text: /////////////////////////////////////////////////////////////////////////////
  // Name:        combo.h
  // Purpose:     interface of wxComboCtrl and wxComboPopup
  // Author:      wxWidgets team
  // RCS-ID:      $Id$
  // Licence:     wxWindows licence
  /////////////////////////////////////////////////////////////////////////////
  
  //
  // New window styles for wxComboCtrlBase
  //
  enum
  {
      // Double-clicking a read-only combo triggers call to popup's OnComboPopup.
      // In wxOwnerDrawnComboBox, for instance, it cycles item.
      wxCC_SPECIAL_DCLICK             = 0x0100,
  
      // Dropbutton acts like standard push button.
      wxCC_STD_BUTTON                 = 0x0200
  };
  
  
  /**
      @class wxComboPopup
  
      In order to use a custom popup with wxComboCtrl, an interface class must be
      derived from wxComboPopup.
  
      For more information on how to use it, see @ref comboctrl_custompopup.
  
      @library{wxcore}
      @category{ctrl}
  
      @see wxComboCtrl
  */
  class wxComboPopup
  {
  public:
      /**
          Default constructor. It is recommended that internal variables are
          prepared in Init() instead (because m_combo is not valid in
          constructor).
      */
      wxComboPopup();
  
      /**
          The derived class must implement this to create the popup control.
  
          @return @true if the call succeeded, @false otherwise.
      */
      virtual bool Create(wxWindow* parent) = 0;
  
      /**
          You only need to implement this member function if you create
          your popup class in non-standard way. The default implementation can
          handle both multiple-inherited popup control (as seen in wxComboCtrl
          samples) and one allocated separately in heap.
  
          If you do completely re-implement this function, make sure it calls
          Destroy() for the popup control and also deletes @a this object
          (usually as the last thing).
      */
      virtual void DestroyPopup();
  
      /**
          Utility function that hides the popup.
      */
      void Dismiss();
  
      /**
          Implement to customize matching of value string to an item container
          entry.
          
          @param item
              String entered, usually by user or from SetValue() call.
              
          @param trueItem
              When item matches an entry, but the entry's string representation
              is not exactly the same (case mismatch, for example), then the
              true item string should be written back to here, if it is not
              a NULL pointer.
  
          @remarks
              Default implementation always return true and does not alter
              trueItem.
      */
      virtual bool FindItem(const wxString& item, wxString* trueItem=NULL);
  
      /**
          The derived class may implement this to return adjusted size for the
          popup control, according to the variables given.
  
          @param minWidth
              Preferred minimum width.
          @param prefHeight
              Preferred height. May be -1 to indicate no preference.
          @param maxHeight
              Max height for window, as limited by screen size.
  
          @remarks This function is called each time popup is about to be shown.
      */
      virtual wxSize GetAdjustedSize(int minWidth, int prefHeight, int maxHeight);
  
      /**
          Returns pointer to the associated parent wxComboCtrl.
      */
      wxComboCtrl* GetComboCtrl() const;
  
      /**
          The derived class must implement this to return pointer to the
          associated control created in Create().
      */
      virtual wxWindow* GetControl() = 0;
  
      /**
          The derived class must implement this to return string representation
          of the value.
      */
      virtual wxString GetStringValue() const = 0;
  
      /**
          The derived class must implement this to initialize its internal
          variables. This method is called immediately after construction
          finishes. m_combo member variable has been initialized before the call.
      */
      virtual void Init();
  
      /**
          Utility method that returns @true if Create has been called.
  
          Useful in conjunction with LazyCreate().
      */
      bool IsCreated() const;
      
      /**
          The derived class may implement this to return @true if it wants to
          delay call to Create() until the popup is shown for the first time. It
          is more efficient, but on the other hand it is often more convenient to
          have the control created immediately.
  
          @remarks Base implementation returns @false.
      */
      virtual bool LazyCreate();
  
      /**
          The derived class may implement this to do something when the parent
          wxComboCtrl gets double-clicked.
      */
      virtual void OnComboDoubleClick();
  
      /**
          The derived class may implement this to receive key events from the
          parent wxComboCtrl.
  
          Events not handled should be skipped, as usual.
      */
      virtual void OnComboKeyEvent(wxKeyEvent& event);
  
      /**
          The derived class may implement this to do special processing when
          popup is hidden.
      */
      virtual void OnDismiss();
  
      /**
          The derived class may implement this to do special processing when
          popup is shown.
      */
      virtual void OnPopup();
  
      /**
          The derived class may implement this to paint the parent wxComboCtrl.
  
