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Balloon Help as a non-modal replacement for MessageBox()

, 7 Aug 2002
Although sometimes useful, message boxes used to display information are often just annoying. This article describes a non-modal replacement.
balloonhelpr2_demo.zip
BalloonTest.exe
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BalloonTest.ico
BalloonTest.manifest
BalloonTest.dsw
BalloonTest.dsp
balloonhelpr2_src.zip
balloonhelpr3_demo.zip
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balloonhelpr3_src.zip
balloonhelp_demo.zip
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BalloonTest.dsw
BalloonTest.dsp
balloonhelp_src.zip
bh-atl.zip
BalloonTest.dsp
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BalloonTestps.mk
BalloonTestps.def
BalloonTest.rgs
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BalloonTest.suo
wtl_balloonhelp_demo.zip
BalloonTest
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Release
BalloonTest.exe
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<!----------------------------- Article Starts ----------------------------->
Release #3:
<ul class="download">
	<li>
		<a href='BalloonHelp/BalloonHelpR3_src.zip'>Download source files - 26 Kb</a>
	<li>
		<a href='BalloonHelp/BalloonHelpR3_demo.zip'>Download demo project and .exe - 70 
			Kb</a>
</ul>
Previous release:
<ul class="download">
	<li>
		<a href='BalloonHelp/BalloonHelpR2_src.zip'>Download source files - 16 Kb</a>
	<li>
		<a href='BalloonHelp/BalloonHelpR2_demo.zip'>Download demo project and .exe - 60 
			Kb</a>
</ul>
Ports:
<ul class="download">
	<li>
		<a href='BalloonHelp/WTL_BalloonHelp_Demo.zip'>Download Maximilian H�nel's WTL 
			port (source + demo) - 58Kb</a></li>
	<li>
		<a href='BalloonHelp/BH-ATL.zip'>Download Fil Mackay's ATL port (source + demo) - 
			40Kb</a></li>
</ul>
<h3>Update Notes</h3>
<p>The primary reason for this release is a bug I found with the open location 
	feature: it would access deallocated memory! In addition, I've worked in a few 
	other changes to make writing custom <code>LaunchBalloon()</code> methods 
	easier, fixed a bug in the demo, and added two new options:</p>
<p><code>unDELAY_CLOSE</code> works in tandem with a timeout value to delay the 
	action caused by the other <code>unCLOSE_*</code> options. This allows you to 
	keep a balloon active indefinately (until the user gets back from coffee break, 
	etc. and has time to take a look at it). For long timeout values, I'd advise 
	also using <code>unSHOW_CLOSE_BUTTON</code> so the user can still get rid of it 
	quickly if need be.</p>
<p><code>unDISABLE_XP_SHADOW</code> is exactly what it sounds like: if set, that 
	cool dropshadow XP uses for tooltips and menus isn't shown. Note that the user 
	can also disable dropshadows globally, in which case this option has no effect.
</p>
<p>I want to add some new demos, there are more things that can be done with this 
	than what I'm currently demonstrating, but I felt these bug fixes needed to be 
	released, and I'm probably too lazy to get the demos done as soon as i'd like 
	anyway. So, I'll do another update when they are finished. In the meantime, 
	Rama Krishna either has already, or will soon be releasing his <b>.NET Version</b>, 
	so there'll be plenty of Balloon Goodness around. :)</p>
<P align="center">
	<img src="BalloonHelp/Balloons.jpg" width="498" height="512" alt="Balloons"><br>
	<i>CBalloonHelp test app, running under Windows XP.</i></P>
<P>
	<a href="#Intro">Introduction</a><br>
	<a href="#Using">Using CBalloonHelp</a><br>
	<a href="#API">API</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API Important">Important stuff</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API SetAnchorPoint">SetAnchorPoint()</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API SetBackgroundColor">SetBackgroundColor()</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API SetForegroundColor">SetForegroundColor()</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API SetTitle">SetTitle()</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API SetContent">SetContent()</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API SetTitleFont">SetTitleFont()</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API SetContentFont">SetContentFont()</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API SetURL">SetURL()</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API SetIcon">SetIcon()</a><br>
	&nbsp;&nbsp;&nbsp;<a href="#API LaunchBalloon">LaunchBalloon()</a><br>
	<a href="#Features">Features</a><br>
	<a href="#Compatibility">Compatibility</a><br>
	<a href="#Internals">Internals</a><br>
	<a href="#Updates">Updates</a><br>
	<a href="#Links">Related Articles</a><br>
	<a href="#TODO">TODO</a><br>
	<a href="#Thanks">Thanks</a><br>
</P>
<h2><a name="Intro">Introduction</a></h2>
<h3>I hate message boxes.</h3>
<P>Or really,&nbsp;I hate <code>MessageBox()</code>s. Something about having a 
	form of output <I>sooo</I> convenient, a single function call, no need for 
	resources to be added, for interfaces to be designed, for any planning or 
	preparation <I>at all</I> � not even a window handle is needed (!) � seems 
	almost to <I>force</I> programmers to use it whenever there is any doubt about 
	what the user should know. Is there a chance a user will perform an action in 
	error? Better get confirmation... Just pop up a <code>MessageBox()</code>! 
