init Files

libraries/lvgl/examples/widgets/label/lv_example_label_4.c

@@ -0,0 +1,55 @@
+#include "../../lv_examples.h"
+
+#if LV_USE_LABEL && LV_FONT_MONTSERRAT_24 && LV_USE_CANVAS && LV_BUILD_EXAMPLES && LV_DRAW_SW_COMPLEX
+
+#define MASK_WIDTH 150
+#define MASK_HEIGHT 60
+
+static void generate_mask(lv_draw_buf_t * mask, int32_t w, int32_t h, const char * txt)
+{
+    /*Create a "8 bit alpha" canvas and clear it*/
+    lv_obj_t * canvas = lv_canvas_create(lv_screen_active());
+    lv_canvas_set_draw_buf(canvas, mask);
+    lv_canvas_fill_bg(canvas, lv_color_black(), LV_OPA_TRANSP);
+
+    lv_layer_t layer;
+    lv_canvas_init_layer(canvas, &layer);
+
+    /*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;
+    label_dsc.text = txt;
+    label_dsc.font = &lv_font_montserrat_24;
+    lv_area_t a = {0, 0, w - 1, h - 1};
+    lv_draw_label(&layer, &label_dsc, &a);
+
+    lv_canvas_finish_layer(canvas, &layer);
+
+    lv_obj_delete(canvas);
+}
+
+/**
+ * Draw label with gradient color
+ */
+void lv_example_label_4(void)
+{
+    /* Create the mask of a text by drawing it to a canvas*/
+    LV_DRAW_BUF_DEFINE_STATIC(mask, MASK_WIDTH, MASK_HEIGHT, LV_COLOR_FORMAT_L8);
+    LV_DRAW_BUF_INIT_STATIC(mask);
+
+    generate_mask(&mask, MASK_WIDTH, MASK_HEIGHT, "Text with gradient");
+
+    /* 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_screen_active());
+    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_set_style_bitmap_mask_src(grad, &mask, 0);
+}
+
+#endif