1 files changed, 105 insertions, 0 deletions
diff --git a/src/com/android/launcher3/model/AppNameComparator.java b/src/com/android/launcher3/model/AppNameComparator.java
new file mode 100644
index 000000000..706f7515d
--- /dev/null
+++ b/src/com/android/launcher3/model/AppNameComparator.java
@@ -0,0 +1,105 @@
+package com.android.launcher3.model;
+
+import android.content.Context;
+
+import com.android.launcher3.AppInfo;
+import com.android.launcher3.ItemInfo;
+import com.android.launcher3.compat.UserHandleCompat;
+import com.android.launcher3.compat.UserManagerCompat;
+import java.text.Collator;
+import java.util.Comparator;
+import java.util.HashMap;
+
+/**
+ * Class to manage access to an app name comparator.
+ * <p>
+ * Used to sort application name in all apps view and widget tray view.
+ */
+public class AppNameComparator {
+    private final UserManagerCompat mUserManager;
+    private final Collator mCollator;
+    private final Comparator<ItemInfo> mAppInfoComparator;
+    private final Comparator<String> mSectionNameComparator;
+    private HashMap<UserHandleCompat, Long> mUserSerialCache = new HashMap<>();
+
+    public AppNameComparator(Context context) {
+        mCollator = Collator.getInstance();
+        mUserManager = UserManagerCompat.getInstance(context);
+        mAppInfoComparator = new Comparator<ItemInfo>() {
+
+            public final int compare(ItemInfo a, ItemInfo b) {
+                // Order by the title in the current locale
+                int result = compareTitles(a.title.toString(), b.title.toString());
+                if (result == 0 && a instanceof AppInfo && b instanceof AppInfo) {
+                    AppInfo aAppInfo = (AppInfo) a;
+                    AppInfo bAppInfo = (AppInfo) b;
+                    // If two apps have the same title, then order by the component name
+                    result = aAppInfo.componentName.compareTo(bAppInfo.componentName);
+                    if (result == 0) {
+                        // If the two apps are the same component, then prioritize by the order that
+                        // the app user was created (prioritizing the main user's apps)
+                        if (UserHandleCompat.myUserHandle().equals(a.user)) {
+                            return -1;
+                        } else {
+                            Long aUserSerial = getAndCacheUserSerial(a.user);
+                            Long bUserSerial = getAndCacheUserSerial(b.user);
+                            return aUserSerial.compareTo(bUserSerial);
+                        }
+                    }
+                }
+                return result;
+            }
+        };
+        mSectionNameComparator = new Comparator<String>() {
+            @Override
+            public int compare(String o1, String o2) {
+                return compareTitles(o1, o2);
+            }
+        };
+    }
+
+    /**
+     * Returns a locale-aware comparator that will alphabetically order a list of applications.
+     */
+    public Comparator<ItemInfo> getAppInfoComparator() {
+        // Clear the user serial cache so that we get serials as needed in the comparator
+        mUserSerialCache.clear();
+        return mAppInfoComparator;
+    }
+
+    /**
+     * Returns a locale-aware comparator that will alphabetically order a list of section names.
+     */
+    public Comparator<String> getSectionNameComparator() {
+        return mSectionNameComparator;
+    }
+
+    /**
+     * Compares two titles with the same return value semantics as Comparator.
+     */
+    private int compareTitles(String titleA, String titleB) {
+        // Ensure that we de-prioritize any titles that don't start with a linguistic letter or digit
+        boolean aStartsWithLetter = Character.isLetterOrDigit(titleA.codePointAt(0));
+        boolean bStartsWithLetter = Character.isLetterOrDigit(titleB.codePointAt(0));
+        if (aStartsWithLetter && !bStartsWithLetter) {
+            return -1;
+        } else if (!aStartsWithLetter && bStartsWithLetter) {
+            return 1;
+        }
+
+        // Order by the title in the current locale
+        return mCollator.compare(titleA, titleB);
+    }
+
+    /**
+     * Returns the user serial for this user, using a cached serial if possible.
+     */
+    private Long getAndCacheUserSerial(UserHandleCompat user) {
+        Long userSerial = mUserSerialCache.get(user);
+        if (userSerial == null) {
+            userSerial = mUserManager.getSerialNumberForUser(user);
+            mUserSerialCache.put(user, userSerial);
+        }
+        return userSerial;
+    }
+}