ChoiceListButton Control

Synopsis

I wanted to have a button that would display a selection of choices to the user.

I could of course use an ownerdraw dropdown box.
The problem with that solution, is that, when the dropdown is collapsed
it will display the last chosen item always insted of some descriptive text.


That was why i opted for a custom
solution.

 

ITCLib

Optionally, the control can use the freeware library ‘ITCLib’
from Interface technologies, Inc.
This is a great library and I will suggest that every MFC developer takes a look
at it – it is a real time saver.

ITCLib has only been used for painting the small arrow
on the button, and is as such not an integreated part of the control. That is
why all references to ITCLib is initially disabled via preprocessor statements,
so the sample should compile fine on installations without the library.

To enable ITCLib:


  • If you have ITCLib installed and you want to enable
    it, do the following:

  • In Project Settings – C/C++ – Preprocessor –
    Preprocessor definitions, add _ITCDLL

  • In Project Settings – C/C++ – Preprocessor –
    Additional include directories, add the folder with your ITCLib header files

  • In Project Settings – Link – Input – Additional
    Library Path, add the folder with your ITCLib lib-files

That’s it!


If you want to use you own button class for painting the
arrow or what ever it is you want to paint on the button surface, you could
enherit CChoiceWindowBtn from your own class instead of
CButton or ITCImageButton.


 


Using the control


To use the control, create a project and add these
files:


ChoiceWindow.h
ChoiceWindow.cpp
ChoiceWindowBtn.h
ChoiceWindowBtn.cpp
drop_arrow.bmp
(or another bitmap)


Assign the bitmap the resource name “DROP_ARROW” –
notice as  a string – not as an integer ID.


Next add a button to a dialog and use the member
functions from you WM_INITDIALOG handler.


Add an object of type CChoiceWindowBtn to the dialog
class. Make sure to add the header include too.


Example – notice the use of preprocessor
definitions.





// TODO: Add extra initialization here

#ifdef _ITCDLL
m_btnDropDown.SubclassControl(IDC_OPTIONS, this);
m_btnDropDown.AddImage("DROP_ARROW", -1, RGB(255,0,255));
m_btnDropDown.SetImageAlign(DT_RIGHT|DT_VCENTER);
#else
m_btnDropDown.SubclassDlgItem(IDC_OPTIONS, this);
#endif

m_btnDropDown.AddChoice("Name", TRUE);
m_btnDropDown.AddChoice("Address", TRUE);
m_btnDropDown.AddChoice("Notes", FALSE);
m_btnDropDown.AddChoice("Telephone", TRUE);


 


Interface


The control is accessed through the class
CChoiceWindowButton. It has a few simple member functions:


 


CChoiceWindowButton::AddChoice


void AddChoice(LPCTSTR szText, BOOL bChecked=FALSE)


Return
value
None
Parameters
szText: The text to
display as a choice.
bChecked: Should the choice be
iniitally checked or not.
Remarks
Adds a new choice
to the list.


 


CChoiceWindowButton::Reset


void Reset()


Return
value
None
Parameters
None
Remarks
Deletes all the items from the
choice list.


CChoiceWindowButton::GetCheck


BOOL GetCheck(int iItem)


Return
value
Boolean – the state of the choice specified by
iItem
Parameters
nItem: Zero based index of the item to
query the state for.
Remarks
Returns TRUE if
the choice had a check mark, and FALSE if the choice was not checked by the
user.


 


CChoiceWindowButton::SetCheck


void SetCheck(int iItem, BOOL bCheck=TRUE)


Return
value
void
Parameters
iItem: Zero based index of the item to
query the state for.
bCheck: Boolean value. If true, the item is checked otherwise it is
unchecked.


CChoiceWindowButton::GetItemCount


int  GetItemCount()


Return
value
The number of items in the list.
Parameters
none


 


CChoiceWindowButton::GetListCtrl


CListCtrl&  GetListCtrl()


Return
value
A reference to the underlying CListCtrl object 
Parameters
none
Remarks
You access the list control like this:
CListCtrl& list =
btnChoiceList.GetListCtrl();


 


CChoiceWindowButton::RemoveAt


void  RemoveAt(int iIndex)


Return
value
None
Parameters
The index of the item to remove from the list.


 


CChoiceWindowButton::m_bDisableIfEmpty

BOOL m_bDisableIfEmpty

Remarks
Boolean value, that specifies if the button is
disbaled if the choice list does not contain any items. The default value is
TRUE.


 


CChoiceWindowButton::Reset


vid Reset()


Return
value
None
Parameters
None
Remarks
Removes all the items from the list.




Downloads

Download demo project – 25 KB

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