2015-10-30-在Launcher的固定View上添加Widget_墨迹天气

首先感谢thl789博客中关于widget的解释，看后受益很多。有益的文章链接如下：
Android AppWidget系统框架
Android中选取并绑定AppWidget
Android中AppWidget的分析与应用：AppWidgetProvider
Android中Launcher对于AppWidget处理的分析：AppWidgetHost角色
Android中RemoteViews的实现

下面是我的内容：

获取系统已安装的widget列表

测试代码：

// Test code，获取系统已安装的Widget列表。
List<AppWidgetProviderInfo> installed = Launcher.mAppWidgetManager.getInstalledProviders();
for(int index = 0; index < installed.size(); index ++) {
    ComponentName cn = installed.get(index).provider;
    Log.i("test", "" + cn.getPackageName() + ", " + cn.getClassName());
}

打印log示例如下：

Line 1093: 08-23 12:54:39.469 I/test    ( 5772): com.moji.moweather, com.moji.moweather.widget.CMojiWidget4x1
Line 1095: 08-23 12:54:39.469 I/test    ( 5772): com.moji.moweather, com.moji.moweather.widget.CMojiWidget4x2

添加widget到某个View中

总共分为5步：
1. 使用AppHost分配appWidgetId。
2. 绑定appWidetId到墨迹天气Intent上。
3. AppWidgetmanaget根据appWidgetId解析出appWidgetInfo。
4. AppWidgetHostView使用appWidgetId和appWidgetInfo创建View。
5. 将上一步创建好的View添加到目标测试View中。

int appWidgetId = Launcher.mAppWidgetHost.allocateAppWidgetId();
Intent intent = new Intent();
intent.setClassName("com.moji.moweather", "com.moji.moweather.widget.CMojiWidget4x2");
Launcher.mAppWidgetManager.bindAppWidgetId(appWidgetId, intent.getComponent());
AppWidgetProviderInfo appWidgetInfo = Launcher.mAppWidgetManager.getAppWidgetInfo(appWidgetId);
Launcher.mAppWidgetHostView = (LauncherAppWidgetHostView) Launcher.mAppWidgetHost.createView(context, appWidgetId, appWidgetInfo);
testView.addView(Launcher.mAppWidgetHostView);// 添加widget到测试view中

其他：

// 获取系统已安装的AppWidgetManager.ACTION_APPWIDGET_UPDATE的类列表
Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
String pkgName = "com.moji.moweather";
intent.setPackage(pkgName);
PackageManager pkgManger = context.getPackageManager();
List<ResolveInfo> broadcastReceivers = pkgManger
        .queryBroadcastReceivers(intent, PackageManager.GET_META_DATA);
final int N = broadcastReceivers == null ? 0 : broadcastReceivers
        .size();
for (int i = 0; i < N; i++) {
    ResolveInfo ri = broadcastReceivers.get(i);
    ActivityInfo ai = ri.activityInfo;
    if ((ai.applicationInfo.flags & ApplicationInfo.FLAG_EXTERNAL_STORAGE) != 0) {
        continue;
    }
    Log.i("test", "" + ai.packageName + ", " + ai.applicationInfo.className); //打印包名和类名
    if (pkgName.equals(ai.packageName)) {
    }
}

Android原生launcher中的LauncherAppWidgetHost.java和LauncherAppWidgetHostView.java代码如下：
LauncherAppWidgetHost.java

/* * 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. */

import android.appwidget.AppWidgetHost;
import android.appwidget.AppWidgetHostView;
import android.appwidget.AppWidgetProviderInfo;
import android.content.Context;

/** * Specific {@link AppWidgetHost} that creates our {@link LauncherAppWidgetHostView} * which correctly captures all long-press events. This ensures that users can * always pick up and move widgets. */
public class LauncherAppWidgetHost extends AppWidgetHost {

    Launcher mLauncher;

    public LauncherAppWidgetHost(Launcher launcher, int hostId) {
        super(launcher, hostId);
        mLauncher = launcher;
    }

    @Override
    protected AppWidgetHostView onCreateView(Context context, int appWidgetId,
            AppWidgetProviderInfo appWidget) {
        return new LauncherAppWidgetHostView(context);
    }

    @Override
    public void stopListening() {
        super.stopListening();
        clearViews();
    }

    protected void onProvidersChanged() {
        // Once we get the message that widget packages are updated, we need to rebind items
        // in AppsCustomize accordingly.
        mLauncher.bindPackagesUpdated();
    }
}

LauncherAppWidgetHostView.java

package com.android.launcher2;

import android.appwidget.AppWidgetHostView;
import android.content.ComponentName;
import android.content.ContentValues;

/** * Represents a widget (either instantiated or about to be) in the Launcher. */
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;
    }
}