Make LanguageOnSpacebarHelper as utility class

Change-Id: I546f3b1943999a41803222bd14f9ddd23aa87a51

1 files changed, 100 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/latin/utils/LanguageOnSpacebarUtils.java b/java/src/com/android/inputmethod/latin/utils/LanguageOnSpacebarUtils.java
new file mode 100644
index 000000000..fa1583b7a
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/utils/LanguageOnSpacebarUtils.java
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2014 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.inputmethod.latin.utils;
+
+import android.view.inputmethod.InputMethodSubtype;
+
+import com.android.inputmethod.latin.RichInputMethodSubtype;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Locale;
+
+import javax.annotation.Nonnull;
+
+/**
+ * This class determines that the language name on the spacebar should be displayed in what format.
+ */
+public final class LanguageOnSpacebarUtils {
+    public static final int FORMAT_TYPE_NONE = 0;
+    public static final int FORMAT_TYPE_LANGUAGE_ONLY = 1;
+    public static final int FORMAT_TYPE_FULL_LOCALE = 2;
+    public static final int FORMAT_TYPE_MULTIPLE = 3;
+
+    private static List<InputMethodSubtype> sEnabledSubtypes = Collections.emptyList();
+    private static boolean sIsSystemLanguageSameAsInputLanguage;
+
+    private LanguageOnSpacebarUtils() {
+        // This utility class is not publicly instantiable.
+    }
+
+    public static int getLanguageOnSpacebarFormatType(
+            @Nonnull final RichInputMethodSubtype subtype) {
+        if (subtype.isNoLanguage()) {
+            return FORMAT_TYPE_FULL_LOCALE;
+        }
+        // Only this subtype is enabled and equals to the system locale.
+        if (sEnabledSubtypes.size() < 2 && sIsSystemLanguageSameAsInputLanguage) {
+            return FORMAT_TYPE_NONE;
+        }
+        final Locale[] locales = subtype.getLocales();
+        if (1 < locales.length) {
+            return FORMAT_TYPE_MULTIPLE;
+        }
+        final String keyboardLanguage = locales[0].getLanguage();
+        final String keyboardLayout = subtype.getKeyboardLayoutSetName();
+        int sameLanguageAndLayoutCount = 0;
+        for (final InputMethodSubtype ims : sEnabledSubtypes) {
+            final String language = SubtypeLocaleUtils.getSubtypeLocale(ims).getLanguage();
+            if (keyboardLanguage.equals(language) && keyboardLayout.equals(
+                    SubtypeLocaleUtils.getKeyboardLayoutSetName(ims))) {
+                sameLanguageAndLayoutCount++;
+            }
+        }
+        // Display full locale name only when there are multiple subtypes that have the same
+        // locale and keyboard layout. Otherwise displaying language name is enough.
+        return sameLanguageAndLayoutCount > 1 ? FORMAT_TYPE_FULL_LOCALE
+                : FORMAT_TYPE_LANGUAGE_ONLY;
+    }
+
+    public static void setEnabledSubtypes(@Nonnull final List<InputMethodSubtype> enabledSubtypes) {
+        sEnabledSubtypes = enabledSubtypes;
+    }
+
+    public static void onSubtypeChanged(@Nonnull final RichInputMethodSubtype subtype,
+           final boolean implicitlyEnabledSubtype, @Nonnull final Locale systemLocale) {
+        final Locale[] newLocales = subtype.getLocales();
+        if (newLocales.length > 1) {
+            // In multi-locales mode, the system language is never the same as the input language
+            // because there is no single input language.
+            sIsSystemLanguageSameAsInputLanguage = false;
+            return;
+        }
+        final Locale newLocale = newLocales[0];
+        if (systemLocale.equals(newLocale)) {
+            sIsSystemLanguageSameAsInputLanguage = true;
+            return;
+        }
+        if (!systemLocale.getLanguage().equals(newLocale.getLanguage())) {
+            sIsSystemLanguageSameAsInputLanguage = false;
+            return;
+        }
+        // If the subtype is enabled explicitly, the language name should be displayed even when
+        // the keyboard language and the system language are equal.
+        sIsSystemLanguageSameAsInputLanguage = implicitlyEnabledSubtype;
+    }
+}