interface/wx/combo.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        combo.h
   3 // Purpose:     interface of wxComboCtrl and wxComboPopup
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @class wxComboPopup
  11
  12     In order to use a custom popup with wxComboCtrl, an interface class must be
  13     derived from wxComboPopup.
  14
  15     For more information on how to use it, see @ref comboctrl_custompopup.
  16
  17     @library{wxcore}
  18     @category{ctrl}
  19
  20     @see wxComboCtrl
  21 */
  22 class wxComboPopup
  23 {
  24 public:
  25     /**
  26         Default constructor. It is recommended that internal variables are
  27         prepared in Init() instead (because m_combo is not valid in
  28         constructor).
  29     */
  30     wxComboPopup();
  31
  32     /**
  33         The derived class must implement this to create the popup control.
  34
  35         @return @true if the call succeeded, @false otherwise.
  36     */
  37     virtual bool Create(wxWindow* parent) = 0;
  38
  39     /**
  40         Utility function that hides the popup.
  41     */
  42     void Dismiss();
  43
  44     /**
  45         The derived class may implement this to return adjusted size for the
  46         popup control, according to the variables given.
  47
  48         @param minWidth
  49             Preferred minimum width.
  50         @param prefHeight
  51             Preferred height. May be -1 to indicate no preference.
  52         @param maxHeight
  53             Max height for window, as limited by screen size.
  54
  55         @remarks This function is called each time popup is about to be shown.
  56     */
  57     virtual wxSize GetAdjustedSize(int minWidth, int prefHeight, int maxHeight);
  58
  59     /**
  60         Returns pointer to the associated parent wxComboCtrl.
  61     */
  62     wxComboCtrl* GetComboCtrl() const;
  63
  64     /**
  65         The derived class must implement this to return pointer to the
  66         associated control created in Create().
  67     */
  68     virtual wxWindow* GetControl() = 0;
  69
  70     /**
  71         The derived class must implement this to return string representation
  72         of the value.
  73     */
  74     virtual wxString GetStringValue() const = 0;
  75
  76     /**
  77         The derived class must implement this to initialize its internal
  78         variables. This method is called immediately after construction
  79         finishes. m_combo member variable has been initialized before the call.
  80     */
  81     virtual void Init();
  82
  83     /**
  84         Utility method that returns @true if Create has been called.
  85
  86         Useful in conjunction with LazyCreate().
  87     */
  88     bool IsCreated() const;
  89
  90     /**
  91         The derived class may implement this to return @true if it wants to
  92         delay call to Create() until the popup is shown for the first time. It
  93         is more efficient, but on the other hand it is often more convenient to
  94         have the control created immediately.
  95
  96         @remarks Base implementation returns @false.
  97     */
  98     virtual bool LazyCreate();
  99
 100     /**
 101         The derived class may implement this to do something when the parent
 102         wxComboCtrl gets double-clicked.
 103     */
 104     virtual void OnComboDoubleClick();
 105
 106     /**
 107         The derived class may implement this to receive key events from the
 108         parent wxComboCtrl.
 109
 110         Events not handled should be skipped, as usual.
 111     */
 112     virtual void OnComboKeyEvent(wxKeyEvent& event);
 113
 114     /**
 115         The derived class may implement this to do special processing when
 116         popup is hidden.
 117     */
 118     virtual void OnDismiss();
 119
 120     /**
 121         The derived class may implement this to do special processing when
 122         popup is shown.
 123     */
 124     virtual void OnPopup();
 125
 126     /**
 127         The derived class may implement this to paint the parent wxComboCtrl.
 128
 129         Default implementation draws value as string.
 130     */
 131     virtual void PaintComboControl(wxDC& dc, const wxRect& rect);
 132
 133     /**
 134         The derived class must implement this to receive string value changes
 135         from wxComboCtrl.
 136     */
 137     virtual void SetStringValue(const wxString& value);
 138
 139 protected:
 140     /**
 141         Parent wxComboCtrl. This member variable is prepared automatically
 142         before Init() is called.
 143     */
 144     wxComboCtrl*    m_combo;
 145 };
 146
 147
 148
 149 /**
 150     Features enabled for wxComboCtrl.
 151
 152     @see wxComboCtrl::GetFeatures()
 153 */
 154 struct wxComboCtrlFeatures
 155 {
 156     enum
 157     {
 158         MovableButton   = 0x0001, ///< Button can be on either side of control.
 159         BitmapButton    = 0x0002, ///< Button may be replaced with bitmap.
 160         ButtonSpacing   = 0x0004, ///< Button can have spacing from the edge
 161                                   ///< of the control.