          Default implementation draws value as string.
      */
      virtual void PaintComboControl(wxDC& dc, const wxRect& rect);
  
      /**
          The derived class must implement this to receive string value changes
          from wxComboCtrl.
      */
      virtual void SetStringValue(const wxString& value);
  
  protected:
      /**
          Parent wxComboCtrl. This member variable is prepared automatically
          before Init() is called.
      */
      wxComboCtrl*    m_combo;
  };
  
  
  
  /**
      Features enabled for wxComboCtrl.
  
      @see wxComboCtrl::GetFeatures()
  */
  struct wxComboCtrlFeatures
  {
      enum
      {
          MovableButton   = 0x0001, ///< Button can be on either side of control.
          BitmapButton    = 0x0002, ///< Button may be replaced with bitmap.
          ButtonSpacing   = 0x0004, ///< Button can have spacing from the edge
                                    ///< of the control.
          TextIndent      = 0x0008, ///< wxComboCtrl::SetMargins() can be used.
          PaintControl    = 0x0010, ///< Combo control itself can be custom painted.
          PaintWritable   = 0x0020, ///< A variable-width area in front of writable
                                    ///< combo control's textctrl can be custom
                                    ///< painted.
          Borderless      = 0x0040, ///< wxNO_BORDER window style works.
  
          All             = MovableButton | BitmapButton | ButtonSpacing |
                            TextIndent | PaintControl | PaintWritable |
                            Borderless ///< All features.
      };
  };
  
  
  /**
      @class wxComboCtrl
  
      A combo control is a generic combobox that allows totally custom popup. In
      addition it has other customization features. For instance, position and
      size of the dropdown button can be changed.
  
      @section comboctrl_custompopup Setting Custom Popup for wxComboCtrl
  
      wxComboCtrl needs to be told somehow which control to use and this is done
      by SetPopupControl(). However, we need something more than just a wxControl
      in this method as, for example, we need to call
      SetStringValue("initial text value") and wxControl doesn't have such
      method. So we also need a wxComboPopup which is an interface which must be
      implemented by a control to be usable as a popup.
  
      We couldn't derive wxComboPopup from wxControl as this would make it
      impossible to have a class deriving from a wxWidgets control and from it,
      so instead it is just a mix-in.
  
      Here's a minimal sample of wxListView popup:
  
      @code
      #include <wx/combo.h>
      #include <wx/listctrl.h>
  
      class wxListViewComboPopup : public wxListView, public wxComboPopup
      {
      public:
          // Initialize member variables
          virtual void Init()
          {
              m_value = -1;
          }
  
          // Create popup control
          virtual bool Create(wxWindow* parent)
          {
              return wxListView::Create(parent,1,wxPoint(0,0),wxDefaultSize);
          }
  
          // Return pointer to the created control
          virtual wxWindow *GetControl() { return this; }
  
          // Translate string into a list selection
          virtual void SetStringValue(const wxString& s)
          {
              int n = wxListView::FindItem(-1,s);
              if ( n >= 0 && n < wxListView::GetItemCount() )
                  wxListView::Select(n);
          }
  
          // Get list selection as a string
          virtual wxString GetStringValue() const
          {
              if ( m_value >= 0 )
              return wxListView::GetItemText(m_value);
              return wxEmptyString;
          }
  
          // Do mouse hot-tracking (which is typical in list popups)
          void OnMouseMove(wxMouseEvent& event)
          {
              // TODO: Move selection to cursor
          }
  
          // On mouse left up, set the value and close the popup
          void OnMouseClick(wxMouseEvent& WXUNUSED(event))
          {
              m_value = wxListView::GetFirstSelected();
  
              // TODO: Send event as well
  
              Dismiss();
          }
  
      protected:
  
          int m_value; // current item index
  
      private:
          wxDECLARE_EVENT_TABLE();
      };
  
      wxBEGIN_EVENT_TABLE(wxListViewComboPopup, wxListView)
          EVT_MOTION(wxListViewComboPopup::OnMouseMove)
          EVT_LEFT_UP(wxListViewComboPopup::OnMouseClick)
      wxEND_EVENT_TABLE()
      @endcode
  
      Here's how you would create and populate it in a dialog constructor:
  
      @code
      wxComboCtrl* comboCtrl = new wxComboCtrl(this, wxID_ANY, wxEmptyString);
  
      wxListViewComboPopup* popupCtrl = new wxListViewComboPopup();
  
