5.3.1 Registration and Usage of Controls

You need to register new controls in the grid object (with CGXGridCore::RegisterControl) before using them as cell controls. You do this using a string resource identifier at run time. The name of the registered control will be displayed in the list box of the Controls page in the pre-built CGXStyleSheet dialog. It is not necessary to register existing Objective Grid controls. They are registered by the control factory as needed.

Follow these steps to register a control:

1. Add a string resource using Visual Studio Resource View by opening the string table in the resource file and adding your custom string resource. Your .RC - file will change accordingly:

   STRINGTABLE DISCARDABLE BEGIN IDS_CTRL_BITMAP "Welcome bitmap" END

2. In OnInitialUpdate(), pass a new instance of the object as well as the string resource ID to RegisterControl().

   void CGridSampleView::OnInitialUpdate() { ... RegisterControl(IDS_CTRL_BITMAP, new CGXBitmapButton(this, IDB_WELCOME)); }

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   If you are registering a control derived from an existing Objective Grid control, you should check the control factory code for creation information. Some built-in controls simply need to be constructed while others require additional steps. The control creation code is in the CGXControlFactory::CreateControl() method in gxfactry.cpp.

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   // Snippet from gxfactry.cpp. This code demonstrates // the steps necessary when creating an instance of // CGXMaskControl case GX_IDS_CTRL_MASKEDIT: CGXMaskControl* pEditCtrl = new CGXMaskControl(pGrid, GX_IDS_CTRL_MASKEDIT); pEditCtrl->CreateControl(); pControl = pEditCtrl; break; // In contrast, here's the code necessary to create an // instance of CGXEditControl case GX_IDS_CTRL_EDIT: // default edit box pControl = new CGXEditControl(pGrid, GX_IDS_CTRL_EDIT); break;

3. Now, apply the control to any cell in the grid with CGXStyle::SetControl().

   // Display the welcome bitmap SetStyleRange(CGXRange(3, 2), CGXStyle() .SetControl(IDS_CTRL_BITMAP));