Embedded/lvgl
1
0
Fork 0
mirror of https://github.com/lvgl/lvgl.git synced 2025-01-14 06:42:58 +08:00
Code Issues Projects Releases Wiki Activity

examples: obj_usage: comment updates

Browse Source
This commit is contained in:
Gabor 2017-08-12 10:09:27 +02:00
parent 4924e871b2
commit 125b199f85
1 changed files with 100 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

111
lv_examples/1_2_obj_usage/obj_usage.c
View File

@ -4,16 +4,18 @@
*/
/*
* The basic building blocks in LittlevGL are the graphical objects.
* The basic building blocks (components or widgets) in LittlevGL are the graphical objects.
* For example:
* - Buttons
* - Labels
* - Charts
* - Sliders etc
*
* Regardless to the object type the 'lv_obj_t' is used stores objects
* and you can refer to an object with an lv_obj_t pointer (lv_obj_t *)
* In this part you can learn the basics of the objects like creating, positioning, sizing etc.
* You will also meet some different object types and their attributes.
*
* Regardless to the object type the 'lv_obj_t' variable type is used stores the objects
* and you can refer to an object with an lv_obj_t pointer (lv_obj_t *)
*
* INHERITANCE
* -------------
@ -31,13 +33,13 @@
* PARENT-CHILD
* -------------
* A parent can be considered as the container of its children.
* Every object has exactly one parent object (except screens) but
* a parent can have unlimited number of children.
* Every object has exactly one parent object (except screens).
* A parent can have unlimited number of children.
* There is no limitation for the type of the parent.
*
* The children are visible only on their parent. The parts outside will be cropped (not displayed)
*
* If the parent is moved the children move with it.
* If the parent is moved the children will be moved with it.
*
* The earlier created object (and its children) will drawn earlier.
* Using this layers can be built.
@ -46,6 +48,10 @@
* -------------
* - General overview: http://www.gl.littlev.hu/objects
* - Detailed description of types: http://www.gl.littlev.hu/object-types
*
* NOTES
* -------------
* - Be sure 'LV_OBJ_FREE_P' is enabled in 'lv_conf.h'
*/
/*********************
@ -68,6 +74,7 @@
* STATIC PROTOTYPES
**********************/
static lv_action_res_t btn_rel_action(lv_obj_t * btn, lv_dispi_t * dispi);
static lv_action_res_t ddlist_action(lv_obj_t * ddlist, lv_dispi_t * dispi);
/**********************
* STATIC VARIABLES
@ -82,27 +89,39 @@ static lv_action_res_t btn_rel_action(lv_obj_t * btn, lv_dispi_t * dispi);
**********************/
/**
*
* Initialize the Object usage example
*/
void lv_obj_usage_init(void)
{
/********************
* CREATE A SCREEN
*******************/
/* Create a new screen and load it
* Screen can be created from any type object
* Now a Page is used which is an objects with scrollable content*/
lv_obj_t * scr = lv_page_create(NULL, NULL);
lv_scr_load(scr);
/*Add a title*/
/****************
* ADD A TITLE
****************/
lv_obj_t * label = lv_label_create(scr, NULL); /*First parameters (scr) is the parent*/
lv_label_set_text(label, "Object usage demo"); /*Set the text*/
lv_obj_set_x(label, 50); /*Labels are inherited from Basic object so 'lv_obj_...' functions can be used*/
/********************
* CREATE TWO BUTTONS
********************/
/*Create a button*/
lv_obj_t * btn1 = lv_btn_create(lv_scr_act(), NULL); /*Create a button the currently loaded screen*/
lv_obj_t * btn1 = lv_btn_create(lv_scr_act(), NULL); /*Create a button on the currently loaded screen*/
lv_btn_set_rel_action(btn1, btn_rel_action); /*Set function to call when the button is released*/
lv_obj_align(btn1, label, LV_ALIGN_OUT_BOTTOM_LEFT, 0, 20); /*Align below the label*/
