this implementation avoids the display content jumping the full
screensaver offset from right to left when the modulo operator
wraps. this change makes the display content walk from right to
left as it did walk from left to right.
in case the total production is larger than 1 MWh, i.e., 1000 kWh, the
text on the respective line becomes too large such that it reaches out
of the display when the screensaver is enabled.
this happens on the small and large displays.
this change switches the number format to a float without decimal places
if the total production is larger or equal to 1000 kWh. this saves a dot
and a digit, making the text short enough to fit the display even when
the screensaver moved the display contents as far to the right as it
does.
fix calculation of the text baselines, using getAscent() in favor of
getMaxCharHeight(), which includes ascent and descent. this moves the
first text up and allows to insert margin between the lines until the
display area is fully utilized.
on large displays, if the small diagram is selected, keep the first line
rather low to avoid collision with the diagram y-axis label. in this mode,
there is still more space between the text lines as before, allowing for
improved readability.
To reduce the heap usage it is necessary to send the inverters one by one instead of a huge response. A simple call to `/api/livedata/status` returns just some very general information. If detailed inverter information are required the inverter serial number has to appended `?inv=<serial number>`.
The websocket also returns only one inverter at a time. It as to be assembled at client side.
this change adds the values of ESP.gteMaxAllocHeap() and
ESP.getMinFreeHead() to the prometheus metrics and the system
information object. the web UI uses these values to diplay the size of
the largest free contiguous block, calculate a rough estimate for the
level of fragmentation, and the maximum usage of heap memory since boot
in absolute and relative amounts.
