《学习笔记》android6.0 锁屏壁纸功能

1.需求

Three entrance for this feature. one is in Home screen, the second is in Settings>Display screen, the third one is in Gallery>single view a picture>Set picture as>Wallaper screen.

2.方案

思路：

通过对WallpaperManager和SystemUI中添加对应的方法，来实现对外提供设置锁屏壁纸的接口。

步骤：
1.设置锁屏壁纸，将选好的壁纸存入SystemUI对应目录下；
2.读取锁屏壁纸，当屏幕点亮后从SystemUI对应目录下读取图片对当前锁屏界面进行背景的设置，达到效果。

代码路径：
frameworks/base/core/java/android/app/WallpaperManager.java
frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java

具体实现代码：

/** * 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()}. * * <p> An app can check whether wallpapers are supported for the current user, by calling * {@link #isWallpaperSupported()}. */public class WallpaperManager {    private static String TAG = "WallpaperManager";    private static boolean DEBUG = true;    private static final String WALLPAPERDIR = "/data/data/com.android.systemui/";    static final String MENUWALLPAPERNAME = "menuwallpaper.png";    static final String LOCKWALLPAPERNAME = "lockwallpaper.png";    /** {@hide} */    public static final int SCREEN_WP_MODE = 0;    /** {@hide} */    public static final int LOCK_WP_MODE = 1;    /** {@hide} */    public static final int ALL_WP_MODE = 2;    private final Context mContext;    <中间部分省略>...    //默认设置壁纸的方法    public void setStream(InputStream data) throws IOException {        if (sGlobals.mService == null) {            Log.w(TAG, "WallpaperService not running");            return;        }        try {            ParcelFileDescriptor fd = sGlobals.mService.setWallpaper(null,                    mContext.getOpPackageName());            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) {            // Ignore        }    }    //将选好的图片流写到指定路径    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);        }    }    //通过指定图片文件路径，得到一个文件描述符对象    private ParcelFileDescriptor getLockWallpaperPath() {        File dir = new File(WALLPAPERDIR);        if(!dir.exists()){          dir.mkdirs();        }        FileUtils.setPermissions(WALLPAPERDIR,0777,-1,-1);        File file = null;        file = new File(dir, LOCKWALLPAPERNAME);        try {            file.createNewFile();        } catch (IOException io) {            io.printStackTrace();        }        ParcelFileDescriptor fd=null;        try{            fd = ParcelFileDescriptor.open(file,ParcelFileDescriptor.MODE_CREATE|ParcelFileDescriptor.MODE_READ_WRITE);        }catch(Exception e) {            e.printStackTrace();        }        return fd;    }    //设置锁屏壁纸，将图片存入到指定路径下    public void setLockStream(InputStream data) throws IOException {        Log.w(TAG, "setLockStream...");        if (sGlobals.mService == null) {            return;        }        if(data==null)        {            //如果图片不存在，就以默认壁纸作为锁屏壁纸来设置            data=sGlobals.openDefaultWallpaperRes(mContext);        }        try {            ParcelFileDescriptor fd = getLockWallpaperPath();            if (fd == null) {                return;            }            FileOutputStream fos = null;            try {                fos = new ParcelFileDescriptor.AutoCloseOutputStream(fd);                setWallpaper(data, fos);            } finally {                if (fos != null) {                    fos.close();                }            }        } catch (Exception e) {            e.printStackTrace();        }        FileUtils.setPermissions(WALLPAPERDIR+"/"+LOCKWALLPAPERNAME,0777,-1,-1);    }    //这个方法的两个参数应该是一样的。    //应用场景：一张图片同事被设置成壁纸和锁屏壁纸。    public void setAllStream(InputStream data_home,InputStream data_lock) throws IOException {        if (sGlobals.mService == null) {            return;        }        if(data_home == null) {            data_home=sGlobals.openDefaultWallpaperRes(mContext);        }else if(data_lock == null) {            data_lock = sGlobals.openDefaultWallpaperRes(mContext);        }        try {            ParcelFileDescriptor fd_lock = getLockWallpaperPath();            ParcelFileDescriptor fd_home = sGlobals.mService.setWallpaper(null,                    mContext.getOpPackageName());            if (fd_lock != null) {                FileOutputStream fos_lock = null;                try {                    fos_lock = new ParcelFileDescriptor.AutoCloseOutputStream(fd_lock);                    setWallpaper(data_lock, fos_lock);                } finally {                    if (fos_lock != null) {                        fos_lock.close();                    }                }            }else if(fd_home != null){                try {                    fos_home = new ParcelFileDescriptor.AutoCloseOutputStream(fd_home);                    setWallpaper(data_home, fos_home);                } finally {                    if (fos_home != null) {                        fos_home.close();                    }                }            }        } catch (Exception e) {            e.printStackTrace();        }    }    //上面是存入的过程，这个方法是得到锁屏壁纸，用于设置背景。    public Bitmap getCurrentLockWallpaper() {        try {            File file = new File(WALLPAPERDIR, LOCKWALLPAPERNAME);            ParcelFileDescriptor fd = ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY);            if (fd != null) {                try {                    BitmapFactory.Options options = new BitmapFactory.Options();                    Bitmap bm = BitmapFactory.decodeFileDescriptor(                            fd.getFileDescriptor(), null, options);                    return bm;                } catch (OutOfMemoryError e) {                } finally {                    try {                        fd.close();                    } catch (IOException e) {                    }                }            }        } catch (Exception e) {        }        return null;    }}

