Fix 5021968: Add input method switcher button to lock screen.

This adds an IME switcher button to lock screen.  It is only
shown if the user has more than one applicable and enabled IME installed.

Change-Id: I5f9503a205c2edb27170825539ba4a6ef25418ed

1 files changed, 67 insertions, 3 deletions

diff --git a/policy/src/com/android/internal/policy/impl/PasswordUnlockScreen.java b/policy/src/com/android/internal/policy/impl/PasswordUnlockScreen.java
index 7c1f93a..d70b3bb 100644
--- a/policy/src/com/android/internal/policy/impl/PasswordUnlockScreen.java
+++ b/policy/src/com/android/internal/policy/impl/PasswordUnlockScreen.java
@@ -16,6 +16,8 @@
 
 package com.android.internal.policy.impl;
 
+import java.util.List;
+
 import android.app.admin.DevicePolicyManager;
 import android.content.Context;
 import android.content.res.Configuration;
@@ -27,18 +29,18 @@ import com.android.internal.widget.PasswordEntryKeyboardView;
 import android.os.CountDownTimer;
 import android.os.SystemClock;
 import android.security.KeyStore;
-import android.telephony.TelephonyManager;
 import android.text.Editable;
 import android.text.InputType;
 import android.text.TextWatcher;
 import android.text.method.DigitsKeyListener;
 import android.text.method.TextKeyListener;
-import android.util.Log;
 import android.view.KeyEvent;
 import android.view.LayoutInflater;
 import android.view.View;
-import android.view.View.OnClickListener;
 import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputMethodInfo;
+import android.view.inputmethod.InputMethodManager;
+import android.view.inputmethod.InputMethodSubtype;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.LinearLayout;
@@ -159,6 +161,68 @@ public class PasswordUnlockScreen extends LinearLayout implements KeyguardScreen
                 }
             }
         });
+
+        // If there's more than one IME, enable the IME switcher button
+        View switchImeButton = findViewById(R.id.switch_ime_button);
+        final InputMethodManager imm = (InputMethodManager) getContext().getSystemService(
+                Context.INPUT_METHOD_SERVICE);
+        if (switchImeButton != null && hasMultipleEnabledIMEsOrSubtypes(imm, false)) {
+            switchImeButton.setVisibility(View.VISIBLE);
+            switchImeButton.setOnClickListener(new OnClickListener() {
+                public void onClick(View v) {
+                    mCallback.pokeWakelock(); // Leave the screen on a bit longer
+                    imm.showInputMethodPicker();
+                }
+            });
+        }
+    }
+
+    /**
+     * Method adapted from com.android.inputmethod.latin.Utils
+     *
+     * @param imm The input method manager
+     * @param shouldIncludeAuxiliarySubtypes
+     * @return true if we have multiple IMEs to choose from
+     */
+    private boolean hasMultipleEnabledIMEsOrSubtypes(InputMethodManager imm,
+            final boolean shouldIncludeAuxiliarySubtypes) {
+        final List<InputMethodInfo> enabledImis = imm.getEnabledInputMethodList();
+
+        // Number of the filtered IMEs
+        int filteredImisCount = 0;
+
+        for (InputMethodInfo imi : enabledImis) {
+            // We can return true immediately after we find two or more filtered IMEs.
+            if (filteredImisCount > 1) return true;
+            final List<InputMethodSubtype> subtypes =
+                    imm.getEnabledInputMethodSubtypeList(imi, true);
+            // IMEs that have no subtypes should be counted.
+            if (subtypes.isEmpty()) {
+                ++filteredImisCount;
+                continue;
+            }
+
+            int auxCount = 0;
+            for (InputMethodSubtype subtype : subtypes) {
+                if (subtype.isAuxiliary()) {
+                    ++auxCount;
+                }
+            }
+            final int nonAuxCount = subtypes.size() - auxCount;
+
+            // IMEs that have one or more non-auxiliary subtypes should be counted.
+            // If shouldIncludeAuxiliarySubtypes is true, IMEs that have two or more auxiliary
+            // subtypes should be counted as well.
+            if (nonAuxCount > 0 || (shouldIncludeAuxiliarySubtypes && auxCount > 1)) {
+                ++filteredImisCount;
+                continue;
+            }
+        }
+
+        return filteredImisCount > 1
+        // imm.getEnabledInputMethodSubtypeList(null, false) will return the current IME's enabled
+        // input method subtype (The current IME should be LatinIME.)
+                || imm.getEnabledInputMethodSubtypeList(null, false).size() > 1;
     }
 
     @Override