	&nbsp;I can't delete a file in the windows explorer without having to click 
	through at least one <code>MessageBox()</code>. Am I sure? But, the file is 
	executable... Am i <I>really</I> sure? But, it might affect registered 
	programs... Am&nbsp;I <I>really, <B>really</B></I> sure? ...&nbsp;If a check 
	box was provided to let you hide the message in the future... But that would 
	require extra effort, and there's this <B>ready to use, almost good enough</B> function 
	that will suffice...</P>
<P>But worse yet are programs that feel the need to inform you, after performing 
	an action that you <I>explicitly requested</I>, that the action has indeed been 
	performed, using � you guessed it � <code>MessageBox()</code>. Nothing wrong 
	with a little feedback, especially if the action had effects not necessarily 
	intuitive to first-time users, but to do it in a way that requires you to stop 
	what you're doing, (and what is sometimes worse, what the <I>program</I> is 
	doing) just to acknowledge it... That is not funny.
</P>
<h3>OK...</h3>
<P>Enough hypocritical griping however. Solutions do exist � creating message 
	boxes with check boxes or �yes to all� / �no to all� buttons is not difficult. 
	For the purpose of feedback, displaying a short message in a status bar will 
	often suffice, or possibly adding a log pane. But both of these options really 
	only work for the main window of an application, and have other drawbacks in 
	terms of visibility and screen real-estate as well.</P>
<P>With Windows 2000, Microsoft began a practice of using balloons (of the comic 
	strip dialog variety) for displaying messages from system tray icons. This 
	seems to work quite well; when I dial into the Internet, once the connection is 
	made, a small icon appears in the tray, along with a balloon giving details on 
	my connection speed. A <code>MessageBox()</code> here would be inexcusable, but 
	a balloon is small, unobtrusive, and does not require any action on my part. 
	After a few seconds, it quietly fades away. Windows XP provides this feature 
	for many more tray icons, from system updates to the activation reminder, 
	adding another feature to them in the form of a close button that will dismiss 
	the balloon instantly, in case I'm annoyed by it and don't want to wait for it 
	to time out. (Windows XP also uses similar balloons in other situations, but 
	that fits more in line with the general XP aping of MacOS...)</P>
<P>Note that balloons as described above are not ToolTips. ToolTips, also in use 
	by tray icons by the way, serve well in their current form: small unobtrusive 
	pieces of text that show up when you hover the mouse over a control, and 
	disappear immediately upon moving the mouse away. Anyone who has used 
	BalloonHelp on the MacOS (Ref: <A HREF="http://developer.apple.com/techpubs/mac/HIGuidelines/HIGuidelines-240.html">
		http://developer.apple.com/techpubs/mac/HIGuidelines/HIGuidelines-240.html</A>) 
	should know the advantages Microsoft's ToolTips have when used for this 
	purpose.
</P>
<P>With Internet Explorer 5 and later, Microsoft make the Balloon ToolTip style 
	available for general use (via the <code>TTS_BALLOON</code> style). But it is 
	not very simple to use, and of course not useable at all on systems without 
	IE5.
