BUG: WhatsThisHelpID on Toolbar Does Not Function as Expected

ID: Q197027

The information in this article applies to:

Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a, 6.0

SUMMARY

MORE INFORMATION

The following file is available for download from the Microsoft Software Library:

WTHelp.exe

Release Date: Dec-09-1998

For more information about downloading files from the Microsoft Software Library, please see the following article in the Microsoft Knowledge Base:

Q119591 How to Obtain Microsoft Support Files from Online Services


  File Name               Size
   ---------------------------------------------------------

   Readme.txt               10,324 bytes
   Help2.bmp                 1,318 bytes
   Whatthis.hlp             13,660 bytes
   Whatthis.hpj                631 bytes
   Whatthis.rtf             18,902 bytes
   WhatsThisHelp.vcx         2,122 bytes
   WhatsThisHelp.vct         1,910 bytes
   WhatsThis.scx             2,014 bytes
   WhatsThis.sct            10,980 bytes

NOTE: Four of these files ship with Visual FoxPro.

To work with the sample files, extract them into a directory of your choice and set the Visual FoxPro default to the directory you choose.

Help2.bmp is one of the sample graphics files found in the ...\Graphics\Bitmaps\TlBr_W95 folder in the VFP\Samples folder with Visual FoxPro 5.x or in the Common folder for Visual Studio or Visual FoxPro 6.0.

The three files, Whatthis.hlp, Whatthis.hpj and Whatthis.rtf, are a sample Windows Help file, the Help project file, and the Help text source rich text file. These files ship with Visual FoxPro and are found in the ...\Solution\Forms folder, which is found in the VFP\Samples folder with Visual FoxPro 5.x or the Visual Studio\MSDN98\98vs\1033\Samples\VFP98 folder with Visual Studio 6.0. These files have not been modified and are included to provide a sample Help file with WhatsThisHelp ID numbers. The Help text in this Help file does not match the controls on the sample form included herein. This is just an illustration.

The remaining files listed in the previous table were created for this sample.

The WhatsThisHelp.vcx and .vct files are a visual class library that contains the toolbar class definition that is used with the sample form.

The sample form files are WhatsThis.scx and .sct.

Working with the Sample Form

To see the problem and the workaround, run the WhatsThis.scx form. Follow these steps when the form is running:

Click WhatsThisHelp on the form (it is the button in the top-right corner with the "?" on it).

Click on any of the objects on the form (even the form itself). Repeat this until you have tested all the objects.

The form should display the following WhatsThisHelp topic for the CustomerID from the Help file:
Contains a unique identifier for each customer. The ID is the first five letters of the Company name.
Note that Quit displays the following:
No Help topic is associated with this item.
The check box displays the Help topic for the Company. The other command button displays the Help topic for the City.

Now test all the objects on the toolbar. Click WhatsThisHelp on the form, and click on each the toolbar button. The WhatsThisHelp topic for the form (Customer ID) appears. The toolbar objects display whatever WhatsThisHelp topic is set for the form.

Try the workaround by clicking the simulated WhatsThisHelp button on the toolbar. It has a "?" and a mouse pointer on it. Click on the Close button (it is the button in the top-right corner with the "x" on it). There is no WhatsThisHelp topic associated with this button. Next, click the simulated WhatsThisHelp button, and click the button with the 4 on it. Be careful not to let the mouse pointer move over the ToolButton with the 5 on it. Finally, click the simulated WhatsThisHelp button and move the mouse pointer over the ToolButton with the 5 on it. Notice that clicking on this button is not necessary for the WhatsThisHelp topic to appear. The buttons have a 4 and a 5 on them because this is the WhatsThisHelpID assigned to them. The 5 is the Address Help topic, the 4 is the Title Help topic. Note that these buttons also have ToolTips and WAIT WINDOW commands in their click events.

Note that when you click the simulated WhatsThisHelp button on the toolbar, clicking on the form has no effect and resets the button. If you press the ESC key and the simulated WhatsThisHelp button simultaneously, clicking on the form also has no effect and resets the button. However, if you click on either command button or the check box, the WhatsThisHelp topic appears. These objects could also be set to behave in the same manner as the form when you use the simulated WhatsThisHelp button on the toolbar. They were made to function the same way under either the form's WhatsThisHelp button or the button on the toolbar to illustrate that it was possible. Note that the background of the check box does not refresh properly. This might be a drawback.

