Detect end of scroll

--- find the end for scrolling
the easiest way is, to check after (or before) every scroll action, wether in the region at the bottom of the app area some footer image (something, below the table) gets visible.

--- scroll to top again
yes, the easiest method is to count the down-scrolls and then scroll back the same number of wheel steps.

another option is, to scroll to top as long as some top image gets visible again at the top of the app area.

Thank you Raiman. The problem is that only the table rows are scrolling, not the screen itself, so there are no changes to detect in the region. I was thinking maybe I could try to detect an image of the scrollbar when it's in the end-of-table position. Seems a little tricky because it is located on the opposite side of the screen, outside the scrolling region and there are other tables/scrollbars on the screen. Would have to find a way to make sure I find only the specific scrollbar associated with the scrolling table.

Appreciate the info!

ok, understood.

Then you should do it this way:

If the table cannot be scrolled anymore, the area shold not change its content after a scroll.

# capture a significant part of the table
tabPart = capture(some_region)

# make one scroll step

# check, wether things changed
if some_region.exists(tabPart):
     print "reached end of table"
     break # see continue
else:
     print "some more to scroll"
     continue # supposing we are in a loop

Just an addition because I had to solve this problem myself some days ago, I used the onChange observer:
The goal was to find an entry in the scrollable list.
It utilizes the fact that the appearance of the list will not change once the bottom or top is reached, because the scrolling stops there, but will change while scrolling is still possible.
The advantage of my script is that it does not need a bottom or top image of the list and automatically scrolls up and down. It probably isn't as fast as RaiMan's approach, I guess.

# direction of wheeling/scrolling
direction = WHEEL_DOWN

# flag to see if bottom of the list was reached
reachedBottom = False

# flag to see if top of the list was reached
reachedTop = False

# ist set True if the image was found
entryFound = False

# maximum number of scroll attempts, this may not be to small.
maxScrolls = 10

# the image that is searched in the list
goalImage = Pattern("xyz.png")

# global var to save all changeobserver results
changeResults = None

# start asynchronous observation
def startChangeObserve(region, time):
    global changeResults
    changeResults = []

    def changeHandler(result):
        changeResults.append(result)

    region.onChange(10,changeHandler)
    region.observe(time,background=True)

# I don't like loops that have any possibility to run endless, so I set a max. It is not needed normally, thnough.
for i in range(maxScrolls):
            if (listregion.wait(goalImage,0.3) == False): # no entry found
                # start searching for changes (asynchronous), see method below
                startChangeObserve(listregion, 0.5)
                # scroll down
                wheel(wheelLocation,direction,1)
                # wait for changelistener to complete
                wait(0.5)
                # check if any changes occurred
                if (len(changeresults) == 0): # no changes, scrolling did not change dropdown list, bottom or top reached.
                    if (direction == WHEEL_DOWN): # bottom reached, change wheel direction
                        reachedBottom = True
                        direction = WHEEL_UP
                    else: # top reached, change wheel direction
                        reachedTop = True
                        direction = WHEEL_DOWN
                    if (reachedTop == True and reachedBottom == True): # both ends of the dropdown-menu were reached, no more scrolling needed.
                        break
            else: # entry was found
                entryFound = True
                break

if (entryFound):
# do stuff if successfull

Maybe this can help someone sometime.