enter key is applied.

  procedure DoExit; override;

Updates the control when the CM_EXIT control message is handled.

  procedure DrawItem(); virtual;

Draws a list item, using the OnDrawItem handler (when assigned).

  procedure KeyUpAfterInterface(); override;

Handles key up events forwarded from the LCL interface.

  procedure MeasureItem(); virtual;

Gets the height for an item in the drop-down list.

  class function GetControlClassDefaultSize; override;

Returns the default dimensions for new instances of the class.

  procedure LMChanged(); message;

Handles the LM_CHANGED message for the control.

  procedure CMWantSpecialKey(); message;

Handles the CM_WANTSPECIALKEY control message for the control.

  procedure Change; virtual;

Signals the OnChange event handler when the value for the control is changed.

  procedure Select; virtual;

Signals the OnSelect event handler when ItemIndex is changed.

  procedure DropDown; virtual;

Signals the OnDropDown event handler.

  procedure GetItems; virtual;

Signals the OnGetItems event handler.

  procedure SetItems(); virtual;

Sets the value for the Items property.

  procedure CloseUp; virtual;

Called when the drop-down list is closed.

  procedure AdjustDropDown; virtual;

Adjusts the extent for the drop-down list.

  procedure DoAutoAdjustLayout(); override;

Performs actions needed to auto-adjust the control using the specified layout policy.

  function GetItemCount;

Returns the number of items defined in the drop-down list.

  function GetItemHeight; virtual;

Gets the value for the ItemHeight property.

  function GetSelLength; virtual;

Gets the value for the SelLength property.

  function GetSelStart; virtual;

Gets the value for the SelStart property.

  function GetSelText; virtual;

Gets the value for the SelText property.

  function GetItemIndex; virtual;

Gets the value for the ItemIndex property.

  function GetMaxLength; virtual;

Gets the value for the MaxLength property.

  procedure SetDropDownCount(); virtual;

Sets the value for the DropDownCount property.

  procedure SetDroppedDown(); virtual;

Sets the value for the DroppedDown property.

  procedure SetItemHeight(); virtual;

Sets the value for the ItemHeight property.

  procedure SetItemIndex(); virtual;

Sets the value for the ItemIndex property.

  procedure SetMaxLength(); virtual;

Sets the value for the MaxLength property.

  procedure SetSelLength(); virtual;

Sets the value for the SelLength property.

  procedure SetSelStart(); virtual;

Sets the value for the SelStart property.

  procedure SetSelText(); virtual;

Sets the value for the SelText property.

  procedure SetSorted(); virtual;

Sets the value for the Sorted property.

  procedure SetStyle(); virtual;

Sets the value for the Style property.

  function RealGetText; override;

Gets the text/caption for the control.

  procedure RealSetText(); override;

Updates ItemIndex when the new value for the control is updated.

  procedure KeyDown(); override;

Filters keys used to traverse the list.

  procedure KeyUp(); override;

Handles AutoComplete and AutoSelect for the control.

  procedure UTF8KeyPress(); override;

UTF8KeyPress converts character case if required then calls the inherited method.

  procedure MouseUp(); override;

Highlights the selected text in the control when the left mouse button is released.

  function SelectItem();

Selects the list item with the specified text.

  procedure ShouldAutoAdjust(); override;

Indicates if the width and/or height for the control can be adjusted by a layout policy.

  property ItemHeight: Integer; [rw]

The default height of an item in the drop-down for the control.

  property ItemWidth: Integer; [rw]

The minimum width of the items in the drop-down list.

  property MaxLength: Integer; [rw]

The maximum length for text entered in the edit box for the control.

  property OnChange: TNotifyEvent; [rw]

Event handler signalled for user changes to the text in the edit box.

  property OnCloseUp: TNotifyEvent; [rw]

Handler invoked when the drop-down list closes.

  property OnDrawItem: TDrawItemEvent; [rw]

Handler for special painting of an item (in owner-draw mode).

  property OnDropDown: TNotifyEvent; [rw]

Handler invoked when the list has dropped down.

  property OnGetItems: TNotifyEvent; [rw]

Handler invoked when widgetset items list can be populated.

  property OnMeasureItem: TMeasureItemEvent; [rw]

Handler invoked when the height for an item is needed.

  property OnSelect: TNotifyEvent; [rw]

Handler invoked when an item is selected.

  property ParentColor: Boolean;

Uses the Color from the Parent control, when enabled.

  property Sorted: Boolean; [rw]

Determines whether the list entries are sorted in alphanumeric order.

public

  constructor Create(); override;

Constructor for the class instance.

  destructor Destroy; override;

Destructor for the class instance.

  procedure IntfGetItems;

Gets the values in the Items property for the widgetset class.

  procedure AddItem(); virtual;

Adds the specified string (and optional object) to the Items displayed in the control.

  function MatchListItem();

Gets the position for the specified value in Items using the AutoCompleteText settings for the control.

  procedure AddHistoryItem();

Add an item as the first entry in the history list for the control.

  procedure Clear; virtual;

Removes all items from the list, and clears the edit box.

  procedure ClearSelection;

Removes the item selection in the list box for the control.

  property CharCase: TEditCharCase; [rw]

Indicates the case conversion applied to the value entered in the edit box for the control.

  property DroppedDown: Boolean; [rw]

Indicates whether the drop-down list has been displayed.

  procedure SelectAll;

Selects the text content in the edit box for the control.

  property AutoComplete: Boolean; [rw]

Positions the list box using partial text matching.

  property AutoCompleteText: TComboBoxAutoCompleteText; [rw]

Options for the behavior of the Auto-Complete feature.

  property AutoDropDown: Boolean; [rw]

Makes the drop-down list appear as soon as the user starts entering text.

  property AutoSelect: Boolean; [rw]

Selects the entire content of the edit box when the control receives the focus.

  property AutoSelected: Boolean; [rw]

True indicates that the selection was marked automatically by the control.

  property AutoSize: Boolean;

Allows automatic adjustment of the size for the control, according to its content.

  property ArrowKeysTraverseList: Boolean; [rw]

Indicates if keyboard Arrow (or cursor) keys can be used to move through the list.

  property Canvas: TCanvas; [r]

Provides access to the drawing surface for the control.

  property DropDownCount: Integer; [rw]

The maximum number of Items visible in the drop-down list for the control.

  property EmulatedTextHintStatus: TEmulatedTextHintStatus; [r]

Status for the emulated TextHint in the control.

  property Items: TStrings; [rw]

The list of items displayed in the combo-box control.

  property ItemIndex: Integer; [rw]

The index of the currently selected item, or -1 if none is selected.

  property ReadOnly: Boolean; [rw]

Disallows free-form entry of Text into the combo-box edit field.

  property SelLength: Integer; [rw]

The number of selected UTF-8 characters in the edit box.

  property SelStart: Integer; [rw]

zero-based index to the UTF-8 character at the beginning of the selected text in the edit box.

  property SelText: string; [rw]

The selected text in the edit box for the control.

  property Style: TComboBoxStyle; [rw]

Controls the appearance and behavior for the combo-box.

  property TabStop: Boolean;

Enables or disables keyboard navigation using the Tab or Shift+Tab keys.

  property Text: TCaption;

The value in the edit box for the control.

  property TextHint: TTranslateString; [rw]

Default hint text shown when the Text property is empty for the control.

end;

TCustomComboBox

The base class for combo-box components.

TWinControl

Implements a windowed control which can contain other child controls.

TControl

The base class for visible controls.

TLCLComponent

The base class for LCL components which have an associated widget.

TComponent,IUnknown,IInterfaceComponentReference

TPersistent,IFPObserved

TObject