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

8 files changed, 308 insertions, 1 deletions

diff --git a/core/java/android/hardware/input/IInputManager.aidl b/core/java/android/hardware/input/IInputManager.aidl
index f1e7e98..4214115 100644
--- a/core/java/android/hardware/input/IInputManager.aidl
+++ b/core/java/android/hardware/input/IInputManager.aidl
@@ -19,6 +19,7 @@ package android.hardware.input;
 import android.hardware.input.InputDeviceIdentifier;
 import android.hardware.input.KeyboardLayout;
 import android.hardware.input.IInputDevicesChangedListener;
+import android.hardware.input.TouchCalibration;
 import android.os.IBinder;
 import android.view.InputDevice;
 import android.view.InputEvent;
@@ -39,6 +40,11 @@ interface IInputManager {
     // applications, the caller must have the INJECT_EVENTS permission.
     boolean injectInputEvent(in InputEvent ev, int mode);
 
+    // Calibrate input device position
+    TouchCalibration getTouchCalibrationForInputDevice(String inputDeviceDescriptor);
+    void setTouchCalibrationForInputDevice(String inputDeviceDescriptor,
+            in TouchCalibration calibration);
+
     // Keyboard layouts configuration.
     KeyboardLayout[] getKeyboardLayouts();
     KeyboardLayout getKeyboardLayout(String keyboardLayoutDescriptor);
diff --git a/core/java/android/hardware/input/InputManager.java b/core/java/android/hardware/input/InputManager.java
index a2aeafb..ece5d82 100644
--- a/core/java/android/hardware/input/InputManager.java
+++ b/core/java/android/hardware/input/InputManager.java
@@ -500,6 +500,44 @@ public final class InputManager {
     }
 
     /**
+     * Gets the TouchCalibration applied to the specified input device's coordinates.
+     *
+     * @param inputDeviceDescriptor The input device descriptor.
+     * @return The TouchCalibration currently assigned for use with the given
+     * input device. If none is set, an identity TouchCalibration is returned.
+     *
+     * @hide
+     */
+    public TouchCalibration getTouchCalibration(String inputDeviceDescriptor) {
+        try {
+            return mIm.getTouchCalibrationForInputDevice(inputDeviceDescriptor);
+        } catch (RemoteException ex) {
+            Log.w(TAG, "Could not get calibration matrix for input device.", ex);
+            return TouchCalibration.IDENTITY;
+        }
+    }
+
+    /**
+     * Sets the TouchCalibration to apply to the specified input device's coordinates.
+     * <p>
+     * This method may have the side-effect of causing the input device in question
+     * to be reconfigured. Requires {@link android.Manifest.permissions.SET_INPUT_CALIBRATION}.
+     * </p>
+     *
+     * @param inputDeviceDescriptor The input device descriptor.
+     * @param calibration The calibration to be applied
+     *
+     * @hide
+     */
+    public void setTouchCalibration(String inputDeviceDescriptor, TouchCalibration calibration) {
+        try {
+            mIm.setTouchCalibrationForInputDevice(inputDeviceDescriptor, calibration);
+        } catch (RemoteException ex) {
+            Log.w(TAG, "Could not set calibration matrix for input device.", ex);
+        }
+    }
+
+    /**
      * Gets the mouse pointer speed.
      * <p>
      * Only returns the permanent mouse pointer speed.  Ignores any temporary pointer
diff --git a/core/java/android/hardware/input/TouchCalibration.aidl b/core/java/android/hardware/input/TouchCalibration.aidl
new file mode 100644
index 0000000..2c28774
--- /dev/null
+++ b/core/java/android/hardware/input/TouchCalibration.aidl
@@ -0,0 +1,19 @@
+/*
+ * 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;
+
+parcelable TouchCalibration;
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);
+    }
+}
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 4c0ddeb..b99cb90 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -2069,6 +2069,14 @@
         android:description="@string/permdesc_setPointerSpeed"
         android:protectionLevel="signature" />
 