      // It is important to call SetPopupControl() as soon as possible
      comboCtrl->SetPopupControl(popupCtrl);
  
      // Populate using wxListView methods
      popupCtrl->InsertItem(popupCtrl->GetItemCount(), "First Item");
      popupCtrl->InsertItem(popupCtrl->GetItemCount(), "Second Item");
      popupCtrl->InsertItem(popupCtrl->GetItemCount(), "Third Item");
      @endcode
  
      @beginStyleTable
      @style{wxCB_READONLY}
             Text will not be editable.
      @style{wxCB_SORT}
             Sorts the entries in the list alphabetically.
      @style{wxTE_PROCESS_ENTER}
             The control will generate the event @c wxEVT_COMMAND_TEXT_ENTER
             (otherwise pressing Enter key is either processed internally by the
             control or used for navigation between dialog controls). Windows
             only.
      @style{wxCC_SPECIAL_DCLICK}
             Double-clicking triggers a call to popup's OnComboDoubleClick.
             Actual behaviour is defined by a derived class. For instance,
             wxOwnerDrawnComboBox will cycle an item. This style only applies if
             wxCB_READONLY is used as well.
      @style{wxCC_STD_BUTTON}
             Drop button will behave more like a standard push button.
      @endStyleTable
  
      @beginEventEmissionTable{wxCommandEvent}
      @event{EVT_TEXT(id, func)}
             Process a @c wxEVT_COMMAND_TEXT_UPDATED event, when the text changes.
      @event{EVT_TEXT_ENTER(id, func)}
             Process a @c wxEVT_COMMAND_TEXT_ENTER event, when RETURN is pressed in
             the combo control.
      @event{EVT_COMBOBOX_DROPDOWN(id, func)}
             Process a @c wxEVT_COMMAND_COMBOBOX_DROPDOWN event, which is generated
             when the popup window is shown (drops down).
      @event{EVT_COMBOBOX_CLOSEUP(id, func)}
             Process a @c wxEVT_COMMAND_COMBOBOX_CLOSEUP event, which is generated
             when the popup window of the combo control disappears (closes up).
             You should avoid adding or deleting items in this event.
      @endEventTable
  
      @library{wxbase}
      @category{ctrl}
      @appearance{comboctrl.png}
  
      @see wxComboBox, wxChoice, wxOwnerDrawnComboBox, wxComboPopup,
           wxCommandEvent
  */
  class wxComboCtrl : public wxControl,
                      public wxTextEntry
  {
  public:
      /**
          Default constructor.
      */
      wxComboCtrl();
  
      /**
          Constructor, creating and showing a combo control.
  
          @param parent
              Parent window. Must not be @NULL.
          @param id
              Window identifier. The value wxID_ANY indicates a default value.
          @param value
              Initial selection string. An empty string indicates no selection.
          @param pos
              Window position.
              If ::wxDefaultPosition is specified then a default position is chosen.
          @param size
              Window size. 
              If ::wxDefaultSize is specified then the window is sized appropriately.
          @param style
              Window style. See wxComboCtrl.
          @param validator
              Window validator.
          @param name
              Window name.
  
          @see Create(), wxValidator
      */
      wxComboCtrl(wxWindow* parent, wxWindowID id = wxID_ANY,
                  const wxString& value = wxEmptyString,
                  const wxPoint& pos = wxDefaultPosition,
                  const wxSize& size = wxDefaultSize,
                  long style = 0,
                  const wxValidator& validator = wxDefaultValidator,
                  const wxString& name = wxComboBoxNameStr);
  
      /**
          Destructor, destroying the combo control.
      */
      virtual ~wxComboCtrl();
  
      /**
          Copies the selected text to the clipboard.
      */
      virtual void Copy();
  
      /**
          Creates the combo control for two-step construction. Derived classes
          should call or replace this function. See wxComboCtrl() for further
          details.
      */
      bool Create(wxWindow* parent, wxWindowID id = wxID_ANY,
                  const wxString& value = wxEmptyString,
                  const wxPoint& pos = wxDefaultPosition,
                  const wxSize& size = wxDefaultSize,
                  long style = 0,
                  const wxValidator& validator = wxDefaultValidator,
                  const wxString& name = wxComboBoxNameStr);
  
      /**
          Copies the selected text to the clipboard and removes the selection.
      */
      virtual void Cut();
  
      /**
          Dismisses the popup window.
  
          Notice that calling this function will generate a
          @c wxEVT_COMMAND_COMBOBOX_CLOSEUP event.
  
