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Android example source code file (WallpaperManager.java)

This example Android source code file (WallpaperManager.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" TM.

Java - Android tags/keywords

android, bitmap, bundle, drawable, drawing, fastbitmapdrawable, fileoutputstream, globals, graphics, ioexception, not, os, override, paint, parcelfiledescriptor, remoteexception, string, ui, unsupportedoperationexception, wallpapermanager

The WallpaperManager.java Android example source code

/*
 * Copyright (C) 2009 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 android.app;

import android.content.Context;
import android.content.Intent;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.os.Message;
import android.os.ParcelFileDescriptor;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.ViewRoot;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * Provides access to the system wallpaper. With WallpaperManager, you can
 * get the current wallpaper, get the desired dimensions for the wallpaper, set
 * the wallpaper, and more. Get an instance of WallpaperManager with
 * {@link #getInstance(android.content.Context) getInstance()}. 
 */
public class WallpaperManager {
    private static String TAG = "WallpaperManager";
    private static boolean DEBUG = false;
    private float mWallpaperXStep = -1;
    private float mWallpaperYStep = -1;

    /**
     * Launch an activity for the user to pick the current global live
     * wallpaper.
     */
    public static final String ACTION_LIVE_WALLPAPER_CHOOSER
            = "android.service.wallpaper.LIVE_WALLPAPER_CHOOSER";
    
    /**
     * Command for {@link #sendWallpaperCommand}: reported by the wallpaper
     * host when the user taps on an empty area (not performing an action
     * in the host).  The x and y arguments are the location of the tap in
     * screen coordinates.
     */
    public static final String COMMAND_TAP = "android.wallpaper.tap";
    
    /**
     * Command for {@link #sendWallpaperCommand}: reported by the wallpaper
     * host when the user drops an object into an area of the host.  The x
     * and y arguments are the location of the drop.
     */
    public static final String COMMAND_DROP = "android.home.drop";
    
    private final Context mContext;
    
    /**
     * Special drawable that draws a wallpaper as fast as possible.  Assumes
     * no scaling or placement off (0,0) of the wallpaper (this should be done
     * at the time the bitmap is loaded).
     */
    static class FastBitmapDrawable extends Drawable {
        private final Bitmap mBitmap;
        private final int mWidth;
        private final int mHeight;
        private int mDrawLeft;
        private int mDrawTop;

        private FastBitmapDrawable(Bitmap bitmap) {
            mBitmap = bitmap;
            mWidth = bitmap.getWidth();
            mHeight = bitmap.getHeight();
            setBounds(0, 0, mWidth, mHeight);
        }

        @Override
        public void draw(Canvas canvas) {
            canvas.drawBitmap(mBitmap, mDrawLeft, mDrawTop, null);
        }

        @Override
        public int getOpacity() {
            return PixelFormat.OPAQUE;
        }

        @Override
        public void setBounds(int left, int top, int right, int bottom) {
            mDrawLeft = left + (right-left - mWidth) / 2;
            mDrawTop = top + (bottom-top - mHeight) / 2;
        }

        @Override
        public void setBounds(Rect bounds) {
            // TODO Auto-generated method stub
            super.setBounds(bounds);
        }

        @Override
        public void setAlpha(int alpha) {
            throw new UnsupportedOperationException(
                    "Not supported with this drawable");
        }

        @Override
        public void setColorFilter(ColorFilter cf) {
            throw new UnsupportedOperationException(
                    "Not supported with this drawable");
        }

        @Override
        public void setDither(boolean dither) {
            throw new UnsupportedOperationException(
                    "Not supported with this drawable");
        }

        @Override
        public void setFilterBitmap(boolean filter) {
            throw new UnsupportedOperationException(
                    "Not supported with this drawable");
        }

        @Override
        public int getIntrinsicWidth() {
            return mWidth;
        }

        @Override
        public int getIntrinsicHeight() {
            return mHeight;
        }

        @Override
        public int getMinimumWidth() {
            return mWidth;
        }

        @Override
        public int getMinimumHeight() {
            return mHeight;
        }
    }
    
    static class Globals extends IWallpaperManagerCallback.Stub {
        private IWallpaperManager mService;
        private Bitmap mWallpaper;
        private Bitmap mDefaultWallpaper;
        
        private static final int MSG_CLEAR_WALLPAPER = 1;
        
        private final Handler mHandler;
        