+    <!-- Allows low-level access to setting input device calibration.
+         <p>Not for use by normal applications.
+         @hide -->
+    <permission android:name="android.permission.SET_INPUT_CALIBRATION"
+        android:label="@string/permlab_setInputCalibration"
+        android:description="@string/permdesc_setInputCalibration"
+        android:protectionLevel="signature" />
+
     <!-- Allows low-level access to setting the keyboard layout.
          <p>Not for use by third-party applications.
          @hide -->
diff --git a/core/res/res/values/strings.xml b/core/res/res/values/strings.xml
index afb7085..f1bcf65 100644
--- a/core/res/res/values/strings.xml
+++ b/core/res/res/values/strings.xml
@@ -2012,6 +2012,10 @@
     <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
     <string name="permdesc_accessNetworkConditions">Allows an application to listen for observations on network conditions. Should never be needed for normal apps.</string>
 
+    <string name="permlab_setInputCalibration">change input device calibration</string>
+    <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
+    <string name="permdesc_setInputCalibration">Allows the app to modify the calibration parameters of the touch screen. Should never be needed for normal apps.</string>
+
     <!-- Policy administration -->
 
     <!-- Title of policy access to limiting the user's password choices -->
diff --git a/services/core/java/com/android/server/input/InputManagerService.java b/services/core/java/com/android/server/input/InputManagerService.java
index e49382e..16972f6 100644
--- a/services/core/java/com/android/server/input/InputManagerService.java
+++ b/services/core/java/com/android/server/input/InputManagerService.java
@@ -52,6 +52,7 @@ import android.hardware.input.InputDeviceIdentifier;
 import android.hardware.input.InputManager;
 import android.hardware.input.InputManagerInternal;
 import android.hardware.input.KeyboardLayout;
+import android.hardware.input.TouchCalibration;
 import android.os.Binder;
 import android.os.Bundle;
 import android.os.Environment;
@@ -700,6 +701,40 @@ public class InputManagerService extends IInputManager.Stub
         mTempFullKeyboards.clear();
     }
 
+    @Override // Binder call
+    public TouchCalibration getTouchCalibrationForInputDevice(String inputDeviceDescriptor) {
+        if (inputDeviceDescriptor == null) {
+            throw new IllegalArgumentException("inputDeviceDescriptor must not be null");
+        }
+
+        synchronized (mDataStore) {
+            return mDataStore.getTouchCalibration(inputDeviceDescriptor);
+        }
+    }
+
+    @Override // Binder call
+    public void setTouchCalibrationForInputDevice(String inputDeviceDescriptor,
+            TouchCalibration calibration) {
+        if (!checkCallingPermission(android.Manifest.permission.SET_INPUT_CALIBRATION,
+                "setTouchCalibrationForInputDevice()")) {
+            throw new SecurityException("Requires SET_INPUT_CALIBRATION permission");
+        }
+        if (inputDeviceDescriptor == null) {
+            throw new IllegalArgumentException("inputDeviceDescriptor must not be null");
+        }
+        if (calibration == null) {
+            throw new IllegalArgumentException("calibration must not be null");
+        }
+
+        synchronized (mDataStore) {
+            try {
+                mDataStore.setTouchCalibration(inputDeviceDescriptor, calibration);
+            } finally {
+                mDataStore.saveIfNeeded();
+            }
+        }
+    }
+
     // Must be called on handler.
     private void showMissingKeyboardLayoutNotification() {
         if (!mKeyboardLayoutNotificationShown) {
diff --git a/services/core/java/com/android/server/input/PersistentDataStore.java b/services/core/java/com/android/server/input/PersistentDataStore.java
index 71de776..9ea369d 100644
--- a/services/core/java/com/android/server/input/PersistentDataStore.java
+++ b/services/core/java/com/android/server/input/PersistentDataStore.java
@@ -24,6 +24,7 @@ import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
 import org.xmlpull.v1.XmlSerializer;
 
