FooButton

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Introduction

This article describes FooButton, a lightweight owner-drawn button class that's served me well for several years.  Although there are plenty of other excellent button classes at CodeProject, I thought I'd add this trusty friend to the pile in the hope that someone may find it equally useful.

Features

FooButton lets you use a vanilla CButton as a:

• standard pushbutton
• pushbutton button with a drop-down indicator
• multi pushbutton (like IE's "Back" and "Next" buttons)
• checkbutton
• hyperlink
• static text control that's responsive to mouse clicks
• check box
• radio button

Support is also provided for:

• bitmaps (currently only 16-color)
• left-justified, centered and multi-line captions
• colored captions
• gradient shaded button backgrounds
• popup menus
• hot tracking
• optional focus rectangle and "default button" indicator
• grouped checkbuttons

How to use FooButton

1. First, associate a standard button control (eg: IDC_FOO_BUTTON) in your dialog with an instance of the object.

   Copy Code ///////////// // MyDialog.h #include "FooButton.h" ... FooButton m_fooButton; Copy Code /////////////// // MyDialog.cpp void CMyDialog::DoDataExchange(CDataExchange* pDX) { CDialog::DoDataExchange(pDX); //{{AFX_DATA_MAP(CMyDialog) DDX_Control(pDX, IDC_FOO_BUTTON, m_fooButton); //}}AFX_DATA_MAP }

2. Then, initialize the instance in your dialog's OnInitDialog() method to suit your needs.  In this example, the button is set to display a bitmap and a drop-down indicator.

   Copy Code // Initialize FooButton m_fooButton.setBitmapId (IDB_FOO_BUTTON); m_fooButton.setType (FooButton::Type::pushButtonDropDown);

API

Method Purpose  getType(), setType() Gets and sets the button's type   getTextStyle(), setTextStyle() Gets and sets the button's text style   getTextColor(), setTextColor() Gets and sets the button's text color   getFocusStyle(), setFocusStyle() Gets and sets the button's focus style   getGradient(), setGradient() Gets and sets the button's gradient property   getBitmapId(), setBitmapId() Gets and sets the button's (optional) bitmap id

displayPopupMenu() Displays a popup menu below the button   isChecked(), check() Gets and sets a checkButton's checked state   isMultiClicked(), clearMultiClick() Gets and resets a multiPushButton's multi-clicked state   addToGroup(), removeFromGroup() Adds/removes a checkButton to/from a button group   reset() Frees storage used by all button groups

 

Using FooButton as a check button

You can freely change any property of the button at run time.  This code snippet turns the button into a checkbutton and checks it.  Use check() and isChecked() to set and retrieve the button's checked state.

Copy Code // Make it a checkbutton and check it m_fooButton.setType (FooButton::Type::checkButton); m_fooButton.check (true); ASSERT (m_fooButton.isChecked()); // testing

Gradient shading

Pushbuttons and checkbuttons can be set to display a gradient shaded background by calling setGradient().  This method has no effect if the button isn't a pushbutton or checkbutton.

Copy Code // Use a gradient shaded background m_fooButton.setGradient (true);

Button groups

You can make a bunch of checkButtons behave as mutually exclusive radio buttons by adding them to a button group.  A button group is just a named collection of buttons.  FooButton automatically handles group creation, membership and cleanup.

Copy Code // Make "size" checkbuttons mutually exclusive m_btnSmall.addToGroup (_T("foo")); m_btnMedium.addToGroup (_T("foo")); m_btnLarge.addToGroup (_T("foo")); m_btnXLarge.addToGroup (_T("foo"));

Displaying a popup menu

To display a popup menu in response to a button click, call displayPopupMenu().  You can call this method for any type of FooButton.

Copy Code void CMyDialog::OnFooButton() { CMenu menu; menu.LoadMenu (IDR_POPUP_MENU); CMenu* pPopupMenu = menu.GetSubMenu (0); int nResult = m_fooButton.displayPopupMenu (pPopupMenu); if (0 != nResult) PostMessage (WM_COMMAND, nResult); }

Multi-pushbuttons

A multi-pushbutton behaves as two buttons in one, similar to IE's "Back" and "Next" buttons.  When the user clicks the button's drop-down region, FooButton sets its "multi-clicked" property to true.  You can query this property by calling isMultiClicked().  Regardless of whether the user clicked in the button's main or drop-down region, a standard notification is sent to the parent.  To clear the button's multi-click property, call clearMultiClick().

