Java tutorial
/* * Copyright 2014 Chris Banes * * 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.sckftr.android.app.view; import android.animation.ObjectAnimator; import android.content.Context; import android.content.res.Resources; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Rect; import android.graphics.drawable.ColorDrawable; import android.graphics.drawable.Drawable; import android.support.v4.view.ViewCompat; import android.util.AttributeSet; import android.widget.FrameLayout; import com.sckftr.android.securephoto.R; /** * A layout that draws something in the insets passed to {@link #fitSystemWindows(android.graphics.Rect)}, i.e. the * area above UI chrome (status and navigation bars, overlay action bars). */ public class InsetFrameLayout extends FrameLayout { private Drawable mDefaultInsetBackground; private Drawable mInsetBackground; // animation properties private int mStartColor, mEndColor; private float mAnimationProgress; private int mAnimationDuration = 300; private ObjectAnimator objectAnimator = ObjectAnimator .ofFloat(this, "animationProgress", 0f, (float) mAnimationDuration).setDuration(mAnimationDuration); private Rect mInsets; private Rect mTempRect = new Rect(); private OnInsetsCallback mOnInsetsCallback; private int mTopAlpha = 255; public InsetFrameLayout(Context context) { super(context); init(context, null, 0); } public InsetFrameLayout(Context context, AttributeSet attrs) { super(context, attrs); init(context, attrs, 0); } public InsetFrameLayout(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; mDefaultInsetBackground = mInsetBackground = a .getDrawable(R.styleable.DrawInsetsFrameLayout_insetBackground); a.recycle(); setWillNotDraw(true); } @Override protected boolean fitSystemWindows(Rect insets) { mInsets = new Rect(insets); setWillNotDraw(mInsetBackground == null); ViewCompat.postInvalidateOnAnimation(this); if (mOnInsetsCallback != null) mOnInsetsCallback.onInsetsChanged(insets); return true; // consume insets } @Override public void draw(Canvas canvas) { super.draw(canvas); if (mInsets != null && mInsetBackground != null) { // Top mTempRect.set(0, 0, getWidth(), mInsets.top); mInsetBackground.setBounds(mTempRect); mInsetBackground.setAlpha(mTopAlpha); mInsetBackground.draw(canvas); } } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); if (mInsetBackground != null) { mInsetBackground.setCallback(this); } } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); if (mInsetBackground != null) mInsetBackground.setCallback(null); if (objectAnimator.isRunning()) objectAnimator.cancel(); } public void resetInsetBackground() { if (mInsetBackground != mDefaultInsetBackground) { setInsetBackground(mDefaultInsetBackground); } } /** * Allows the calling container to specify a callback for custom processing when insets change * (i.e. when {@link #fitSystemWindows(android.graphics.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 void setTopInsetAlpha(int alpha) { mTopAlpha = alpha; ViewCompat.postInvalidateOnAnimation(this); } public void setInsetBackgroundColor(int color) { // Resources r = getResources(); setInsetBackgroundColorRaw( Color.argb(Color.alpha(color), Color.red(color), Color.green(color), Color.blue(color))); } void setInsetBackgroundColorRaw(int color) { setInsetBackground(new ColorDrawable(color)); } private void setInsetBackground(Drawable background) { if (mInsetBackground != null) mInsetBackground.setCallback(null); mInsetBackground = background; if (mInsetBackground != null && getWindowToken() != null) mInsetBackground.setCallback(this); ViewCompat.postInvalidateOnAnimation(this); } public void setAnimationProgress(float progress) { this.mAnimationProgress = progress; float fraction = progress / (float) mAnimationDuration; setInsetBackgroundColor(Color.argb(evaluate(fraction, Color.alpha(mStartColor), Color.alpha(mEndColor)), //alpha evaluate(fraction, Color.red(mStartColor), Color.red(mEndColor)), // red evaluate(fraction, Color.green(mStartColor), Color.green(mEndColor)), // green evaluate(fraction, Color.blue(mStartColor), Color.blue(mEndColor)))); // blue } public float getAnimationProgress() { return mAnimationProgress; } private static int evaluate(float fraction, int startValue, int endValue) { return (int) (startValue + fraction * (endValue - startValue)); } public void setBackgroundDrawableWithAnimation(int colorResId) { Resources resources = getResources(); if (mInsetBackground == null) mInsetBackground = new ColorDrawable(resources.getColor(android.R.color.transparent)); if (!(mInsetBackground instanceof ColorDrawable)) throw new IllegalArgumentException("Can't animate background changing from non-ColorDrawable!"); mStartColor = ((ColorDrawable) mInsetBackground).getColor(); mEndColor = resources.getColor(colorResId); if (objectAnimator.isRunning()) objectAnimator.cancel(); objectAnimator.start(); } public void setBackgroundDrawableWithAnimation(int startColorResID, int endColorResID) { Resources resources = getResources(); if (mInsetBackground == null) mInsetBackground = new ColorDrawable(resources.getColor(startColorResID)); mStartColor = resources.getColor(startColorResID); mEndColor = resources.getColor(endColorResID); if (objectAnimator.isRunning()) objectAnimator.cancel(); objectAnimator.start(); } public static interface OnInsetsCallback { public void onInsetsChanged(Rect insets); } }