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58 lines
1.8 KiB
C
58 lines
1.8 KiB
C
#include "../../lv_examples.h"
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#if LV_USE_TINY_TTF && LV_BUILD_EXAMPLES && LV_USE_OBSERVER
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static void font_size_observer_cb(lv_subject_t * subject, lv_observer_t * observer);
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static lv_subject_t subject_font;
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/**
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* Change font size with Tiny_TTF
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*/
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void lv_example_tiny_ttf_3(void)
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{
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extern const uint8_t ubuntu_font[];
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extern const int ubuntu_font_size;
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lv_subject_init_int(&subject_font, 25);
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/*Create style with the new font*/
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static lv_style_t style;
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lv_style_init(&style);
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lv_font_t * font = lv_tiny_ttf_create_data(ubuntu_font, ubuntu_font_size, 25);
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lv_style_set_text_font(&style, font);
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lv_style_set_text_align(&style, LV_TEXT_ALIGN_CENTER);
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lv_obj_t * slider = lv_slider_create(lv_screen_active());
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lv_obj_center(slider);
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lv_slider_set_range(slider, 5, 50);
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lv_obj_align(slider, LV_ALIGN_BOTTOM_MID, 0, -50);
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lv_slider_bind_value(slider, &subject_font);
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lv_obj_t * slider_label = lv_label_create(lv_screen_active());
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lv_obj_align_to(slider_label, slider, LV_ALIGN_OUT_BOTTOM_MID, 0, 10);
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lv_label_bind_text(slider_label, &subject_font, "%d");
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/*Create a label with the new style*/
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lv_obj_t * label = lv_label_create(lv_screen_active());
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lv_obj_add_style(label, &style, 0);
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lv_obj_set_size(label, LV_SIZE_CONTENT, LV_SIZE_CONTENT);
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lv_label_set_text(label, "Hello world!");
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lv_obj_center(label);
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lv_subject_add_observer(&subject_font, font_size_observer_cb, &style);
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}
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static void font_size_observer_cb(lv_subject_t * subject, lv_observer_t * observer)
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{
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lv_style_t * style = observer->user_data;
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lv_style_value_t v;
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lv_style_get_prop(style, LV_STYLE_TEXT_FONT, &v);
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lv_font_t * font = (lv_font_t *) v.ptr;
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int32_t size = lv_subject_get_int(subject);
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lv_tiny_ttf_set_size(font, size);
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lv_obj_report_style_change(style);
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}
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#endif
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