ScrimInsetsFrameLayout.java

package com.ladjzero.uzlee;


import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.support.v4.view.ViewCompat;
import android.util.AttributeSet;
import android.view.WindowInsets;
import android.widget.FrameLayout;


/**
 * A layout that draws something in the insets passed to {@link #fitSystemWindows(Rect)}, i.e. the area above UI chrome
 * (status and navigation bars, overlay action bars).
 */
public class ScrimInsetsFrameLayout extends FrameLayout {
	private Drawable mInsetForeground;

	private Rect mInsets;
	private Rect mTempRect = new Rect();

	public ScrimInsetsFrameLayout(Context context) {
		super(context);
		init(context, null, 0);
	}

	public ScrimInsetsFrameLayout(Context context, AttributeSet attrs) {
		super(context, attrs);
		init(context, attrs, 0);
	}

	public ScrimInsetsFrameLayout(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
		init(context, attrs, defStyle);
	}

	private void init(Context context, AttributeSet attrs, int defStyle) {
		final TypedArray a = context.obtainStyledAttributes(attrs,
				R.styleable.ScrimInsetsView, defStyle, 0);
		if (a == null) {
			return;
		}
		mInsetForeground = a.getDrawable(R.styleable.ScrimInsetsView_insetForeground);
		a.recycle();

		setWillNotDraw(true);

	}

	@Override
	public WindowInsets dispatchApplyWindowInsets(WindowInsets insets) {
		mInsets = new Rect();
		mInsets.bottom = insets.getSystemWindowInsetBottom();
		mInsets.top = insets.getSystemWindowInsetTop();
		mInsets.left = insets.getSystemWindowInsetLeft();
		mInsets.right = insets.getSystemWindowInsetRight();
		setWillNotDraw(mInsetForeground == null);
		ViewCompat.postInvalidateOnAnimation(this);
		return insets;
	}

	@Override
	protected boolean fitSystemWindows(Rect insets) {
		if (Build.VERSION.SDK_INT < 20) {
			mInsets = new Rect(insets);
			setWillNotDraw(mInsetForeground == null);
			ViewCompat.postInvalidateOnAnimation(this);
			return true; // consume insetsJH
		} else {
			return super.fitSystemWindows(insets);
		}
	}

	@Override
	public void draw(Canvas canvas) {
		super.draw(canvas);

		int width = getWidth();
		int height = getHeight();
		if (mInsets != null && mInsetForeground != null) {
			int sc = canvas.save();
			canvas.translate(getScrollX(), getScrollY());

			// Top
			mTempRect.set(0, 0, width, mInsets.top);
			mInsetForeground.setBounds(mTempRect);
			mInsetForeground.draw(canvas);

			// Bottom
			mTempRect.set(0, height - mInsets.bottom, width, height);
			mInsetForeground.setBounds(mTempRect);
			mInsetForeground.draw(canvas);

			// Left
			mTempRect.set(0, mInsets.top, mInsets.left, height - mInsets.bottom);
			mInsetForeground.setBounds(mTempRect);
			mInsetForeground.draw(canvas);

			// Right
			mTempRect.set(width - mInsets.right, mInsets.top, width, height - mInsets.bottom);
			mInsetForeground.setBounds(mTempRect);
			mInsetForeground.draw(canvas);

			canvas.restoreToCount(sc);
		}
	}

	@Override
	protected void onAttachedToWindow() {
		super.onAttachedToWindow();
		if (mInsetForeground != null) {
			mInsetForeground.setCallback(this);
		}
	}

	@Override
	protected void onDetachedFromWindow() {
		super.onDetachedFromWindow();
		if (mInsetForeground != null) {
			mInsetForeground.setCallback(null);
		}
	}
}