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上一篇文章说了Googel Search Widget在不同的版本是在不同ap里面实现的，那今天就代码来分析一下：

1，在android 1.5上 Google Search 确切地说不是一个真正的Android 的widget, 因为它不是通过android.appwidget.action.APPWIDGET_UPDATE 和android.appwidget.provider来配置的，而只是Launcher 里面通过workspace主动加载它而已，他的主要相关的代码是Search.java.看看Launcher是如何加载它的：

LauncherProvider.java:

private int loadFavorites(SQLiteDatabase db) {<br /> Intent intent = new Intent(Intent.ACTION_MAIN, null);<br /> intent.addCategory(Intent.CATEGORY_LAUNCHER);<br /> ContentValues values = new ContentValues();<br /> PackageManager packageManager = mContext.getPackageManager();<br /> int i = 0;<br /> try {<br /> XmlResourceParser parser = mContext.getResources().getXml(R.xml.default_workspace);<br /> AttributeSet attrs = Xml.asAttributeSet(parser);<br /> XmlUtils.beginDocument(parser, TAG_FAVORITES);<br /> ……<br /> ……<br /> if (TAG_FAVORITE.equals(name)) {<br /> added = addShortcut(db, values, a, packageManager, intent);<br /> } else if (TAG_SEARCH.equals(name)) {<br /> added = addSearchWidget(db, values);<br /> } else if (TAG_CLOCK.equals(name)) {<br /> added = addClockWidget(db, values);<br /> }<br /> …..<br />

if (TAG_SEARCH.equals(name)) {

added = addSearchWidget(db, values);

} 这一行

private boolean addSearchWidget(SQLiteDatabase db, ContentValues values) {<br /> // Add a search box<br /> values.put(Favorites.ITEM_TYPE, Favorites.ITEM_TYPE_WIDGET_SEARCH);<br /> values.put(Favorites.SPANX, 4);<br /> values.put(Favorites.SPANY, 1);<br /> db.insert(TABLE_FAVORITES, null, values);<br /> return true;<br /> }<br />

2,在android 2.2的上，Google Search Widget是一个真正的widget,它通过android.appwidget.action.APPWIDGET_UPDATE 和android.appwidget.provider来配置的，其主要代码是SearchWidgetProvider.java。那我们看看Launcher是如何加载它的：

LauncherProvider.java:

/**<br /> * Loads the default set of favorite packages from an xml file.<br /> *<br /> * @param db The database to write the values into<br /> */<br /> private int loadFavorites(SQLiteDatabase db) {<br /> Intent intent = new Intent(Intent.ACTION_MAIN, null);<br /> intent.addCategory(Intent.CATEGORY_LAUNCHER);<br /> ContentValues values = new ContentValues();<br /> PackageManager packageManager = mContext.getPackageManager();<br /> int i = 0;<br /> try {<br /> XmlResourceParser parser = mContext.getResources().getXml(R.xml.default_workspace);<br /> ….<br /> ….<br /> if (TAG_FAVORITE.equals(name)) {<br /> added = addAppShortcut(db, values, a, packageManager, intent);<br /> } else if (TAG_SEARCH.equals(name)) {<br /> added = addSearchWidget(db, values);<br /> } else if (TAG_CLOCK.equals(name)) {<br /> added = addClockWidget(db, values);<br /> } else if (TAG_APPWIDGET.equals(name)) {<br /> added = addAppWidget(db, values, a, packageManager);<br /> } else if (TAG_SHORTCUT.equals(name)) {<br /> added = addUriShortcut(db, values, a);<br /> }<br /> ….

if (TAG_SEARCH.equals(name)) {

added = addSearchWidget(db, values);

}这一行

private boolean addSearchWidget(SQLiteDatabase db, ContentValues values) {<br /> ComponentName cn = getSearchWidgetProvider();<br /> return addAppWidget(db, values, cn, 4, 1);<br /> }

private ComponentName getSearchWidgetProvider() {<br /> SearchManager searchManager =<br /> (SearchManager) mContext.getSystemService(Context.SEARCH_SERVICE);<br /> ComponentName searchComponent = searchManager.getGlobalSearchActivity();<br /> if (searchComponent == null) return null;<br /> return getProviderInPackage(searchComponent.getPackageName());<br /> }

从代码就可以看得出android1.5和android 2.2的区别了。不过共同点就是在default_workspace.xml都是用search tag来定义Google search widget.

<search

launcher:screen=”2″

launcher:x=”0″

launcher:y=”0″ />

3,通过上面我们也知道Launcher 加载default 的ap或者widget是通过default_workspace.xml定义，然后通过LauncherProvider中的loadFavorites的函数来解析这个xml.