Hyperion Entertainment Message Boards

Posted: **Thu Feb 11, 2016 5:52 pm**

What is the message structure GM_HANDLESCROLL receives in a BOOPSI class dispatcher ?

Posted: **Thu Feb 11, 2016 7:06 pm**

Same as GM_HANDLEINPUT GM_GOACTIVE etc

Posted: **Thu Feb 11, 2016 8:38 pm**

So it's struct gpInput. But how do I get how much wheel was rotated and to which direction ?

Posted: **Thu Feb 11, 2016 11:10 pm**

Is that the best way to do it?

I use the IDCMP Hook function and collect IDCMP_EXTENDEDMOUSE messages. They appear as a struct IntuiMsg, which gives the data like this:

Code: Select all

		case	IDCMP_EXTENDEDMOUSE:
			code = intuiMsg->Code;
			qual = intuiMsg->Qualifier;

		//	check that mouse is over the window and ignore if not
			if ((intuiMsg->MouseX < 0) ||
				(intuiMsg->MouseX > win->Window->Width) ||
				(intuiMsg->MouseY < 0) ||
				(intuiMsg->MouseY > win->Window->Height))
			{
				break;
			}
			wheelData = (struct IntuiWheelData *)intuiMsg->IAddress;

			if ((code == IMSGCODE_INTUIWHEELDATA) && (wheelData != NULL))
			{
				deltaY = wheelData->WheelY;
			}
(etc)

Posted: **Fri Feb 12, 2016 2:00 pm**

TSK wrote:So it's struct gpInput. But how do I get how much wheel was rotated and to which direction ?

Heres an incomplete fragment from a HandleInpt function.that should give a hint as to how to procede.

Code: Select all

		switch(gpi->gpi_IEvent->ie_Class)
		{
#if defined(__amigaos4__)
			case IECLASS_MOUSEWHEEL:
				{
							if(gpi->gpi_IEvent->ie_Qualifier & (IEQUALIFIER_RSHIFT | IEQUALIFIER_LSHIFT))
							{
								igd->igd_Top += gpi->gpi_IEvent->ie_Y *  ((struct Gadget *)o)->Height;
							}
							else
							{
								igd->igd_Top += gpi->gpi_IEvent->ie_Y * 8;
							}
							if(igd->igd_Top < 0)
							{
								igd->igd_Top = 0;
							}
							if(igd->igd_Top + ((struct Gadget *)o)->Height > igd->igd_Height)
							{
								igd->igd_Top = igd->igd_Height - ((struct Gadget *)o)->Height; 
							}

						}
					}
					retval = GMR_MEACTIVE;
				}
				break;
#endif

Posted: **Fri Feb 12, 2016 2:03 pm**

tonyw wrote:Is that the best way to do it?

Definetly if you need to write a gadget that supports scrolling via the mouse wheel when being hovered over and not actually the active gadget.

If you are writing an app that needs to scroll an area independant of mouse posistion, then you way is good too.

Posted: **Fri Feb 12, 2016 5:10 pm**

@broadblues, tonyw

I got it working. I forgot I had the related code in my input handler already.

Thanks both of you !

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(Solved) Message structure of GM_HANDLESCROLL ?

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