2.2.4.32.16 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); 
			}
		}
    }
}