</P>
<h3>So get to the point already...</h3>
<P>The point of all this of course is that I've written an easy to use balloon 
	control. I stress easy to use: in order to convince myself and others to go 
	this way, I wanted it to be as easy to pop up a help balloon as popping up a <code>
		MessageBox()</code>.</P>
<h2><a name="Using">Using CBalloonHelp</a></h2>
<P>Add BalloonHelp.cpp and BalloonHelp.h in your project.</P>
<h2><a name="API">API</a></h2>
<h3><a name="API Important">The important stuff</a></h3>
<P>The easiest way to create a balloon is to use the LaunchBalloon() static 
	function:</P>
<pre>void CBalloonHelp::LaunchBalloon(const CString&amp; strTitle, 
                                 const CString&amp; strContent, 
      const CPoint&amp; ptAnchor, 
      LPCTSTR szIcon /*= IDI_EXCLAMATION*/
      unsigned int unOptions /*= unSHOW_CLOSE_BUTTON*/,
      CWnd* pParentWnd /*= NULL*/,
      const CString strURL /*= &quot;&quot;*/,
      unsigned int unTimeout /*= 10000*/)</pre>
<P>
	This will allocate a new <code>CBalloonHelp</code> object, create the window, 
	and show it. When the window closes, the <code>CBalloonHelp</code> object will 
	be deleted automatically. Parameters are as follows:</P>
<PRE>strTitle    |  Title of balloon
strContent  |  Content of balloon
ptAnchor    |  point tail of balloon  will  be &quot;anchor&quot;ed to.
               This is  in client coordinates if pParentWnd is given, 
               otherwise it is in screen coordinates.
szIcon      |  One of:
     IDI_APPLICATION
     IDI_INFORMATION IDI_ASTERISK (same)
     IDI_ERROR IDI_HAND (same)
     IDI_EXCLAMATION IDI_WARNING (same)
     IDI_QUESTION
     IDI_WINLOGO
unOptions   |  One or more of:
     unCLOSE_ON_LBUTTON_DOWN |  closes window on WM_LBUTTON_DOWN
     unCLOSE_ON_MBUTTON_DOWN |  closes window on WM_MBUTTON_DOWN
     unCLOSE_ON_RBUTTON_DOWN |  closes window on WM_RBUTTON_DOWN
     unCLOSE_ON_LBUTTON_UP   |  closes window on WM_LBUTTON_UP
     unCLOSE_ON_MBUTTON_UP   |  closes window on WM_MBUTTON_UP
     unCLOSE_ON_RBUTTON_UP   |  closes window on WM_RBUTTON_UP
     unCLOSE_ON_MOUSE_MOVE   |  closes window when user moves mouse 
                             |    past threshhold
     unCLOSE_ON_KEYPRESS     |  closes window on the next keypress message sent
                                  to this thread.
     unCLOSE_ON_ANYTHING     |  all of the above.
     unDELAY_CLOSE           |  when a user action triggers the close, 
                             |   begins timer.  closes when timer expires.
     unSHOW_CLOSE_BUTTON     |  shows close button in upper right
     unSHOW_INNER_SHADOW     |  draw inner shadow in balloon
     unSHOW_TOPMOST          |  place balloon above all other windows
     unDISABLE_XP_SHADOW     |  disable Windows XP's drop-shadow effect 
                             |   (overrides system and user settings)
     unDISABLE_FADE          |  disable the fade-in/fade-out effects 
                             |   (overrides system and user settings)
     unDISABLE_FADEIN        |  disable the fade-in effect
     unDISABLE_FADEOUT       |  disable the fade-out effect
pParentWnd  |  Parent window/anchor window.  If NULL, balloon will be anchored
               in screen coordinates, and owned by the application's main window.
strURL      |  If not empty, when the balloon is clicked ShellExecute() 
            |    will be called, with strURL passed in.
