[Change]

开始USB摄像头的功能集成，还无法获取usb连接广播需要调试

Signed-off-by: donghongyu <donghongyu@zhidaoauto.com>

libraries/map-usbcamera/src/main/java/com/serenegiant/usb/ParentPreviewConstraintLayout.java

@@ -0,0 +1,47 @@
+package com.serenegiant.usb;
+
+import android.content.Context;
+import android.util.AttributeSet;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.constraintlayout.widget.ConstraintLayout;
+
+/**
+ * @author mogoauto
+ */
+public abstract class ParentPreviewConstraintLayout extends ConstraintLayout {
+    private boolean mDestroyed;
+
+    public ParentPreviewConstraintLayout(@NonNull Context context) {
+        super(context);
+    }
+
+    public ParentPreviewConstraintLayout(@NonNull Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public ParentPreviewConstraintLayout(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public ParentPreviewConstraintLayout(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    public boolean isDestroyed() {
+        return mDestroyed;
+    }
+
+    @Override
+    protected void onAttachedToWindow() {
+        super.onAttachedToWindow();
+        mDestroyed = false;
+    }
+
+    @Override
+    protected void onDetachedFromWindow() {
+        super.onDetachedFromWindow();
+        mDestroyed = true;
+    }
+}