Java tutorial
/* * Copyright (C) 2014 Charalampakis Basilis - Blur ActionBarDrawerToggle * * 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.sismics.bluractionbar; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.os.Build; import android.support.v4.app.ActionBarDrawerToggle; import android.support.v4.widget.DrawerLayout; import android.view.View; import android.view.ViewGroup; import android.view.animation.AlphaAnimation; import android.widget.ImageView; import android.widget.RelativeLayout; public class BlurActionBarDrawerToggle extends ActionBarDrawerToggle { private Context context; /** * the layout that we take snapshot */ private View mLayout; /** * an imageview to display the blurred snapshot/bitmap */ private ImageView mBlurredImageView; /** * Blur radius used for the background. */ private int mBlurRadius = 5; /** * Down scale factor to reduce blurring time and memory allocation. */ private float mDownScaleFactor = 5; /** * Render flag * * If true we must render * if false, we have already blurred the background */ private boolean prepareToRender = true; /** * flag for "fake" sliding detection */ private boolean isOpening = false; public BlurActionBarDrawerToggle(Activity activity, DrawerLayout drawerLayout, int drawerImageRes, int openDrawerContentDescRes, int closeDrawerContentDescRes) { super(activity, drawerLayout, drawerImageRes, openDrawerContentDescRes, closeDrawerContentDescRes); this.context = activity.getBaseContext(); } public BlurActionBarDrawerToggle(Activity activity, DrawerLayout drawerLayout, int drawerImageRes, int openDrawerContentDescRes, int closeDrawerContentDescRes, View layout) { super(activity, drawerLayout, drawerImageRes, openDrawerContentDescRes, closeDrawerContentDescRes); this.context = activity.getBaseContext(); init(layout, mBlurRadius); } public BlurActionBarDrawerToggle(Activity activity, DrawerLayout drawerLayout, int drawerImageRes, int openDrawerContentDescRes, int closeDrawerContentDescRes, View layout, int radius) { super(activity, drawerLayout, drawerImageRes, openDrawerContentDescRes, closeDrawerContentDescRes); this.context = activity.getBaseContext(); init(layout, radius); } public void init(final View layout) { init(layout, mBlurRadius); } /** * This function must be invoked if "default" (1st) constructor is called * or if you want to change the blurred layout. * <p/> * We make a fake ImageView with width and height MATCH_PARENT. * This ImageView will host the blurred snapshot/bitmap. * * @param layout A {@link android.widget.RelativeLayout} to take snapshot of it. * @param radius Blur radius */ public void init(final View layout, int radius) { this.mLayout = layout; this.mBlurRadius = radius; mBlurredImageView = new ImageView(context); RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT); mBlurredImageView.setLayoutParams(params); mBlurredImageView.setClickable(false); mBlurredImageView.setVisibility(View.GONE); mBlurredImageView.setScaleType(ImageView.ScaleType.FIT_XY); ((RelativeLayout) this.mLayout).addView(mBlurredImageView); } @Override public void onDrawerSlide(final View drawerView, final float slideOffset) { super.onDrawerSlide(drawerView, slideOffset); //must check this for "fake" sliding.. if (slideOffset == 0.f) isOpening = false; else isOpening = true; render(); setAlpha(mBlurredImageView, slideOffset, 100); } @Override public void onDrawerClosed(View view) { prepareToRender = true; mBlurredImageView.setVisibility(View.GONE); } @Override public void onDrawerStateChanged(int newState) { super.onDrawerStateChanged(newState); // "fake" sliding detection if (newState == DrawerLayout.STATE_IDLE && !isOpening) { handleRecycle(); } } /** * Snapshots the specified layout and scale it using scaleBitmap() function * then we blur the scaled bitmap with the preferred blur radius. * Finally, we post it to our fake {@link android.widget.ImageView}. */ private void render() { if (prepareToRender) { prepareToRender = false; Bitmap bitmap = loadBitmapFromView(mLayout); bitmap = scaleBitmap(bitmap); bitmap = Blur.fastblur(context, bitmap, mBlurRadius, false); mBlurredImageView.setVisibility(View.VISIBLE); mBlurredImageView.setImageBitmap(bitmap); } } public void setRadius(int radius) { mBlurRadius = radius < 1 ? 1 : radius; } public void setDownScaleFactor(float downScaleFactor) { mDownScaleFactor = downScaleFactor < 1 ? 1 : downScaleFactor; } private void setAlpha(View view, float alpha, long durationMillis) { if (Build.VERSION.SDK_INT < 11) { final AlphaAnimation animation = new AlphaAnimation(alpha, alpha); animation.setDuration(durationMillis); animation.setFillAfter(true); view.startAnimation(animation); } else { view.setAlpha(alpha); } } private Bitmap loadBitmapFromView(View mView) { Bitmap b = Bitmap.createBitmap(mView.getWidth(), mView.getHeight(), Bitmap.Config.ARGB_8888); Canvas c = new Canvas(b); // With the following, screen blinks //v.layout(0, 0, v.getLayoutParams().width, v.getLayoutParams().height); mView.draw(c); return b; } private Bitmap scaleBitmap(Bitmap myBitmap) { int width = (int) (myBitmap.getWidth() / mDownScaleFactor); int height = (int) (myBitmap.getHeight() / mDownScaleFactor); return Bitmap.createScaledBitmap(myBitmap, width, height, false); } private void handleRecycle() { Drawable drawable = mBlurredImageView.getDrawable(); if (drawable instanceof BitmapDrawable) { BitmapDrawable bitmapDrawable = ((BitmapDrawable) drawable); Bitmap bitmap = bitmapDrawable.getBitmap(); if (bitmap != null) bitmap.recycle(); mBlurredImageView.setImageBitmap(null); } prepareToRender = true; } }