optimize module floaty and add two samples

app/src/main/assets/sample/悬浮窗/动态悬浮文字.js

@@ -0,0 +1,32 @@
+var window = floaty.window(
+    <frame gravity="center">
+        <text id="text" textSize="16sp" textColor="#f44336"/>
+    </frame>
+);
+
+window.text.click(()=>{
+    window.setAdjustEnabled(!window.isAdjustEnabled());
+});
+
+setInterval(()=>{
+    //对控件的操作需要在UI线程中执行
+    ui.run(function(){
+        window.text.setText(dynamicText());
+    });
+}, 1000);
+
+function dynamicText(){
+    var date = new Date();
+    var str = util.format("时间: %d:%d:%d\n", date.getHours(), date.getMinutes(), date.getSeconds());
+    str += util.format("内存使用量: %d%%\n", getMemoryUsage());
+    str += "当前活动: " + currentActivity() + "\n";
+    str += "当前包名: " + currentPackage();
+    return str;
+}
+
+//获取内存使用率
+function getMemoryUsage(){
+    var usage = (100 * device.getAvailMem() / device.getTotalMem());
+    //保留一位小数
+    return Math.round(usage * 10) / 10;
+}

app/src/main/assets/sample/悬浮窗/悬浮文字.js

@@ -0,0 +1,11 @@
+var window = floaty.window(
+    <frame gravity="center">
+        <text id="text" text="点击可调整位置" textSize="16sp"/>
+    </frame>
+);
+
+window.text.click(()=>{
+    window.setAdjustEnabled(!window.isAdjustEnabled());
+});
+
+setInterval(()=>{}, 1000);