        Globals(Looper looper) {
            IBinder b = ServiceManager.getService(Context.WALLPAPER_SERVICE);
            mService = IWallpaperManager.Stub.asInterface(b);
            mHandler = new Handler(looper) {
                @Override
                public void handleMessage(Message msg) {
                    switch (msg.what) {
                        case MSG_CLEAR_WALLPAPER:
                            synchronized (this) {
                                mWallpaper = null;
                                mDefaultWallpaper = null;
                            }
                            break;
                    }
                }
            };
        }
        
        public void onWallpaperChanged() {
            /* The wallpaper has changed but we shouldn't eagerly load the
             * wallpaper as that would be inefficient. Reset the cached wallpaper
             * to null so if the user requests the wallpaper again then we'll
             * fetch it.
             */
            mHandler.sendEmptyMessage(MSG_CLEAR_WALLPAPER);
        }
        
        public Bitmap peekWallpaperBitmap(Context context, boolean returnDefault) {
            synchronized (this) {
                if (mWallpaper != null) {
                    return mWallpaper;
                }
                if (mDefaultWallpaper != null) {
                    return mDefaultWallpaper;
                }
                mWallpaper = null;
                try {
                    mWallpaper = getCurrentWallpaperLocked(context);
                } catch (OutOfMemoryError e) {
                    Log.w(TAG, "No memory load current wallpaper", e);
                }
                if (mWallpaper == null && returnDefault) {
                    mDefaultWallpaper = getDefaultWallpaperLocked(context);
                    return mDefaultWallpaper;
                }
                return mWallpaper;
            }
        }
        
        private Bitmap getCurrentWallpaperLocked(Context context) {
            try {
                Bundle params = new Bundle();
                ParcelFileDescriptor fd = mService.getWallpaper(this, params);
                if (fd != null) {
                    int width = params.getInt("width", 0);
                    int height = params.getInt("height", 0);
                    
                    if (width <= 0 || height <= 0) {
                        // Degenerate case: no size requested, just load
                        // bitmap as-is.
                        Bitmap bm = BitmapFactory.decodeFileDescriptor(
                                fd.getFileDescriptor(), null, null);
                        try {
                            fd.close();
                        } catch (IOException e) {
                        }
                        if (bm != null) {
                            bm.setDensity(DisplayMetrics.DENSITY_DEVICE);
                        }
                        return bm;
                    }
                    
                    // Load the bitmap with full color depth, to preserve
                    // quality for later processing.
                    BitmapFactory.Options options = new BitmapFactory.Options();
                    options.inDither = false;
                    options.inPreferredConfig = Bitmap.Config.ARGB_8888;
                    Bitmap bm = BitmapFactory.decodeFileDescriptor(
                            fd.getFileDescriptor(), null, options);
                    try {
                        fd.close();
                    } catch (IOException e) {
                    }
                    
                    return generateBitmap(context, bm, width, height);
                }
            } catch (RemoteException e) {
            }
            return null;
        }
        
        private Bitmap getDefaultWallpaperLocked(Context context) {
            try {
                InputStream is = context.getResources().openRawResource(
                        com.android.internal.R.drawable.default_wallpaper);
                if (is != null) {
                    int width = mService.getWidthHint();
                    int height = mService.getHeightHint();
                    
                    if (width <= 0 || height <= 0) {
                        // Degenerate case: no size requested, just load
                        // bitmap as-is.
                        Bitmap bm = BitmapFactory.decodeStream(is, null, null);
                        try {
                            is.close();
                        } catch (IOException e) {
                        }
                        if (bm != null) {
                            bm.setDensity(DisplayMetrics.DENSITY_DEVICE);
                        }
                        return bm;
                    }
                    
                    // Load the bitmap with full color depth, to preserve
                    // quality for later processing.
                    BitmapFactory.Options options = new BitmapFactory.Options();
                    options.inDither = false;
                    options.inPreferredConfig = Bitmap.Config.ARGB_8888;
                    Bitmap bm = BitmapFactory.decodeStream(is, null, options);
                    try {
                        is.close();
                    } catch (IOException e) {
                    }
                    
                    try {
                        return generateBitmap(context, bm, width, height);
                    } catch (OutOfMemoryError e) {
                        Log.w(TAG, "Can't generate default bitmap", e);
                        return bm;
                    }
                }
            } catch (RemoteException e) {
            }
            return null;
        }
    }
    
    private static Object mSync = new Object();
    private static Globals sGlobals;

    static void initGlobals(Looper looper) {
        synchronized (mSync) {
            if (sGlobals == null) {
                sGlobals = new Globals(looper);
            }
        }
    }
    
    /*package*/ WallpaperManager(Context context, Handler handler) {
        mContext = context;
        initGlobals(context.getMainLooper());
    }

    /**
     * Retrieve a WallpaperManager associated with the given Context.
     */
    public static WallpaperManager getInstance(Context context) {
        return (WallpaperManager)context.getSystemService(
                Context.WALLPAPER_SERVICE);
    }
    
