Move non-distinct multitouch support to a separate class

Move code that support non-distinct multitouch screen device to the
NonDistinchMultitouchHelper class.

Change-Id: I2e44f782b83dbcd095ee8e51c36b0766da0cd457

1 files changed, 90 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/keyboard/internal/NonDistinctMultitouchHelper.java b/java/src/com/android/inputmethod/keyboard/internal/NonDistinctMultitouchHelper.java
new file mode 100644
index 000000000..53fff6986
--- /dev/null
+++ b/java/src/com/android/inputmethod/keyboard/internal/NonDistinctMultitouchHelper.java
@@ -0,0 +1,90 @@
+/*
+ * 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.inputmethod.keyboard.internal;
+
+import android.util.Log;
+import android.view.MotionEvent;
+
+import com.android.inputmethod.keyboard.Key;
+import com.android.inputmethod.keyboard.PointerTracker;
+import com.android.inputmethod.keyboard.PointerTracker.KeyEventHandler;
+import com.android.inputmethod.latin.utils.CoordinateUtils;
+
+public final class NonDistinctMultitouchHelper {
+    private static final String TAG = NonDistinctMultitouchHelper.class.getSimpleName();
+
+    private int mOldPointerCount = 1;
+    private Key mOldKey;
+
+    public void processMotionEvent(final MotionEvent me, final KeyEventHandler keyEventHandler) {
+        final int pointerCount = me.getPointerCount();
+        final int oldPointerCount = mOldPointerCount;
+        mOldPointerCount = pointerCount;
+        // Ignore continuous multitouch events because we can't trust the coordinates in mulitouch
+        // events.
+        if (pointerCount > 1 && oldPointerCount > 1) {
+            return;
+        }
+
+        final int action = me.getActionMasked();
+        final int index = me.getActionIndex();
+        final long eventTime = me.getEventTime();
+        final int x = (int)me.getX(index);
+        final int y = (int)me.getY(index);
+        // Use only main (id=0) pointer tracker.
+        final PointerTracker mainTracker = PointerTracker.getPointerTracker(0, keyEventHandler);
+
+        // In single touch.
+        if (oldPointerCount == 1 && pointerCount == 1) {
+            mainTracker.processMotionEvent(action, x, y, eventTime, keyEventHandler);
+            return;
+        }
+
+        // Single-touch to multi-touch transition.
+        if (oldPointerCount == 1 && pointerCount == 2) {
+            // Send an up event for the last pointer, be cause we can't trust the corrdinates of
+            // this multitouch event.
+            final int[] lastCoords = CoordinateUtils.newInstance();
+            mainTracker.getLastCoordinates(lastCoords);
+            mOldKey = mainTracker.getKeyOn(
+                    CoordinateUtils.x(lastCoords), CoordinateUtils.y(lastCoords));
+            // TODO: Stop calling PointerTracker.onUpEvent directly.
+            mainTracker.onUpEvent(
+                    CoordinateUtils.x(lastCoords), CoordinateUtils.y(lastCoords), eventTime);
+            return;
+        }
+
+        // Multi-touch to single touch transition.
+        if (oldPointerCount == 2 && pointerCount == 1) {
+            // Send a down event for the latest pointer if the key is different from the
+            // previous key.
+            final Key newKey = mainTracker.getKeyOn(x, y);
+            if (mOldKey != newKey) {
+                // TODO: Stop calling PointerTracker.onDownEvent directly.
+                mainTracker.onDownEvent(x, y, eventTime, keyEventHandler);
+                if (action == MotionEvent.ACTION_UP) {
+                    // TODO: Stop calling PointerTracker.onUpEvent directly.
+                    mainTracker.onUpEvent(x, y, eventTime);
+                }
+            }
+            return;
+        }
+
+        Log.w(TAG, "Unknown touch panel behavior: pointer count is "
+                + pointerCount + " (previously " + oldPointerCount + ")");
+    }
+}