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@ -50,7 +50,7 @@ LVGL provides everything you need to create embedded GUI with easy-to-use graphi
* **Documentation** and API references
## Supported devices
Basically, every modern controller (which is able to drive a display( is suitable to run LVGL. The minimal requirements are:
Basically, every modern controller (which is able to drive a display) is suitable to run LVGL. The minimal requirements are:
- 16, 32 or 64 bit microcontroller or processor
- > 16 MHz clock speed is recommended
- Flash/ROM: > 64 kB for the very essential components (> 180 kB is recommended)
@ -90,11 +90,11 @@ Choose a project with your favourite IDE:
The steps below show how to setup LVGL on an embedded system with a display and a touchpad.
You can use the [Simulators](https://docs.lvgl.io/v7/en/html/get-started/pc-simulator) to get ready to use projects which can be run on your PC.
1. [Download](https://lvgl.com/developers) or [Clone](https://github.com/lvgl/lvgl) the library
1. [Download](https://github.com/lvgl/lvgl/archive/master.zip) or [Clone](https://github.com/lvgl/lvgl) the library
2. Copy the `lvgl` folder into your project
3. Copy `lvgl/lv_conf_template.h` as `lv_conf.h` next to the `lvgl` folder and set at least `LV_HOR_RES_MAX`, `LV_VER_RES_MAX` and `LV_COLOR_DEPTH`. Don't forget to **change the `#if 0` statement near the top of the file to `#if 1`**, otherwise you will get compilation errors.
3. Copy `lvgl/lv_conf_template.h` as `lv_conf.h` next to the `lvgl` folder, change the `#if 0` statement near the top of the file to `#if 1` and set at least `LV_HOR_RES_MAX`, `LV_VER_RES_MAX` and `LV_COLOR_DEPTH`.
4. Include `lvgl/lvgl.h` where you need to use LVGL related functions.
5. Call `lv_tick_inc(x)` every `x` milliseconds **in a Timer or Task** (`x` should be between 1 and 10). It is required for the internal timing of LVGL.
5. Call `lv_tick_inc(x)` every `x` milliseconds (should be 1..10) in a Timer or Task. It is required for the internal timing of LVGL.
6. Call `lv_init()`
7. Create a display buffer for LVGL
```c
@ -102,7 +102,7 @@ static lv_disp_buf_t disp_buf;
static lv_color_t buf[LV_HOR_RES_MAX * 10]; /*Declare a buffer for 10 lines*/
lv_disp_buf_init(&disp_buf, buf, NULL, LV_HOR_RES_MAX * 10); /*Initialize the display buffer*/
```
8. Implement and register a function which can **copy a pixel array** to an area of your display:
8. Implement and register a function which can copy a pixel array to an area of your display:
```c
lv_disp_drv_t disp_drv; /*Descriptor of a display driver*/
lv_disp_drv_init(&disp_drv); /*Basic initialization*/
@ -115,7 +115,7 @@ void my_disp_flush(lv_disp_t * disp, const lv_area_t * area, lv_color_t * color_
int32_t x, y;
for(y = area->y1; y <= area->y2; y++) {
for(x = area->x1; x <= area->x2; x++) {
set_pixel(x, y, *color_p); /* Put a pixel to the display.*/
my_set_pixel(x, y, *color_p); /* Put a pixel to the display.*/
color_p++;
}
}
@ -124,7 +124,7 @@ void my_disp_flush(lv_disp_t * disp, const lv_area_t * area, lv_color_t * color_
}
```
9. Implement and register a function which can **read an input device**. E.g. for a touch pad:
9. Implement and register a function which can read an input device. E.g. for a touch pad:
```c
lv_indev_drv_init(&indev_drv); /*Descriptor of a input device driver*/
indev_drv.type = LV_INDEV_TYPE_POINTER; /*Touch pad is a pointer-like device*/
@ -133,16 +133,8 @@ lv_indev_drv_register(&indev_drv); /*Finally register the driver*/
bool my_touchpad_read(lv_indev_drv_t * indev_driver, lv_indev_data_t * data)
{
static lv_coord_t last_x = 0;
static lv_coord_t last_y = 0;
/*Save the state and save the pressed coordinate*/
data->state = touchpad_is_pressed() ? LV_INDEV_STATE_PR : LV_INDEV_STATE_REL;
if(data->state == LV_INDEV_STATE_PR) touchpad_get_xy(&last_x, &last_y);
/*Set the coordinates (if released use the last pressed coordinates)*/
data->point.x = last_x;
data->point.y = last_y;
data->state = my_touchpad_is_pressed() ? LV_INDEV_STATE_PR : LV_INDEV_STATE_REL;
if(data->state == LV_INDEV_STATE_PR) touchpad_get_xy(&data->point.x, &data->point.y);
return false; /*Return `false` because we are not buffering and no more data to read*/
}
@ -153,17 +145,17 @@ It will redraw the screen if required, handle input devices etc.