 162         TextIndent      = 0x0008, ///< wxComboCtrl::SetMargins() can be used.
 163         PaintControl    = 0x0010, ///< Combo control itself can be custom painted.
 164         PaintWritable   = 0x0020, ///< A variable-width area in front of writable
 165                                   ///< combo control's textctrl can be custom
 166                                   ///< painted.
 167         Borderless      = 0x0040, ///< wxNO_BORDER window style works.
 168
 169         All             = MovableButton | BitmapButton | ButtonSpacing |
 170                           TextIndent | PaintControl | PaintWritable |
 171                           Borderless ///< All features.
 172     };
 173 };
 174
 175
 176 /**
 177     @class wxComboCtrl
 178
 179     A combo control is a generic combobox that allows totally custom popup. In
 180     addition it has other customization features. For instance, position and
 181     size of the dropdown button can be changed.
 182
 183     @section comboctrl_custompopup Setting Custom Popup for wxComboCtrl
 184
 185     wxComboCtrl needs to be told somehow which control to use and this is done
 186     by SetPopupControl(). However, we need something more than just a wxControl
 187     in this method as, for example, we need to call
 188     SetStringValue("initial text value") and wxControl doesn't have such
 189     method. So we also need a wxComboPopup which is an interface which must be
 190     implemented by a control to be usable as a popup.
 191
 192     We couldn't derive wxComboPopup from wxControl as this would make it
 193     impossible to have a class deriving from a wxWidgets control and from it,
 194     so instead it is just a mix-in.
 195
 196     Here's a minimal sample of wxListView popup:
 197
 198     @code
 199     #include <wx/combo.h>
 200     #include <wx/listctrl.h>
 201
 202     class wxListViewComboPopup : public wxListView, public wxComboPopup
 203     {
 204     public:
 205         // Initialize member variables
 206         virtual void Init()
 207         {
 208             m_value = -1;
 209         }
 210
 211         // Create popup control
 212         virtual bool Create(wxWindow* parent)
 213         {
 214             return wxListView::Create(parent,1,wxPoint(0,0),wxDefaultSize);
 215         }
 216
 217         // Return pointer to the created control
 218         virtual wxWindow *GetControl() { return this; }
 219
 220         // Translate string into a list selection
 221         virtual void SetStringValue(const wxString& s)
 222         {
 223             int n = wxListView::FindItem(-1,s);
 224             if ( n >= 0 && n < wxListView::GetItemCount() )
 225                 wxListView::Select(n);
 226         }
 227
 228         // Get list selection as a string
 229         virtual wxString GetStringValue() const
 230         {
 231             if ( m_value >= 0 )
 232             return wxListView::GetItemText(m_value);
 233             return wxEmptyString;
 234         }
 235
 236         // Do mouse hot-tracking (which is typical in list popups)
 237         void OnMouseMove(wxMouseEvent& event)
 238         {
 239             // TODO: Move selection to cursor
 240         }
 241
 242         // On mouse left up, set the value and close the popup
 243         void OnMouseClick(wxMouseEvent& WXUNUSED(event))
 244         {
 245             m_value = wxListView::GetFirstSelected();
 246
 247             // TODO: Send event as well
 248
 249             Dismiss();
 250         }
 251
 252     protected:
 253
 254         int m_value; // current item index
 255
 256     private:
 257         DECLARE_EVENT_TABLE()
 258     };
 259
 260     BEGIN_EVENT_TABLE(wxListViewComboPopup, wxListView)
 261         EVT_MOTION(wxListViewComboPopup::OnMouseMove)
 262         EVT_LEFT_UP(wxListViewComboPopup::OnMouseClick)
 263     END_EVENT_TABLE()
 264     @endcode
 265
 266     Here's how you would create and populate it in a dialog constructor:
 267
 268     @code
 269     wxComboCtrl* comboCtrl = new wxComboCtrl(this, wxID_ANY, wxEmptyString);
 270
 271     wxListViewComboPopup* popupCtrl = new wxListViewComboPopup();
 272
 273     // It is important to call SetPopupControl() as soon as possible
 274     comboCtrl->SetPopupControl(popupCtrl);
 275
 276     // Populate using wxListView methods
 277     popupCtrl->InsertItem(popupCtrl->GetItemCount(), "First Item");
 278     popupCtrl->InsertItem(popupCtrl->GetItemCount(), "Second Item");
 279     popupCtrl->InsertItem(popupCtrl->GetItemCount(), "Third Item");
