init Files

libraries/lvgl/examples/widgets/button/lv_example_button_3.c

@@ -0,0 +1,45 @@
+#include "../../lv_examples.h"
+#if LV_BUILD_EXAMPLES && LV_USE_BUTTON
+
+/**
+ * Create a style transition on a button to act like a gum when clicked
+ */
+void lv_example_button_3(void)
+{
+    /*Properties to transition*/
+    static lv_style_prop_t props[] = {
+        LV_STYLE_TRANSFORM_WIDTH, LV_STYLE_TRANSFORM_HEIGHT, LV_STYLE_TEXT_LETTER_SPACE, 0
+    };
+
+    /*Transition descriptor when going back to the default state.
+     *Add some delay to be sure the press transition is visible even if the press was very short*/
+    static lv_style_transition_dsc_t transition_dsc_def;
+    lv_style_transition_dsc_init(&transition_dsc_def, props, lv_anim_path_overshoot, 250, 100, NULL);
+
+    /*Transition descriptor when going to pressed state.
+     *No delay, go to presses state immediately*/
+    static lv_style_transition_dsc_t transition_dsc_pr;
+    lv_style_transition_dsc_init(&transition_dsc_pr, props, lv_anim_path_ease_in_out, 250, 0, NULL);
+
+    /*Add only the new transition to he default state*/
+    static lv_style_t style_def;
+    lv_style_init(&style_def);
+    lv_style_set_transition(&style_def, &transition_dsc_def);
+
+    /*Add the transition and some transformation to the presses state.*/
+    static lv_style_t style_pr;
+    lv_style_init(&style_pr);
+    lv_style_set_transform_width(&style_pr, 10);
+    lv_style_set_transform_height(&style_pr, -10);
+    lv_style_set_text_letter_space(&style_pr, 10);
+    lv_style_set_transition(&style_pr, &transition_dsc_pr);
+
+    lv_obj_t * btn1 = lv_button_create(lv_screen_active());
+    lv_obj_align(btn1, LV_ALIGN_CENTER, 0, -80);
+    lv_obj_add_style(btn1, &style_pr, LV_STATE_PRESSED);
+    lv_obj_add_style(btn1, &style_def, 0);
+
+    lv_obj_t * label = lv_label_create(btn1);
+    lv_label_set_text(label, "Gum");
+}
+#endif