OriginObject::GetEventHandler

GetEventHandler

1 Description
2 Syntax
3 Parameters
4 Return
5 Examples
6 Remark
7 See Also
8 Header to Include

Description

Get the event handler class name if present

Syntax

string GetEventHandler( BOOL bCheckValid = false, BOOL bDeafult = FALSE )

Parameters

bCheckValid: [input] TRUE will check to see if class name represents a compiled Origin C class that is registered with the OC_REGISTERED keyword
bDeafult: [input] TRUE will return an internal deafult name, of no name has been set using SetEventHandler

Return

If bCheckValid = [input] false, simply return the class name or empty string if no event handler was installed.

If bCheckValid = [input] true, then only return the class name if it is valid.

Examples

EX1

this example shows how to use SetEventHandler and GetEventHandler to show a menu after right-click on a rectangle in a graph, so please make sure the active graph layer has a rectangle named "Rect"

#include <Origin.h>
#include <control.h>
#include <..\OriginLab\OriginEvents.h>
   
// The following code installs an Event Handler class called MyEvent into a rectangle named "Rect" in active graph layer

// MyEvent is a class to trap right-click on GraphObject
// You can create your own class and install it into origin object that require customized event handling.
// Make sure your class is based on OriginEventsBase.
class OC_REGISTERED MyEvent : public OriginEventsBase
{
public:
        //show a test menu
        virtual bool OnContextMenu(int x, int y, DWORD dwControl = 0)
        {
                Menu muMenu;
                muMenu.Add(_L("test menu"), 1, MF_STRING); 
                
                int        nSelCmd;
                muMenu.TrackPopupMenu(0, x, y, GetWindow(), &nSelCmd);
                return true;
        }
        
        virtual    bool SetObj(OriginObject& obj) //obj with the Event Handler
        {
                m_Object = obj;
                
                if( m_Object )
                        return true;
                
                return false;
        }
        
protected:    
        GraphObject             m_Object; 
};

//set an Event Handler to the Rect object.
//then you can right on the rect to see the test menu
void OriginObject_SetEventHandler_Ex1()
{
    GraphLayer lay = Project.ActiveLayer();
    
    //get the Rect object on the graph
    GraphObject goMe;
    if(lay)
        goMe = lay.GraphObjects("Rect");
    
    if(goMe)
        goMe.SetEventHandler("MyEvent"); //event class name
}

//Get the event handler class name
//run this function to show the test menu
void OriginObject_GetEventHandler_Ex1()
{
    GraphLayer lay = Project.ActiveLayer();
    
    //get the Rect object on the graph
    GraphObject goMe;
    if(lay)
        goMe = lay.GraphObjects("Rect");
    
    if(goMe)
    {
        //use the event handler class name to get the event class to show test menu
        string strClassName = goMe.GetEventHandler(true);
        if(!strClassName.IsEmpty())
                {
                        MyEvent& event = (MyEvent&)Project.FindClass(strClassName);
                        if(event)
                        {
                                out_str("Found handler, invoking context menu");
                                
                                int x = 500;
                                int y = 500;
                                event.OnContextMenu(x, y); 
                        }
                }
    }
}