【Launcher2源码解读】Launcher中的数据模型

Launcher中显示的App，Shortcut，Folder，Widget都是数据模型

继承关系图：

看一下ItemInfo.java 

重要属性：X、Y坐标，占用位置（用于Widget），标题等

重要方法：初始构造，数据库存储，bitmap在db的读和存

class ItemInfo {
    
    static final int NO_ID = -1;
    
    //数据库中的Id
    long id = NO_ID;
    //Item类型，app，shortcut，folder,appwidget
    int itemType;
    //用来区分item在workspace还是在dock，还是在文件夹中
    long container = NO_ID;
    
    //在第几个屏幕上
    int screen = -1;
    
    //横坐标
    int cellX = -1;

    //从坐标
    int cellY = -1;

    //横向占用位置
    int spanX = 1;

    //纵向占用位置
    int spanY = 1;

    /**
     * Indicates the minimum X cell span.
     */


    int minSpanX = 1;

    /**
     * Indicates the minimum Y cell span.
     */
    int minSpanY = 1;

    //是否需要更新
    boolean requiresDbUpdate = false;

    //标题文本
    CharSequence title;
    

    //拖拽位置
    int[] dropPos = null;

    ItemInfo() {
    }

    ItemInfo(ItemInfo info) {
        id = info.id;
        cellX = info.cellX;
        cellY = info.cellY;
        spanX = info.spanX;
        spanY = info.spanY;
        screen = info.screen;
        itemType = info.itemType;
        container = info.container;
        // tempdebug:
        LauncherModel.checkItemInfo(this);
    }

    /** Returns the package name that the intent will resolve to, or an empty string if
     *  none exists. */
    static String getPackageName(Intent intent) {
        if (intent != null) {
            String packageName = intent.getPackage();
            if (packageName == null && intent.getComponent() != null) {
                packageName = intent.getComponent().getPackageName();
            }
            if (packageName != null) {
                return packageName;
            }
        }
        return "";
    }

    /**
     * Write the fields of this item to the DB
     * 
     * @param values
     */
    void onAddToDatabase(ContentValues values) { 
        values.put(LauncherSettings.BaseLauncherColumns.ITEM_TYPE, itemType);
        values.put(LauncherSettings.Favorites.CONTAINER, container);
        values.put(LauncherSettings.Favorites.SCREEN, screen);
        values.put(LauncherSettings.Favorites.CELLX, cellX);
        values.put(LauncherSettings.Favorites.CELLY, cellY);
        values.put(LauncherSettings.Favorites.SPANX, spanX);
        values.put(LauncherSettings.Favorites.SPANY, spanY);
    }

    void updateValuesWithCoordinates(ContentValues values, int cellX, int cellY) {
        values.put(LauncherSettings.Favorites.CELLX, cellX);
        values.put(LauncherSettings.Favorites.CELLY, cellY);
    }

    static byte[] flattenBitmap(Bitmap bitmap) {
        // Try go guesstimate how much space the icon will take when serialized
        // to avoid unnecessary allocations/copies during the write.
        int size = bitmap.getWidth() * bitmap.getHeight() * 4;
        ByteArrayOutputStream out = new ByteArrayOutputStream(size);
        try {
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);
            out.flush();
            out.close();
            return out.toByteArray();
        } catch (IOException e) {
            Log.w("Favorite", "Could not write icon");
            return null;
        }
    }

    static void writeBitmap(ContentValues values, Bitmap bitmap) {
        if (bitmap != null) {
            byte[] data = flattenBitmap(bitmap);
            values.put(LauncherSettings.Favorites.ICON, data);
        }
    }

    /**
     * It is very important that sub-classes implement this if they contain any references
     * to the activity (anything in the view hierarchy etc.). If not, leaks can result since
     * ItemInfo objects persist across rotation and can hence leak by holding stale references
     * to the old view hierarchy / activity.
     */
    void unbind() {
    }

    @Override
    public String toString() {
        return "Item(id=" + this.id + " type=" + this.itemType + " container=" + this.container
            + " screen=" + screen + " cellX=" + cellX + " cellY=" + cellY + " spanX=" + spanX
            + " spanY=" + spanY + " dropPos=" + dropPos + ")";
    }

ApplicationInfo.java

继承ItemInfo.java 增加了Intent属性，ComponentName，PackageName，StartActivity等属性和方法。

class ApplicationInfo extends ItemInfo {
    private static final String TAG = "Launcher2.ApplicationInfo";

    /**
     * The intent used to start the application.
     */
    Intent intent;

    /**
     * A bitmap version of the application icon.
     */
    Bitmap iconBitmap;

    /**
     * The time at which the app was first installed.
     */
    long firstInstallTime;

    ComponentName componentName;

    static final int DOWNLOADED_FLAG = 1;
    static final int UPDATED_SYSTEM_APP_FLAG = 2;

    int flags = 0;

