Java tutorial
package com.florianmski.spongeframework.ui.widgets; /* * Copyright 2014 Google Inc. * * 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. */ 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.v4.view.ViewCompat; import android.util.AttributeSet; import android.widget.FrameLayout; import com.florianmski.spongeframework.R; /** * 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 DrawInsetsFrameLayout extends FrameLayout { private Drawable mInsetStatusBarBackground; private Drawable mInsetNavBarBackground; private Rect mInsets; private Rect mTempRect = new Rect(); private OnInsetsCallback mOnInsetsCallback; public DrawInsetsFrameLayout(Context context) { super(context); init(context, null, 0); } public DrawInsetsFrameLayout(Context context, AttributeSet attrs) { super(context, attrs); init(context, attrs, 0); } public DrawInsetsFrameLayout(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.DrawInsetsFrameLayout, defStyle, 0); if (a == null) { return; } mInsetStatusBarBackground = a.getDrawable(R.styleable.DrawInsetsFrameLayout_insetStatusBarBackground); mInsetNavBarBackground = a.getDrawable(R.styleable.DrawInsetsFrameLayout_insetNavBarBackground); a.recycle(); setWillNotDraw(true); } @Override protected boolean fitSystemWindows(Rect insets) { mInsets = new Rect(insets); setWillNotDraw(mInsetNavBarBackground == null); ViewCompat.postInvalidateOnAnimation(this); if (mOnInsetsCallback != null) { mOnInsetsCallback.onInsetsChanged(insets); } return true; // consume insets } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); int width = getWidth(); int height = getHeight(); if (mInsets != null && mInsetNavBarBackground != null) { // Top mTempRect.set(0, 0, width, mInsets.top); mInsetStatusBarBackground.setBounds(mTempRect); mInsetStatusBarBackground.draw(canvas); // Bottom mTempRect.set(0, height - mInsets.bottom, width, height); mInsetNavBarBackground.setBounds(mTempRect); mInsetNavBarBackground.draw(canvas); // Left mTempRect.set(0, mInsets.top, mInsets.left, height - mInsets.bottom); mInsetNavBarBackground.setBounds(mTempRect); mInsetNavBarBackground.draw(canvas); // Right mTempRect.set(width - mInsets.right, mInsets.top, width, height - mInsets.bottom); mInsetNavBarBackground.setBounds(mTempRect); mInsetNavBarBackground.draw(canvas); } } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); if (mInsetNavBarBackground != null) { mInsetNavBarBackground.setCallback(this); } } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); if (mInsetNavBarBackground != null) { mInsetNavBarBackground.setCallback(null); } } public void setInsetNavBarBackground(Drawable d) { mInsetNavBarBackground = d; invalidate(); } public void setInsetStatusBarBackground(Drawable d) { mInsetStatusBarBackground = d; invalidate(); } public Drawable getInsetStatusBarBackground() { return mInsetStatusBarBackground; } /** * Allows the calling container to specify a callback for custom processing when insets change (i.e. when * {@link #fitSystemWindows(Rect)} is called. This is useful for setting padding on UI elements based on * UI chrome insets (e.g. a Google Map or a ListView). When using with ListView or GridView, remember to set * clipToPadding to false. */ public void setOnInsetsCallback(OnInsetsCallback onInsetsCallback) { mOnInsetsCallback = onInsetsCallback; } public static interface OnInsetsCallback { public void onInsetsChanged(Rect insets); } }