 280     @endcode
 281
 282     @beginStyleTable
 283     @style{wxCB_READONLY}
 284            Text will not be editable.
 285     @style{wxCB_SORT}
 286            Sorts the entries in the list alphabetically.
 287     @style{wxTE_PROCESS_ENTER}
 288            The control will generate the event wxEVT_COMMAND_TEXT_ENTER
 289            (otherwise pressing Enter key is either processed internally by the
 290            control or used for navigation between dialog controls). Windows
 291            only.
 292     @style{wxCC_SPECIAL_DCLICK}
 293            Double-clicking triggers a call to popup's OnComboDoubleClick.
 294            Actual behaviour is defined by a derived class. For instance,
 295            wxOwnerDrawnComboBox will cycle an item. This style only applies if
 296            wxCB_READONLY is used as well.
 297     @style{wxCC_STD_BUTTON}
 298            Drop button will behave more like a standard push button.
 299     @endStyleTable
 300
 301     @beginEventEmissionTable{wxCommandEvent}
 302     @event{EVT_TEXT(id, func)}
 303            Process a wxEVT_COMMAND_TEXT_UPDATED event, when the text changes.
 304     @event{EVT_TEXT_ENTER(id, func)}
 305            Process a wxEVT_COMMAND_TEXT_ENTER event, when RETURN is pressed in
 306            the combo control.
 307     @event{EVT_COMBOX_DROPDOWN(id, func)}
 308            Process a wxEVT_COMMAND_COMBOBOX_DROPDOWN event, which is generated
 309            when the popup window is shown (drops down).
 310     @event{EVT_COMBOX_CLOSEUP(id, func)}
 311            Process a wxEVT_COMMAND_COMBOBOX_CLOSEUP event, which is generated
 312            when the popup window of the combo control disappears (closes up).
 313     @endEventTable
 314
 315     @library{wxbase}
 316     @category{ctrl}
 317     @appearance{comboctrl.png}
 318
 319     @see wxComboBox, wxChoice, wxOwnerDrawnComboBox, wxComboPopup,
 320          wxCommandEvent
 321 */
 322 class wxComboCtrl : public wxControl
 323 {
 324 public:
 325     /**
 326         Default constructor.
 327     */
 328     wxComboCtrl();
 329
 330     /**
 331         Constructor, creating and showing a combo control.
 332
 333         @param parent
 334             Parent window. Must not be @NULL.
 335         @param id
 336             Window identifier. The value wxID_ANY indicates a default value.
 337         @param value
 338             Initial selection string. An empty string indicates no selection.
 339         @param pos
 340             Window position.
 341             If ::wxDefaultPosition is specified then a default position is chosen.
 342         @param size
 343             Window size.
 344             If ::wxDefaultSize is specified then the window is sized appropriately.
 345         @param style
 346             Window style. See wxComboCtrl.
 347         @param validator
 348             Window validator.
 349         @param name
 350             Window name.
 351
 352         @see Create(), wxValidator
 353     */
 354     wxComboCtrl(wxWindow* parent, wxWindowID id = wxID_ANY,
 355                 const wxString& value = wxEmptyString,
 356                 const wxPoint& pos = wxDefaultPosition,
 357                 const wxSize& size = wxDefaultSize,
 358                 long style = 0,
 359                 const wxValidator& validator = wxDefaultValidator,
 360                 const wxString& name = wxComboBoxNameStr);
 361
 362     /**
 363         Destructor, destroying the combo control.
 364     */
 365     virtual ~wxComboCtrl();
 366
 367     /**
 368         Copies the selected text to the clipboard.
 369     */
 370     virtual void Copy();
 371
 372     /**
 373         Creates the combo control for two-step construction. Derived classes
 374         should call or replace this function. See wxComboCtrl() for further
 375         details.
 376     */
 377     bool Create(wxWindow* parent, wxWindowID id = wxID_ANY,
 378                 const wxString& value = wxEmptyString,
 379                 const wxPoint& pos = wxDefaultPosition,
 380                 const wxSize& size = wxDefaultSize,
 381                 long style = 0,
 382                 const wxValidator& validator = wxDefaultValidator,
 383                 const wxString& name = wxComboBoxNameStr);
 384
 385     /**
 386         Copies the selected text to the clipboard and removes the selection.
 387     */
 388     virtual void Cut();
 389
 390     /**
 391         Enables or disables popup animation, if any, depending on the value of
 392         the argument.