    /** @hide */
    public IWallpaperManager getIWallpaperManager() {
        return sGlobals.mService;
    }
    
    /**
     * Retrieve the current system wallpaper; if
     * no wallpaper is set, the system default wallpaper is returned.
     * This is returned as an
     * abstract Drawable that you can install in a View to display whatever
     * wallpaper the user has currently set. 
     *
     * @return Returns a Drawable object that will draw the wallpaper.
     */
    public Drawable getDrawable() {
        Bitmap bm = sGlobals.peekWallpaperBitmap(mContext, true);
        if (bm != null) {
            Drawable dr = new BitmapDrawable(mContext.getResources(), bm);
            dr.setDither(false);
            return dr;
        }
        return null;
    }

    /**
     * Retrieve the current system wallpaper; if there is no wallpaper set,
     * a null pointer is returned. This is returned as an
     * abstract Drawable that you can install in a View to display whatever
     * wallpaper the user has currently set.  
     *
     * @return Returns a Drawable object that will draw the wallpaper or a
     * null pointer if these is none.
     */
    public Drawable peekDrawable() {
        Bitmap bm = sGlobals.peekWallpaperBitmap(mContext, false);
        if (bm != null) {
            Drawable dr = new BitmapDrawable(mContext.getResources(), bm);
            dr.setDither(false);
            return dr;
        }
        return null;
    }

    /**
     * Like {@link #getDrawable()}, but the returned Drawable has a number
     * of limitations to reduce its overhead as much as possible. It will
     * never scale the wallpaper (only centering it if the requested bounds
     * do match the bitmap bounds, which should not be typical), doesn't
     * allow setting an alpha, color filter, or other attributes, etc.  The
     * bounds of the returned drawable will be initialized to the same bounds
     * as the wallpaper, so normally you will not need to touch it.  The
     * drawable also assumes that it will be used in a context running in
     * the same density as the screen (not in density compatibility mode).
     *
     * @return Returns a Drawable object that will draw the wallpaper.
     */
    public Drawable getFastDrawable() {
        Bitmap bm = sGlobals.peekWallpaperBitmap(mContext, true);
        if (bm != null) {
            Drawable dr = new FastBitmapDrawable(bm);
            return dr;
        }
        return null;
    }

    /**
     * Like {@link #getFastDrawable()}, but if there is no wallpaper set,
     * a null pointer is returned.
     *
     * @return Returns an optimized Drawable object that will draw the
     * wallpaper or a null pointer if these is none.
     */
    public Drawable peekFastDrawable() {
        Bitmap bm = sGlobals.peekWallpaperBitmap(mContext, false);
        if (bm != null) {
            Drawable dr = new FastBitmapDrawable(bm);
            return dr;
        }
        return null;
    }

    /**
     * If the current wallpaper is a live wallpaper component, return the
     * information about that wallpaper.  Otherwise, if it is a static image,
     * simply return null.
     */
    public WallpaperInfo getWallpaperInfo() {
        try {
            return sGlobals.mService.getWallpaperInfo();
        } catch (RemoteException e) {
            return null;
        }
    }
    
    /**
     * Change the current system wallpaper to the bitmap in the given resource.
     * The resource is opened as a raw data stream and copied into the
     * wallpaper; it must be a valid PNG or JPEG image.  On success, the intent
     * {@link Intent#ACTION_WALLPAPER_CHANGED} is broadcast.
     *
     * @param resid The bitmap to save.
     *
     * @throws IOException If an error occurs reverting to the default
     * wallpaper.
     */
    public void setResource(int resid) throws IOException {
        try {
            Resources resources = mContext.getResources();
            /* Set the wallpaper to the default values */
            ParcelFileDescriptor fd = sGlobals.mService.setWallpaper(
                    "res:" + resources.getResourceName(resid));
            if (fd != null) {
                FileOutputStream fos = null;
                try {
                    fos = new ParcelFileDescriptor.AutoCloseOutputStream(fd);
                    setWallpaper(resources.openRawResource(resid), fos);
                } finally {
                    if (fos != null) {
                        fos.close();
                    }
                }
            }
        } catch (RemoteException e) {
        }
    }
    