+import android.hardware.input.TouchCalibration;
 import android.util.AtomicFile;
 import android.util.Slog;
 import android.util.Xml;
@@ -82,6 +83,25 @@ final class PersistentDataStore {
         }
     }
 
+    public TouchCalibration getTouchCalibration(String inputDeviceDescriptor) {
+        InputDeviceState state = getInputDeviceState(inputDeviceDescriptor, false);
+        if (state == null) {
+            return TouchCalibration.IDENTITY;
+        }
+        else {
+            return state.getTouchCalibration();
+        }
+    }
+
+    public boolean setTouchCalibration(String inputDeviceDescriptor, TouchCalibration calibration) {
+        InputDeviceState state = getInputDeviceState(inputDeviceDescriptor, true);
+        if (state.setTouchCalibration(calibration)) {
+            setDirty();
+            return true;
+        }
+        return false;
+    }
+
     public String getCurrentKeyboardLayout(String inputDeviceDescriptor) {
         InputDeviceState state = getInputDeviceState(inputDeviceDescriptor, false);
         return state != null ? state.getCurrentKeyboardLayout() : null;
@@ -275,9 +295,25 @@ final class PersistentDataStore {
     }
 
     private static final class InputDeviceState {
+        private static final String[] CALIBRATION_NAME = { "x_scale",
+                "x_ymix", "x_offset", "y_xmix", "y_scale", "y_offset" };
+
+        private TouchCalibration mTouchCalibration = TouchCalibration.IDENTITY;
         private String mCurrentKeyboardLayout;
         private ArrayList<String> mKeyboardLayouts = new ArrayList<String>();
 
+        public TouchCalibration getTouchCalibration() {
+            return mTouchCalibration;
+        }
+
+        public boolean setTouchCalibration(TouchCalibration calibration) {
+            if (calibration.equals(mTouchCalibration)) {
+                return false;
+            }
+            mTouchCalibration = calibration;
+            return true;
+        }
+
         public String getCurrentKeyboardLayout() {
             return mCurrentKeyboardLayout;
         }
@@ -389,6 +425,31 @@ final class PersistentDataStore {
                         }
                         mCurrentKeyboardLayout = descriptor;
                     }
+                } else if (parser.getName().equals("calibration")) {
+                    String format = parser.getAttributeValue(null, "format");
+                    if (format == null) {
+                        throw new XmlPullParserException(
+                                "Missing format attribute on calibration.");
+                    }
+                    if (format.equals("affine")) {
+                        float[] matrix = TouchCalibration.IDENTITY.getAffineTransform();
+                        int depth = parser.getDepth();
+                        while (XmlUtils.nextElementWithin(parser, depth)) {
+                            String tag = parser.getName().toLowerCase();
+                            String value = parser.nextText();
+
+                            for (int i = 0; i < matrix.length && i < CALIBRATION_NAME.length; i++) {
+                                if (tag.equals(CALIBRATION_NAME[i])) {
+                                    matrix[i] = Float.parseFloat(value);
+                                    break;
+                                }
+                            }
+                        }
+                        mTouchCalibration = new TouchCalibration(matrix[0], matrix[1], matrix[2],
+                                matrix[3], matrix[4], matrix[5]);
+                    } else {
+                        throw new XmlPullParserException("Unsupported format for calibration.");
+                    }
                 }
             }
 
@@ -411,6 +472,16 @@ final class PersistentDataStore {
                 }
                 serializer.endTag(null, "keyboard-layout");
             }
+
+            serializer.startTag(null, "calibration");
+            serializer.attribute(null, "format", "affine");
+            float[] transform = mTouchCalibration.getAffineTransform();
+            for (int i = 0; i < transform.length && i < CALIBRATION_NAME.length; i++) {
+                serializer.startTag(null, CALIBRATION_NAME[i]);
+                serializer.text(Float.toString(transform[i]));
+                serializer.endTag(null, CALIBRATION_NAME[i]);
+            }
+            serializer.endTag(null, "calibration");
         }
     }
-}
\ No newline at end of file
+}