id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	blockedby	blocking	notify_on_close	platform	project
962	Can't re-contour and re-zone Volume in same graphics update	Tristan Croll	Tom Goddard	"For example, my Mousemode method below acts on a Volume object (or subclass such as my Clipper Xmap). The `adjust_threshold_level()` method calls `set_parameters()` to set the new contours, then I check the Volume object for an added `_surface_zone` property (which just contains the coordinate(s) and mask radius) and calls `surface_zone()` if it finds it. If I understand correctly, the problem is that with the new VolumeUpdateManager implementation, the changes to the triangle mask get over-written at the next redraw, so the results of the `surface_zone()` call are thrown away. This breaks things for me in a few different places - ISOLDE relies fairly heavily on the ability to change contours on masked maps.

Looks like I can work around it for my derived Volume classes by re-implementing `_update_drawings()`, but an official solution would be nice.  

{{{
    def wheel(self, event):
        d = event.wheel_value()
        v = self.selector.picked_volume
        if v is not None:
            self.target_volume = v
            sd = v.mean_sd_rms()[1]
            step = d/30 * sd
            rep, levels = adjust_threshold_level(v, step, self.symmetrical)
            lsig = tuple(l/sd for l in levels)
            if rep != 'solid':
                lstr = ', '.join(format(l, '.3f') for l in levels)
                sstr = ', '.join(format(s, '.3f') for s in lsig)
                self.session.logger.status('Volume {} contour level(s): {} ({} sigma)'.format(v.name, lstr, sstr))
            if hasattr(v, '_surface_zone'):
                sz = v._surface_zone
                coords = sz.all_coords
                distance = sz.distance
                if coords is not None:
                    from chimerax.core.surface.zone import surface_zone
                    surface_zone(v, coords, distance)

}}}
"	defect	closed	major		Graphics		fixed						all	ChimeraX