feat(test_keyboard): add keyboard test (#5739)

Signed-off-by: lhdjply <lhdjply@126.com>

tests/src/test_cases/widgets/test_keyboard.c

@@ -0,0 +1,41 @@
+#if LV_BUILD_TEST
+#include "../lvgl.h"
+
+#include "unity/unity.h"
+
+static lv_obj_t * active_screen = NULL;
+
+void setUp(void)
+{
+    active_screen = lv_screen_active();
+}
+
+void tearDown(void)
+{
+    lv_obj_clean(active_screen);
+}
+
+void test_keyboard_mode(void)
+{
+    lv_obj_t * keyboard  = lv_keyboard_create(active_screen);
+    lv_obj_set_size(keyboard, LV_PCT(100), LV_PCT(50));
+    lv_obj_align(keyboard, LV_ALIGN_BOTTOM_MID, 0, 0);
+    lv_obj_set_style_text_font(keyboard, &lv_font_dejavu_16_persian_hebrew, LV_PART_MAIN);
+    lv_keyboard_set_mode(keyboard, LV_KEYBOARD_MODE_TEXT_LOWER);
+
+    TEST_ASSERT_EQUAL_SCREENSHOT("widgets/keyboard_1.png");
+
+    lv_keyboard_set_mode(keyboard, LV_KEYBOARD_MODE_TEXT_UPPER);
+
+    TEST_ASSERT_EQUAL_SCREENSHOT("widgets/keyboard_2.png");
+
+    lv_keyboard_set_mode(keyboard, LV_KEYBOARD_MODE_SPECIAL);
+
+    TEST_ASSERT_EQUAL_SCREENSHOT("widgets/keyboard_3.png");
+
+    lv_keyboard_set_mode(keyboard, LV_KEYBOARD_MODE_NUMBER);
+
+    TEST_ASSERT_EQUAL_SCREENSHOT("widgets/keyboard_4.png");
+}
+
+#endif