Copy Code void CMyDialog::OnFooButton() { if (m_fooButton.isMultiClicked()) { // Display menu if drop-down region was clicked CMenu menu; menu.LoadMenu (IDR_POPUP_MENU); CMenu* pPopupMenu = menu.GetSubMenu (0); int nResult = m_fooButton.displayPopupMenu (pPopupMenu); if (0 != nResult) PostMessage (WM_COMMAND, nResult); // Remember to clear the button's multi-click property! m_fooButton.clearMultiClick(); } else { // Otherwise do default action PostMessage (WM_COMMAND, IDC_DEFAULT_ACTION); } }

Check boxes and radio buttons

You can make a FooButton appear as a standard check box or radio button by using the FooButton:Type::checkBox and FooButton:Type::radio types.  Of course, this is really only useful when you want to also display a bitmap or add menu support to the button.

Copy Code // Appear as check box and radio button m_fooButton1.setType (FooButton::Type::checkBox); m_fooButton2.setType (FooButton::Type::radio);

Hyperlink button

A hyperlink button is just a regular button that renders itself as a hyperlink.  You can navigate to a URL or perform any other action in the button's handler.

Copy Code // Appear as hyperlink m_fooButton.setType (FooButton::Type::hyperink);

Text color

You can change the color of the button's text at any time by calling setTextColor().  The text of hyperlink buttons is always rendered in C_HyperlinkColor and that of disabled buttons is always rendered in the standard etched format.

Copy Code // Draw caption in red m_fooButton.setTextColor (RGB (192, 0, 0));

Focus rectangle

By default, a FooButton doesn't display a focus rectangle.  Call setFocusStyle() with FooButton::Focus::normalFocus to enable the button to display a focus rectangle.

Copy Code // Allow focus rectangle to be displayed m_fooButton.setFocusStyle (FooButton::Focus::normalFocus);

Default button indicator

To enable a default FooButton to display its standard dark border, call setFocusStyle() with FooButton::Focus::defaultFocus.

Copy Code // Allow focus rectangle and default indicator to be displayed m_fooButton.setFocusStyle (FooButton::Focus::defaultFocus);

Rendering disabled bitmaps

Use the standard MFC EnableWindow() API to enable and disable the button.  FooButton uses its original bitmap to render a disabled version.

Copy Code m_fooButton.EnableWindow (TRUE); // enable button m_fooButton.EnableWindow (FALSE); // disable button

Acknowledgement

• Drawing a bitmap transparently by Zafir Anjum
• Draw bitmap with grayed 3D effect by Jean-Edouard Lachand-Robert
• Hyperlink control by Chris Maunder
• A Gradient Static Control by Irek Zielinski
• Thanks to those who've reported bugs, identified solutions and suggested features!

Revision history

7 Oct 2006

• Bug Fix:  m_hMsimg32 should be set to NULL in destructor. (Thanks, C. Young!)
• Bug Fix:  Memory leak in DisabledBlt(). (Thanks, Corrado Valli!)

6 Mar 2005

• Bug Fix:  Added definition of COLOR_HOTLIGHT to enable compilation on older systems.

5 Mar 2005

• Enhancement:  Added support for gradient shaded buttons.
• Bug Fix:  Reusing a group name across dialog invocations would cause a crash in FooButton::removeFromGroup().

19 Feb 2005

• Enhancement:  Added support for colored captions.
• Enhancement:  Removed requirement to call FooButton::reset() when your app terminates.
• Enhancement:  Now uses standard Win2000/XP hyperlink cursor.
• Enhancement:  Code now ASSERTs if you're not subclassing from a button control.
• Bug Fix:  All calls to Invalidate() now validate window handle, allowing a FooButton to be safely destroyed when clicked.

Fixed typo in default state rendering logic

17 Jul 2004

• Added support for check boxes and radio buttons
• Fixed typo in default state rendering logic

11 Jul 2004

• Optimized fix for "unreferenced identifier" compiler warning
• Exposed focus rectangle and default state modes
• Added support for button groups

4 Jul 2004
Added multi-pushbutton and hyperlink styles.

3 Jul 2004
Submitted to CodeProject.

12 Sep 1998
Initial version.