Android Open Source - utwitterapi Abs Applications Loader

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License

The source code is released under:

GNU General Public License

Java Source Code

package org.mariotaku.utwitterapi.loader;
//from  w w  w. ja v  a 2 s.  com
import java.text.Collator;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Locale;

import android.content.AsyncTaskLoader;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.ActivityInfo;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Build;
import android.text.TextUtils;

public abstract class AbsApplicationsLoader extends AsyncTaskLoader<List<ApplicationInfo>> {

  private PackageIntentReceiver mPackageObserver;

  private final InterestingConfigChanges mLastConfig = new InterestingConfigChanges();
  private final PackageManager mPackageManager;

  private final CharSequence mKeyword;

  public AbsApplicationsLoader(final Context context) {
    this(context, context.getPackageManager(), null);
  }

  public AbsApplicationsLoader(final Context context, final CharSequence keyword) {
    this(context, context.getPackageManager(), keyword);
  }

  public AbsApplicationsLoader(final Context context, final PackageManager pm) {
    this(context, pm, null);
  }

  public AbsApplicationsLoader(final Context context, final PackageManager pm, final CharSequence keyword) {
    super(context);
    mPackageManager = pm;
    mKeyword = keyword;
  }

  @Override
  public List<ApplicationInfo> loadInBackground() {
    final List<ApplicationInfo> result = new ArrayList<ApplicationInfo>();
    for (final ApplicationInfo info : mPackageManager.getInstalledApplications(0)) {
      if (!isFiltered(info) && isKeywordMatch(info)) {
        result.add(info);
      }
    }
    Collections.sort(result, new ApplicationNameComparator(mPackageManager));
    return result;
  }

  protected abstract boolean isFiltered(ApplicationInfo info);

  /**
   * Handles a request to completely reset the Loader.
   */
  @Override
  protected void onReset() {
    super.onReset();

    // Ensure the loader is stopped
    onStopLoading();

    // Stop monitoring for changes.
    if (mPackageObserver != null) {
      getContext().unregisterReceiver(mPackageObserver);
      mPackageObserver = null;
    }
  }

  /**
   * Handles a request to start the Loader.
   */
  @Override
  protected void onStartLoading() {

    // Start watching for changes in the app data.
    if (mPackageObserver == null) {
      mPackageObserver = new PackageIntentReceiver(this);
    }

    // Has something interesting in the configuration changed since we
    // last built the app list?
    final boolean configChange = mLastConfig.applyNewConfig(getContext().getResources());

    if (takeContentChanged() || configChange) {
      // If the data has changed since the last time it was loaded
      // or is not currently available, start a load.
      forceLoad();
    }
  }

  /**
   * Handles a request to stop the Loader.
   */
  @Override
  protected void onStopLoading() {
    // Attempt to cancel the current load task if possible.
    cancelLoad();
  }

  private boolean isKeywordMatch(final ApplicationInfo info) {
    if (TextUtils.isEmpty(mKeyword)) return true;
    final String keyword = String.valueOf(mKeyword).toLowerCase();
    final String pname = info.packageName;
    final CharSequence label = info.loadLabel(mPackageManager);
    return pname.toLowerCase().contains(keyword) || label != null
        && label.toString().toLowerCase().contains(keyword);
  }

  public static final class ApplicationNameComparator implements Comparator<ApplicationInfo> {

    private final PackageManager packageManager;
    private final Collator collator;

    public ApplicationNameComparator(final PackageManager pm) {
      packageManager = pm;
      collator = Collator.getInstance(Locale.getDefault());
    }

    @Override
    public int compare(final ApplicationInfo lhs, final ApplicationInfo rhs) {
      final CharSequence lLabel = lhs.loadLabel(packageManager);
      final CharSequence rLabel = rhs.loadLabel(packageManager);
      return collator.compare(String.valueOf(lLabel), String.valueOf(rLabel));
    }

  }

  /**
   * Helper for determining if the configuration has changed in an interesting
   * way so we need to rebuild the app list.
   */
  public static class InterestingConfigChanges {

    final Configuration mLastConfiguration = new Configuration();
    int mLastDensity;

    boolean applyNewConfig(final Resources res) {
      final int configChanges = mLastConfiguration.updateFrom(res.getConfiguration());
      final boolean densityChanged = mLastDensity != res.getDisplayMetrics().densityDpi;
      if (densityChanged
          || (configChanges & (ActivityInfo.CONFIG_LOCALE | ActivityInfo.CONFIG_UI_MODE | ActivityInfo.CONFIG_SCREEN_LAYOUT)) != 0) {
        mLastDensity = res.getDisplayMetrics().densityDpi;
        return true;
      }
      return false;
    }
  }

  /**
   * Helper class to look for interesting changes to the installed apps so
   * that the loader can be updated.
   */
  public static class PackageIntentReceiver extends BroadcastReceiver {

    final AbsApplicationsLoader mLoader;

    public PackageIntentReceiver(final AbsApplicationsLoader loader) {
      mLoader = loader;
      final IntentFilter filter = new IntentFilter(Intent.ACTION_PACKAGE_ADDED);
      filter.addAction(Intent.ACTION_PACKAGE_REMOVED);
      filter.addAction(Intent.ACTION_PACKAGE_CHANGED);
      filter.addDataScheme("package");
      mLoader.getContext().registerReceiver(this, filter);
      // Register for events related to sdcard installation.
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.FROYO) {
        final IntentFilter sdFilter = new IntentFilter();
        sdFilter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE);
        sdFilter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE);
        mLoader.getContext().registerReceiver(this, sdFilter);
      }
    }

    @Override
    public void onReceive(final Context context, final Intent intent) {
      // Tell the loader about the change.
      mLoader.onContentChanged();
    }
  }

}

Java Source Code List

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