Java tutorial
/* * 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. */ package com.holmes.ponderosa.ui.debug; 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.util.AttributeSet; import android.widget.FrameLayout; import com.holmes.ponderosa.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). * <p> * Unlike the {@code ScrimInsetsFrameLayout} in the design support library, this variant does not * consume the insets. */ public final class NonConsumingScrimInsetsFrameLayout extends FrameLayout { private Drawable insetForeground; private Rect insets; private Rect tempRect = new Rect(); public NonConsumingScrimInsetsFrameLayout(Context context) { super(context); init(context, null, 0); } public NonConsumingScrimInsetsFrameLayout(Context context, AttributeSet attrs) { super(context, attrs); init(context, attrs, 0); } public NonConsumingScrimInsetsFrameLayout(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(context, attrs, defStyle); } private void init(Context context, AttributeSet attrs, int defStyle) { TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.NonConsumingScrimInsetsView, defStyle, 0); if (a == null) { return; } insetForeground = a.getDrawable(R.styleable.NonConsumingScrimInsetsView_insetForeground); a.recycle(); setWillNotDraw(true); } @Override protected boolean fitSystemWindows(@NonNull Rect insets) { this.insets = new Rect(insets); setWillNotDraw(insetForeground == null); ViewCompat.postInvalidateOnAnimation(this); return false; // Do not consume insets. } @Override public void draw(@NonNull Canvas canvas) { super.draw(canvas); int width = getWidth(); int height = getHeight(); if (insets != null && insetForeground != null) { int sc = canvas.save(); canvas.translate(getScrollX(), getScrollY()); // Top tempRect.set(0, 0, width, insets.top); insetForeground.setBounds(tempRect); insetForeground.draw(canvas); // Bottom tempRect.set(0, height - insets.bottom, width, height); insetForeground.setBounds(tempRect); insetForeground.draw(canvas); // Left tempRect.set(0, insets.top, insets.left, height - insets.bottom); insetForeground.setBounds(tempRect); insetForeground.draw(canvas); // Right tempRect.set(width - insets.right, insets.top, width, height - insets.bottom); insetForeground.setBounds(tempRect); insetForeground.draw(canvas); canvas.restoreToCount(sc); } } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); if (insetForeground != null) { insetForeground.setCallback(this); } } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); if (insetForeground != null) { insetForeground.setCallback(null); } } }