 393     */
 394     void EnablePopupAnimation(bool enable = true);
 395
 396     /**
 397         Returns disabled button bitmap that has been set with
 398         SetButtonBitmaps().
 399
 400         @return A reference to the disabled state bitmap.
 401     */
 402     const wxBitmap& GetBitmapDisabled() const;
 403
 404     /**
 405         Returns button mouse hover bitmap that has been set with
 406         SetButtonBitmaps().
 407
 408         @return A reference to the mouse hover state bitmap.
 409     */
 410     const wxBitmap& GetBitmapHover() const;
 411
 412     /**
 413         Returns default button bitmap that has been set with
 414         SetButtonBitmaps().
 415
 416         @return A reference to the normal state bitmap.
 417     */
 418     const wxBitmap& GetBitmapNormal() const;
 419
 420     /**
 421         Returns depressed button bitmap that has been set with
 422         SetButtonBitmaps().
 423
 424         @return A reference to the depressed state bitmap.
 425     */
 426     const wxBitmap& GetBitmapPressed() const;
 427
 428     /**
 429         Returns current size of the dropdown button.
 430     */
 431     wxSize GetButtonSize();
 432
 433     /**
 434         Returns custom painted area in control.
 435
 436         @see SetCustomPaintWidth().
 437     */
 438     int GetCustomPaintWidth() const;
 439
 440     /**
 441         Returns features supported by wxComboCtrl. If needed feature is
 442         missing, you need to instead use wxGenericComboCtrl, which however may
 443         lack a native look and feel (but otherwise sports identical API).
 444
 445         @return Value returned is a combination of the flags defined in
 446                 wxComboCtrlFeatures.
 447     */
 448     static int GetFeatures();
 449
 450     /**
 451         Returns the insertion point for the combo control's text field.
 452
 453         @note Under Windows, this function always returns 0 if the combo
 454               control doesn't have the focus.
 455     */
 456     virtual long GetInsertionPoint() const;
 457
 458     /**
 459         Returns the last position in the combo control text field.
 460     */
 461     virtual long GetLastPosition() const;
 462
 463     /**
 464         Returns the margins used by the control. The @c x field of the returned
 465         point is the horizontal margin and the @c y field is the vertical one.
 466
 467         @remarks If given margin cannot be accurately determined, its value
 468                 will be set to -1.
 469
 470         @see SetMargins()
 471
 472         @since 2.9.1
 473     */
 474     wxPoint GetMargins() const;
 475
 476     /**
 477         Returns current popup interface that has been set with
 478         SetPopupControl().
 479     */
 480     wxComboPopup* GetPopupControl();
 481
 482     /**
 483         Returns popup window containing the popup control.
 484     */
 485     wxWindow* GetPopupWindow() const;
 486
 487     /**
 488         Get the text control which is part of the combo control.
 489     */
 490     wxTextCtrl* GetTextCtrl() const;
 491
 492     /**
 493         Returns actual indentation in pixels.
 494
 495         @deprecated Use GetMargins() instead.
 496     */
 497     wxCoord GetTextIndent() const;
 498
 499     /**
 500         Returns area covered by the text field (includes everything except
 501         borders and the dropdown button).
 502     */
 503     const wxRect& GetTextRect() const;
 504
 505     /**
 506         Returns text representation of the current value. For writable combo
 507         control it always returns the value in the text field.
 508     */
 509     virtual wxString GetValue() const;
 510
 511     /**
 512         Dismisses the popup window.
 513
 514         @param generateEvent
 515             Set this to @true in order to generate
 516             wxEVT_COMMAND_COMBOBOX_CLOSEUP event.
 517     */
 518     virtual void HidePopup(bool generateEvent=false);
 519
 520     /**
 521         Returns @true if the popup is currently shown
 522     */
 523     bool IsPopupShown() const;
 524
 525     /**
 526         Returns @true if the popup window is in the given state. Possible
 527         values are:
 528
 529         @beginTable
 530         @row2col{wxComboCtrl::Hidden,    Popup window is hidden.}
 531         @row2col{wxComboCtrl::Animating, Popup window is being shown, but the
 532                                          popup animation has not yet finished.}
 533         @row2col{wxComboCtrl::Visible,   Popup window is fully visible.}
 534         @endTable
 535     */
 536     bool IsPopupWindowState(int state) const;
 537
 538     /**
 539         Implement in a derived class to define what happens on dropdown button
 540         click. Default action is to show the popup.
