Java tutorial
/* * Copyright (C) 2015 The Android Open Source Project * * 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. */ package com.appeaser.sublimenavigationviewlibrary; 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.view.View; import android.widget.FrameLayout; /** * Borrowed from Support Design library */ public class ScrimInsetsFrameLayout extends FrameLayout { private Drawable mInsetForeground; private Rect mInsets; private Rect mTempRect; 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); this.mTempRect = new Rect(); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SnvScrimInsetsFrameLayout, defStyleAttr, R.style.SnvScrimInsetsFrameLayout); this.mInsetForeground = a.getDrawable(R.styleable.SnvScrimInsetsFrameLayout_snvInsetForeground); a.recycle(); this.setWillNotDraw(true); ViewCompat.setOnApplyWindowInsetsListener(this, new android.support.v4.view.OnApplyWindowInsetsListener() { public WindowInsetsCompat onApplyWindowInsets(View v, WindowInsetsCompat insets) { if (null == ScrimInsetsFrameLayout.this.mInsets) { ScrimInsetsFrameLayout.this.mInsets = new Rect(); } ScrimInsetsFrameLayout.this.mInsets.set(insets.getSystemWindowInsetLeft(), insets.getSystemWindowInsetTop(), insets.getSystemWindowInsetRight(), insets.getSystemWindowInsetBottom()); ScrimInsetsFrameLayout.this.setWillNotDraw(ScrimInsetsFrameLayout.this.mInsets.isEmpty() || ScrimInsetsFrameLayout.this.mInsetForeground == null); ViewCompat.postInvalidateOnAnimation(ScrimInsetsFrameLayout.this); return insets.consumeSystemWindowInsets(); } }); } public void draw(@NonNull Canvas canvas) { super.draw(canvas); int width = this.getWidth(); int height = this.getHeight(); if (mInsets != null && mInsetForeground != null) { int sc = canvas.save(); canvas.translate(getScrollX(), getScrollY()); this.mTempRect.set(0, 0, width, this.mInsets.top); this.mInsetForeground.setBounds(this.mTempRect); this.mInsetForeground.draw(canvas); this.mTempRect.set(0, height - this.mInsets.bottom, width, height); this.mInsetForeground.setBounds(this.mTempRect); this.mInsetForeground.draw(canvas); this.mTempRect.set(0, this.mInsets.top, this.mInsets.left, height - this.mInsets.bottom); this.mInsetForeground.setBounds(this.mTempRect); this.mInsetForeground.draw(canvas); this.mTempRect.set(width - this.mInsets.right, this.mInsets.top, width, height - this.mInsets.bottom); this.mInsetForeground.setBounds(this.mTempRect); this.mInsetForeground.draw(canvas); canvas.restoreToCount(sc); } } protected void onAttachedToWindow() { super.onAttachedToWindow(); if (this.mInsetForeground != null) { this.mInsetForeground.setCallback(this); } } protected void onDetachedFromWindow() { super.onDetachedFromWindow(); if (this.mInsetForeground != null) { this.mInsetForeground.setCallback(null); } } }