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83 lines
2.7 KiB
C
83 lines
2.7 KiB
C
#include "../../lv_examples.h"
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#if LV_USE_ROLLER && LV_DRAW_SW_COMPLEX && LV_BUILD_EXAMPLES && 1
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static void generate_mask(lv_draw_buf_t * mask)
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{
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/*Create a "8 bit alpha" canvas and clear it*/
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lv_obj_t * canvas = lv_canvas_create(lv_screen_active());
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lv_canvas_set_draw_buf(canvas, mask);
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lv_canvas_fill_bg(canvas, lv_color_white(), LV_OPA_TRANSP);
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lv_layer_t layer;
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lv_canvas_init_layer(canvas, &layer);
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/*Draw a label to the canvas. The result "image" will be used as mask*/
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lv_draw_rect_dsc_t rect_dsc;
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lv_draw_rect_dsc_init(&rect_dsc);
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rect_dsc.bg_grad.dir = LV_GRAD_DIR_VER;
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rect_dsc.bg_grad.stops[0].color = lv_color_black();
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rect_dsc.bg_grad.stops[1].color = lv_color_white();
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rect_dsc.bg_grad.stops[0].opa = LV_OPA_COVER;
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rect_dsc.bg_grad.stops[1].opa = LV_OPA_COVER;
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lv_area_t a = {0, 0, mask->header.w - 1, mask->header.h / 2 - 10};
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lv_draw_rect(&layer, &rect_dsc, &a);
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a.y1 = mask->header.h / 2 + 10;
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a.y2 = mask->header.h - 1;
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rect_dsc.bg_grad.stops[0].color = lv_color_white();
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rect_dsc.bg_grad.stops[1].color = lv_color_black();
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lv_draw_rect(&layer, &rect_dsc, &a);
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lv_canvas_finish_layer(canvas, &layer);
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/*Comment it to make the mask visible*/
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lv_obj_delete(canvas);
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}
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/**
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* Add a fade mask to roller.
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*/
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void lv_example_roller_3(void)
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{
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lv_obj_set_style_bg_color(lv_screen_active(), lv_palette_main(LV_PALETTE_BLUE_GREY), 0);
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static lv_style_t style;
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lv_style_init(&style);
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lv_style_set_bg_color(&style, lv_color_black());
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lv_style_set_text_color(&style, lv_color_white());
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lv_style_set_border_width(&style, 0);
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lv_style_set_radius(&style, 0);
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lv_obj_t * roller1 = lv_roller_create(lv_screen_active());
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lv_obj_add_style(roller1, &style, 0);
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lv_obj_set_style_bg_opa(roller1, LV_OPA_50, LV_PART_SELECTED);
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lv_roller_set_options(roller1,
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"January\n"
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"February\n"
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"March\n"
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"April\n"
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"May\n"
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"June\n"
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"July\n"
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"August\n"
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"September\n"
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"October\n"
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"November\n"
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"December",
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LV_ROLLER_MODE_NORMAL);
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lv_obj_center(roller1);
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lv_roller_set_visible_row_count(roller1, 4);
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/* Create the mask to make the top and bottom part of roller faded.
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* The width and height are empirical values for simplicity*/
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LV_DRAW_BUF_DEFINE_STATIC(mask, 130, 150, LV_COLOR_FORMAT_L8);
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LV_DRAW_BUF_INIT_STATIC(mask);
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generate_mask(&mask);
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lv_obj_set_style_bitmap_mask_src(roller1, &mask, 0);
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}
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#endif
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