Define shortcuts for toggling IME layouts.

Out of the box, we want Alt-Left to toggle Emojis, while Alt-Right
toggles the shifted symbols layout.

Bug: 23954008
Bug: 24369173

Change-Id: I93dd66fb469e5d0a831359ff3a786fe68e1d73ea
(cherry picked from commit 411841b374aa04e333ea5a438dfd539f49ec589a)

1 files changed, 95 insertions, 43 deletions

diff --git a/java/src/com/android/inputmethod/latin/EmojiAltPhysicalKeyDetector.java b/java/src/com/android/inputmethod/latin/EmojiAltPhysicalKeyDetector.java
index 2a92daebc..2529424c0 100644
--- a/java/src/com/android/inputmethod/latin/EmojiAltPhysicalKeyDetector.java
+++ b/java/src/com/android/inputmethod/latin/EmojiAltPhysicalKeyDetector.java
@@ -16,88 +16,140 @@
 
 package com.android.inputmethod.latin;
 
+import android.content.res.Resources;
 import android.util.Log;
 import android.view.KeyEvent;
 
 import com.android.inputmethod.keyboard.KeyboardSwitcher;
 import com.android.inputmethod.latin.settings.Settings;
 
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import javax.annotation.Nonnull;
+
 /**
  * A class for detecting Emoji-Alt physical key.
  */
 final class EmojiAltPhysicalKeyDetector {
     private static final String TAG = "EmojiAltPhysicalKeyDetector";
 
-    private final RichInputConnection mRichInputConnection;
+    private final Map<Integer, Integer> mEmojiSwitcherMap;
+    private final Map<Integer, Integer> mSymbolsShiftedSwitcherMap;
+    private final Map<Integer, Integer> mCombinedSwitcherMap;
 
-    // True if the Alt key has been used as a modifier. In this case the Alt key up isn't
-    // recognized as an emoji key.
-    private boolean mAltHasBeenUsedAsAModifier;
+    // Set of keys codes that have been used as modifiers.
+    private Set<Integer> mActiveModifiers;
 
-    public EmojiAltPhysicalKeyDetector(final RichInputConnection richInputConnection) {
-        mRichInputConnection = richInputConnection;
+    public EmojiAltPhysicalKeyDetector(@Nonnull final Resources resources) {
+        mEmojiSwitcherMap = parseSwitchDefinition(resources, R.array.keyboard_switcher_emoji);
+        mSymbolsShiftedSwitcherMap = parseSwitchDefinition(
+                resources, R.array.keyboard_switcher_symbols_shifted);
+        mCombinedSwitcherMap = new HashMap<>();
+        mCombinedSwitcherMap.putAll(mEmojiSwitcherMap);
+        mCombinedSwitcherMap.putAll(mSymbolsShiftedSwitcherMap);
+        mActiveModifiers = new HashSet<>();
     }
 
-    /**
-     * Record a down key event.
-     * @param keyEvent a down key event.
-     */
-    public void onKeyDown(final KeyEvent keyEvent) {
-        if (isAltKey(keyEvent)) {
-            mAltHasBeenUsedAsAModifier = false;
-        }
-        if (containsAltModifier(keyEvent)) {
-            mAltHasBeenUsedAsAModifier = true;
+    private static Map<Integer, Integer> parseSwitchDefinition(
+            @Nonnull final Resources resources,
+            final int resourceId) {
+        final Map<Integer, Integer> definition = new HashMap<>();
+        final String name = resources.getResourceEntryName(resourceId);
+        final String[] values = resources.getStringArray(resourceId);
+        for (int i = 0; values != null && i < values.length; i++) {
+            String[] valuePair = values[i].split(",");
+            if (valuePair.length != 2) {
+                Log.w(TAG, "Expected 2 integers in " + name + "[" + i + "] : " + values[i]);
+            }
+            try {
+                definition.put(Integer.parseInt(valuePair[0]), Integer.parseInt(valuePair[1]));
+            } catch (NumberFormatException e) {
+                Log.w(TAG, "Failed to parse " + name + "[" + i + "] : " + values[i], e);
+            }
         }
+        return definition;
     }
 
