Allow persistence of input device calibration

This patch extends the PersistentDataStore store to read and write
input device calibration data. A new SET_INPUT_CALIBRATION permission
grants apps the ability to update this information, and a new
TouchCalibration class is used to wrap the raw calibration data.

Change-Id: I4daac2b15ef03616ea5b068c1e77bebd0ce7b8c1

1 files changed, 126 insertions, 0 deletions

diff --git a/core/java/android/hardware/input/TouchCalibration.java b/core/java/android/hardware/input/TouchCalibration.java
new file mode 100644
index 0000000..025fad0
--- /dev/null
+++ b/core/java/android/hardware/input/TouchCalibration.java
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2014 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.hardware.input;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * Encapsulates calibration data for input devices.
+ *
+ * @hide
+ */
+public class TouchCalibration implements Parcelable {
+
+    public static final TouchCalibration IDENTITY = new TouchCalibration();
+
+    public static final Parcelable.Creator<TouchCalibration> CREATOR
+            = new Parcelable.Creator<TouchCalibration>() {
+        public TouchCalibration createFromParcel(Parcel in) {
+            return new TouchCalibration(in);
+        }
+
+        public TouchCalibration[] newArray(int size) {
+            return new TouchCalibration[size];
+        }
+    };
+
+    private final float mXScale, mXYMix, mXOffset;
+    private final float mYXMix, mYScale, mYOffset;
+
+    /**
+     * Create a new TouchCalibration initialized to the identity transformation.
+     */
+    public TouchCalibration() {
+        this(1,0,0,0,1,0);
+    }
+
+    /**
+     * Create a new TouchCalibration from affine transformation paramters.
+     * @param xScale   Influence of input x-axis value on output x-axis value.
+     * @param xyMix    Influence of input y-axis value on output x-axis value.
+     * @param xOffset  Constant offset to be applied to output x-axis value.
+     * @param yXMix    Influence of input x-axis value on output y-axis value.
+     * @param yScale   Influence of input y-axis value on output y-axis value.
+     * @param yOffset  Constant offset to be applied to output y-axis value.
+     */
+    public TouchCalibration(float xScale, float xyMix, float xOffset,
+            float yxMix, float yScale, float yOffset) {
+        mXScale  = xScale;
+        mXYMix   = xyMix;
+        mXOffset = xOffset;
+        mYXMix   = yxMix;
+        mYScale  = yScale;
+        mYOffset = yOffset;
+    }
+
+    public TouchCalibration(Parcel in) {
+        mXScale  = in.readFloat();
+        mXYMix   = in.readFloat();
+        mXOffset = in.readFloat();
+        mYXMix   = in.readFloat();
+        mYScale  = in.readFloat();
+        mYOffset = in.readFloat();
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        dest.writeFloat(mXScale);
+        dest.writeFloat(mXYMix);
+        dest.writeFloat(mXOffset);
+        dest.writeFloat(mYXMix);
+        dest.writeFloat(mYScale);
+        dest.writeFloat(mYOffset);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    public float[] getAffineTransform() {
+        return new float[] { mXScale, mXYMix, mXOffset, mYXMix, mYScale, mYOffset };
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) {
+            return true;
+        } else if (obj instanceof TouchCalibration) {
+            TouchCalibration cal = (TouchCalibration)obj;
+
+            return (cal.mXScale  == mXScale)  &&
+                   (cal.mXYMix   == mXYMix)   &&
+                   (cal.mXOffset == mXOffset) &&
+                   (cal.mYXMix   == mYXMix)   &&
+                   (cal.mYScale  == mYScale)  &&
+                   (cal.mYOffset == mYOffset);
+        } else {
+            return false;
+        }
+    }
+
+    @Override
+    public int hashCode() {
+        return Float.floatToIntBits(mXScale)  ^
+               Float.floatToIntBits(mXYMix)   ^
+               Float.floatToIntBits(mXOffset) ^
+               Float.floatToIntBits(mYXMix)   ^
+               Float.floatToIntBits(mYScale)  ^
+               Float.floatToIntBits(mYOffset);
+    }
+}