unTimeout   |  If not 0, balloon will automatically close after unTimeout 
            |    milliseconds.</PRE>
<h3><a name="API Use">Use:</a></h3>
<pre>CBalloonHelp::LaunchBalloon(&quot;BoogaBooga&quot;, 
     &quot;What the hell is \&quot;Booga Booga\&quot; supposed to mean, anyway?&quot;, 
     CPoint(0,0));

CBalloonHelp::LaunchBalloon(&quot;You are holding down the right mouse button!&quot;, 
     &quot;Blah&quot;, Cpoint(0,0), IDI_WARNING, 
      CballoonHelp::unCLOSE_ON_RBUTTON_UP|CBalloonHelp::unSHOW_INNER_SHADOW, 
                                          this, &quot;&quot;, 0);</pre>
<P>
	The first line above will show a balloon with the title �BoogaBooga� and 
	associated message anchored to the top left corner of the screen (point is in 
	screen coordinates). Ideally, you'd anchor it to something more meaningful, 
	such as the center of a control, or a status bar icon. The default options will 
	cause this balloon to disappear after 10 seconds, and to show the standard 
	information icon at top left, and a close button at top right.</P>
<P>The second line above will show a balloon, this time anchored to the top left 
	corner of the window represented by <code>this</code>, this time with the 
	standard warning icon. The CBalloonHelp::unCLOSE_ON_RBUTTON_UP option will 
	cause it to be destroyed when the right mouse button is released � if a mouse 
	button is being held down, then mouse input is captured, so the balloon will 
	close whenever the right mouse button is released. If no mouse button is held 
	down, the user will have to release the right mouse button somewhere in a 
	window owned by the same thread in order for it to close. The 
	CballoonHelp::unSHOW_INNER_SHADOW option will cause the balloon to be drawn 
	with an inner hilight and shadow... Not all that interesting, but if you're not 
	running on Windows XP, it's the only shadow you can get.</P>
<P>It is also possible to create a balloon using the Create() function, in which 
	case you can opt not to have the object automatically deleted when the window 
	closes (the LaunchBalloon() function always adds the option 
	CBalloonHelp::unDELETE_THIS_ON_CLOSE to force this, but it may not be desirable 
	if, for instance, you allocate a CBalloonHelp object from the stack). This 
	function gives much greater potential for customization as well (see below for 
	more info).</P>
<h3>Complete API</h3>
<pre><a name="API Create"></a>BOOL CBalloonHelp::Create(const CString&amp; strTitle, 
               const CString&amp; strContent, 
               const CPoint&amp; ptAnchor, unsigned int unOptions,
               CWnd* pParentWnd /*=NULL*/,
               const CString strURL /*= &quot;&quot;*/,
               unsigned int unTimeout /*= 0*/,
               HICON hIcon /*= NULL*/);
      </pre>
<p>This will create and display a balloon window. Title and content override any 
	set for the object prior to this call. <code>ptAnchor</code> indicates anchor 
	location in screen coordinates. <code>unOptions</code> should be a combination 
	of one or more of the following:
</p>
<pre>CBalloonHelp::unCLOSE_ON_LBUTTON_DOWN //  closes window on WM_LBUTTON_DOWN
CBalloonHelp::unCLOSE_ON_MBUTTON_DOWN //  closes window on WM_MBUTTON_DOWN
CBalloonHelp::unCLOSE_ON_RBUTTON_DOWN //  closes window on WM_RBUTTON_DOWN
CBalloonHelp::unCLOSE_ON_LBUTTON_UP   //  closes window on WM_LBUTTON_UP
CBalloonHelp::unCLOSE_ON_MBUTTON_UP   //  closes window on WM_MBUTTON_UP
CBalloonHelp::unCLOSE_ON_RBUTTON_UP   //  closes window on WM_RBUTTON_UP
CBalloonHelp::unCLOSE_ON_RBUTTON_UP   //  closes window on WM_RBUTTON_UP
CBalloonHelp::unCLOSE_ON_MOUSE_MOVE   //  closes window when user moves mouse past 
                                      //  threshhold
CBalloonHelp::unCLOSE_ON_KEYPRESS     //  closes window on the next keypress message sent
                                      //  to this thread.
CBalloonHelp::unCLOSE_ON_ANYTHING;    //  all of the above
CBalloonHelp::unDELAY_CLOSE;          //  when a user action triggers the close, 
                                      //  begins timer.  closes when timer expires.
