1 files changed, 132 insertions, 0 deletions
diff --git a/src/com/android/gallery3d/ui/GestureRecognizer.java b/src/com/android/gallery3d/ui/GestureRecognizer.java
new file mode 100644
index 000000000..1e5250b9b
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+++ b/src/com/android/gallery3d/ui/GestureRecognizer.java
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+/*
+ * Copyright (C) 2012 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.gallery3d.ui;
+
+import android.content.Context;
+import android.os.SystemClock;
+import android.view.GestureDetector;
+import android.view.MotionEvent;
+import android.view.ScaleGestureDetector;
+
+// This class aggregates three gesture detectors: GestureDetector,
+// ScaleGestureDetector, and DownUpDetector.
+public class GestureRecognizer {
+    @SuppressWarnings("unused")
+    private static final String TAG = "GestureRecognizer";
+
+    public interface Listener {
+        boolean onSingleTapUp(float x, float y);
+        boolean onDoubleTap(float x, float y);
+        boolean onScroll(float dx, float dy, float totalX, float totalY);
+        boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY);
+        boolean onScaleBegin(float focusX, float focusY);
+        boolean onScale(float focusX, float focusY, float scale);
+        void onScaleEnd();
+        void onDown(float x, float y);
+        void onUp();
+    }
+
+    private final GestureDetector mGestureDetector;
+    private final ScaleGestureDetector mScaleDetector;
+    private final DownUpDetector mDownUpDetector;
+    private final Listener mListener;
+
+    public GestureRecognizer(Context context, Listener listener) {
+        mListener = listener;
+        mGestureDetector = new GestureDetector(context, new MyGestureListener(),
+                null, true /* ignoreMultitouch */);
+        mScaleDetector = new ScaleGestureDetector(
+                context, new MyScaleListener());
+        mDownUpDetector = new DownUpDetector(new MyDownUpListener());
+    }
+
+    public void onTouchEvent(MotionEvent event) {
+        mGestureDetector.onTouchEvent(event);
+        mScaleDetector.onTouchEvent(event);
+        mDownUpDetector.onTouchEvent(event);
+    }
+
+    public boolean isDown() {
+        return mDownUpDetector.isDown();
+    }
+
+    public void cancelScale() {
+        long now = SystemClock.uptimeMillis();
+        MotionEvent cancelEvent = MotionEvent.obtain(
+                now, now, MotionEvent.ACTION_CANCEL, 0, 0, 0);
+        mScaleDetector.onTouchEvent(cancelEvent);
+        cancelEvent.recycle();
+    }
+
+    private class MyGestureListener
+                extends GestureDetector.SimpleOnGestureListener {
+        @Override
+        public boolean onSingleTapUp(MotionEvent e) {
+            return mListener.onSingleTapUp(e.getX(), e.getY());
+        }
+
+        @Override
+        public boolean onDoubleTap(MotionEvent e) {
+            return mListener.onDoubleTap(e.getX(), e.getY());
+        }
+
+        @Override
+        public boolean onScroll(
+                MotionEvent e1, MotionEvent e2, float dx, float dy) {
+            return mListener.onScroll(
+                    dx, dy, e2.getX() - e1.getX(), e2.getY() - e1.getY());
+        }
+
+        @Override
+        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
+                float velocityY) {
+            return mListener.onFling(e1, e2, velocityX, velocityY);
+        }
+    }
+
+    private class MyScaleListener
+            extends ScaleGestureDetector.SimpleOnScaleGestureListener {
+        @Override
+        public boolean onScaleBegin(ScaleGestureDetector detector) {
+            return mListener.onScaleBegin(
+                    detector.getFocusX(), detector.getFocusY());
+        }
+
+        @Override
+        public boolean onScale(ScaleGestureDetector detector) {
+            return mListener.onScale(detector.getFocusX(),
+                    detector.getFocusY(), detector.getScaleFactor());
+        }
+
+        @Override
+        public void onScaleEnd(ScaleGestureDetector detector) {
+            mListener.onScaleEnd();
+        }
+    }
+
+    private class MyDownUpListener implements DownUpDetector.DownUpListener {
+        @Override
+        public void onDown(MotionEvent e) {
+            mListener.onDown(e.getX(), e.getY());
+        }
+
+        @Override
+        public void onUp(MotionEvent e) {
+            mListener.onUp();
+        }
+    }
+}