Hook function on image disables menu functions

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Wed, 09/23/2015 - 08:11 am

I have a hook function on an image, i.e.:

Function myHook(s)
    STRUCT WMWinHookStruct &s
   
    // get mouse position
    variable xpos =  AxisValFromPixel("", "Bottom", s.mouseLoc.h)
    variable ypos = AxisValFromPixel("", "Left", s.mouseLoc.v)
   
    switch(s.eventCode)
       
        case 3:                 // handle left mouse click  
       
            print xpos, ypos       
            break
                       
    endswitch
   
    return 1
End


and e.g.

make/N=(100,100) M_Image = p+q
NewImage/N=TestImage M_Image
SetWindow TestImage,hook(s)=myHook


Clicking on the image prints the mouse position on that image into the history.
Now I would like to use "Save Graphics" to save the image, but clicking onto that menu option (directly after clicking on the image) does not open the expected dialog.

Is this a bug or a feature?
Your hook function is returning 1 for every possible event. That includes some menu hook events, thereby disabling the menu. You should be experiencing a complete failure of virtually everything you can do with your image plot!

I suspect you want to return 0. Are you intending to disable the various things you can do with mouse clicks in a graph?

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

September 23, 2015 at 09:39 am - Permalink

johnweeks wrote:
Your hook function is returning 1 for every possible event. That includes some menu hook events, thereby disabling the menu. You should be experiencing a complete failure of virtually everything you can do with your image plot!


Thanks for pointing this out! Yes, almost everything is disabled!

johnweeks wrote:

I suspect you want to return 0. Are you intending to disable the various things you can do with mouse clicks in a graph?


Rather yes. In the actual case, clicking on an image pixel reveals a spectrum that is stored along the z-axis of a 3D wave. There is no reason to do modifications to the graph. But good to know why the above happens!

Thanks!

September 23, 2015 at 01:42 pm - Permalink

You should probably go through the list of event codes and figure out exactly which you need to block.
Quote:
Clicking on the image prints the mouse position on that image into the history.
Now I would like to use "Save Graphics" to save the image, but clicking onto that menu option (directly after clicking on the image) does not open the expected dialog.

Is this a bug or a feature?

Did you return 0 for event code 9 (enable menu) and 10 (menu)?

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

September 24, 2015 at 09:27 am - Permalink

ChrLie wrote:
Actually now I remember that I had issues with that function before and why I returned 1:

http://www.igorexchange.com/node/5677

If the choice is between 0 and 1 then I prefer the latter, since it took me more than a year to realise the effect ;-)

I think you need to be more selective in the events for which you return 1. For the previous problem I think you can return 1 just for mouse events:
    Variable retVal = 0
    switch(s.eventCode)
 
        case 3:                 // handle left mouse click  
 
            print xpos, ypos   
            retVal = 1 
            break
        case 4:             // mouse moved
            retVal = 1
            break;
        case 5:             // mouse up
            retVal = 1
            break;
 
    endswitch

    return retVal

That will prevent the appearance of a marquee or any other mouse-related stuff. It will allow the menu events.

In Igor 7 there is a UI interaction control keyword with which you can disable features of a graph on a feature-by-feature basis.

John Weeks
WaveMetrics, Inc.
support@wavemetrics.com

September 25, 2015 at 12:14 pm - Permalink