tv_lvgl_theme Esphome Component

Release 0.0.1

The tv_lvgl_theme component is a flexible tool for customizing the visual appearance of LVGL objects in ESPHome. It allows you to create themes that define the colors, fonts, and sizes of various elements on the screen, buttons, and labels and other widgets. This allows you to create a consistent and visually appealing user interface for your ESPHome projects.

Usage/Purpose

The tv_lvgl_theme component is used to create themes that are applied to LVGL objects.

Parameters

Parameter	Description
id	Component id.
name	The name of the theme.
primary_color	The color of the primary theme color. For you own usage. Can be given as a lv_color_t value, or a uint32_t
secondary_color	The color of the secondary theme color. For you own usage. Can be given as a lv_color_t value, or a uint32_t
parent_theme	The id of a parent tv_lvgl_theme to inherit from, or lambda code that returns pointer to a lv_theme_t.
apply_theme	Whether to apply the theme immediately. Can be true or false. If it's true, it will also force update all existing objects. Instead you can use these sub items:
	apply Whether to apply at setup. Only screen/display changed if force is false
	force Whether to force the theme to be applied to all object now.
select_parent_theme	This select the parent theme. Options:
	DefaultTheme Sets the parent theme to the default theme.
	DarkDefaultTheme Sets the parent theme to the dark default theme.
	MonoTheme Sets the parent theme to the mono theme.
	DarkMonoTheme Sets the parent theme to the dark mono theme.
	BasicTheme Sets the parent theme to the basic theme.
	CustomTheme Sets the parent theme to a custom theme spesified by parent_theme parameter.
	NoParentTheme No parent theme will be used.

Style lambdas

This table lists all the available style lambdas for customizing the appearance of widgets in LVGL. Each lambda has a default state and can also be customized for different states such as pressed, disabled, and focused.

Style lambda name	Description
style_screen	Customizes the overall appearance of the screen.
style_button	Customizes the appearance of buttons.
style_button_disabled	Customizes the appearance of disabled buttons.
style_button_pressed	Customizes the appearance of buttons when pressed.
style_button_checked	Customizes the appearance of buttons when checked.
style_button_focused	Customizes the appearance of buttons when focused.
style_slider	Customizes the appearance of sliders.
style_slider_pressed	Customizes the appearance of sliders when pressed.
style_slider_disabled	Customizes the appearance of disabled sliders.
style_checkbox	Customizes the appearance of checkboxes.
style_checkbox_pressed	Customizes the appearance of checkboxes when pressed.
style_switch	Customizes the appearance of switches.
style_switch_pressed	Customizes the appearance of switches when pressed.
style_switch_disabled	Customizes the appearance of disabled switches.
style_switch_focused	Customizes the appearance of switches when focused.
style_spinner	Customizes the appearance of spinners.
style_spinner_pressed	Customizes the appearance of spinners when pressed.
style_spinner_disabled	Customizes the appearance of disabled spinners.
style_spinner_focused	Customizes the appearance of spinners when focused.
style_label	Customizes the appearance of labels.
style_img	Customizes the appearance of images.
style_list	Customizes the appearance of lists.
style_chart	Customizes the appearance of charts.
style_bar	Customizes the appearance of bars.
style_table	Customizes the appearance of tables.
style_dropdown	Customizes the appearance of dropdown menus.
style_textarea	Customizes the appearance of textareas.

Example:

This example shows how to use the style_screen lambda to customize the background color and text color:

style_screen: !lambda |-
    lv_style_set_text_color(style, lv_color_hex(0x555555));
    lv_style_set_bg_color(style, lv_color_hex(0x222222));
    lv_style_set_bg_opa(style, LV_OPA_COVER);

Lambda callbacks:

Parameter	Description	Arguments
setup_lambda	A lambda that is called when the theme is first created.	sender a pointer to the tv_lvgl_theme object. theme is a pointer to the lv_theme_t object.
after_setup_lambda	A lambda that is called after the theme has been changed/updated.	sender a pointer to the tv_lvgl_theme object. theme is a pointer to the lv_theme_t object.
apply_lambda	A lambda that is called to apply the theme to all objects. Here you can add code to change styles not directly supported by the component.	sender a pointer to the tv_lvgl_theme object. obj pointer the lvgl object to modify.

Callable c++ (lambda) functions:

Parameter	Description	Argument
setPrimaryColor_lv	Call this to modify primary color.	lv_color_t
setPrimaryColor	Call this to modify primary color.	uint32_t
setSecondaryColor_lv	Call this to modify primary color.	lv_color_t
setSecondaryColor	Call this to modify primary color.	uint32_t
selectParentTheme	Select parent theme type	See select_parent_theme parameter.
setParentTheme	Set the user theme.	lv_theme_t
initialize_theme	Initialize/reinitalize theme.	void
set_apply_theme	Make initialize apply the theme.	bool
set_force_apply_theme	When apply, force update to all current objects	bool

Complete usage example:

tv_lvgl_theme:
  - id: theme1
    name: "Theme 1"
    select_parent_theme: DefaultTheme
    style_button: !lambda |-
      lv_style_set_border_width(style, 5);
      lv_style_set_text_color(style, lv_color_hex(0xCFCFFF));

  - id: theme2
    name: Theme 2
    primary_color: !lambda |-
      return lv_color_hex(0x123456);
    secondary_color: 0x0000ff
    setup_lambda: !lambda |-
      ESP_LOGD("test", "setup_lambda");
    after_setup_lambda: !lambda |-
      ESP_LOGD("test", "after_setup_lambda");
    style_button_checked: !lambda |-
      lv_style_set_bg_color(style, lv_color_hex(0x888822));
    style_label: !lambda |-
      lv_style_set_bg_opa(style, LV_OPA_0);
    apply_theme: 
      apply: true
      force: true
    select_parent_theme: CustomTheme
    parent_theme: !lambda |-
        return id(theme1).theme();

  - id: theme3
    parent_theme: theme2

Written by ToViNi during many dedicated nights, navigating the strange intricacies of Python and C++, learning by the way.