## Learn the basics
In this section you can ready the very basics. For a more detailed guide check the [Quick overview](https://docs.lvgl.io/v7/en/html/get-started/quick-overview.html#learn-the-basics) in the documentation.
In this section you can read the very basics of LVGL. For a more detailed guide check the [Quick overview](https://docs.lvgl.io/v7/en/html/get-started/quick-overview.html#learn-the-basics) in the documentation.
### Widgets (Objects)
The graphical elements like Buttons, Labels, Sliders, Charts etc are called objects in LittelvGL. Go to [Object types](https://docs.lvgl.io/v7/en/html/widgets/index) to see the full list of available types.
The graphical elements like Buttons, Labels, Sliders, Charts etc are called objects or widgets in LVGL. Go to [Widgets](https://docs.lvgl.io/v7/en/html/widgets/index) to see the full list of available types.
Every object has a parent object. The child object moves with the parent and if you delete the parent the children will be deleted too. Children can be visible only on their parent.
The *screen* are the "root" parents. To get the current screen call `lv_scr_act()`.
You can create a new object with `lv_<type>_create(parent, obj_to_copy)`. It will return an `lv_obj_t *` variable which should be used as a reference to the object to set its parameters.
You can create a new object with `lv_<type>_create(parent, obj_to_copy)`. It will return an `lv_obj_t *` variable which should be used as a reference to the object to set its parameters later.
The first parameter is the desired *parent*, the second parameters can be an object to copy (`NULL` if unused).
For example:
```c
@ -177,15 +169,22 @@ lv_obj_set_y(btn1, 10);
lv_obj_set_size(btn1, 200, 50);
```
The objects has type specific parameters too which can be set by `lv_<type>_set_<paramters_name>(obj, <value>)` functions. For example:
The objects have type specific parameters too which can be set by `lv_<type>_set_<paramters_name>(obj, <value>)` functions. For example:
```c
lv_slider_set_value(slider1, 70, LV_ANIM_ON);
```
To see the full API visit the documentation of the object types or the related header file (e.g. `lvgl/src/lv_objx/lv_slider.h`).
To create a new screen pass `NULL` as the fisrt paramater of a *create* function:
```c
lv_obj_t * scr2 = lv_obj_create(NULL, NULL); /*Create a screen*/
lv_scr_load(scr2); /*Load the new screen*/
```
### Styles
Widgets are created with a default appearance but it can be changed by adding new styles to the object. A new style can be created like this:
Widgets are created with a default appearance but it can be changed by adding new styles to them. A new style can be created like this:
```c
static lv_style_t style1; /*Should be static, global or dynamically allocated*/
lv_style_init(&style1);
@ -193,15 +192,15 @@ lv_style_set_bg_color(&style1, LV_STATE_DEFAULT, LV_COLOR_RED); /*Default backg
lv_style_set_bg_color(&style1, LV_STATE_PRESSED, LV_COLOR_BLUE); /*Pressed background color*/
```
The wigedt have *parts* which can be referenced via `LV_<TYPE>_PART_<PART_NAME>`. E.g. `LV_BRN_PART_MAIN` or `LV_SLIDER_PART_KNOB`. See the documentation of the widgets to see the exisitng parts.
The wigedt have *parts* which can be referenced via `LV_<TYPE>_PART_<PART_NAME>`. E.g. `LV_BTN_PART_MAIN` or `LV_SLIDER_PART_KNOB`. See the documentation of the widgets to see the exisitng parts.
To add the style to a button:
```
```c
lv_obj_add_style(btn1, LV_BTN_PART_MAIN, &style1);
```
To remove all styles from an object use:
```c
To remove all styles from a part of an object:
```cc
lv_obj_reset_style_list(obj, LV_OBJ_PART_MAIN);
```
@ -211,7 +210,7 @@ Learn more in [Style overview](https://docs.lvgl.io/v7/en/html/overview/style) s
Events are used to inform the user if something has happened with an object. You can assign a callback to an object which will be called if the object is clicked, released, dragged, being deleted etc. It should look like this:
```c
lv_obj_set_event_cb(btn, btn_event_cb); /*Assign a callback to the button*/
lv_obj_set_event_cb(btn, btn_event_cb); /*Assign a callback to the button*/
...
@ -282,6 +281,7 @@ LVGL has a monthly periodic release cycle.
  - Make a patch release from `master`.
  - After that merge the new features from the `dev` to `master` branch.
  - In the rest of the month merge only patches into `master` and new features into `dev` branch.
## Contributing
To ask questions please use the [Forum](https://forum.lvgl.io).
For development-related things (bug reports, feature suggestions) use [GitHub's Issue tracker](https://github.com/lvgl/lvgl/issues).