    /**
     * Change the current system wallpaper to a bitmap.  The given bitmap is
     * converted to a PNG and stored as the wallpaper.  On success, the intent
     * {@link Intent#ACTION_WALLPAPER_CHANGED} is broadcast.
     *
     * @param bitmap The bitmap to save.
     *
     * @throws IOException If an error occurs reverting to the default
     * wallpaper.
     */
    public void setBitmap(Bitmap bitmap) throws IOException {
        try {
            ParcelFileDescriptor fd = sGlobals.mService.setWallpaper(null);
            if (fd == null) {
                return;
            }
            FileOutputStream fos = null;
            try {
                fos = new ParcelFileDescriptor.AutoCloseOutputStream(fd);
                bitmap.compress(Bitmap.CompressFormat.PNG, 90, fos);
            } finally {
                if (fos != null) {
                    fos.close();
                }
            }
        } catch (RemoteException e) {
        }
    }

    /**
     * Change the current system wallpaper to a specific byte stream.  The
     * give InputStream is copied into persistent storage and will now be
     * used as the wallpaper.  Currently it must be either a JPEG or PNG
     * image.  On success, the intent {@link Intent#ACTION_WALLPAPER_CHANGED}
     * is broadcast.
     *
     * @param data A stream containing the raw data to install as a wallpaper.
     *
     * @throws IOException If an error occurs reverting to the default
     * wallpaper.
     */
    public void setStream(InputStream data) throws IOException {
        try {
            ParcelFileDescriptor fd = sGlobals.mService.setWallpaper(null);
            if (fd == null) {
                return;
            }
            FileOutputStream fos = null;
            try {
                fos = new ParcelFileDescriptor.AutoCloseOutputStream(fd);
                setWallpaper(data, fos);
            } finally {
                if (fos != null) {
                    fos.close();
                }
            }
        } catch (RemoteException e) {
        }
    }

    private void setWallpaper(InputStream data, FileOutputStream fos)
            throws IOException {
        byte[] buffer = new byte[32768];
        int amt;
        while ((amt=data.read(buffer)) > 0) {
            fos.write(buffer, 0, amt);
        }
    }

    /**
     * Returns the desired minimum width for the wallpaper. Callers of
     * {@link #setBitmap(android.graphics.Bitmap)} or
     * {@link #setStream(java.io.InputStream)} should check this value
     * beforehand to make sure the supplied wallpaper respects the desired
     * minimum width.
     *
     * If the returned value is <= 0, the caller should use the width of
     * the default display instead.
     *
     * @return The desired minimum width for the wallpaper. This value should
     * be honored by applications that set the wallpaper but it is not
     * mandatory.
     */
    public int getDesiredMinimumWidth() {
        try {
            return sGlobals.mService.getWidthHint();
        } catch (RemoteException e) {
            // Shouldn't happen!
            return 0;
        }
    }

    /**
     * Returns the desired minimum height for the wallpaper. Callers of
     * {@link #setBitmap(android.graphics.Bitmap)} or
     * {@link #setStream(java.io.InputStream)} should check this value
     * beforehand to make sure the supplied wallpaper respects the desired
     * minimum height.
     *
     * If the returned value is <= 0, the caller should use the height of
     * the default display instead.
     *
     * @return The desired minimum height for the wallpaper. This value should
     * be honored by applications that set the wallpaper but it is not
     * mandatory.
     */
    public int getDesiredMinimumHeight() {
        try {
            return sGlobals.mService.getHeightHint();
        } catch (RemoteException e) {
            // Shouldn't happen!
            return 0;
        }
    }

    /**
     * For use only by the current home application, to specify the size of
     * wallpaper it would like to use.  This allows such applications to have
     * a virtual wallpaper that is larger than the physical screen, matching
     * the size of their workspace.
     * @param minimumWidth Desired minimum width
     * @param minimumHeight Desired minimum height
     */
    public void suggestDesiredDimensions(int minimumWidth, int minimumHeight) {
        try {
            sGlobals.mService.setDimensionHints(minimumWidth, minimumHeight);
        } catch (RemoteException e) {
        }
    }
    
    /**
     * Set the position of the current wallpaper within any larger space, when
     * that wallpaper is visible behind the given window.  The X and Y offsets
     * are floating point numbers ranging from 0 to 1, representing where the
     * wallpaper should be positioned within the screen space.  These only
     * make sense when the wallpaper is larger than the screen.
     * 
     * @param windowToken The window who these offsets should be associated
     * with, as returned by {@link android.view.View#getWindowToken()
     * View.getWindowToken()}.
     * @param xOffset The offset along the X dimension, from 0 to 1.
     * @param yOffset The offset along the Y dimension, from 0 to 1.
     */
    public void setWallpaperOffsets(IBinder windowToken, float xOffset, float yOffset) {
        try {
            //Log.v(TAG, "Sending new wallpaper offsets from app...");
            ViewRoot.getWindowSession(mContext.getMainLooper()).setWallpaperPosition(
                    windowToken, xOffset, yOffset, mWallpaperXStep, mWallpaperYStep);
            //Log.v(TAG, "...app returning after sending offsets!");
        } catch (RemoteException e) {
            // Ignore.
        }
    }
    