在WallpaperManager类中，仿照默认设置壁纸方法，添加了两个方法。setLockStream（）（单独对锁屏设置背景）和setAllStream（）（将同一张图片分别应用于待机壁纸和锁屏壁纸），同时添加了对锁屏壁纸获取的方法 getCurrentLockWallpaper（）；

PhoneStatusBar.java管理着PanelHolder 以及 NotificationPanelView下的各个控件，showKeyguard 方法和 hideKeyguard方法中都调用了updateKeyguardState（）来实时更新锁屏状态和调整各控件的位置大小。具体锁屏结构和流程有时间再整理。
附上代码：

public class PhoneStatusBar extends BaseStatusBar implements DemoMode,        DragDownHelper.DragDownCallback, ActivityStarter, OnUnlockMethodChangedListener,        HeadsUpManager.OnHeadsUpChangedListener {    ... ...    private void updateKeyguardState(boolean goingToFullShade, boolean fromShadeLocked) {        if (mState == StatusBarState.KEYGUARD) {            mKeyguardIndicationController.setVisible(true);            mNotificationPanel.resetViews();            mKeyguardUserSwitcher.setKeyguard(true, fromShadeLocked);            mStatusBarView.removePendingHideExpandedRunnables();        } else {            mKeyguardIndicationController.setVisible(false);            mKeyguardUserSwitcher.setKeyguard(false,                    goingToFullShade || mState == StatusBarState.SHADE_LOCKED || fromShadeLocked);        }        //如果当前mState 处于锁屏状态，通过wallpaperManager.getCurrentLockWallpaper取出图片资源作为PanelHolder的背景。        if (mState == StatusBarState.KEYGUARD || mState == StatusBarState.SHADE_LOCKED) {            Bitmap bm = getCurrentWallpaperLocked();            if (bm != null) {            Drawable dr = new BitmapDrawable(mContext.getResources(), generateBitmap(bm, 480, 1280));            dr.setDither(false);            mHolder.setBackground(dr);            }else            {                mHolder.setBackgroundResource(0);            }            mScrimController.setKeyguardShowing(true);            mIconPolicy.setKeyguardShowing(true);        } else {        //如果mState 为其他状态，比如待机状态等，将PanelHolder背景清除。否则会出现状态栏花屏现象，因为此时PanelHolder的大小即为状态栏大小，无法呈现图片。            mHolder.setBackgroundResource(0);            mScrimController.setKeyguardShowing(false);            mIconPolicy.setKeyguardShowing(false);        }        mNotificationPanel.setBarState(mState, mKeyguardFadingAway, goingToFullShade);        updateDozingState();        updatePublicMode();        updateStackScrollerState(goingToFullShade);        updateNotifications();        checkBarModes();        /// M: Support "Operator plugin - Customize Carrier Label for PLMN". @{        updateCarrierLabelVisibility(false);        /// M: Support "Operator plugin - Customize Carrier Label for PLMN". @}        updateMediaMetaData(false);        mKeyguardMonitor.notifyKeyguardState(mStatusBarKeyguardViewManager.isShowing(),                mStatusBarKeyguardViewManager.isSecure());    }    private Bitmap getCurrentWallpaperLocked() {        WallpaperManager wallpaperManager = WallpaperManager.getInstance(mContext);        return wallpaperManager.getCurrentLockWallpaper();    }   //通过给定的长宽比对Bitmap图片进行缩放，铺满屏幕    private Bitmap generateBitmap(Bitmap bm, int width, int height) {        if (bm == null) {            return null;        }        bm.setDensity(DisplayMetrics.DENSITY_HIGH);        if (width <= 0 || height <= 0                || (bm.getWidth() == width && bm.getHeight() == height)) {            return bm;        }        // This is the final bitmap we want to return.        try {            Bitmap newbm = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);            newbm.setDensity(DisplayMetrics.DENSITY_HIGH);            Canvas c = new Canvas(newbm);            Rect targetRect = new Rect();            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;                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.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));            c.drawBitmap(bm, null, targetRect, paint);            bm.recycle();            c.setBitmap(null);            return newbm;        } catch (OutOfMemoryError e) {            return bm;        }    }}