The Sample Code

The key code in the sample that enables you to call the proper WhatsThisHelp topic for the toolbar buttons is in either the MouseDown or MouseMove events for the toolbar buttons. The ToolButton with the caption of 5 has the code in the MouseMove. The ToolButton with the caption of 4 and the buttons on the form have the code in the MouseDown event. Placing the code in the MouseMove event is easier to implement, but it does not have the same functionality as the real WhatsThisHelp button. The code is as follows:


   LPARAMETERS nButton, nShift, nXCoord, nYCoord
   IF !This.Parent.Command4.Enabled AND nButton=1
      This.Parent.WhatsThisHelpID=This.WhatsThisHelpID
      This.Parent.ShowWhatsThis
      This.Parent.Command4.Enabled=.T.
   ELSE
      IF nButton=1
         This.Click
      ENDIF
   ENDIF

You do not need the ELSE portion of the IF...ENDIF block if you are using the MouseMove event.

When the user clicks the simulated WhatsThisHelp button on the toolbar, it is disabled. Then, when the user click the toolbar button, the MouseDown event fires, which checks to see if the simulated WhatsThisHelp button is disabled and if the user used the left mouse button. If so, the WhatsThisHelpID of the toolbar is set to the WhatsThisHelpID of the toolbar button that was clicked. Following this, the ShowWhatsThis method of the toolbar is called to display the WhatsThisHelpID that is assigned to the toolbar. The NODEFAULT keyword has been placed in the MouseUp event to prevent the ToolButton's click event from firing. Therefore, when you do not want the WhatThisHelp, the MouseDown has to call the click event. In the code above, this only happens if the user uses the left mouse button. This is not necessary when the WhatsThisHelp is called from the MouseMove event.

Similar code is required in the MouseDown and MouseUp events of the objects on the form to allow them to work with the simulated WhatsThisHelp button on the toolbar.

In addition, the WhatsThisHelp button on the form cancels if the user presses the ESC key. This has also been implemented in the simulated WhatsThisHelp button on the toolbar. To do this, the ESC key needs to be trapped on the form. In the click method of the simulated WhatsThisHelp button, the form's KeyPreview property is set to true(.T.). The following code is in the KeyPress event of the form:


   IF !Thisformset.WhatsThisBar1.Command4.Enabled
      NODEFAULT
   ENDIF

   IF nKeyCode=27
      Thisformset.WhatsThisBar1.Command4.Enabled=.T.
      This.KeyPreview=.F.
   ENDIF

This code checks to see if the user depressed the simulated WhatsThisHelp button on the toolbar. If so, default KeyPress actions are disabled with NODEFAULT. Note that you cannot press the SPACEBAR to fire the Quit button's click event and quit the form. Next, the nKeyCode is checked to see if the user pressed the ESC key. If so, the simulated WhatsThisHelp button is re-enabled and the form's KeyPreview property is set back to false(.F.).

The Click event of the form has been programmed to behave differently if the user uses the simulated WhatsThisHelp button on the toolbar instead of the WhatsThisHelp button on the form. The following code is in the MouseDown event of the form to reset the simulated WhatsThisHelp button:


   IF !This.parent.WhatsThisBar1.Command4.Enabled
      This.parent.WhatsThisBar1.Command4.Enabled=.T.
   ENDIF

You could place this code in the MouseDown event of any of the objects on the form so that WhatsThisHelp would not be available to the objects if the user presses the simulated WhatsThisHelp button on the toolbar.

The WhatsThisHelpIDs for the Help file topics are in the Whatthis.hpj file. You can open this file in Notepad or Visual FoxPro (MODIFY FILE whatthis.hpj). Look in the [MAP] section for the ID numbers.

The following table lists all the objects in the formset and the settings for the WhatsThisHelpID:


   Object                      WhatsThisHelpID
   ------------------------------------------------------------------------
   Form1                         1 - CustomerID
   Command1                     -1 - nothing
   Command2                      6 - City
   Check1                        2 - Company
   WhatsThisBar1                -1 - nothing
   Command1(on toolbar)          4 - Title
   Command2(on toolbar)          5 - Address
   Command3(on toolbar)         -1 - nothing
   Command4(on toolbar)         -1 - nothing, its the WhatsThisHelp button

SYMPTOMS

The WhatsThisHelpID property of the command buttons on a toolbar is ignored when you use the WhatsThisHelp button on a form to get "What's This Help" for objects on the form.

RESOLUTION

To work around this, you can place a WhatsThisHelp button on the toolbar to provide "What's This Help" for the buttons on the toolbar. WTHelp.exe contains a sample form with a toolbar to illustrate this workaround.

WTHelp.exe is a sample that demonstrates a workaround for the WhatsThisHelpID property of objects on a toolbar that are ignored when you use the WhatsThisHelp button on a form.

Additional query words:

Keywords : kbfile kbsample kbOOP kbVFp500abug kbVFp600bug
Version : WINDOWS:5.0,5.0a,6.0
Platform : WINDOWS
Issue type : kbbug