    /**
     * For applications that use multiple virtual screens showing a wallpaper,
     * specify the step size between virtual screens. For example, if the
     * launcher has 3 virtual screens, it would specify an xStep of 0.5,
     * since the X offset for those screens are 0.0, 0.5 and 1.0
     * @param xStep The X offset delta from one screen to the next one 
     * @param yStep The Y offset delta from one screen to the next one
     */
    public void setWallpaperOffsetSteps(float xStep, float yStep) {
        mWallpaperXStep = xStep;
        mWallpaperYStep = yStep;
    }
    
    /**
     * Send an arbitrary command to the current active wallpaper.
     * 
     * @param windowToken The window who these offsets should be associated
     * with, as returned by {@link android.view.View#getWindowToken()
     * View.getWindowToken()}.
     * @param action Name of the command to perform.  This must be a scoped
     * name to avoid collisions, such as "com.mycompany.wallpaper.DOIT".
     * @param x Arbitrary integer argument based on command.
     * @param y Arbitrary integer argument based on command.
     * @param z Arbitrary integer argument based on command.
     * @param extras Optional additional information for the command, or null.
     */
    public void sendWallpaperCommand(IBinder windowToken, String action,
            int x, int y, int z, Bundle extras) {
        try {
            //Log.v(TAG, "Sending new wallpaper offsets from app...");
            ViewRoot.getWindowSession(mContext.getMainLooper()).sendWallpaperCommand(
                    windowToken, action, x, y, z, extras, false);
            //Log.v(TAG, "...app returning after sending offsets!");
        } catch (RemoteException e) {
            // Ignore.
        }
    }
    
    /**
     * Clear the offsets previously associated with this window through
     * {@link #setWallpaperOffsets(IBinder, float, float)}.  This reverts
     * the window to its default state, where it does not cause the wallpaper
     * to scroll from whatever its last offsets were.
     * 
     * @param windowToken The window who these offsets should be associated
     * with, as returned by {@link android.view.View#getWindowToken()
     * View.getWindowToken()}.
     */
    public void clearWallpaperOffsets(IBinder windowToken) {
        try {
            ViewRoot.getWindowSession(mContext.getMainLooper()).setWallpaperPosition(
                    windowToken, -1, -1, -1, -1);
        } catch (RemoteException e) {
            // Ignore.
        }
    }
    
    /**
     * Remove any currently set wallpaper, reverting to the system's default
     * wallpaper. On success, the intent {@link Intent#ACTION_WALLPAPER_CHANGED}
     * is broadcast.
     *
     * @throws IOException If an error occurs reverting to the default
     * wallpaper.
     */
    public void clear() throws IOException {
        setResource(com.android.internal.R.drawable.default_wallpaper);
    }
    
    static Bitmap generateBitmap(Context context, Bitmap bm, int width, int height) {
        if (bm == null) {
            return bm;
        }
        bm.setDensity(DisplayMetrics.DENSITY_DEVICE);
        
        // This is the final bitmap we want to return.
        // XXX We should get the pixel depth from the system (to match the
        // physical display depth), when there is a way.
        Bitmap newbm = Bitmap.createBitmap(width, height,
                Bitmap.Config.RGB_565);
        newbm.setDensity(DisplayMetrics.DENSITY_DEVICE);
        Canvas c = new Canvas(newbm);
        c.setDensity(DisplayMetrics.DENSITY_DEVICE);
        Rect targetRect = new Rect();
        targetRect.left = targetRect.top = 0;
        targetRect.right = bm.getWidth();
        targetRect.bottom = bm.getHeight();
        
        int deltaw = width - targetRect.right;
        int deltah = height - targetRect.bottom;
        
        if (deltaw > 0 || deltah > 0) {
            // We need to scale up so it covers the entire
            // area.
            float scale = 1.0f;
            if (deltaw > deltah) {
                scale = width / (float)targetRect.right;
            } else {
                scale = height / (float)targetRect.bottom;
            }
            targetRect.right = (int)(targetRect.right*scale);
            targetRect.bottom = (int)(targetRect.bottom*scale);
            deltaw = width - targetRect.right;
            deltah = height - targetRect.bottom;
        }
        
        targetRect.offset(deltaw/2, deltah/2);
        Paint paint = new Paint();
        paint.setFilterBitmap(true);
        paint.setDither(true);
        c.drawBitmap(bm, null, targetRect, paint);
        
        bm.recycle();
        return newbm;
    }
}

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