这个时候已经将锁屏壁纸一些基础功能完成，目前已经可以通过调用wallpaperManager.java的方法对待机壁纸和锁屏壁纸进行分别设置了。

3.例子

接下来通过对原生图库进行修改,效果如下：

用自定义pupopWindow弹框替代原生直接设置壁纸的流程，然后将通过点击选项触发相应的操作。
代码路径：
packages/apps/Launcher3/WallpaperPicker/src/com/android/launcher3/WallpaperCropActivity.java
packages/apps/Launcher3/WallpaperPicker/src/com/android/gallery3d/common/BitmapCropTask.java

 public class WallpaperCropActivity extends BaseActivity implements Handler.Callback {     protected void init() {           ...        //set wallpaper Button        final ActionBar actionBar = getActionBar();        actionBar.setCustomView(R.layout.actionbar_set_wallpaper);        actionBar.getCustomView().setOnClickListener(                new View.OnClickListener() {                    @Override                    public void onClick(View v) {            //会有弹窗，所以这里不需要避免多次点击。                        //mSetWallpaperButton.setEnabled(false);                        boolean finishActivityWhenDone = true;                        BitmapCropTask.OnBitmapCroppedHandler h =                              new BitmapCropTask.OnBitmapCroppedHandler() {                        public void onBitmapCropped(byte[] imageBytes) {                            Point thumbSize = getDefaultThumbnailSize(                                WallpaperCropActivity.this.getResources());                            Bitmap thumb = createThumbnail(                                    thumbSize, null, null, imageBytes, null, 0, 0, true);                            mSavedWallpaper.writeImage(thumb, imageBytes);                        }                    };                    //从图库进入这个界面，mWallpaperMode 初始值为-1.                    if(mWallpaperMode < 0){                     //执行 自定义pupopWindow。                        OperationPopupWindow pw = new OperationPopupWindow(WallpaperCropActivity.this,imageUri, h, finishActivityWhenDone);                        pw.show(WallpaperCropActivity.this);                    }else{                        //从主页壁纸设置入口进入的，mWallpaperMode 是指定好的；                        //直接根据mWallpaperMode 来设置壁纸类型。                        cropImageAndSetWallpaper(imageUri, h, finishActivityWhenDone);                    }                    ///M.                    }                });       ....//GellaryBottomPopupWindow 就不贴出来了，就是继承了PupopWindow，public class OperationPopupWindow extends GellaryBottomPopupWindow<Void> {        public Uri uri = null;        public BitmapCropTask.OnBitmapCroppedHandler onBitmapCroppedHandler = null;        public boolean finishActivityWhenDone ;        public OperationPopupWindow(Context context,Uri uri,            BitmapCropTask.OnBitmapCroppedHandler onBitmapCroppedHandler, final boolean finishActivityWhenDone) {            super(context, null);            this.uri = uri;            this.onBitmapCroppedHandler =onBitmapCroppedHandler;            this.finishActivityWhenDone = finishActivityWhenDone;        }        public void onsave(){           //最终执行的方法，为了适应屏幕对图片进行剪切，然后进入设置壁纸的流程            cropImageAndSetWallpaper(uri, onBitmapCroppedHandler, finishActivityWhenDone);        }        @Override        protected View generateCustomView(Void data) {            View root = View.inflate(context, R.layout.popup_wallpaper_opreation_gellary, null);            View homeView = root.findViewById(R.id.home);            homeView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                 dismiss();                 // Ensure that a tile is slelected and loaded.                 mWallpaperMode = 0;                            onsave();                }            });            View lockView = root.findViewById(R.id.lock);            lockView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    dismiss();                    mWallpaperMode = 1;                               onsave();                }            });            View allView = root.findViewById(R.id.all);            allView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                     mWallpaperMode = 2;                                onsave();                }            });            View cancelView = root.findViewById(R.id.cancel);            cancelView.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    dismiss();                }            });            return root;        }        ...    protected void cropImageAndSetWallpaper(Uri uri, BitmapCropTask.OnBitmapCroppedHandler onBitmapCroppedHandler, final boolean finishActivityWhenDone) {        ...        //6.0上应该首次用BitmapCropTask 这种异步任务将耗时操作分离了出来。        BitmapCropTask cropTask = new BitmapCropTask(getContext(), uri,                cropRect, cropRotation, outWidth, outHeight, true, false, onEndCrop);        cropTask.setCropSize(outWidth, outHeight);        if (onBitmapCroppedHandler != null) {            cropTask.setOnBitmapCropped(onBitmapCroppedHandler);        }        cropTask.setWallpaperMode(mWallpaperMode);        cropTask.execute();    }}

