Important Notes for Visual C++ Users

To use FlowChartX in Visual C++ version 6.0 follow these steps:

Open "Project\Add To Project\Component and Controls" menu
Open "Registered ActiveX Controls" folder
Choose "FlowChartX Control 1.0" from the list and click Insert
From "Confirm Classes" dialog box select all available classes and click OK

The wizard generates C++ wrapper classes for the objects from FlowChartX type library and an item for the control is added to "Controls toolbox". Now you can start using the control.

Note Note
In Visual C++ 7.0 there is a problem importing ActiveX controls in general and FlowChartX particularly: unlike version 6 importing the control through MFC wizard will not generate wrapper classes for the whole FlowChartX object hierarchy. If you use the "Add class from ActiveX control" wizard it will generate a class just for the FlowChart object, but not for Box, Arrow, Boxes and Arrows collections. Respectively "Add class from Type Library" wizard generates a class for all FlowChartX objects but with faults - FlowChartX properties and methods' parameters that are object references are declared as LPDISPATCH instead of CBoxItem, CArrowItem, CBoxes or CArrows as in Visual C++ 6.0.

Note
In Visual C++ 7.0 there is a problem importing ActiveX controls in general and FlowChartX particularly: unlike version 6 importing the control through MFC wizard will not generate wrapper classes for the whole FlowChartX object hierarchy. If you use the "Add class from ActiveX control" wizard it will generate a class just for the FlowChart object, but not for Box, Arrow, Boxes and Arrows collections. Respectively "Add class from Type Library" wizard generates a class for all FlowChartX objects but with faults - FlowChartX properties and methods' parameters that are object references are declared as LPDISPATCH instead of CBoxItem, CArrowItem, CBoxes or CArrows as in Visual C++ 6.0.

In order to help you workaround these problems we have included in FlowChartX installation the control wrapper classes as generated by Visual C++ 6. You can find them in "MFC wrapper" subfolder in your root installation folder. Following steps describe how to use them in Visual C++ 7.0 projects:

Open "Dialog editor"
From Toolbox context menu choose "Customize…"
Add FlowChartX control 1.0
Drag the new FlowChartX object that has appeared in Toolbox to the form
Right-click it and choose "Add variable" from the context menu
Name the MFC wrapper class CFlowChart and its files - flowchart.h and flowchart.cpp
Copy all files from "MFC wrapper" folder to your project folder, overwriting flowchart.h and flowchart.cpp
From "Project->Add Existing Item..." add all the files to your project.

You can also use these files in Visual C++ 6.0, since we have manually added the enumeration constants. SetPolyShape is fixed too because it was not correctly imported by Visual C++ 6.0 due to parameter type conversion error.

Event handling

Remember to pay special attention to event handling in all Visual C++ versions. Event methods that receive as parameter reference to a box, table or arrow object should not change its reference count. Still the COleDispatchDriver-derived wrapper classes by default call the attached COM object Release function in their destructor, which decreases the reference count. As a result the count might go to zero and the item be destroyed unexpectedly. To avoid this, either set the wrapper object m_bAutoRelease member to FALSE, or call Detach method before the object goes out of scope:

C++ Copy Code
void App::OnTableCreated(LPDISPATCH pTableItem)
{
    TableItem table = pTableItem;

    table.SetCellBorders(cbNone);
    table.DetachDispatch();
}

C++ Copy Code
void App::OnTableCreated(LPDISPATCH pTableItem) { TableItem table = pTableItem; table.SetCellBorders(cbNone); table.DetachDispatch(); }

Validation events and MFC wizard-generated handler prototypes

All Request* validation events have a VARIANT_BOOL output pointer argument, but the event wizard erroneously declares that argument as a pointer to BOOL. Size of the VARIANT_BOOL type is 2 bytes, and that of BOOL is 4 bytes. Assigning a BOOL TRUE or FALSE constant value directly to the output argument would cause a big mess in the stack, potentially overwriting the method return address or local variables of other methods. To work-around that, cast the argument to VARIANT_BOOL pointer and assign VARIANT_TRUE or VARIANT_FALSE values as shown below:

C++ Copy Code
void CTreeLayoutDlg::RequestSelectArrow(LPDISPATCH arrow, BOOL* pbSelect)
{
    // NOTE: the event wizard erroneously declares pbSelect as BOOL*;
    // pbSelect is pointing to VARIANT_BOOL, which is 2 bytes long, e.g. short;
    // setting it to BOOL FALSE (4 bytes) would cause a big mess in the stack
    *(VARIANT_BOOL*)pbSelect = VARIANT_FALSE;
}

C++ Copy Code
void CTreeLayoutDlg::RequestSelectArrow(LPDISPATCH arrow, BOOL* pbSelect) { // NOTE: the event wizard erroneously declares pbSelect as BOOL; // pbSelect is pointing to VARIANT_BOOL, which is 2 bytes long, e.g. short; // setting it to BOOL FALSE (4 bytes) would cause a big mess in the stack (VARIANT_BOOL*)pbSelect = VARIANT_FALSE; }

#import

The #import compiler directive works fine in both versions of Visual C++ and imports the whole object hierarchy. It will generate smart pointers for the FlowChartX objects but it's harder to use them in a MFC application because FlowChartPtr object is not derived from CWnd. Anyway if you develop C++ application without using the MFC library then #import is your best choice.