    ApplicationInfo() {
        itemType = LauncherSettings.BaseLauncherColumns.ITEM_TYPE_SHORTCUT;
    }

    /**
     * Must not hold the Context.
     */
    public ApplicationInfo(PackageManager pm, ResolveInfo info, IconCache iconCache,
            HashMap<Object, CharSequence> labelCache) {
        final String packageName = info.activityInfo.applicationInfo.packageName;

        this.componentName = new ComponentName(packageName, info.activityInfo.name);
        this.container = ItemInfo.NO_ID;
        this.setActivity(componentName,
                Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);

        try {
            int appFlags = pm.getApplicationInfo(packageName, 0).flags;
            if ((appFlags & android.content.pm.ApplicationInfo.FLAG_SYSTEM) == 0) {
                flags |= DOWNLOADED_FLAG;

                if ((appFlags & android.content.pm.ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0) {
                    flags |= UPDATED_SYSTEM_APP_FLAG;
                }
            }
            firstInstallTime = pm.getPackageInfo(packageName, 0).firstInstallTime;
        } catch (NameNotFoundException e) {
            Log.d(TAG, "PackageManager.getApplicationInfo failed for " + packageName);
        }

        iconCache.getTitleAndIcon(this, info, labelCache);
    }

    public ApplicationInfo(ApplicationInfo info) {
        super(info);
        componentName = info.componentName;
        title = info.title.toString();
        intent = new Intent(info.intent);
        flags = info.flags;
        firstInstallTime = info.firstInstallTime;
    }

    /** Returns the package name that the shortcut's intent will resolve to, or an empty string if
     *  none exists. */
    String getPackageName() {
        return super.getPackageName(intent);
    }

    /**
     * Creates the application intent based on a component name and various launch flags.
     * Sets {@link #itemType} to {@link LauncherSettings.BaseLauncherColumns#ITEM_TYPE_APPLICATION}.
     *
     * @param className the class name of the component representing the intent
     * @param launchFlags the launch flags
     */
    final void setActivity(ComponentName className, int launchFlags) {
        intent = new Intent(Intent.ACTION_MAIN);
        intent.addCategory(Intent.CATEGORY_LAUNCHER);
        intent.setComponent(className);
        intent.setFlags(launchFlags);
        itemType = LauncherSettings.BaseLauncherColumns.ITEM_TYPE_APPLICATION;
    }

    @Override
    public String toString() {
        return "ApplicationInfo(title=" + title.toString() + ")";
    }

    public static void dumpApplicationInfoList(String tag, String label,
            ArrayList<ApplicationInfo> list) {
        Log.d(tag, label + " size=" + list.size());
        for (ApplicationInfo info: list) {
            Log.d(tag, "   title=\"" + info.title + "\" iconBitmap="
                    + info.iconBitmap + " firstInstallTime="
                    + info.firstInstallTime);
        }
    }

    public ShortcutInfo makeShortcut() {
        return new ShortcutInfo(this);
    }
}

剩下的都是类似的，继承ItemInfo，再根据具体的需求添加属性和方法。

FolderInfo.item

class FolderInfo extends ItemInfo {

    /**
     * Whether this folder has been opened
     */
    boolean opened;

    /**
     * The apps and shortcuts
     */
    ArrayList<ShortcutInfo> contents = new ArrayList<ShortcutInfo>();

    ArrayList<FolderListener> listeners = new ArrayList<FolderListener>();

    FolderInfo() {
        itemType = LauncherSettings.Favorites.ITEM_TYPE_FOLDER;
    }

    /**
     * Add an app or shortcut
     *
     * @param item
     */
    public void add(ShortcutInfo item) {
        contents.add(item);
        for (int i = 0; i < listeners.size(); i++) {
            listeners.get(i).onAdd(item);
        }
        itemsChanged();
    }

    /**
     * Remove an app or shortcut. Does not change the DB.
     *
     * @param item
     */
    public void remove(ShortcutInfo item) {
        contents.remove(item);
        for (int i = 0; i < listeners.size(); i++) {
            listeners.get(i).onRemove(item);
        }
        itemsChanged();
    }

    public void setTitle(CharSequence title) {
        this.title = title;
        for (int i = 0; i < listeners.size(); i++) {
            listeners.get(i).onTitleChanged(title);
        }
    }

    @Override
    void onAddToDatabase(ContentValues values) {
        super.onAddToDatabase(values);
        values.put(LauncherSettings.Favorites.TITLE, title.toString());
    }

    void addListener(FolderListener listener) {
        listeners.add(listener);
    }

    void removeListener(FolderListener listener) {
        if (listeners.contains(listener)) {
            listeners.remove(listener);
        }
    }

    void itemsChanged() {
        for (int i = 0; i < listeners.size(); i++) {
            listeners.get(i).onItemsChanged();
        }
    }