CBalloonHelp::unDELETE_THIS_ON_CLOSE  //  deletes object when window is closed.  Used by 
                                      //  LaunchBalloon(), use with care
CBalloonHelp::unSHOW_CLOSE_BUTTON     //  shows close button in upper right
CBalloonHelp::unSHOW_INNER_SHADOW     //  draw inner shadow in balloon
CBalloonHelp::unSHOW_TOPMOST          //  place balloon above all other windows
CBalloonHelp::unDISABLE_XP_SHADOW;    //  disable Windows XP's drop-shadow effect 
                                      //  (overrides system and user settings)
CBalloonHelp::unDISABLE_FADE          //  disable the fade-in/fade-out effects 
                                      //  (overrides system and user settings)
CBalloonHelp::unDISABLE_FADEIN        //  disable the fade-in effect
CBalloonHelp::unDISABLE_FADEOUT       //  disable the fade-out effect
      </pre>
<p>
	If <code>pParentWnd</code> is <code>NULL</code>, the balloon will be anchored 
	in screen coordinates, and owned by the application's main window (<code>AfxGetMainWnd())</code>. 
	If there is no main window, and <code>pParentWnd</code> is <code>NULL</code>, 
	creation will fail. <code>strURL</code> if not empty will be passed to <code>ShellExecute()</code>
	when the balloon is clicked. If not 0, <code>unTimeout</code> specifies the 
	time in milliseconds until the balloon closes automatically. And <code>hIcon</code>
	if not NULL specifies the icon shown in the upper left corner of the balloon; 
	it is copied on creation, so the icon can safely be destroyed after <code>Create()</code>
	returns.
</p>
<pre><a name="API SetAnchorPoint"></a>      void CBalloonHelp::SetAnchorPoint(CPoint ptAnchor, CWnd* pWndAnchor = NULL);      </pre>
<p>Sets the point to which the balloon is anchored (the point the balloon's tail 
	attaches to). Calling this before the balloon is created has no effect, since 
	the anchor is a required parameter of <code>Create()</code>. If <code>pWndAnchor</code>
	is <code>NULL</code>, <code>ptAnchor</code> is assumed to be in screen 
	coordinates, otherwise it is assumed to be relative to the client area of <code>pWndAnchor</code>
</p>
<pre><a name="API SetBackgroundColor"></a>      void CBalloonHelp::SetBackgroundColor(COLORREF crBackground);</pre>
<p>Sets the background color of the balloon. Can be called before or after the 
	balloon is created.
</p>
<pre><a name="API SetForegroundColor"></a>      void CBalloonHelp::SetForegroundColor(COLORREF crForeground);</pre>
<p>Sets the foreground (borders &amp; text) color of the balloon. Can be called 
	before or after the balloon is created.
</p>
<pre><a name="API SetTitle"></a>      void CBalloonHelp::SetTitle(const CString&amp; strTitle);</pre>
<p>Sets the title of the balloon. Can be called before or after the balloon is 
	created.
</p>
<pre><a name="API SetContent"></a>      void CBalloonHelp::SetContent(const CString&amp; strContent);</pre>
<p>Sets the content of the balloon. Can be called before or after the balloon is 
	created.
</p>
<pre><a name="API SetTitleFont"></a>      void CBalloonHelp::SetTitleFont(CFont* pFont);</pre>
<p>Sets the font used to draw the title of the balloon. Can be called before or 
	after the balloon is created. The font and the CFont object are stored and 
	eventually deleted by the balloon; do not use either after calling this 
	function.
</p>
<pre><a name="API SetContentFont"></a>      void CBalloonHelp::SetContentFont(CFont* pFont);    </pre>
<p>Sets the font used to draw the contents of the balloon. Can be called before or 
	after the balloon is created. If this is called before creation, and the title 
	font is not explicitly set (via <code>SetTitleFont()</code>) then a bold 
	version of this font is used for the title (even if this font is already bold). 
	The font and the CFont object are stored and eventually deleted by the balloon; 
	do not use either after calling this function.
</p>
<pre><a name="API SetURL"></a>      void CBalloonHelp::SetURL(const CString&amp; strURL);    </pre>
<p>Sets the URL or file to be opened by the balloon when clicked. Set to "" to 
	disable. Can be called before or after the balloon is created.
