Colour Picker image

In an effort to have the latest and greatest wizz-bang features in my programs I unashamedly ripped of the colour picker from Office 97.

Initially I tried to modify an owner drawn combo box and combine that with a multicolumn combobox, but current multicolumn combo boxes are really just a single column with dividing lines drawn in. I then decided to write the whole thing from scratch based on a button, since it would at least give me a BN_CLICKED notification to get things started.

The colour picker is in two parts: an owner drawn button that reflects the currently selected colour, and a popup colour chooser window to select this colour. When the user clicks on the button the popup window appears and all mouse messages are captured until the left mouse button is clicked, or until the Enter or Escape keys are pressed. The popup window can be navigated using the mouse or the keyboard and includes tooltips explaining what each colour is.

The control can be incorporated into a project like any other CButton derived control. Either Create the control manually, subclass an existing CButton or DDX_control it. The control also comes with a DDX_ColourPicker routine to get/set the colour of the control using a variable of type COLORREF.

The Colour Picker is contained in the class CColourPicker. It uses the class CColourPopup for the popup window. These classes are contained in the file colour_picker_src.zip, and a sample project is contained in colour_picker_demo.zip.

CColourPicker only has the following public member functions:

void     SetColour(COLORREF crColour);
COLORREF GetColour();

void     SetDefaultText(LPCTSTR szDefaultText);
void     SetCustomText(LPCTSTR szCustomText);

void     SetSelectionMode(UINT nMode); // Either CP_MODE_TEXT or CP_MODE_BK


UINT     GetSelectionMode();

void     SetBkColour(COLORREF crColourBk);
COLORREF GetBkColour();
  
void     SetTextColour(COLORREF crColourText);
COLORREF GetTextColour();

SetDefaultText allows you to set the text that will appear in the "Default" area of the colour chooser. If you pass NULL, then the Default area will not be available to the user. If this area is availble and the user selects it, the value CLR_DEFAULT will be returned.

SetCustomText allows you to set the text that will appear in the "Custom" area of the colour chooser. If you pass NULL, then the Custom area will not be available to the user. The Custom area allows the user to select a custom colour using the standard windows colour selection dialog.

You can choose whether the colour chosen using the dropdown colour chooser will affect the text or the background colour using the function SetSelectionMode(int nMode). Possible values for nMode are CP_MODE_TEXT to make colour changes affect the text colour, and CP_MODE_BK to make changes affect the background (default).

SetColour, GetColour and the the DDX-function will set and get the colour according to the current selection mode. To access the text colour and the background colour directly use the Set/GetTextColour and Set/GetBkColour functions.

There are also a number of user messages that may be handled to get more information from the control. These are:

Message	Description
CPN_SELCHANGE	Colour Picker Selection change
CPN_DROPDOWN	Colour Picker drop down
CPN_CLOSEUP	Colour Picker close up
CPN_SELENDOK	Colour Picker end OK
CPN_SELENDCANCEL	Colour Picker end (cancelled)

These messages can be handled using ON_MESSAGE(< MESSAGE>, MessageFn) in you message map entries, where MessageFn is of the form

afx_msg LONG MessageFn(UINT lParam, LONG wParam);

The demo program gives an example of how to do this.

Acknowledgments

Alexander Bischofberger kindly supplied the Selection mode modifications, as well as the background and text color methods. Paul Wilkerson fixed a focus related bug, and Geir Arne Trillhus also helped fix a few bugs.

Office 97 style Colour Picker control