github-code/lvgl
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

feat(example) add text with gradient example

Browse Source 
fixes #2778
This commit is contained in:
Gabor Kiss-Vamosi
2021-11-09 15:35:08 +01:00
parent cc78ef4506
commit 462fbcbf49
4 changed files with 71 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
examples/widgets/label/index.rst
View File

@@ -17,3 +17,9 @@ Show LTR, RTL and Chinese texts
.. lv_example:: widgets/label/lv_example_label_3
:language: c
Draw label with gradient color
""""""""""""""""""""""""""""""""""""
.. lv_example:: widgets/label/lv_example_label_4
:language: c

2
examples/widgets/label/lv_example_label_3.c
View File

@@ -2,7 +2,7 @@
#if LV_USE_LABEL && LV_BUILD_EXAMPLES && LV_FONT_DEJAVU_16_PERSIAN_HEBREW && LV_FONT_SIMSUN_16_CJK && LV_USE_BIDI
/**
* Show mixed LTR, RTL and Chiease label
* Show mixed LTR, RTL and Chinese label
*/
void lv_example_label_3(void)
{

63
examples/widgets/label/lv_example_label_4.c Normal file
View File

@@ -0,0 +1,63 @@
#include "../../lv_examples.h"
#if LV_USE_LABEL && LV_BUILD_EXAMPLES && LV_DRAW_COMPLEX
#define MASK_WIDTH 100
#define MASK_HEIGHT 45
static void add_mask_event_cb(lv_event_t * e)
{
static lv_draw_mask_map_param_t m;
static int16_t mask_id;
lv_event_code_t code = lv_event_get_code(e);
lv_obj_t * obj = lv_event_get_target(e);
lv_opa_t * mask_map = lv_event_get_user_data(e);
if(code == LV_EVENT_COVER_CHECK) {
lv_event_set_cover_res(e, LV_COVER_RES_MASKED);
}
else if(code == LV_EVENT_DRAW_MAIN_BEGIN) {
lv_draw_mask_map_init(&m, &obj->coords, mask_map);
mask_id = lv_draw_mask_add(&m, NULL);
}
else if(code == LV_EVENT_DRAW_MAIN_END) {
lv_draw_mask_free_param(&m);
lv_draw_mask_remove_id(mask_id);
}
}
/**
* Draw label with gradient color
*/
void lv_example_label_4(void)
{
/* Create the mask of a text by drawing it to a canvas*/
static lv_opa_t mask_map[MASK_WIDTH * MASK_HEIGHT];
/*Create a "8 bit alpha" canvas and clear it*/
lv_obj_t * canvas = lv_canvas_create(lv_scr_act());
lv_canvas_set_buffer(canvas, mask_map, MASK_WIDTH, MASK_HEIGHT, LV_IMG_CF_ALPHA_8BIT);
lv_canvas_fill_bg(canvas, lv_color_black(), LV_OPA_TRANSP);
/*Draw a label to the canvas. The result "image" will be used as mask*/
lv_draw_label_dsc_t label_dsc;
lv_draw_label_dsc_init(&label_dsc);
label_dsc.color = lv_color_white();
label_dsc.align = LV_TEXT_ALIGN_CENTER;
lv_canvas_draw_text(canvas, 5, 5, MASK_WIDTH, &label_dsc, "Text with gradient");
/*The mask is reads the canvas is not required anymore*/
lv_obj_del(canvas);
/* Create an object from where the text will be masked out.
* Now it's a rectangle with a gradient but it could be an image too*/
lv_obj_t * grad = lv_obj_create(lv_scr_act());
lv_obj_set_size(grad, MASK_WIDTH, MASK_HEIGHT);
lv_obj_center(grad);
lv_obj_set_style_bg_color(grad, lv_color_hex(0xff0000), 0);
lv_obj_set_style_bg_grad_color(grad, lv_color_hex(0x0000ff), 0);
lv_obj_set_style_bg_grad_dir(grad, LV_GRAD_DIR_HOR, 0);
lv_obj_add_event_cb(grad, add_mask_event_cb, LV_EVENT_ALL, mask_map);
}
#endif

1
examples/widgets/lv_example_widgets.h
View File

@@ -81,6 +81,7 @@ void lv_example_keyboard_1(void);
void lv_example_label_1(void);
void lv_example_label_2(void);
void lv_example_label_3(void);
void lv_example_label_4(void);
void lv_example_led_1(void);