          @since 2.9.2
      */
      virtual void Dismiss();
  
  
      /**
          Enables or disables popup animation, if any, depending on the value of
          the argument.
      */
      void EnablePopupAnimation(bool enable = true);
  
      
      /**
         Returns true if given key combination should toggle the popup.
      */
      virtual bool IsKeyPopupToggle(const wxKeyEvent& event) const;
  
  
      /**
         Prepare background of combo control or an item in a dropdown list in a
         way typical on platform. This includes painting the focus/disabled
         background and setting the clipping region.
  
         Unless you plan to paint your own focus indicator, you should always
         call this in your wxComboPopup::PaintComboControl implementation.  In
         addition, it sets pen and text colour to what looks good and proper
         against the background.
  
         flags: wxRendererNative flags:
                wxCONTROL_ISSUBMENU: is drawing a list item instead of combo control
                wxCONTROL_SELECTED: list item is selected
                wxCONTROL_DISABLED: control/item is disabled
      */
      virtual void PrepareBackground( wxDC& dc, const wxRect& rect, int flags ) const;
  
      /**
         Returns true if focus indicator should be drawn in the control.
      */
      bool ShouldDrawFocus() const;
  
      /**
          Returns disabled button bitmap that has been set with
          SetButtonBitmaps().
  
          @return A reference to the disabled state bitmap.
      */
      const wxBitmap& GetBitmapDisabled() const;
  
      /**
          Returns button mouse hover bitmap that has been set with
          SetButtonBitmaps().
  
          @return A reference to the mouse hover state bitmap.
      */
      const wxBitmap& GetBitmapHover() const;
  
      /**
          Returns default button bitmap that has been set with
          SetButtonBitmaps().
  
          @return A reference to the normal state bitmap.
      */
      const wxBitmap& GetBitmapNormal() const;
  
      /**
          Returns depressed button bitmap that has been set with
          SetButtonBitmaps().
  
          @return A reference to the depressed state bitmap.
      */
      const wxBitmap& GetBitmapPressed() const;
  
      /**
          Returns current size of the dropdown button.
      */
      wxSize GetButtonSize();
  
      /**
          Returns custom painted area in control.
  
          @see SetCustomPaintWidth().
      */
      int GetCustomPaintWidth() const;
  
      /**
          Returns features supported by wxComboCtrl. If needed feature is
          missing, you need to instead use wxGenericComboCtrl, which however may
          lack a native look and feel (but otherwise sports identical API).
  
          @return Value returned is a combination of the flags defined in
                  wxComboCtrlFeatures.
      */
      static int GetFeatures();
  
      /**
          Returns the current hint string.
  
          See SetHint() for more information about hints.
  
          @since 2.9.1
      */
      virtual wxString GetHint() const;
  
      /**
          Returns the insertion point for the combo control's text field.
  
          @note Under Windows, this function always returns 0 if the combo
                control doesn't have the focus.
      */
      virtual long GetInsertionPoint() const;
  
      /**
          Returns the last position in the combo control text field.
      */
      virtual long GetLastPosition() const;
  
      /**
          Returns the margins used by the control. The @c x field of the returned
          point is the horizontal margin and the @c y field is the vertical one.
  
          @remarks If given margin cannot be accurately determined, its value
                  will be set to -1.
  
          @see SetMargins()
  
          @since 2.9.1
      */
      wxPoint GetMargins() const;
  
      /**
          Returns current popup interface that has been set with
          SetPopupControl().
      */
      wxComboPopup* GetPopupControl();
  
      /**
          Returns popup window containing the popup control.
      */
      wxWindow* GetPopupWindow() const;
  
      /**
          Get the text control which is part of the combo control.
      */
      wxTextCtrl* GetTextCtrl() const;
  
      /**
          Returns actual indentation in pixels.
  
          @deprecated Use GetMargins() instead.
      */
      wxCoord GetTextIndent() const;
  
      /**
          Returns area covered by the text field (includes everything except
          borders and the dropdown button).
      */
      const wxRect& GetTextRect() const;
  
      /**
          Returns text representation of the current value. For writable combo
          control it always returns the value in the text field.
      */
      virtual wxString GetValue() const;
  
      /**
          Dismisses the popup window.
  
          @param generateEvent
              Set this to @true in order to generate
              @c wxEVT_COMMAND_COMBOBOX_CLOSEUP event.
  