     /**
-     * Determine whether an up key event is a special key up or not.
+     * Determine whether an up key event came from a mapped modifier key.
+     *
      * @param keyEvent an up key event.
      */
-    public void onKeyUp(final KeyEvent keyEvent) {
+    public void onKeyUp(@Nonnull final KeyEvent keyEvent) {
+        Log.d(TAG, "onKeyUp() : " + keyEvent);
+        if (!Settings.getInstance().getCurrent().mEnableEmojiAltPhysicalKey) {
+            // The feature is disabled.
+            Log.d(TAG, "onKeyUp() : Disabled");
+            return;
+        }
         if (keyEvent.isCanceled()) {
             // This key up event was a part of key combinations and should be ignored.
+            Log.d(TAG, "onKeyUp() : Canceled");
             return;
         }
-        if (!isAltKey(keyEvent)) {
-            mAltHasBeenUsedAsAModifier |= containsAltModifier(keyEvent);
+        final Integer mappedModifier = getMappedModifier(keyEvent);
+        if (mappedModifier != null) {
+            // If the key was modified by a mapped key, then ignore the next time
+            // the same modifier key comes up.
+            Log.d(TAG, "onKeyUp() : Using Modifier: " + mappedModifier);
+            mActiveModifiers.add(mappedModifier);
             return;
         }
-        if (containsAltModifier(keyEvent)) {
-            mAltHasBeenUsedAsAModifier = true;
+        final int keyCode = keyEvent.getKeyCode();
+        if (mActiveModifiers.contains(keyCode)) {
+            // Used as a modifier, not a standalone key press.
+            Log.d(TAG, "onKeyUp() : Used as Modifier: " + keyCode);
+            mActiveModifiers.remove(keyCode);
             return;
         }
-        if (!Settings.getInstance().getCurrent().mEnableEmojiAltPhysicalKey) {
+        if (!isMappedKeyCode(keyEvent)) {
+            // Nothing special about this key.
+            Log.d(TAG, "onKeyUp() : Not Mapped: " + keyCode);
             return;
         }
-        if (mAltHasBeenUsedAsAModifier) {
-            return;
+        final KeyboardSwitcher switcher = KeyboardSwitcher.getInstance();
+        if (mEmojiSwitcherMap.keySet().contains(keyCode)) {
+            switcher.onToggleKeyboard(KeyboardSwitcher.KeyboardSwitchState.EMOJI);
+        } else if (mSymbolsShiftedSwitcherMap.keySet().contains(keyCode)) {
+            switcher.onToggleKeyboard(KeyboardSwitcher.KeyboardSwitchState.SYMBOLS_SHIFTED);
+        } else {
+            Log.w(TAG, "Cannot toggle on keyCode: " + keyCode);
         }
-        onEmojiAltKeyDetected();
     }
 
-    private static void onEmojiAltKeyDetected() {
-        KeyboardSwitcher.getInstance().onToggleEmojiKeyboard();
+    /**
+     * @param keyEvent pressed key event
+     * @return true iff the user pressed a mapped modifier key.
+     */
+    private boolean isMappedKeyCode(@Nonnull final KeyEvent keyEvent) {
+        return mCombinedSwitcherMap.get(keyEvent.getKeyCode()) != null;
     }
 
-    private static boolean isAltKey(final KeyEvent keyEvent) {
+    /**
+     * @param keyEvent pressed key event
+     * @return the mapped modifier used with this key opress, if any.
+     */
+    private Integer getMappedModifier(@Nonnull final KeyEvent keyEvent) {
         final int keyCode = keyEvent.getKeyCode();
-        return keyCode == KeyEvent.KEYCODE_ALT_LEFT || keyCode == KeyEvent.KEYCODE_ALT_RIGHT;
-    }
-
-    private static boolean containsAltModifier(final KeyEvent keyEvent) {
         final int metaState = keyEvent.getMetaState();
-        // TODO: Support multiple keyboards. Take device id into account.
-        switch (keyEvent.getKeyCode()) {
-        case KeyEvent.KEYCODE_ALT_LEFT:
-            // Return true if Left-Alt is pressed with Right-Alt pressed.
-            return (metaState & KeyEvent.META_ALT_RIGHT_ON) != 0;
-        case KeyEvent.KEYCODE_ALT_RIGHT:
-            // Return true if Right-Alt is pressed with Left-Alt pressed.
-            return (metaState & KeyEvent.META_ALT_LEFT_ON) != 0;
-        default:
-            return (metaState & (KeyEvent.META_ALT_LEFT_ON | KeyEvent.META_ALT_RIGHT_ON)) != 0;
+        for (int mappedKeyCode : mCombinedSwitcherMap.keySet()) {
+            if (keyCode == mappedKeyCode) {
+                Log.d(TAG, "getMappedModifier() : KeyCode = MappedKeyCode = " + mappedKeyCode);
+                continue;
+            }
+            final Integer mappedMeta = mCombinedSwitcherMap.get(mappedKeyCode);
+            if (mappedMeta == null || mappedMeta.intValue() == -1) {
+                continue;
+            }
+            if ((metaState & mappedMeta) != 0) {
+                Log.d(TAG, "getMappedModifier() : MetaState(" + metaState
+                        + ") contains MappedMeta(" + mappedMeta + ")");
+                return mappedKeyCode;
+            }
         }
+        return null;
     }
 }