Slot 'setLinePlot' of itom2dqwtplot does nothing if plot has no current data object (especially in case of connected cameras)

[M. Gronle]

The following code does not do the expected behaviour:

‌

a = dataIO("DummyGrabber")

[i,h] = plot(dataObject.randN([100,100]))
h["camera"] = a #internal object of plot will be invalidated and the new data object will be created once the first image from the camera arrive.
h.call("setLinePlot", 0,0,100,100) #does not work, since no image is currently arrived at this point.

Usually, we would expect a line cut to popup. However the assignment of a camera immeditaly
resets the internal data object of the 2d plot. The object is only re-created once the first image of
the camera arrives. However this is after the ‘setLinePlot’ slot, therefore no line cut is created.

[M. Gronle]

Will be fixed, however the fact remains, that the line plot is always limited to the size of the currently displayed dataObject or latest camera image.

[M. Gronle]

fixes issue #31: slot 'setLinePlot' of itom2dqwtplot also plots a line plot, if a camera has recently be assigned to this 2d plot. However, the latest displayed object of the plot must be bigger than the extent of the new line cut, else the line cut will be reduced to the size of the latest data object.

→ <<cset dc21efda396e>>