          @deprecated Use Dismiss() instead.
      */
      virtual void HidePopup(bool generateEvent=false);
  
      /**
          Returns @true if the popup is currently shown
      */
      bool IsPopupShown() const;
  
      /**
          Returns @true if the popup window is in the given state. Possible
          values are:
  
          @beginTable
          @row2col{wxComboCtrl::Hidden,    Popup window is hidden.}
          @row2col{wxComboCtrl::Animating, Popup window is being shown, but the
                                           popup animation has not yet finished.}
          @row2col{wxComboCtrl::Visible,   Popup window is fully visible.}
          @endTable
      */
      bool IsPopupWindowState(int state) const;
  
      /**
          Implement in a derived class to define what happens on dropdown button
          click. Default action is to show the popup.
  
          @note If you implement this to do something else than show the popup,
                you must then also implement DoSetPopupControl() to always return
                @NULL.
      */
      virtual void OnButtonClick();
  
      /**
          Pastes text from the clipboard to the text field.
      */
      virtual void Paste();
  
      /**
          Shows the popup portion of the combo control.
  
          Notice that calling this function will generate a
          @c wxEVT_COMMAND_COMBOBOX_DROPDOWN event.
  
          @since 2.9.2
      */
      virtual void Popup();
  
      /**
          Removes the text between the two positions in the combo control text
          field.
  
          @param from
              The first position.
          @param to
              The last position.
      */
      virtual void Remove(long from, long to);
  
      /**
          Replaces the text between two positions with the given text, in the
          combo control text field.
  
          @param from
              The first position.
          @param to
              The second position.
          @param text
              The text to insert.
      */
      virtual void Replace(long from, long to, const wxString& text);
  
      /**
          Sets custom dropdown button graphics.
  
          @param bmpNormal
              Default button image.
          @param pushButtonBg
              If @true, blank push button background is painted below the image.
          @param bmpPressed
              Depressed button image.
          @param bmpHover
              Button image when mouse hovers above it. This should be ignored on
              platforms and themes that do not generally draw different kind of
              button on mouse hover.
          @param bmpDisabled
              Disabled button image.
      */
      void SetButtonBitmaps(const wxBitmap& bmpNormal,
                            bool pushButtonBg = false,
                            const wxBitmap& bmpPressed = wxNullBitmap,
                            const wxBitmap& bmpHover = wxNullBitmap,
                            const wxBitmap& bmpDisabled = wxNullBitmap);
  
      /**
          Sets size and position of dropdown button.
  
          @param width
              Button width. Value = 0 specifies default.
          @param height
              Button height. Value = 0 specifies default.
          @param side
              Indicates which side the button will be placed. Value can be wxLEFT
              or wxRIGHT.
          @param spacingX
              Horizontal spacing around the button. Default is 0.
      */
      void SetButtonPosition(int width = -1, int height = -1,
                             int side = wxRIGHT, int spacingX = 0);
  
      /**
          Set width, in pixels, of custom painted area in control without
          @c wxCB_READONLY style. In read-only wxOwnerDrawnComboBox, this is used
          to indicate area that is not covered by the focus rectangle.
      */
      void SetCustomPaintWidth(int width);
  
      /**
          Sets a hint shown in an empty unfocused combo control.
  
          Notice that hints are known as <em>cue banners</em> under MSW or
          <em>placeholder strings</em> under OS X.
  
          @see wxTextEntry::SetHint()
  
          @since 2.9.1
      */
      virtual bool SetHint(const wxString& hint);
  
      /**
          Sets the insertion point in the text field.
  
          @param pos
              The new insertion point.
      */
      virtual void SetInsertionPoint(long pos);
  
      /**
          Sets the insertion point at the end of the combo control text field.
      */
      virtual void SetInsertionPointEnd();
  
      //@{
      /**
          Attempts to set the control margins. When margins are given as wxPoint,
          x indicates the left and y the top margin. Use -1 to indicate that
          an existing value should be used.
  
          @return
              @true if setting of all requested margins was successful.
  
          @since 2.9.1
      */
      bool SetMargins(const wxPoint& pt);
      bool SetMargins(wxCoord left, wxCoord top = -1);
      //@}
  
      /**
          Set side of the control to which the popup will align itself. Valid
          values are @c wxLEFT, @c wxRIGHT and 0. The default value 0 means that
          the most appropriate side is used (which, currently, is always
          @c wxLEFT).
      */
      void SetPopupAnchor(int anchorSide);
  
      /**
          Set popup interface class derived from wxComboPopup. This method should
          be called as soon as possible after the control has been created,
          unless OnButtonClick() has been overridden.
      */
      void SetPopupControl(wxComboPopup* popup);
  
      /**
          Extends popup size horizontally, relative to the edges of the combo
          control.
  
