LVGL tips

[cicciocb]

Given that the implementation of the LVGL library introduces many features, I propose gathering useful tricks and tips here as we discover how to use them.
The goal is to gather everything in one place to make searching easier.

[cicciocb]

Hi,
I've just uploaded a little video showing how use the msgbox ojbect in LVGL.


The code is :

Code: [Local Link Removed for Guests]

lvgl.init WHITE, 0x003a57
lvgl.set_theme 0x107090, 0xff9900, 12, 0, 0 ' character 12, dark 0, mode 3
lvgl.remove_flag lvgl.screen, 0x20 'remove elasticity on scroll
lvgl.clean
img1 = lvgl.image "/greece.jpg"
but1 = lvgl.button "msgbox"
but2 = lvgl.button "msgbox custom", 160, 0
lvgl.add_event but1, 7, but1_pressed
lvgl.add_event but2, 7, but2_pressed

while 1
lvgl.refresh
wend

but1_pressed:
msgBox = lvgl.msgBox "This is Header", "This is content"
footer = lvgl.get_child msgbox, 2 'get the buttons zone
b_OK = lvgl.get_child footer, 0 ' extract the button OK
lvgl.add_Event b_OK, 7, b_OK_clicked 'add an event when OK clicked
return

but2_pressed:
msgBox = lvgl.msgBox "Entry Date", "Enter Data Validated"
header = lvgl.get_child msgbox, 0 'get the header zone
content = lvgl.get_child msgbox, 1 'get the content zone
footer = lvgl.get_child msgbox, 2 'get the buttons zone
b_OK = lvgl.get_child footer, 0 ' extract the button OK
b_cancel = lvgl.get_child footer, 1 ' extract the button cancel
lvgl.visible b_cancel, 0 'hide the button cancel
lvgl.add_Event b_OK, 7, b_OK_clicked 'add an event when OK clicked
t = lvgl.get_child b_ok,0 'get the first child (is a label)
lvgl.set_text t, "Tutto Bene" ' now change the text of the button OK
'now change the colors
''' HEADER '''
lvgl.set_bg_opa msgbox, 128 'set the box transparent
lvgl.set_text_color header, white 'set the text color to white
lvgl.set_bg_color header, red 'set the background color to red
lvgl.set_bg_opa header, 128 ' transparent at 50%
''' CONTENT '''
lvgl.set_text_color content, Yellow 'set the text color to yellow
lvgl.set_bg_color content, black 'set the background color to black
lvgl.set_bg_opa content, 128 ' transparent at 50%
''' FOOTER '''
lvgl.set_bg_color footer, black 'set the background color to black
lvgl.set_bg_opa footer, 128 ' transparent at 50%
return

b_OK_clicked:
LVGL.MSGBOX_CLOSE msgbox
return

[karlkloss]

I made this picture to visualize the possible positions of LVGL Alignment Enums (lv_align_t):

grafik.png

grafik.png

grafik.png

[cicciocb]

How remove the KNOB (button) from an ARC objact

Code: [Local Link Removed for Guests]

arc = lvgl.arc
lvgl.set_bg_opa arc, 0, 0x030000 ' change the knob transparent
lvgl.remove_flag arc, 2 ' disable the object (no clickable)