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.
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:
#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: DECLARE_EVENT_TABLE() }; BEGIN_EVENT_TABLE(wxListViewComboPopup, wxListView) EVT_MOTION(wxListViewComboPopup::OnMouseMove) EVT_LEFT_UP(wxListViewComboPopup::OnMouseClick) END_EVENT_TABLE()Here's how you would create and populate it in a dialog constructor:
wxComboCtrl* comboCtrl = new wxComboCtrl(this,wxID_ANY,wxEmptyString); wxListViewComboPopup* popupCtrl = new wxListViewComboPopup(); comboCtrl->SetPopupControl(popupCtrl); // Populate using wxListView methods popupCtrl->InsertItem(popupCtrl->GetItemCount(),wxT("First Item")); popupCtrl->InsertItem(popupCtrl->GetItemCount(),wxT("Second Item")); popupCtrl->InsertItem(popupCtrl->GetItemCount(),wxT("Third Item"));Derived from
wxControl
wxWindow
wxEvtHandler
wxObject
Include files
<combo.h>
Window styles
wxCB_READONLY | Text will not be editable. |
wxCB_SORT | Sorts the entries in the list alphabetically. |
wxPROCESS_ENTER | The control will generate the event wxEVT_COMMAND_TEXT_ENTER (otherwise pressing Enter key is either processed internally by the control or used for navigation between dialog controls). Windows only. |
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. |
wxCC_ALT_KEYS | Use keyboard behaviour alternate to platform default: up and down keys will show popup (instead of cycling value, for instance, on wxMSW). |
wxCC_STD_BUTTON | Drop button will behave more like a standard push button. |
See also window styles overview.
Event handling
EVT_TEXT(id, func) | Process a wxEVT_COMMAND_TEXT_UPDATED event, when the text changes. |
EVT_TEXT_ENTER(id, func) | Process a wxEVT_COMMAND_TEXT_ENTER event, when <RETURN> is pressed in the combo control. |
See also
wxComboBox, wxChoice, wxOwnerDrawnComboBox, wxComboPopup, wxCommandEvent
Members
wxComboCtrl::wxComboCtrl
wxComboCtrl::~wxComboCtrl
wxComboCtrl::Create
wxComboCtrl::Copy
wxComboCtrl::Cut
wxComboCtrl::GetBitmapDisabled
wxComboCtrl::GetBitmapHover
wxComboCtrl::GetBitmapNormal
wxComboCtrl::GetBitmapPressed
wxComboCtrl::GetCustomPaintWidth
wxComboCtrl::GetFeatures
wxComboCtrl::GetInsertionPoint
wxComboCtrl::GetLastPosition
wxComboCtrl::GetPopupControl
wxComboCtrl::GetPopupWindow
wxComboCtrl::GetTextCtrl
wxComboCtrl::GetTextIndent
wxComboCtrl::GetValue
wxComboCtrl::HidePopup
wxComboCtrl::IsPopupShown
wxComboCtrl::OnButtonClick
wxComboCtrl::Paste
wxComboCtrl::Remove
wxComboCtrl::Replace
wxComboCtrl::SetButtonBitmaps
wxComboCtrl::SetButtonPosition
wxComboCtrl::SetCustomPaintWidth
wxComboCtrl::SetInsertionPoint
wxComboCtrl::SetInsertionPointEnd
wxComboCtrl::SetPopupAnchor
wxComboCtrl::SetPopupControl
wxComboCtrl::SetPopupExtents
wxComboCtrl::SetPopupMaxHeight
wxComboCtrl::SetPopupMinWidth
wxComboCtrl::SetSelection
wxComboCtrl::SetText
wxComboCtrl::SetTextIndent
wxComboCtrl::SetValue
wxComboCtrl::ShowPopup
wxComboCtrl::Undo
wxComboCtrl()
Default constructor.
wxComboCtrl(wxWindow* parent, wxWindowID id, const wxString& value = "", const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxDefaultSize, long style = 0, const wxValidator& validator = wxDefaultValidator, const wxString& name = "comboCtrl")
Constructor, creating and showing a combo control.
Parameters
parent
id
value
pos
size
style
validator
name
See also
wxComboCtrl::Create, wxValidator
~wxComboCtrl()
Destructor, destroying the combo control.
bool Create(wxWindow* parent, wxWindowID id, const wxString& value = "", const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxDefaultSize, long style = 0, const wxValidator& validator = wxDefaultValidator, const wxString& name = "comboCtrl")
Creates the combo control for two-step construction. Derived classes should call or replace this function. See wxComboCtrl::wxComboCtrl for further details.
void Copy()
Copies the selected text to the clipboard.
void Cut()
Copies the selected text to the clipboard and removes the selection.
const wxBitmap& GetBitmapDisabled() const
Returns disabled button bitmap that has been set with SetButtonBitmaps.
