Refactor SmsListPreference into AppListPreference.

This generalizes the pattern of needing to offer a selection among a
list of candidate applications.

Also move some reusable logic around querying PackageManager for icons
into AppListPreference, and remove some unnecessary update logic: the
preference will update itself when onPreferenceChange returns true,
and we can set the summary to '%s' to automatically use the entry as
the summary without having to reset it each time.

Change-Id: I007b9ed58359302f93b367a4b86354e93613bf3e

src/com/android/settings/AppListPreference.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2013 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.
+ */
+
+package com.android.settings;
+
+import android.app.Activity;
+import android.app.AlertDialog.Builder;
+import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.graphics.drawable.Drawable;
+import android.preference.ListPreference;
+import android.util.AttributeSet;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ArrayAdapter;
+import android.widget.CheckedTextView;
+import android.widget.ImageView;
+import android.widget.ListAdapter;
+
+/**
+ * Extends ListPreference to allow us to show the icons for a given list of applications. We do this
+ * because the names of applications are very similar and the user may not be able to determine what
+ * app they are selecting without an icon.
+ */
+public class AppListPreference extends ListPreference {
+    private Drawable[] mEntryDrawables;
+
+    public class AppArrayAdapter extends ArrayAdapter<CharSequence> {
+        private Drawable[] mImageDrawables = null;
+        private int mSelectedIndex = 0;
+
+        public AppArrayAdapter(Context context, int textViewResourceId,
+                CharSequence[] objects, Drawable[] imageDrawables, int selectedIndex) {
+            super(context, textViewResourceId, objects);
+            mSelectedIndex = selectedIndex;
+            mImageDrawables = imageDrawables;
+        }
+
+        @Override
+        public View getView(int position, View convertView, ViewGroup parent) {
+            LayoutInflater inflater = ((Activity)getContext()).getLayoutInflater();
+            View view = inflater.inflate(R.layout.app_preference_item, parent, false);
+            CheckedTextView checkedTextView = (CheckedTextView)view.findViewById(R.id.app_label);
+            checkedTextView.setText(getItem(position));
+            if (position == mSelectedIndex) {
+                checkedTextView.setChecked(true);
+            }
+            ImageView imageView = (ImageView)view.findViewById(R.id.app_image);
+            imageView.setImageDrawable(mImageDrawables[position]);
+            return view;
+        }
+    }
+
+    public AppListPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public void setPackageNames(String[] packageNames, String defaultPackageName) {
+        // Look up all package names in PackageManager. Skip ones we can't find.
+        int foundPackages = 0;
+        PackageManager pm = getContext().getPackageManager();
+        ApplicationInfo[] appInfos = new ApplicationInfo[packageNames.length];
+        for (int i = 0; i < packageNames.length; i++) {
+            try {
+                appInfos[i] = pm.getApplicationInfo(packageNames[i], 0);
+                foundPackages++;
+            } catch (NameNotFoundException e) {
+                // Leave appInfos[i] uninitialized; it will be skipped in the list.
+            }
+        }
+
+        // Show the label and icon for each application package.
+        CharSequence[] applicationNames = new CharSequence[foundPackages];
+        mEntryDrawables = new Drawable[foundPackages];
+        int index = 0;
+        int selectedIndex = -1;
+        for (ApplicationInfo appInfo : appInfos) {
+            if (appInfo != null) {
+                applicationNames[index] = appInfo.loadLabel(pm);
+                mEntryDrawables[index] = appInfo.loadIcon(pm);
+                if (appInfo.packageName.contentEquals(defaultPackageName)) {
+                    selectedIndex = index;
+                }
+                index++;
+            }
+        }
+        setEntries(applicationNames);
+        setEntryValues(packageNames);
+        if (selectedIndex != -1) {
+            setValueIndex(selectedIndex);
+        }
+    }
+
+    @Override
+    protected void onPrepareDialogBuilder(Builder builder) {
+        int selectedIndex = findIndexOfValue(getValue());
+        ListAdapter adapter = new AppArrayAdapter(getContext(),
+            R.layout.app_preference_item, getEntries(), mEntryDrawables, selectedIndex);
+        builder.setAdapter(adapter, this);
+        super.onPrepareDialogBuilder(builder);
+    }
+}