cropTask.setWallpaperMode()方法是为了执行不同的壁纸设置新增加的，接下来看看 BitmapCropTask.java文件,只看关键代码：

public class BitmapCropTask extends AsyncTask<Void, Void, Boolean> {    ...    //添加的方法，mWallpaperMode 对应三种壁纸设置模式，默认是待机壁纸。    public void setWallpaperMode(int wpMode){        mWallpaperMode = wpMode;    }    @Override    protected Boolean doInBackground(Void... params) {        return cropBitmap(mWallpaperMode); //上段代码中最后会执行cropTask.execute()，走到这里;    }    @Override    protected void onPostExecute(Boolean result) {      ...    }    public boolean cropBitmap(int flag) {        boolean failure = false;        //M. ALPS01885181, sync with gallery, check the image size.        if (isOutOfSpecLimit()) {            Log.i(LOGTAG, "cropBitmap,image out of spec limit, mInUri:" + mInUri);            return failure;        }        ///M.        //到这里终于看见了WallpaperManager。        WallpaperManager wallpaperManager = null;        //mSetWallpaper = true        if (mSetWallpaper) {            wallpaperManager = WallpaperManager.getInstance(mContext.getApplicationContext());        }        //由于壁纸设置入口很多，mNoCrop在本次流程中为false,留给其他方法调用的;        if (mSetWallpaper && mNoCrop) {             try {                InputStream is_home = regenerateInputStream();                InputStream is_lock = regenerateInputStream();                if (is_home != null && is_lock != null) {                    if(flag == WallpaperManager.LOCK_WP_MODE){                        wallpaperManager.setLockStream(is_lock);                    }else if(flag == WallpaperManager.ALL_WP_MODE){                        wallpaperManager.setAllStream(is_home,is_lock);                    }else{                        wallpaperManager.setStream(is_home);                    }                    Utils.closeSilently(is_home);                    Utils.closeSilently(is_lock);                }            } catch (IOException e) {              ...            }            return !failure;        } else {                 ...                 //一大堆算法，随后剪切缩放得出适应屏幕大小的图片资源                 crop = Bitmap.createBitmap(fullSize, roundedTrueCrop.left,                          roundedTrueCrop.top, roundedTrueCrop.width(),                          roundedTrueCrop.height());            }            if (crop == null) {                Log.w(LOGTAG, "cannot decode file: " + mInUri.toString());                failure = true;                return false;            }            if (mOutWidth > 0 && mOutHeight > 0 || mRotation > 0) {                ByteArrayOutputStream tmpOut = new ByteArrayOutputStream(2048);                //将bitmap压缩成ByteArrayOutputStream;                if (crop.compress(CompressFormat.JPEG, DEFAULT_COMPRESS_QUALITY, tmpOut)) {                    // If we need to set to the wallpaper, set it                    if (mSetWallpaper && wallpaperManager != null) {                        try {                            byte[] outByteArray = tmpOut.toByteArray();                            if(flag == WallpaperManager.LOCK_WP_MODE){                            //仅设置锁屏壁纸                               wallpaperManager.setLockStream(new ByteArrayInputStream(outByteArray));                            }else if(flag == WallpaperManager.ALL_WP_MODE){                            //同时设置锁屏和待机壁纸                               wallpaperManager.setAllStream(new ByteArrayInputStream(outByteArray),new ByteArrayInputStream(outByteArray));                            }else{                            //设置默认壁纸                            wallpaperManager.setStream(new ByteArrayInputStream(outByteArray));                            }                            if (mOnBitmapCroppedHandler != null) {                                mOnBitmapCroppedHandler.onBitmapCropped(outByteArray);                            }                        } catch (IOException e) {                            Log.w(LOGTAG, "cannot write stream to wallpaper", e);                            failure = true;                        }                    }                } else {                    Log.w(LOGTAG, "cannot compress bitmap");                    failure = true;                }        }        return !failure; // True if any of the operations failed    }}

核心流程就是这样，其他细节不做笔记了。对于Keyguard也是一知半解，下次接着写Keyguard流程，巩固知识！