Fix positioning errors in tiled console display

It turns out that specifying height and width explicitly
does not guarantee that the image protocols will actually fill
the specified space. Notably iterm will honor aspect ratio
(which is good), but leave the cursor where the image would
naturally leave it (which is difficult with relative positioning).

Previously, relative positioning was used as a workaround
for the fact that save/restore or any absolute positioning may
be fouled by incurring scroll.

To make cursor save/restore work, we determine the total rows and
print newlines enough to incur scroll and then move cursor back up.
This lets us use save/restore to ignore cursor movement by the image.

confluent_client/bin/nodeconsole

@@ -162,7 +162,13 @@ def determine_tile_size(numnodes):
     if tileheight > (tilewidth * 11 /16):
         tileheight = tilewidth * 11 / 16
         cellshigh = int(tileheight // (pixheight / cheight))
-    bestdims = bestdims + [cellswide, cellshigh]
+    bestdims = bestdims + [cellswide, cellshigh, cellshigh * bestdims[1]]
+    # incur any scrolling we might get. This allows us to accurately
+    # save/restore cursor or even get coordinates without scrolling fouling
+    # the desired target
+    sys.stdout.write('\n' * bestdims[4])
+    sys.stdout.flush()
+    cursor_up(bestdims[4])
     return bestdims
 
 cursor_saved = False
@@ -183,6 +189,18 @@ def sticky_cursor():
         finally:
             indirect_console()
 
+def cursor_up(count=1):
+    sys.stdout.write(f'\x1b[{count}A')
+def cursor_down(count=1):
+    sys.stdout.write(f'\x1b[{count}B')
+def cursor_right(count=1):
+    sys.stdout.write(f'\x1b[{count}C')
+def cursor_left(count=1):
+    sys.stdout.write(f'\x1b[{count}D')
+def cursor_save():
+    sys.stdout.write('\x1b7')
+def cursor_restore():
+    sys.stdout.write('\x1b8')
 
 def draw_image(data, width, height):
     imageformat = os.environ.get('CONFLUENT_IMAGE_PROTOCOL', 'kitty')
@@ -212,7 +230,6 @@ def iterm_draw(data, width, height):
         '\x1b]1337;File=inline=1;width={};height={};size={}:'.format(width,height,datalen))
     sys.stdout.write(data.decode('utf8'))
     sys.stdout.write('\a')
-    sys.stdout.write('\n')
     sys.stdout.flush()
 
 def kitty_draw(data, width, height):
@@ -227,7 +244,7 @@ def kitty_draw(data, width, height):
         data = base64.b64encode(outfile.getbuffer())
     preamble = '\x1b_Ga=T,f=100'
     if height:
-        preamble += f',r={height - 2},c={width}'
+        preamble += f',r={height},c={width}'
     #sys.stdout.write(repr(preamble))
     #sys.stdout.write('\xb[{}D'.format(len(repr(preamble))))
     #return
@@ -242,7 +259,6 @@ def kitty_draw(data, width, height):
         sys.stdout.write(chunk.decode('utf8'))
         sys.stdout.write('\x1b\\')
         sys.stdout.flush()
-    sys.stdout.write('\n')
 
 pass_through_args = []
 killcon = False
@@ -284,18 +300,18 @@ if options.Timestamp:
 def prep_node_tile(node):
     currcolcell, currrowcell = nodepositions[node]
     if currcolcell:
-        sys.stdout.write(f'\x1b[{currcolcell}C')
+        cursor_right(currcolcell)
     if currrowcell:
-        sys.stdout.write(f'\x1b[{currrowcell}B')
+        cursor_down(currrowcell)
     sys.stdout.write(node)
-    sys.stdout.write('\x1b[{}D'.format(len(node)))
-    sys.stdout.write(f'\x1b[1B')
+    cursor_left(len(node))
+    cursor_down()
 
 def reset_cursor(node):
     currcolcell, currrowcell = nodepositions[node]
     if currcolcell:
-        sys.stdout.write(f'\x1b[{currcolcell}D')
-    sys.stdout.write(f'\x1b[{currrowcell + 1}A')
+        cursor_left(currcolcell)
+    cursor_up(currrowcell + 1)
 
 
 nodepositions = {}
@@ -313,7 +329,7 @@ if options.screenshot:
         for res in sess.read('/noderange/{}/nodes/'.format(args[0])):
             allnodes.append(res['item']['href'].replace('/', ''))
             numnodes += 1
-        cols, rows, cwidth, cheight = determine_tile_size(numnodes)
+        cols, rows, cwidth, cheight, numrows = determine_tile_size(numnodes)
         currcol = 1
         currcolcell = 0
         currrowcell = 0
@@ -326,10 +342,10 @@ if options.screenshot:
                 currcol = 1
                 currcolcell = 0
                 currrowcell += cheight
+    elif options.interval is not None:
+        sys.stdout.write('\x1bc')
     firstnodename = None
     dorefresh = True
-    if options.interval is not None:
-        sys.stdout.write('\x1bc')
     while dorefresh:
         for res in sess.read('/noderange/{}/console/ikvm_screenshot'.format(args[0])):
             for node in res.get('databynode', {}):
@@ -342,6 +358,7 @@ if options.screenshot:
                         continue
                     if node in nodepositions:
                         prep_node_tile(node)
+                        cursor_save()
                     else:
                         if options.interval is not None:
                             if node != firstnodename:
@@ -352,8 +369,7 @@ if options.screenshot:
                     # one row is used by our own name, so cheight - 1 for that allowance
                     draw_image(imgdata.encode(), cwidth, cheight - 1 if cheight else cheight)
                     if node in nodepositions:
-                        sys.stdout.write(f'\x1b[{cwidth}D')
-                        sys.stdout.write(f'\x1b[{cheight - 1}A')
+                        cursor_restore()
                         reset_cursor(node)
                     else:
                         sys.stdout.write('\n')