Databrowser scroll wheel support in PP application

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Kent Sorensen - 20 Apr 2005 21:02 GMT

I'm seing that the databrowsers in my PowerPlant windows are not
responding to the scroll wheel on the mouse.

The databrowser in the BasicDataBrowser sample from Apple does
automatically respond to the scroll wheel.

The window in the sample has the Standard handler attribute set, but
that isn't set for my PowerPlant windows.

That is the only significant difference I can see. Can there be other
reasons for a databrowser not to respond to scroll wheel event ?

I have a kEventClassMouse/kEventMouseWheelMoved handler attached to my
windows in order to scroll my custom views. This works fine, but it
makes no difference to the databrowser whether my own handler is
installed or not.

So, I suppose I need to extend my own handler to detect that a scroll
wheel event occurred over the databrowser and manually call a routine to
scroll the databrowser. Any suggestions about how to do that ?

Kent

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Kent Sorensen - 20 Apr 2005 21:55 GMT

I've tried this method to pass the event on to the databrowser control
directly, with no success. The browser does not scroll even when
SendEventToEventTarget returns noErr.

This is part of the event handler for the
kEventClassMouse/kEventMouseWheelMoved event. It is attached to the
window.

ControlPartCode partCode;
ControlRef theControl = FindControlUnderMouse(mouseLoc, window,
&partCode);
if (theControl)
{
// the databrowser is found and partCode is kControlDataBrowserPart
OSStatus controlRes = SendEventToEventTarget( inEvent,
GetControlEventTarget( theControl ) );

// the call succeeds and controlRes is noErr.
if (controlRes != noErr)
{
SysBeep(0);
}
}

Kent

> I'm seing that the databrowsers in my PowerPlant windows are not
> responding to the scroll wheel on the mouse.
[quoted text clipped - 18 lines]
>
> Kent

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Richard Buckle - 25 Apr 2005 20:45 GMT

> I've tried this method to pass the event on to the databrowser control
> directly, with no success. The browser does not scroll even when
> SendEventToEventTarget returns noErr.
>
> [snip]

Try my public domain class that adds scroll wheel support to PowerPlant:
<http://www.sailmaker.co.uk/progtools.html#CScrollWheelAttachment>.
It's very easy to use, just instantiate it in your app's Initialize()
override and you're done.

Enjoy,
Richard.

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Kent Sorensen - 29 Apr 2005 13:56 GMT

> > I've tried this method to pass the event on to the databrowser control
> > directly, with no success. The browser does not scroll even when
[quoted text clipped - 9 lines]
> Enjoy,
> Richard.

Thanks for the suggestion. I have actually used that class for many
years now :-)

It works fine for PowerPlant views. The problem is that it does
obviously not find a LScroller on the LDatabrowser view so it does
nothing.

Then, as I wrote in the other mail, I tried SendEventToEventTarget if
DoScrollEvent did not find anything. This makes no difference..

Thanks
Kent

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Richard Buckle - 30 Apr 2005 04:10 GMT

[snip]

> > Try my public domain class that adds scroll wheel support to PowerPlant:
> > <http://www.sailmaker.co.uk/progtools.html#CScrollWheelAttachment>.
[quoted text clipped - 11 lines]
> nothing.
> [snip]

Kent, YHM. CScrollWheelAttachment has been updated. The latest version
on my website (v1.2.3) *does* support LDataBrowser, courtesy of a
submission by James W Walker. It's controlled by an #ifdef, which is
off by default, merely because LDataBrowser.h is not part of the
standard PowerPlant install.

Share and enjoy,
Richard.

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Mac Forum / Programming / CodeWarrior / April 2005

Databrowser scroll wheel support in PP application