enhancement or my confusion

[kimbrussow]

I have been using EEZ for about 6 months and am enjoying learning the software. I use Platform IO to code to my ESP32 LVGL 9.3. I can build my screens and add widgets. My coding background is OOP C#.
An issue or two I have run into are:
When a series of events take place, check if all "flags" and determine action. A LVGL Dropdown has an index and a text value. Should be able to grab the Text and save that text to a variable... Nope, I have to add extra coding to the call_back to get the e obj and extract the text and copy to the variable.
lv_obj_t * obj = lv_event_get_target(e);
char buf[64];
lv_dropdown_get_selected_str(obj, buf, sizeof(buf));//string var_selected_network
set_var_var_selected_network(buf);
been all through the expression builder and cannot locate anything
A nice to have is an easy method of adding a system monitor widget in the gui to show fps and cpu. (not had any success). Within EEZ Studio, the screens transition nicely. Once the code is compiled and uploaded, transitions are almost non existent unless time is set to 1000+
any thoughts?
thanks for all your work

[salimuddin07]

Getting the text from a dropdown
Yes, LVGL works primarily with the object handles (lv_obj_t*), so to get the text you need to use the callback and extract it like you showed. It’s a bit verbose compared to higher-level frameworks, but that’s how LVGL gives you full control. Your approach with lv_dropdown_get_selected_str(obj, buf, sizeof(buf)) is spot on. I know it’s a little clunky, but once you wrap it in a helper function, it’s much easier to reuse.

Checking flags and triggering actions
In OOP-style languages like C#, you might be used to event binding or properties that automatically update. In LVGL, you typically need to manage state manually. A common approach is to maintain a struct or set of global variables for the flags, then check them in a single update function. This keeps your event callbacks light and centralizes the logic.

System monitor widget (FPS/CPU)
LVGL itself doesn’t have a built-in FPS or CPU monitor widget. One approach is to use lv_timer to measure frame rendering time and calculate FPS, then update a label on the screen periodically. For CPU usage, on ESP32 you could poll esp_get_free_heap_size() or uxTaskGetSystemState() for more advanced profiling, then display it similarly. It takes a bit of manual setup but works reliably.

Screen transitions appearing slow after upload
Yeah, this is a common one. EEZ Studio simulates transitions smoothly because the timing can be exaggerated. On the actual hardware, transitions are tied to your FPS and the display refresh speed. Increasing the transition time (like you mentioned, 1000ms+) works, but you might also want to optimize the widgets on the screen — reducing overlapping objects, heavy redraws, or unnecessary animations can help transitions feel smoother on real hardware.

[kimbrussow]

Fantastic!! Glad I am not going out of my mind. I need to be a bit more patient and accept limitations. My project started off small and grew a mind of its own. Building a system to take audio stream (youtube, spotify, microphone or music files on SD card) output to speakers and sample stream to turn rgb light strips into patterns based off frequency / other parameters. All will be user controllable from touch display.
Thank you for your quick feedback and tips
WiFi scan screen