Return value
A reference to the disabled state bitmap.
const wxBitmap& GetBitmapHover() const
Returns button mouse hover bitmap that has been set with SetButtonBitmaps.
Return value
A reference to the mouse hover state bitmap.
const wxBitmap& GetBitmapNormal() const
Returns default button bitmap that has been set with SetButtonBitmaps.
Return value
A reference to the normal state bitmap.
const wxBitmap& GetBitmapPressed() const
Returns depressed button bitmap that has been set with SetButtonBitmaps.
Return value
A reference to the depressed state bitmap.
int GetCustomPaintWidth() const
Returns custom painted area in control.
See also
wxComboCtrl::SetCustomPaintWidth.
static int GetFeatures()
Returns features supported by wxComboCtrl. If needed feature is missing, you need to instead use wxGenericComboCtrl, which however may lack native look and feel (but otherwise sports identical API).
Return value
Value returned is a combination of following flags:
wxComboCtrlFeatures::MovableButton | Button can be on either side of the control. |
wxComboCtrlFeatures::BitmapButton | Button may be replaced with bitmap. |
wxComboCtrlFeatures::ButtonSpacing | Button can have spacing. |
wxComboCtrlFeatures::TextIndent | SetTextIndent works. |
wxComboCtrlFeatures::PaintControl | Combo control itself can be custom painted. |
wxComboCtrlFeatures::PaintWritable | A variable- width area in front of writable combo control's textctrl can be custom painted. |
wxComboCtrlFeatures::Borderless | wxNO_BORDER window style works. |
wxComboCtrlFeatures::All | All of the above. |
long GetInsertionPoint() const
Returns the insertion point for the combo control's text field.
Note: Under wxMSW, this function always returns 0 if the combo control doesn't have the focus.
long GetLastPosition() const
Returns the last position in the combo control text field.
wxComboPopup* GetPopupControl()
Returns current popup interface that has been set with SetPopupControl.
wxWindow* GetPopupWindow() const
Returns popup window containing the popup control.
wxTextCtrl* GetTextCtrl() const
Get the text control which is part of the combo control.
wxCoord GetTextIndent() const
Returns actual indentation in pixels.
wxString GetValue() const
Returns text representation of the current value. For writable combo control it always returns the value in the text field.
void HidePopup()
Dismisses the popup window.
bool IsPopupShown() const
Returns true if the popup is currently shown
void OnButtonClick()
Implement in a derived class to define what happens on dropdown button click.
Default action is to show the popup.
void Paste()
Pastes text from the clipboard to the text field.
void Remove(long from, long to)
Removes the text between the two positions in the combo control text field.
Parameters
from
to
void Replace(long from, long to, const wxString& value)
Replaces the text between two positions with the given text, in the combo control text field.
Parameters
from
to
text
void SetButtonBitmaps(const wxBitmap& bmpNormal, bool pushButtonBg = false, const wxBitmap& bmpPressed = wxNullBitmap, const wxBitmap& bmpHover = wxNullBitmap, const wxBitmap& bmpDisabled = wxNullBitmap)
Sets custom dropdown button graphics.
Parameters
bmpNormal
void SetButtonPosition(int width = 0, int height = 0, int side = wxRIGHT, int spacingX = 0)
Sets size and position of dropdown button.
Parameters
width
void SetCustomPaintWidth(int width)
Set width, in pixels, of custom painted area in control without wxCB_READONLY style. In read-only wxOwnerDrawnComboBox, this is used to indicate area that is not covered by the focus rectangle.
void SetInsertionPoint(long pos)
Sets the insertion point in the text field.
Parameters
pos
void SetInsertionPointEnd()
Sets the insertion point at the end of the combo control text field.
void SetPopupAnchor(int anchorSide)
Set side of the control to which the popup will align itself. Valid values are wxLEFT, wxRIGHT and 0. The default value 0 means that the most appropriate side is used (which, currently, is always wxLEFT).
void SetPopupControl(wxComboPopup* popup)
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 SetPopupExtents(int extLeft, int extRight)
Extends popup size horizontally, relative to the edges of the combo control.
Parameters
extLeft
Remarks
Popup minimum width may override arguments.
It is up to the popup to fully take this into account.
void SetPopupMaxHeight(int height)
Sets preferred maximum height of the popup.
Remarks
Value -1 indicates the default.
Also, popup implementation may choose to ignore this.
void SetPopupMinWidth(int width)
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 SetSelection(long from, long to)
Selects the text between the two positions, in the combo control text field.
Parameters
from
to
void SetText(const wxString& value)
Sets the text for the text field without affecting the popup. Thus, unlike SetValue, it works equally well with combo control using wxCB_READONLY style.
void SetTextIndent(int indent)
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.
void SetValue(const wxString& value)
Sets the text for the combo control text field.
NB: For a combo control with 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
void ShowPopup()
Show the popup.
void Undo()
Undoes the last edit in the text field. Windows only.