Markups module adds the 'p' key to place a fiducial (currently only enabled if in place mode).

In persistent mode, do you want a right click to leave persistent mode, leaving you in place mode (one more left click will place a fiducial and then it will go back to view transform mode), or do you want a right click to take you out of place mode, leaving persistent mode enabled for the next time place mode is entered?

I believe 2nd option makes more sense to me (-> right click takes you out of place mode leaving persistent mode enabled for next time)

A quick test shows that using the right button release event is clashing with the seed widget, the seeds aren't getting unlocked properly after place mode is exited, and I'm often getting a seed "sticking" to the mouse, stuck in move mode. I'll probably have to use a shortcut key instead.

Another quick test shows that this worked well on the Annotations seed widget on linux, while not working with the Markups seed widget on Mac - more testing needed.

I got the right click to stop place mode working in the Markups module (in 3D only so far though), as of svn 22317[1]. p key will place them under the mouse pointer while in persistent mode as well. Let me know if you need more keyboard shortcuts. I do plan to add the d key to delete fiducials when the mouse is over them.

[1] http://viewvc.slicer.org/viewvc.cgi/Slicer4?view=revision&revision=22317

Whatever we decide, I think we should be consistent between the 2D and the 3D view.

Maybe the right click I suggested is not a good solution as it would clash with the zoom.
How about the Escape key instead ? Or maybe simply define a QAction that controls the "place" state (on/off).

Here is a suggestion (here I suggest that we don't use more than 1 key (p?) for all the fiducials):

• 'p' down and release (no action between down and release): toggle place mode
• 'p' down + left click: drop an annotation (whatever is the currently selected annotation in the mouse toolbar ) even if we are not in "place" mode
• 'p' down + 'del' (or backspace): deletes the last annotation dropped
• 'p' down + ... + escape : cancel the actions when 'p' was down (it's bonus! :-P )
• right click (down and release) on a fiducial: open the Annotations/Markup module and select the point.
• 'del' down and release over fiducial: delete the fiducial

There has to be a key press without mouse click to place fiducials, as precise placement sometimes requires that the mouse not be moved even by accident when pressing the mouse button. The p key was used in Slicer3 which is is why I went back to it.

Other than that, I don't have strong feelings one way or another, maybe open up the discussion to the users list?

Closing resolved issues that have not been updated in more than 3 months