feat(examples): fix examples and add new scroll examples

examples/scroll/lv_example_scroll.h

@@ -0,0 +1,41 @@
+/**
+ * @file lv_example_scroll.h
+ *
+ */
+
+#ifndef LV_EXAMPLE_SCROLL_H
+#define LV_EXAMPLE_SCROLL_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*********************
+ *      INCLUDES
+ *********************/
+
+/*********************
+ *      DEFINES
+ *********************/
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+
+/**********************
+ * GLOBAL PROTOTYPES
+ **********************/
+void lv_example_scroll_1(void);
+void lv_example_scroll_2(void);
+void lv_example_scroll_3(void);
+void lv_example_scroll_4(void);
+
+/**********************
+ *      MACROS
+ **********************/
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /*LV_EXAMPLE_SCROLL_H*/

examples/scroll/lv_example_scroll_1.c

@@ -0,0 +1,48 @@
+#include "../../lvgl.h"
+#if LV_BUILD_EXAMPLES
+
+/**
+ * Demonstrate how scrolling appears automatically
+ */
+void lv_example_scroll_1(void)
+{
+    /*Create an object with the new style*/
+    lv_obj_t * panel = lv_obj_create(lv_scr_act(), NULL);
+    lv_obj_set_size(panel, 200, 200);
+    lv_obj_center(panel);
+
+    lv_obj_t * child;
+    lv_obj_t * label;
+
+    child = lv_obj_create(panel, NULL);
+    lv_obj_set_pos(child, 0, 0);
+    label = lv_label_create(child, NULL);
+    lv_label_set_text(label, "Zero");
+    lv_obj_center(label);
+
+    child = lv_obj_create(panel, NULL);
+    lv_obj_set_pos(child, -40, 100);
+    label = lv_label_create(child, NULL);
+    lv_label_set_text(label, "Left");
+    lv_obj_center(label);
+
+    child = lv_obj_create(panel, NULL);
+    lv_obj_set_pos(child, 90, -30);
+    label = lv_label_create(child, NULL);
+    lv_label_set_text(label, "Top");
+    lv_obj_center(label);
+
+    child = lv_obj_create(panel, NULL);
+    lv_obj_set_pos(child, 150, 80);
+    label = lv_label_create(child, NULL);
+    lv_label_set_text(label, "Right");
+    lv_obj_center(label);
+
+    child = lv_obj_create(panel, NULL);
+    lv_obj_set_pos(child, 60, 170);
+    label = lv_label_create(child, NULL);
+    lv_label_set_text(label, "Bottom");
+    lv_obj_center(label);
+}
+
+#endif

examples/scroll/lv_example_scroll_2.c

@@ -0,0 +1,51 @@
+#include "../../lvgl.h"
+#if LV_BUILD_EXAMPLES
+
+static void sw_event_cb(lv_obj_t * sw, lv_event_t e)
+{
+    if(e == LV_EVENT_VALUE_CHANGED) {
+        lv_obj_t * list = lv_event_get_user_data();
+
+        if(lv_obj_has_state(sw, LV_STATE_CHECKED)) lv_obj_add_flag(list, LV_OBJ_FLAG_SCROLL_ONE);
+        else lv_obj_clear_flag(list, LV_OBJ_FLAG_SCROLL_ONE);
+    }
+}
+
+/**
+ * Show an example to scroll snap
+ */
+void lv_example_scroll_2(void)
+{
+    lv_obj_t * list = lv_obj_create(lv_scr_act(), NULL);
+    lv_obj_set_size(list, 280, 150);
+    lv_obj_set_scroll_snap_align_x(list, LV_SCROLL_SNAP_ALIGN_CENTER);
+    lv_obj_set_layout(list, &lv_flex_queue);
+
+    uint32_t i;
+    for(i = 0; i < 10; i++) {
+        lv_obj_t * btn = lv_btn_create(list, NULL);
+        lv_obj_set_size(btn, 150, 100);
+
+        lv_obj_t * label = lv_label_create(btn, NULL);
+        if(i == 3) {
+            lv_label_set_text_fmt(label, "Panel %d\nno snap", i);
+            lv_obj_clear_flag(btn, LV_OBJ_FLAG_SNAPABLE);
+        } else {
+            lv_label_set_text_fmt(label, "Panel %d", i);
+        }
+
+        lv_obj_center(label);
+    }
+    lv_obj_update_snap(list, LV_ANIM_ON);
+
+
+    /*Switch between "One scroll" and "Normal scroll" mode*/
+    lv_obj_t * sw = lv_switch_create(lv_scr_act(), NULL);
+    lv_obj_align(sw, NULL, LV_ALIGN_IN_TOP_RIGHT, -20, 10);
+    lv_obj_add_event_cb(sw, sw_event_cb, list);
+    lv_obj_t * label = lv_label_create(lv_scr_act(), NULL);
+    lv_label_set_text(label, "One scroll");
+    lv_obj_align(label, sw, LV_ALIGN_OUT_BOTTOM_MID, 0, 10);
+}
+
+#endif