TrImageItem will emit a signal when the image is moved but not when resized

[RussBerg]

Example situation:
UI displays specifics about the current TrImageItem in the plotter such as
center (X,Y), number of pixels (X,Y), range in microns (X,Y) and the size of each pixel for X and Y in microns

If the parent of the plot wants to wants to update these parameters if the image is moved or resized they can do so by handling the SIG_ITEM_MOVED signal, but this is only if the image item is moved, if the TrImageItem is resized no signal is emitted.

here is a visual of what I am talking about, resizing the pattern image in the center of the plot should emit a signal indicating the change, that signal handler then updates the scan parameters on the UI.

[PierreRaybaut]

Fixed by ebfe7c3