</p>
<pre><a name="API SetIcon"></a>      void CBalloonHelp::SetIcon(HICON hIcon);    </pre>
<p>Sets the icon shown at the top left of the balloon. Pass in NULL to show no 
	icon. Icon will not be scaled. Can be called before or after the balloon is 
	created.
</p>
<pre>      void CBalloonHelp::SetIcon(HBITMAP hBitmap, COLORREF crMask);
      </pre>
<p>Sets the icon shown at the top left of the balloon. <code>crMask</code> indicates 
	transparent color. Pass in NULL for <code>hBitmap</code> to show no icon. Icon 
	will not be scaled. Can be called before or after the balloon is created.
</p>
<pre>      void CBalloonHelp::SetIcon(HBITMAP hBitmap, HBITMAP hMask);</pre>
<p>Sets the icon shown at the top left of the balloon. <code>hMask</code> indicates 
	the transparent areas. Both parameters must be valid. Icon will not be scaled. 
	Can be called before or after the balloon is created.
</p>
<pre>      void CBalloonHelp::SetIcon(CImageList* pImageList, int nIconIndex);</pre>
<p>Sets the icon shown at the top left of the balloon. <code>nIconIndex</code> indicates 
	image to use. Both parameters must be valid. Icon will not be scaled. Can be 
	called before or after the balloon is created.
</p>
<pre><a name="API LaunchBalloon"></a>void CBalloonHelp::LaunchBalloon(const CString&amp; strTitle, 
               const CString&amp; strContent,&nbsp;
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; const CPoint&amp; ptAnchor,&nbsp;
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LPCTSTR szIcon /*= IDI_EXCLAMATION*/,
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; unsigned int unOptions /*= unSHOW_CLOSE_BUTTON*/,
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; CWnd* pParentWnd /*= NULL*/,
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; const CString strURL /*= &quot;&quot;*/,
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; unsigned int unTimeout /*= 10000*/)</pre>
<p>Creates and shows a balloon. This is a static function, so calling this on an 
	instance of CBalloonHelp is not too useful. If you need more control, create a 
	derived class, or use <code>Create()</code> and associated property functions. 
	See <a href="#API Use">Use</a> for more information.
</p>
<h2><a name="Features">Features</a></h2>
<UL>
	<LI>
	Easy to use interface.
	<LI>
	Adjusts position depending on anchor position; window will always be completely 
	visible, assuming content size is less than screen size.
	<LI>
	Uses translucency effects if available.
	<LI>
		Uses drop-shadow effect if available.</LI>
</UL>
<h2><a name="Compatibility">Compatibility</a></h2>
<P>Tested on Windows XP, 2000, 98, and 95</P>
<P>Compiles with VC++ 6.0 / MFC 6 and VC++.NET / MFC 7</P>
<h2><a name="Internals">Internals</a></h2>
<P><code>CBalloonHelp</code> is an MFC class, derived from <code>CWnd</code>. The 
	first time a balloon is created, a window class named �BalloonHelpClass� is 
	registered. First, a window class with the <code>CS_DROPSHADOW</code> style is 
	registered; if registration fails, the style is removed, and registration is 
	attempted again. This allows use of the style on Windows XP, while avoiding 
	problems on previous versions of Windows.
</P>
<P>The window is created hidden, and then the size of the content and title are 
	calculated. Margins and space for the tail are added to this, and the window is 
	sized and positioned relative to the anchor point. Finally, the window region 
	is set and the window is shown.</P>
<P>Tip: when doing shaped windows, put the shaped bits in the non-client area; 
	it's a <I>lot</I> easier to deal with if you don't have to account for that 
	stuff when dealing with drawing the client area.</P>
<P><code>AnimateWindow()</code> is used for the fade-in/fade-out effects if 
	available and requested.</P>
<p>Messsage hooks are used to determine when closing mouse actions occur.</p>
<p>Andrew Nosenko's CAuxThunk implementation (renamed to _ThunkImpl) is used for 
	implementing message hooks.</p>
<h2><a name="Updates">Updates</a></h2>
<p>8/2/02
	<ul>
		<li>
			Fixed bug in demo where div by zero balloon would be shown at wrong position.</li>
		<li>
			Fixed bug where deallocated memory was accessed when using the strURL parameter 
			to open a file or location when the balloon was clicked.</li>
		<li>
			Added option: <code>CBalloonHelp::unDELAY_CLOSE</code>.</li>
		<li>
			Added option: <code>CBalloonHelp::unDISABLE_XP_SHADOW</code>.</li>
	</ul>
</p>
<p>5/30/02
	<ul>
		<li>
		Posted Maximilian H�nel's WTL port.
