Drag and Drop transaction prevent other events from being fired

[PJM_labview]

There are a lot of issues here. When in the middle on a drag and drop transaction (start dragging but did not drop yet) a lot of events are no longer fired (or they do fire, but occasionally).

The attached VI demonstrate this.

In this above example, the pane: mouse enter does no longer fire during the transaction but it does fire after the transaction complete; also the pane: mouse leave does fire only once.

By just pocking around a bit more, I realized that a lot of events are affected by this issue.

Note: LV Version >= 8.21 are affected (I have not tested on anything less than 8.21)

PJM

Download File:post-121-1206314759.viLV >= 8.21

[Jim Kring]

Shouldn't you be finding easter eggs in LabVIEW, today, instead of bugs?

(it is Easter Sunday, afterall)

[Tomi Maila]

The attachment name Drag Bug gave me the impression of something like this.

[Tomi Maila]

This is bad. I made PJM's VI reentrant and dropped two copies of it on a block diagram of an empty VI. It appears that the events stop firing not only on the VI where the drag was initiated but on all other VIs as well :( I start drag in one VI and all the UI logic in all my other VIs will stop functioning properly.

[Rolf Kalbermatter]

QUOTE (Tomi Maila @ Mar 25 2008, 04:03 AM)

This is bad. I made PJM's VI reentrant and dropped two copies of it on a block diagram of an empty VI. It appears that the events stop firing not only on the VI where the drag was initiated but on all other VIs as well I start drag in one VI and all the UI logic in all my other VIs will stop functioning properly.

Bad maybe but not entirely unexpected. Dragging is an UI operation and therefore for sure executed in the UI thread, just as all the other events that are in fact UI events. The event structure itself is not executing in the UI thread but the routine fetching the UI events from the OS and distributing them to the various event queues for the event structures sure enough does.

Rolf Kalbermatter