XColorPickerXP - an MFC color picker control with themed look

• Download demo project - 66 Kb

Introduction

For many years I have been using my XColourPicker control, which I based on Chris Maunder's excellent color picker control. Recently my project manager asked me why I wasn't using a control with a modern look. That's when I realized that my control still had the flat Windows 2000 look, even when used in a themed app:

To make this look good in a themed app, I knew I had to add support for visual themes, which has always involved a good deal of effort whenever I tried it. Nevertheless, I decided to look into it. What I discovered was something unexpected that completely surprised me.

Comboboxes and Themes

In trying to decide how to proceed, it struck me that the color picker has the appearance of a combobox, rather than a button (my XColourPicker control is derived from CButton). Because of this, my XColourPicker control needed code to position and draw the down arrow, and a lot of other details to make it look like a combobox.

But what if I started from CComboBox? Could I eliminate some of the drawing code? To investigate this possibility, I started by creating a new class derived from CComboBox. I added the virtual DrawItem() function, which the framework calls for ownerdraw controls. Then I made sure the combobox in the demo was marked as ownerdraw. When I tried the demo app, I was amazed. Without using any of the uxtheme functions at all, the combobox was drawn using visual themes, even though it was marked as ownerdraw. Mouse hover also worked, changing the appearance to hot state. And I did not have to do anything to achieve this!

Naturally this made the job much easier. I added code to DrawItem() to draw a color-filled rect, and I was done.

Here is what the demo app for the new control looks like:

XColorPickerXP API

The programmatic interface to XColorSpectrumCtrl attributes is very simple: just six functions to get/set color and custom colors.

Function	Description
COLORREF GetColor()	Retrieves RGB color value
void GetCustomColors(COLORREF * pCustomColors)	Retrieves array of 16 custom color RGB values
CString GetCustomColors()	Retrieves 16 custom colors as space-separated string of RGB values
CXColorPickerXP& SetColor(COLORREF crColor)	Sets color from RGB value
CXColorPickerXP& SetCustomColors(COLORREF * pCustomColors)	Sets 16 custom colors from array of RGB values
CXColorPickerXP& SetCustomColors(LPCTSTR lpszCustomColors)	Sets 16 custom colors from space-separated string of RGB values

XColorPickerXP DDX Helpers

XColorPickerXP provides two DDX helper functions:

// get/set color value
void AFXAPI DDX_XColorPickerXP(CDataExchange * pDX, int nIDC, COLORREF& crColor);

// get/set custom colors from string of space-separated color values
void AFXAPI DDX_XColorPickerXPCustom(CDataExchange * pDX, int nIDC, CString& strCustomColors);

In the demo app, these functions are used in DoDataExchange() function:

void CXColorPickerXPTestDlg::DoDataExchange(CDataExchange* pDX)
{
    CDialog::DoDataExchange(pDX);
    //{{AFX_DATA_MAP(CXColorPickerXPTestDlg)
    DDX_Control(pDX, IDC_COLOR_SAMPLE, m_stcColorSample);
    DDX_Control(pDX, IDC_BACKGROUND_COLOR, m_ctlBackgroundColor);
    DDX_Control(pDX, IDC_TEXT_COLOR, m_ctlTextColor);
    //}}AFX_DATA_MAP

    DDX_XColorPickerXP(pDX, IDC_TEXT_COLOR, m_rgbText);
    DDX_XColorPickerXP(pDX, IDC_BACKGROUND_COLOR, m_rgbBackground);

    DDX_XColorPickerXPCustom(pDX, IDC_TEXT_COLOR, m_strTextCustomColors);
    DDX_XColorPickerXPCustom(pDX, IDC_BACKGROUND_COLOR, m_strBackgroundCustomColors);
}

How To Use

To integrate XColorPickerXP into your app, you first need to add following files to your project:

• XColorPickerXP.cpp
• XColorPickerXP.h
• XColorPopupXP.cpp
• XColorPopupXP.h

Then use resource editor to add combobox control to your dialog, and use Class Wizard to attach member variable to that control.

Next, include header file XColorPickerXP.h in the dialog's header file. Then replace the CComboBox definition with CXColorPickerXP. Now you are ready to start using XColorPickerXP.

Demo App

The demo dialog processes color changes in the OnColorChange handler:

LRESULT CXColorPickerXPTestDlg::OnColorChange(WPARAM, LPARAM lParam)
{
    TRACE(_T("in CXColorPickerXPTestDlg::OnColorChange\n"));

    if (lParam == IDC_TEXT_COLOR)
    {
        TRACE(_T("IDC_TEXT_COLOR\n"));
    }
    else if (lParam == IDC_BACKGROUND_COLOR)
    {
        TRACE(_T("IDC_BACKGROUND_COLOR\n"));
    }

    if (m_ctlTextColor.GetColor() == m_ctlBackgroundColor.GetColor())
    {
        CXBalloonMsg::Show(_T("Unreadable Colors"),
                           _T("The text and background colors are identical.\r\n")
                           _T("The text will not be readable."),
                           m_ctlBackgroundColor.m_hWnd, 
                           m_hWnd,
                           AfxGetInstanceHandle(),
                           TTI_ERROR);
    }
    else
    {
        m_rgbText = m_ctlTextColor.GetColor();
        m_rgbBackground = m_ctlBackgroundColor.GetColor();
    }

    m_ctlTextColor.SetColor(m_rgbText);
    m_ctlBackgroundColor.SetColor(m_rgbBackground);
    m_stcColorSample.SetTextColor(m_rgbText);
    m_stcColorSample.SetBackgroundColor(m_rgbBackground);

    return 0;
}

Revision History

Version 1.0 - 2008 April 9

• Initial public release.

Usage

This software is released into the public domain. You are free to use it in any way you like, except that you may not sell this source code. If you modify it or extend it, please to consider posting new code here for everyone to share. This software is provided "as is" with no expressed or implied warranty. I accept no liability for any damage or loss of business that this software may cause.