 541
 542         @note If you implement this to do something else than show the popup,
 543               you must then also implement DoSetPopupControl() to always return
 544               @NULL.
 545     */
 546     virtual void OnButtonClick();
 547
 548     /**
 549         Pastes text from the clipboard to the text field.
 550     */
 551     virtual void Paste();
 552
 553     /**
 554         Removes the text between the two positions in the combo control text
 555         field.
 556
 557         @param from
 558             The first position.
 559         @param to
 560             The last position.
 561     */
 562     virtual void Remove(long from, long to);
 563
 564     /**
 565         Replaces the text between two positions with the given text, in the
 566         combo control text field.
 567
 568         @param from
 569             The first position.
 570         @param to
 571             The second position.
 572         @param text
 573             The text to insert.
 574     */
 575     virtual void Replace(long from, long to, const wxString& text);
 576
 577     /**
 578         Sets custom dropdown button graphics.
 579
 580         @param bmpNormal
 581             Default button image.
 582         @param pushButtonBg
 583             If @true, blank push button background is painted below the image.
 584         @param bmpPressed
 585             Depressed button image.
 586         @param bmpHover
 587             Button image when mouse hovers above it. This should be ignored on
 588             platforms and themes that do not generally draw different kind of
 589             button on mouse hover.
 590         @param bmpDisabled
 591             Disabled button image.
 592     */
 593     void SetButtonBitmaps(const wxBitmap& bmpNormal,
 594                           bool pushButtonBg = false,
 595                           const wxBitmap& bmpPressed = wxNullBitmap,
 596                           const wxBitmap& bmpHover = wxNullBitmap,
 597                           const wxBitmap& bmpDisabled = wxNullBitmap);
 598
 599     /**
 600         Sets size and position of dropdown button.
 601
 602         @param width
 603             Button width. Value = 0 specifies default.
 604         @param height
 605             Button height. Value = 0 specifies default.
 606         @param side
 607             Indicates which side the button will be placed. Value can be wxLEFT
 608             or wxRIGHT.
 609         @param spacingX
 610             Horizontal spacing around the button. Default is 0.
 611     */
 612     void SetButtonPosition(int width = -1, int height = -1,
 613                            int side = wxRIGHT, int spacingX = 0);
 614
 615     /**
 616         Set width, in pixels, of custom painted area in control without
 617         @c wxCB_READONLY style. In read-only wxOwnerDrawnComboBox, this is used
 618         to indicate area that is not covered by the focus rectangle.
 619     */
 620     void SetCustomPaintWidth(int width);
 621
 622     /**
 623         Sets the insertion point in the text field.
 624
 625         @param pos
 626             The new insertion point.
 627     */
 628     virtual void SetInsertionPoint(long pos);
 629
 630     /**
 631         Sets the insertion point at the end of the combo control text field.
 632     */
 633     virtual void SetInsertionPointEnd();
 634
 635     //@{
 636     /**
 637         Attempts to set the control margins. When margins are given as wxPoint,
 638         x indicates the left and y the top margin. Use -1 to indicate that
 639         an existing value should be used.
 640
 641         @return
 642             @true if setting of all requested margins was successful.
 643
 644         @since 2.9.1
 645     */
 646     bool SetMargins(const wxPoint& pt);
 647     bool SetMargins(wxCoord left, wxCoord top = -1);
 648     //@}
 649
 650     /**
 651         Set side of the control to which the popup will align itself. Valid
 652         values are @c wxLEFT, @c wxRIGHT and 0. The default value 0 means that
 653         the most appropriate side is used (which, currently, is always
 654         @c wxLEFT).
 655     */
 656     void SetPopupAnchor(int anchorSide);
 657
 658     /**
 659         Set popup interface class derived from wxComboPopup. This method should
 660         be called as soon as possible after the control has been created,
 661         unless OnButtonClick() has been overridden.
 662     */
 663     void SetPopupControl(wxComboPopup* popup);
 664
 665     /**
 666         Extends popup size horizontally, relative to the edges of the combo
 667         control.
 668
 669         @param extLeft
 670             How many pixel to extend beyond the left edge of the control.
 671             Default is 0.
 672         @param extRight
 673             How many pixel to extend beyond the right edge of the control.
 674             Default is 0.
 675
 676         @remarks Popup minimum width may override arguments. It is up to the
 677                  popup to fully take this into account.