          @param extLeft
              How many pixel to extend beyond the left edge of the control.
              Default is 0.
          @param extRight
              How many pixel to extend beyond the right edge of the control.
              Default is 0.
  
          @remarks Popup minimum width may override arguments. It is up to the
                   popup to fully take this into account.
      */
      void SetPopupExtents(int extLeft, int extRight);
  
      /**
          Sets preferred maximum height of the popup.
  
          @remarks Value -1 indicates the default.
      */
      void SetPopupMaxHeight(int height);
  
      /**
          Sets minimum width of the popup. If wider than combo control, it will
          extend to the left.
  
          @remarks Value -1 indicates the default. Also, popup implementation may
                   choose to ignore this.
      */
      void SetPopupMinWidth(int width);
  
      /**
          Selects the text between the two positions, in the combo control text
          field.
  
          @param from
              The first position.
          @param to
              The second position.
      */
      virtual void SetSelection(long from, long to);
  
      /**
          Sets the text for the text field without affecting the popup. Thus,
          unlike SetValue(), it works equally well with combo control using
          @c wxCB_READONLY style.
      */
      void SetText(const wxString& value);
  
      /**
          Set a custom window style for the embedded wxTextCtrl. Usually you
          will need to use this during two-step creation, just before Create().
          For example:
  
          @code
              wxComboCtrl* comboCtrl = new wxComboCtrl();
  
              // Let's make the text right-aligned
              comboCtrl->SetTextCtrlStyle(wxTE_RIGHT);
  
              comboCtrl->Create(parent, wxID_ANY, wxEmptyString);
          @endcode
      */
      void SetTextCtrlStyle( int style );
  
      /**
          This will set the space in pixels between left edge of the control and
          the text, regardless whether control is read-only or not. Value -1 can
          be given to indicate platform default.
  
          @deprecated Use SetMargins() instead.
      */
      void SetTextIndent(int indent);
  
      /**
          Sets the text for the combo control text field.
  
          @note For a combo control with @c wxCB_READONLY style the string must
                be accepted by the popup (for instance, exist in the dropdown
                list), otherwise the call to SetValue() is ignored.
      */
      virtual void SetValue(const wxString& value);
  
      /**
         Changes value of the control as if user had done it by selecting an
         item from a combo box drop-down list.
       */
      void SetValueByUser(const wxString& value);
  
      /**
          Show the popup.
  
          @deprecated Use Popup() instead.
      */
      virtual void ShowPopup();
  
      /**
          Undoes the last edit in the text field. Windows only.
      */
      virtual void Undo();
  
      /**
          Enable or disable usage of an alternative popup window, which
          guarantees ability to focus the popup control, and allows common native
          controls to function normally. This alternative popup window is usually
          a wxDialog, and as such, when it is shown, its parent top-level window
          will appear as if the focus has been lost from it.
      */
      void UseAltPopupWindow(bool enable = true);
  
  protected:
  
      /**
          This member function is not normally called in application code.
          Instead, it can be implemented in a derived class to create a custom
          popup animation.
  
          The parameters are the same as those for DoShowPopup().
  
          @return @true if animation finishes before the function returns,
                  @false otherwise. In the latter case you need to manually call
                  DoShowPopup() after the animation ends.
      */
      virtual bool AnimateShow(const wxRect& rect, int flags);
  
      /**
          This member function is not normally called in application code.
          Instead, it can be implemented in a derived class to return default
          wxComboPopup, in case @a popup is @NULL.
  
          @note If you have implemented OnButtonClick() to do something else than
                show the popup, then DoSetPopupControl() must always set @a popup
                to @NULL.
      */
      virtual void DoSetPopupControl(wxComboPopup* popup);
  
      /**
          This member function is not normally called in application code.
          Instead, it must be called in a derived class to make sure popup is
          properly shown after a popup animation has finished (but only if
          AnimateShow() did not finish the animation within its function scope).
  
          @param rect
              Position to show the popup window at, in screen coordinates.
          @param flags
              Combination of any of the following:
              @beginTable
              @row2col{wxComboCtrl::ShowAbove,
                       Popup is shown above the control instead of below.}
              @row2col{wxComboCtrl::CanDeferShow,
                       Showing the popup can be deferred to happen sometime after
                       ShowPopup() has finished. In this case, AnimateShow() must
                       return false.}
              @endTable
      */
      virtual void DoShowPopup(const wxRect& rect, int flags);
  };
  
  