label = lv_label_create(btn1, NULL); /*Create a label on the button (the 'label' variable can be reused)*/
label = lv_label_create(btn1, NULL); /*Create a label on the button (the 'label' variable can be reused)*/
lv_label_set_text(label, "Button 1");
/*Copy the previous button*/
@ -111,19 +130,89 @@ void lv_obj_usage_init(void)
label = lv_label_create(btn2, NULL); /*Create a label on the button*/
lv_label_set_text(label, "Button 2");
/****************
* ADD A SLIDER
****************/
/*Add a slider (inheritance: lv_obj -> lv_bar -> lv_slider)*/
lv_obj_t * slider = lv_slider_create(scr, NULL);
lv_obj_t * slider = lv_slider_create(scr, NULL); /*Create a slider*/
lv_obj_set_size(slider, lv_obj_get_width(lv_scr_act()) / 3, LV_DPI / 3); /*Set the size*/
lv_obj_align(slider, btn1, LV_ALIGN_OUT_BOTTOM_LEFT, 0, 20); /*Align below the first button*/
lv_bar_set_value(slider, 30); /*Slider is a 'bar' so set its value like a 'bar'*/
/***********************
* ADD A DROP DOWN LIST
************************/
lv_obj_t * ddlist = lv_ddlist_create(lv_scr_act(), NULL);
lv_obj_align(ddlist, slider, LV_ALIGN_OUT_RIGHT_TOP, 20, 0); /*Align next to the slider*/
lv_obj_set_free_p(ddlist, slider); /*Save the pointer of the slider in the ddlist (used in 'ddlist_action()')*/
lv_ddlist_set_options_str(ddlist, "None\nLittle\nHalf\nA lot\nAll"); /*Set the options*/
lv_ddlist_set_action(ddlist, ddlist_action); /*Set function to call on new option choose*/
lv_obj_set_top(ddlist, true); /*Enable the drop down list always be on the top*/
/****************
* CREATE A CHART
****************/
lv_obj_t * chart = lv_chart_create(lv_scr_act(), NULL); /*Craete the chart*/
lv_obj_set_size(chart, lv_obj_get_width(scr) / 2, lv_obj_get_width(scr) / 4); /*Set the size*/
lv_obj_align(chart, slider, LV_ALIGN_OUT_BOTTOM_LEFT, 0, 20); /*Align below the slider*/
lv_chart_set_dl_width(chart, 3 * LV_DOWNSCALE); /*Set the line width (LV_DOWNSCALE compensates anti-aliasing if enabled)*/
/*Add a RED data line and set some points*/
lv_chart_dl_t * dl1 = lv_chart_add_data_line(chart, COLOR_RED);
lv_chart_set_next(chart, dl1, 10);
lv_chart_set_next(chart, dl1, 25);
lv_chart_set_next(chart, dl1, 45);
lv_chart_set_next(chart, dl1, 80);
/*Add a BLUE data line and set some points*/
lv_chart_dl_t * dl2 = lv_chart_add_data_line(chart, COLOR_MAKE(0x40, 0x70, 0xC0));
lv_chart_set_next(chart, dl2, 10);
lv_chart_set_next(chart, dl2, 25);
lv_chart_set_next(chart, dl2, 45);
lv_chart_set_next(chart, dl2, 80);
lv_chart_set_next(chart, dl2, 75);
lv_chart_set_next(chart, dl2, 505);
}
/**********************
* STATIC FUNCTIONS
**********************/
/**
* Called when a button is released
* @param btn pointer to the released button
* @param dispi pointer to caller display input (e.g. touchpad)
* @return LV_ACTION_RES_OK because the object is not deleted in this function
*/
static lv_action_res_t btn_rel_action(lv_obj_t * btn, lv_dispi_t * dispi)
{
/*Increase the button width*/
cord_t width = lv_obj_get_width(btn);
lv_obj_set_width(btn, width + 20);
return LV_ACTION_RES_OK;
}
/**
* Called when a new option is chosen in the drop down list
* @param ddlist pointer to the drop down list
* @param dispi pointer to caller display input (e.g. touchpad)
* @return LV_ACTION_RES_OK because the object is not deleted in this function
*/
static lv_action_res_t ddlist_action(lv_obj_t * ddlist, lv_dispi_t * dispi)
{
uint16_t opt = lv_ddlist_get_selected(ddlist); /*Get the id of selected option*/
lv_obj_t * slider = lv_obj_get_free_p(ddlist); /*Get the saved slider*/
lv_bar_set_value(slider, (opt * 100) / 4); /*Modify the slider value according to the selection*/
return LV_ACTION_RES_OK;
}
#endif /*USE_LV_EXAMPLE != 0*/