 678     */
 679     void SetPopupExtents(int extLeft, int extRight);
 680
 681     /**
 682         Sets preferred maximum height of the popup.
 683
 684         @remarks Value -1 indicates the default.
 685     */
 686     void SetPopupMaxHeight(int height);
 687
 688     /**
 689         Sets minimum width of the popup. If wider than combo control, it will
 690         extend to the left.
 691
 692         @remarks Value -1 indicates the default. Also, popup implementation may
 693                  choose to ignore this.
 694     */
 695     void SetPopupMinWidth(int width);
 696
 697     /**
 698         Selects the text between the two positions, in the combo control text
 699         field.
 700
 701         @param from
 702             The first position.
 703         @param to
 704             The second position.
 705     */
 706     virtual void SetSelection(long from, long to);
 707
 708     /**
 709         Sets the text for the text field without affecting the popup. Thus,
 710         unlike SetValue(), it works equally well with combo control using
 711         @c wxCB_READONLY style.
 712     */
 713     void SetText(const wxString& value);
 714
 715     /**
 716         This will set the space in pixels between left edge of the control and
 717         the text, regardless whether control is read-only or not. Value -1 can
 718         be given to indicate platform default.
 719
 720         @deprecated Use SetMargins() instead.
 721     */
 722     void SetTextIndent(int indent);
 723
 724     /**
 725         Sets the text for the combo control text field.
 726
 727         @note For a combo control with @c wxCB_READONLY style the string must
 728               be accepted by the popup (for instance, exist in the dropdown
 729               list), otherwise the call to SetValue() is ignored.
 730     */
 731     virtual void SetValue(const wxString& value);
 732
 733     /**
 734         Same as SetValue(), but also sends wxCommandEvent of type
 735         wxEVT_COMMAND_TEXT_UPDATED if @a withEvent is @true.
 736     */
 737     void SetValueWithEvent(const wxString& value, bool withEvent = true);
 738
 739     /**
 740         Show the popup.
 741     */
 742     virtual void ShowPopup();
 743
 744     /**
 745         Undoes the last edit in the text field. Windows only.
 746     */
 747     virtual void Undo();
 748
 749     /**
 750         Enable or disable usage of an alternative popup window, which
 751         guarantees ability to focus the popup control, and allows common native
 752         controls to function normally. This alternative popup window is usually
 753         a wxDialog, and as such, when it is shown, its parent top-level window
 754         will appear as if the focus has been lost from it.
 755     */
 756     void UseAltPopupWindow(bool enable = true);
 757
 758 protected:
 759
 760     /**
 761         This member function is not normally called in application code.
 762         Instead, it can be implemented in a derived class to create a custom
 763         popup animation.
 764
 765         The parameters are the same as those for DoShowPopup().
 766
 767         @return @true if animation finishes before the function returns,
 768                 @false otherwise. In the latter case you need to manually call
 769                 DoShowPopup() after the animation ends.
 770     */
 771     virtual bool AnimateShow(const wxRect& rect, int flags);
 772
 773     /**
 774         This member function is not normally called in application code.
 775         Instead, it can be implemented in a derived class to return default
 776         wxComboPopup, incase @a popup is @NULL.
 777
 778         @note If you have implemented OnButtonClick() to do something else than
 779               show the popup, then DoSetPopupControl() must always set @a popup
 780               to @NULL.
 781     */
 782     virtual void DoSetPopupControl(wxComboPopup* popup);
 783
 784     /**
 785         This member function is not normally called in application code.
 786         Instead, it must be called in a derived class to make sure popup is
 787         properly shown after a popup animation has finished (but only if
 788         AnimateShow() did not finish the animation within its function scope).
 789
 790         @param rect
 791             Position to show the popup window at, in screen coordinates.
 792         @param flags
 793             Combination of any of the following:
 794             @beginTable
 795             @row2col{wxComboCtrl::ShowAbove,
 796                      Popup is shown above the control instead of below.}
 797             @row2col{wxComboCtrl::CanDeferShow,
 798                      Showing the popup can be deferred to happen sometime after
 799                      ShowPopup() has finished. In this case, AnimateShow() must
 800                      return false.}
 801             @endTable
 802     */
 803     virtual void DoShowPopup(const wxRect& rect, int flags);
 804 };
 805