I have some suggestions about chart

I hope the chart widgets can specify the position of the every point X-axis as well, because in practice, x’s are not equally spaced in most scenarios.

  • Please refer to emwin or QT for this function is required.

his feature exists in v8.
See the Scatter chart example: Examples — LVGL documentation

Just in Scatter Chart you can set X and Y using lv_chart_set_next_value2 but they are not connected.

So do you need functions like these?

lv_chart_set_value_x(chart, ser, point_index, value);
lv_chart_set_value_y(chart, ser, point_index, value);

That’s fine ,but I don’t care how to call it, I just need to draw a curve on the chart that specifies the XY of each point.

But the gist is to have separate functions for x and y instead of a set_xy function, right?

It’s better to have both and I suggest managing this curve with a float two-dimensional array.
Such as
curve = {{X0,Y0},{X1,Y1},{X2,Y2},{X3,Y3},…}

There is no float in lvgl but you can use lv_chart_set_ext_y_array and lv_chart_set_ext_x_array to set your own array or use lv_chart_get_y_array and lv_chart_get_x_array to get the array where lvgl stores the values.

Ok, so when will the function of the curve be added?

I’m a little bit confused. It seems to me you can use the functions mentioned here and they already exist.

  • All right, I’ll try to make a curve with them

The method you provided does not meet my requirements,I just need to draw a curve on the chart that specifies the XY of each point…maybe what I need is

void lv_chart_set_next_value(lv_obj_t * obj, lv_chart_series_t * ser, lv_coord_t x, lv_coord_t y)

*Sorry to bother you so long, but I really want to find what I’m looking for。

void lv_chart_set_next_value2(lv_obj_t * obj, lv_chart_series_t * ser, lv_coord_t x_value, lv_coord_t y_value)

I have one last question. Can the code I wrote in version 7 be used in version 8?

Yes and no. The two versions are not completely incompatible, but you will need to make substantial modifications for the new style & event APIs.