Move the Gestures API to the framework in android.gesture.

1 files changed, 215 insertions, 0 deletions

diff --git a/core/java/android/gesture/GestureStroke.java b/core/java/android/gesture/GestureStroke.java
new file mode 100644
index 0000000..5160a76
--- /dev/null
+++ b/core/java/android/gesture/GestureStroke.java
@@ -0,0 +1,215 @@
+/*
+ * Copyright (C) 2008-2009 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 android.gesture;
+
+import android.graphics.Canvas;
+import android.graphics.Matrix;
+import android.graphics.Paint;
+import android.graphics.Path;
+import android.graphics.RectF;
+
+import java.io.IOException;
+import java.io.DataOutputStream;
+import java.io.DataInputStream;
+import java.util.ArrayList;
+
+/**
+ * A gesture stroke started on a touch down and ended on a touch up.
+ */
+public class GestureStroke {
+    public final RectF boundingBox;
+
+    public final float length;
+    public final float[] points;
+
+    private final long[] timestamps;
+    private Path mCachedPath;
+
+    /**
+     * Construct a gesture stroke from a list of gesture points
+     * 
+     * @param points
+     */
+    public GestureStroke(ArrayList<GesturePoint> points) {
+        final int count = points.size();
+        final float[] tmpPoints = new float[count * 2];
+        final long[] times = new long[count];
+
+        RectF bx = null;
+        float len = 0;
+        int index = 0;
+
+        for (int i = 0; i < count; i++) {
+            final GesturePoint p = points.get(i);
+            tmpPoints[i * 2] = p.x;
+            tmpPoints[i * 2 + 1] = p.y;
+            times[index] = p.timestamp;
+
+            if (bx == null) {
+                bx = new RectF();
+                bx.top = p.y;
+                bx.left = p.x;
+                bx.right = p.x;
+                bx.bottom = p.y;
+                len = 0;
+            } else {
+                len += Math.sqrt(Math.pow(p.x - tmpPoints[(i - 1) * 2], 2)
+                        + Math.pow(p.y - tmpPoints[(i -1 ) * 2 + 1], 2));
+                bx.union(p.x, p.y);
+            }
+            index++;
+        }
+        
+        timestamps = times;
+        this.points = tmpPoints;
+        boundingBox = bx;
+        length = len;
+    }
+
+    /**
+     * Draw the gesture with a given canvas and paint
+     * 
+     * @param canvas
+     */
+    void draw(Canvas canvas, Paint paint) {
+        if (mCachedPath == null) {
+            final float[] localPoints = points;
+            final int count = localPoints.length;
+
+            Path path = null;
+
+            float mX = 0;
+            float mY = 0;
+
+            for (int i = 0; i < count; i += 2) {
+                float x = localPoints[i];
+                float y = localPoints[i + 1];
+                if (path == null) {
+                    path = new Path();
+                    path.moveTo(x, y);
+                    mX = x;
+                    mY = y;
+                } else {
+                    float dx = Math.abs(x - mX);
+                    float dy = Math.abs(y - mY);
+                    if (dx >= 3 || dy >= 3) {
+                        path.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
+                        mX = x;
+                        mY = y;
+                    }
+                }
+            }
+
+            mCachedPath = path;
+        }
+
+        canvas.drawPath(mCachedPath, paint);
+    }
+
+    /**
+     * Convert the stroke to a Path based on the number of points
+     * 
+     * @param width the width of the bounding box of the target path
+     * @param height the height of the bounding box of the target path
+     * @param numSample the number of points needed
+     * 
+     * @return the path
+     */
+    public Path toPath(float width, float height, int numSample) {
+        final float[] pts = GestureUtilities.temporalSampling(this, numSample);
+        final RectF rect = boundingBox;
+
+        final Matrix matrix = new Matrix();
+        matrix.setTranslate(-rect.left, -rect.top);
+        matrix.postScale(width / rect.width(), height / rect.height());
+        matrix.mapPoints(pts);
+
+        float mX = 0;
+        float mY = 0;
+
+        Path path = null;
+
+        final int count = pts.length;
+
+        for (int i = 0; i < count; i += 2) {
+            float x = pts[i];
+            float y = pts[i + 1];
+            if (path == null) {
+                path = new Path();
+                path.moveTo(x, y);
+                mX = x;
+                mY = y;
+            } else {
+                float dx = Math.abs(x - mX);
+                float dy = Math.abs(y - mY);
+                if (dx >= GestureOverlayView.TOUCH_TOLERANCE ||
+                        dy >= GestureOverlayView.TOUCH_TOLERANCE) {
+                    path.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
+                    mX = x;
+                    mY = y;
+                }
+            }
+        }
+
+        return path;
+    }
+
+    void serialize(DataOutputStream out) throws IOException {
+        final float[] pts = points;
+        final long[] times = timestamps;
+        final int count = points.length;
+
+        // Write number of points
+        out.writeInt(count / 2);
+
+        for (int i = 0; i < count; i += 2) {
+            // Write X
+            out.writeFloat(pts[i]);
+            // Write Y
+            out.writeFloat(pts[i + 1]);
+            // Write timestamp
+            out.writeLong(times[i / 2]);
+        }
+    }
+
+    static GestureStroke deserialize(DataInputStream in) throws IOException {
+        // Number of points
+        final int count = in.readInt();
+
+        final ArrayList<GesturePoint> points = new ArrayList<GesturePoint>(count);
+        for (int i = 0; i < count; i++) {
+            points.add(GesturePoint.deserialize(in));
+        }
+
+        return new GestureStroke(points);
+    }    
+
+    /**
+     * Invalidate the cached path that is used to render the stroke
+     */
+    public void clearPath() {
+        if (mCachedPath != null) mCachedPath.rewind();
+    }
+    
+    /**
+     * Compute an oriented bounding box of the stroke
+     * @return OrientedBoundingBox
+     */
+    public OrientedBoundingBox computeOrientedBoundingBox() {
+        return GestureUtilities.computeOrientedBoundingBox(points);
+    }
+}