    @Override
    void unbind() {
        super.unbind();
        listeners.clear();
    }

    interface FolderListener {
        public void onAdd(ShortcutInfo item);
        public void onRemove(ShortcutInfo item);
        public void onTitleChanged(CharSequence title);
        public void onItemsChanged();
    }
}

LauncherAppWidgetInfo.java

class LauncherAppWidgetInfo extends ItemInfo {

    /**
     * Indicates that the widget hasn't been instantiated yet.
     */
    static final int NO_ID = -1;

    /**
     * Identifier for this widget when talking with
     * {@link android.appwidget.AppWidgetManager} for updates.
     */
    int appWidgetId = NO_ID;

    ComponentName providerName;

    // TODO: Are these necessary here?
    int minWidth = -1;
    int minHeight = -1;

    private boolean mHasNotifiedInitialWidgetSizeChanged;

    /**
     * View that holds this widget after it's been created.  This view isn't created
     * until Launcher knows it's needed.
     */
    AppWidgetHostView hostView = null;

    LauncherAppWidgetInfo(int appWidgetId, ComponentName providerName) {
        itemType = LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET;
        this.appWidgetId = appWidgetId;
        this.providerName = providerName;

        // Since the widget isn't instantiated yet, we don't know these values. Set them to -1
        // to indicate that they should be calculated based on the layout and minWidth/minHeight
        spanX = -1;
        spanY = -1;
    }

    @Override
    void onAddToDatabase(ContentValues values) {
        super.onAddToDatabase(values);
        values.put(LauncherSettings.Favorites.APPWIDGET_ID, appWidgetId);
    }

    /**
     * When we bind the widget, we should notify the widget that the size has changed if we have not
     * done so already (only really for default workspace widgets).
     */
    void onBindAppWidget(Launcher launcher) {
        if (!mHasNotifiedInitialWidgetSizeChanged) {
            notifyWidgetSizeChanged(launcher);
        }
    }

    /**
     * Trigger an update callback to the widget to notify it that its size has changed.
     */
    void notifyWidgetSizeChanged(Launcher launcher) {
        AppWidgetResizeFrame.updateWidgetSizeRanges(hostView, launcher, spanX, spanY);
        mHasNotifiedInitialWidgetSizeChanged = true;
    }

    @Override
    public String toString() {
        return "AppWidget(id=" + Integer.toString(appWidgetId) + ")";
    }

    @Override
    void unbind() {
        super.unbind();
        hostView = null;
    }
}

PendingAddInfo,PendingAddShortcutInfo,PendingAddWidgetInfo

class PendingAddItemInfo extends ItemInfo {
    /**
     * The component that will be created.
     */
    ComponentName componentName;
}

class PendingAddShortcutInfo extends PendingAddItemInfo {

    ActivityInfo shortcutActivityInfo;

    public PendingAddShortcutInfo(ActivityInfo activityInfo) {
        shortcutActivityInfo = activityInfo;
    }

    @Override
    public String toString() {
        return "Shortcut: " + shortcutActivityInfo.packageName;
    }
}

class PendingAddWidgetInfo extends PendingAddItemInfo {
    int minWidth;
    int minHeight;
    int minResizeWidth;
    int minResizeHeight;
    int previewImage;
    int icon;
    AppWidgetProviderInfo info;
    AppWidgetHostView boundWidget;
    Bundle bindOptions = null;

    // Any configuration data that we want to pass to a configuration activity when
    // starting up a widget
    String mimeType;
    Parcelable configurationData;

    public PendingAddWidgetInfo(AppWidgetProviderInfo i, String dataMimeType, Parcelable data) {
        itemType = LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET;
        this.info = i;
        componentName = i.provider;
        minWidth = i.minWidth;
        minHeight = i.minHeight;
        minResizeWidth = i.minResizeWidth;
        minResizeHeight = i.minResizeHeight;
        previewImage = i.previewImage;
        icon = i.icon;
        if (dataMimeType != null && data != null) {
            mimeType = dataMimeType;
            configurationData = data;
        }
    }

    // Copy constructor
    public PendingAddWidgetInfo(PendingAddWidgetInfo copy) {
        minWidth = copy.minWidth;
        minHeight = copy.minHeight;
        minResizeWidth = copy.minResizeWidth;
        minResizeHeight = copy.minResizeHeight;
        previewImage = copy.previewImage;
        icon = copy.icon;
        info = copy.info;
        boundWidget = copy.boundWidget;
        mimeType = copy.mimeType;
        configurationData = copy.configurationData;
        componentName = copy.componentName;
        itemType = copy.itemType;
        spanX = copy.spanX;
        spanY = copy.spanY;
        minSpanX = copy.minSpanX;
        minSpanY = copy.minSpanY;
        bindOptions = copy.bindOptions == null ? null : (Bundle) copy.bindOptions.clone();
    }

    @Override
    public String toString() {
        return "Widget: " + componentName.toShortString();
    }
}