CSwCtl (derived from
CControlBar) fixes itself on the left hand edge of the main frame and can be used to provide a user interface for any tree like hierarchy of data, typically as a starting point user interface for your app.
An example for a real world application could be a financial software’s reporting module node that fans out into sub levels. E.g., Dealer reports, Accounting reports, Management Reports, each having its own special reports.
Somewhat similar controls that I came across while browsing the web, were not meant to support more than two levels. That’s where I felt that
CSwCtl could be useful for cases that need to show any number of levels of the tree like data. Nevertheless, I must mention that
CSwCtl is greatly, rather solely, inspired from an earlier contribution made by Dheth at Code Project as 'Outlookbar' based on
CControlBar, titled 'Outlookbar-style menu interface'. He has provided a very elegant solution that serves for a generic purpose.
CSwCtl rather focuses on a specific requirement. I have to mention further that the idea of
CSwCtl is not new. Those of you who have had a chance to look at MS Access development env, would quickly relate the identity of
CSwCtl with Switchboard.
CSwCtl enhances, in a bit, this concept by providing a default mechanism to handle history of upto 10 item clicks and albeit offers a better look-n-feel. You will also realize that the strength of
CSwCtl lies in the fact that you can programmatically manage this starting point UI of your app. E.g., depending on the user levels (admin user, power user, ordinary user) you can control which modules are available to the current user.
I have been able to use it for my own work on Win XP and found that it's meeting what I was wanting. I hope it helps you too.
To understand the concept, imagine each level of your module hierarchy as a page. Each page has items on it.
Thus in the above tree, first page will contain –
Another page (say page number ‘n’) will have –
- Accounting ….
Another page (say page number ‘m’) will have -
- Enterprise Tools
- Standard Tools
And you will use
CSwCtl::AddItem() to link these pages and arrange them in a logical sequence, e.g. Finance will point to page n, Tools will point to page m.
Using the code
You need to call 3 functions of
CSwCtl in your main frame’s
Create() to create.
AddItem() to Configure the control bar to suit your needs.
Init() to initialize and err check.
- Add the two files (SwCtl.h and SwCtl.cpp) to your project.
- Add the following line to your application’s Main frame (
CFrameWnd derived class) header file.
- Add a member variable (say
m_wndSwCtl) along with the statusbar and toolbar as follows:
- In the
OnCreate() function of your main frame class, add the following line BEFORE creating the toolbar or statusbar.
if (!m_wndSwCtl.Create(1,this)) return -1;
- Customize the
CSwCtl using the
AddItem() member function as –
|and so forth ...|
- After adding all the items, call the
Init() method of
CSwCtl. This is VERY IMPORTANT.
Init() will do a consistency check on the customization you did using
AddItem() and it also does the ground work for display mechanism.
if(!m_wndSwCtl.Init()) return -1;
- Define an enumeration (in your main frame’s header file) that best describes your modules.
- In the
InvokeCommand() function of
CSwCtl, add the dispatching code as follows:
MessageBox("Your code to handle the Finance Module goes here.");
MessageBox("Your code to handle the Production Module goes here.");
- The source files (SwCtl.h and .cpp) alone can not provide you with the icons for Previous, Main Menu and Next button. You will be required to create/import these three icons and assign their IDs to these lines in SwCtl.h
#define ICONID_MAIN IDI_MAIN //<- Change to your
#define ICONID_PREV IDI_PREV //<- Prev
#define ICONID_NEXT IDI_NEXT //<- Next
Lastly, you will have to create the menu
IDR_STYLE as done in the demo project.
Take a note of
#define WINVER 0x0400 in SwCtl.h. This should allow you to avoid using the
GradiantFill() that might hurt VC6 users.
Following these steps, I was able to build and use
CSwCtl with VC6 and VC7 on Win2k and XP. Hope things work out smooth for you too.
Points of interest
- Array of items, that forms quite a normalized data structure. It's extensible and yet intuitive. You will be able to add your own extensions to the existing data of an item (e.g. Tooltips, changing background color for each page ...). Thanks to the original idea from Access.
- Fact that the UI can be programmatically configured to show/hide modules selectively depending on some criteria (say user levels).
- Double click of right mouse switches between small icon look to large icon look. This too can be programmatically controlled by setting
m_bBigIcons member variable to
- As you will notice,
CSwCtl is more a
CWnd class than a
CControlbar class. This makes it quite an easy tweak to use in a Dialog based applications as well.