app/src/main/java/com/androidstudy/andelatrackchallenge/view/ScrimInsetsFrameLayout.java
package com.androidstudy.andelatrackchallenge.view;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.support.annotation.NonNull;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.WindowInsetsCompat;
import android.util.AttributeSet;
import android.widget.FrameLayout;
/**
* Created by anonymous on 11/4/17.
*/
public class ScrimInsetsFrameLayout extends FrameLayout {
Drawable mInsetForeground;
Rect mInsets;
private Rect mTempRect = new Rect();
public ScrimInsetsFrameLayout(Context context) {
this(context, null);
}
public ScrimInsetsFrameLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public ScrimInsetsFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
final TypedArray a = context.obtainStyledAttributes(attrs,
android.support.design.R.styleable.ScrimInsetsFrameLayout, defStyleAttr,
android.support.design.R.style.Widget_Design_ScrimInsetsFrameLayout);
mInsetForeground = a.getDrawable(android.support.design.R.styleable.ScrimInsetsFrameLayout_insetForeground);
a.recycle();
setWillNotDraw(true); // No need to draw until the insets are adjusted
ViewCompat.setOnApplyWindowInsetsListener(this,
(v, insets) -> {
if (null == mInsets) {
mInsets = new Rect();
}
mInsets.set(insets.getSystemWindowInsetLeft(),
insets.getSystemWindowInsetTop(),
insets.getSystemWindowInsetRight(),
insets.getSystemWindowInsetBottom());
onInsetsChanged(insets);
setWillNotDraw(!insets.hasSystemWindowInsets() || mInsetForeground == null);
ViewCompat.postInvalidateOnAnimation(ScrimInsetsFrameLayout.this);
return insets.consumeSystemWindowInsets();
});
}
@Override
public void draw(@NonNull 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);
}
}
protected void onInsetsChanged(WindowInsetsCompat insets) {
}
}