Implement 2D graphic API (#87)

* Implement 2D graphic library based on LittlevGL

* Add lvgl license file

samples/simple/wasm-apps/gui.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2019 Intel Corporation.  All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#include <stdlib.h>
+#include <unistd.h>
+#include "wasm_app.h"
+
+static void btn_event_cb(wgl_obj_t btn, wgl_event_t event);
+
+uint32_t count = 0;
+char count_str[11] = { 0 };
+wgl_obj_t hello_world_label;
+wgl_obj_t count_label;
+wgl_obj_t btn1;
+wgl_obj_t label_count1;
+int label_count1_value = 0;
+char label_count1_str[11] = { 0 };
+
+void timer1_update(user_timer_t timer1)
+{
+    if ((count % 100) == 0) {
+        sprintf(count_str, "%d", count / 100);
+        wgl_label_set_text(count_label, count_str);
+    }
+    ++count;
+}
+
+void on_init()
+{
+    char text[32] = {0};
+
+    hello_world_label = wgl_label_create((wgl_obj_t)NULL, (wgl_obj_t)NULL);
+    wgl_label_set_text(hello_world_label, "Hello world!");
+    wgl_label_get_text(hello_world_label, text, sizeof(text));
+    printf("Label text %d %s \n", wgl_label_get_text_length(hello_world_label), text);
+    wgl_obj_align(hello_world_label, (wgl_obj_t)NULL, WGL_ALIGN_IN_TOP_LEFT, 0, 0);
+
+    count_label = wgl_label_create((wgl_obj_t)NULL, (wgl_obj_t)NULL);
+    wgl_obj_align(count_label, (wgl_obj_t)NULL, WGL_ALIGN_IN_TOP_MID, 0, 0);
+
+    btn1 = wgl_btn_create((wgl_obj_t)NULL, (wgl_obj_t)NULL); /*Create a button on the currently loaded screen*/
+    wgl_obj_set_event_cb(btn1, btn_event_cb); /*Set function to be called when the button is released*/
+    wgl_obj_align(btn1, (wgl_obj_t)NULL, WGL_ALIGN_CENTER, 0, 0); /*Align below the label*/
+
+    /*Create a label on the button*/
+    wgl_obj_t btn_label = wgl_label_create(btn1, (wgl_obj_t)NULL);
+    wgl_label_set_text(btn_label, "Click ++");
+
+    label_count1 = wgl_label_create((wgl_obj_t)NULL, (wgl_obj_t)NULL);
+    wgl_label_set_text(label_count1, "0");
+    wgl_obj_align(label_count1, (wgl_obj_t)NULL, WGL_ALIGN_IN_BOTTOM_MID, 0, 0);
+
+    /* set up a timer */
+    user_timer_t timer;
+    timer = api_timer_create(10, true, false, timer1_update);
+    api_timer_restart(timer, 10);
+}
+
+static void btn_event_cb(wgl_obj_t btn, wgl_event_t event)
+{
+    if(event == WGL_EVENT_RELEASED) {
+        label_count1_value++;
+        sprintf(label_count1_str, "%d", label_count1_value);
+        wgl_label_set_text(label_count1, label_count1_str);
+    }
+}

samples/simple/wasm-apps/gui_lvgl_compatible.c

@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2019 Intel Corporation.  All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include "wasm_app.h"
+#include "lvgl.h"
+
+extern char g_widget_text[];
+
+static void btn_event_cb(lv_obj_t *btn, lv_event_t event);
+
+uint32_t count = 0;
+char count_str[11] = { 0 };
+lv_obj_t *hello_world_label;
+lv_obj_t *count_label;
+lv_obj_t *btn1;
+lv_obj_t *label_count1;
+int label_count1_value = 0;
+char label_count1_str[11] = { 0 };
+
+void timer1_update(user_timer_t timer1)
+{
+    if ((count % 100) == 0) {
+        sprintf(count_str, "%d", count / 100);
+        lv_label_set_text(count_label, count_str);
+    }
+    ++count;
+}
+
+void on_init()
+{
+    char *text;
+
+    hello_world_label = lv_label_create(NULL, NULL);
+    lv_label_set_text(hello_world_label, "Hello world!");
+    text = lv_label_get_text(hello_world_label);
+    printf("Label text %lu %s \n", strlen(text), text);
+    lv_obj_align(hello_world_label, NULL, LV_ALIGN_IN_TOP_LEFT, 0, 0);
+
+    count_label = lv_label_create(NULL, NULL);
+    lv_obj_align(count_label, NULL, LV_ALIGN_IN_TOP_MID, 0, 0);
+
+    btn1 = lv_btn_create(NULL, NULL); /*Create a button on the currently loaded screen*/
+    lv_obj_set_event_cb(btn1, btn_event_cb); /*Set function to be called when the button is released*/
+    lv_obj_align(btn1, NULL, LV_ALIGN_CENTER, 0, 0); /*Align below the label*/
+
+    /*Create a label on the button*/
+    lv_obj_t *btn_label = lv_label_create(btn1, NULL);
+    lv_label_set_text(btn_label, "Click ++");
+
+    label_count1 = lv_label_create(NULL, NULL);
+    lv_label_set_text(label_count1, "0");
+    lv_obj_align(label_count1, NULL, LV_ALIGN_IN_BOTTOM_MID, 0, 0);
+
+    /* set up a timer */
+    user_timer_t timer;
+    timer = api_timer_create(10, true, false, timer1_update);
+    api_timer_restart(timer, 10);
+}
+
+static void btn_event_cb(lv_obj_t *btn, lv_event_t event)
+{
+    if(event == LV_EVENT_RELEASED) {
+        label_count1_value++;
+        sprintf(label_count1_str, "%d", label_count1_value);
+        lv_label_set_text(label_count1, label_count1_str);
+    }
+}