		<li>
		Release #2 (arbitrary number, but needed something)
		<li>
		Added support for multiple monitors
		<li>
		Added support for closing on WM_*BUTTON_DOWN messages.
		<li>
		Added support for anchoring to windows (move with parent).
		<li>
			Reworked message hook code, taken mostly from Max's WTL port.</li>
	</ul>
<p>1/23/02
	<ul>
		<li>
			Posted Fil Mackay's ATL port</li>
	</ul>
<p>12/31/01
	<ul>
		<li>
		Changed utilization of transparency (again), hopefully this will workaround 
		problems with Win2k
		<li>
		Altered border calculation code slightly
		<li>
			Fixed bug where no title would cause balloon to be full screen sized.</li>
	</ul>
<p>12/21/01
	<ul>
		<li>
		Expanded API to allow greater customization
		<li>
		Added example of balloon created manually that moves with parent window
		<li>
		Implemented keyboard hooks to allow close-on-keypress
		<li>
		Separate flags to disable fade-in/fade-out
		<li>
			Smooth scaling of small icons used for <code>LauchBalloon()</code>
		(on Win2k/XP only)
		<li>
			Misc. code cleanup.</li>
	</ul>
<p>12/12/01
	<ul>
		<li>
		Fixed bug with mouse not being released until fade-out had completed.
		<li>
		Added option for disabling fade effects; this is forced if the user has 
		disabled them via the control panel.
		<li>
			Added option for making balloons topmost windows.</li>
	</ul>
	<h2><a name="Links">Related Articles</a></h2>
	<ul>
		<LI>
			<A href="http://www.codeproject.com/useritems/xinfotip.asp">CXInfoTip - 
				Information Tooltip <i>Mark Bozeman</i></A>
		<LI>
			<A href="http://www.codeproject.com/useritems/message_balloons.asp">Message 
				Balloons <i>Prateek Kaul</i></A>
		<li>
			<a href="http://www.codeproject.com/library/classlib.asp">ClassLib, A C++ class 
				library <i>Jan van den Baard</i></a>
		<LI>
			<A href="http://www.codeproject.com/shell/systemtray.asp">Adding Icons to the 
				System Tray <i>Chris Maunder</i></A>
		(this one is on a different topic, but uses the Windows shell's tooltip 
		functionality available in Windows 2000 and later)
		<LI>
			<A href="http://www.codeproject.com/gdi/rgncreator.asp">The RGN Generator <i>Richard 
					de Oude</i></A>
		(information on using regions to create shaped windows)
		<LI>
			<A href="http://www.codeproject.com/gdi/holes.asp">Creating holes in a window <i>Amir 
					Salzbe</i></A> (same as above, but a bit simpler.)<BR>
		</LI>
	</ul>
	<h2><a name="TODO">TODO</a></h2>
<P>Clean up code a bit... most of it is pretty straight forward, but documentation 
	could be better.</P>
<P>Move to straight Win32, not MFC derived class.</P>
<p>Add better code walkthrough to this article.</p>
<h2><a name="Thanks">Thanks...</a></h2>
<p>...Jan van den Baard for showing me the right way to use AnimateWindow(), and 
	for demonstrating how <code>WM_NCHITTEST</code> can be used to provide hot 
	tracking. Check out his <a href="http://www.codeproject.com/library/classlib.asp">ClassLib</a>
	library on CP!</p>
<p>...Maximilian H�nel for his WTL port, and for demonstrating therein a nicer way 
	to handle message hooks.</p>
<p>...To all the people who've provided feedback, positive and negative. It all 
	helps.</p>
<p>...To Mustafa Demirhan, for his suggestion and information on using keyboard 
	hooks.</p>
<p>...To The Code Project, for providing a useable forum for all of us.</p>
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Shog9
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