Gamepad API support for chrome on android

content/public/android/java/src/org/chromium/content/browser/GamepadDevice.java

Index: content/public/android/java/src/org/chromium/content/browser/GamepadDevice.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/GamepadDevice.java b/content/public/android/java/src/org/chromium/content/browser/GamepadDevice.java
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index 0000000000000000000000000000000000000000..3ba0fe2b11d9b3709e1fd011255caff9cd802f1e
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+++ b/content/public/android/java/src/org/chromium/content/browser/GamepadDevice.java
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+/*
+ * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *  * Neither the name of NVIDIA CORPORATION nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+package org.chromium.content.browser;
+
+import android.os.SystemClock;
+import android.view.InputDevice;
+import android.view.InputDevice.MotionRange;
+import android.view.KeyCharacterMap;
+import android.view.KeyEvent;
+import android.view.MotionEvent;
+
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+
+/*
+ * Class to manage information related to each connected gamepad device.
+ */
+
+class GamepadDevice {
+    // An id for the gamepad.
+    protected int mDeviceId;
+    // The index of the gamepad in the Navigator.
+    protected int mDeviceIndex;
+    // An identification string for the gamepad.
+    protected String mDeviceName;
+    // Last time the data for this gamepad was updated.
+    protected long mTimestamp;
+
+    // Array of values for all axes of the gamepad.
+    // All axis values must be linearly normalized to the range [-1.0 .. 1.0].
+    // As appropriate, -1.0 should correspond to "up" or "left", and 1.0
+    // should correspond to "down" or "right".
+    protected float[] mAxisValues;
+    // Array of axes ids.
+    private int[] mAxes;
+
+    // List of keycodes that can be sent by a standard gamepad. Standard gamepad can have
+    // buttons as per the spec:
+    // https://dvcs.w3.org/hg/gamepad/raw-file/default/gamepad.html#remapping
+    // Need to maintain this list to get input device capabilities. We query
+    // input devices with this list and device returns list mentioning which
+    // Keycodes out of these can be sent by a gamepad device.
+    private static final int[] standardGamepadKeyCodes = {
+        KeyEvent.KEYCODE_BUTTON_A, // Button 0
+        KeyEvent.KEYCODE_BUTTON_B, // Button 1
+        KeyEvent.KEYCODE_BUTTON_X, // Button 2
+        KeyEvent.KEYCODE_BUTTON_Y, // Button 3
+        KeyEvent.KEYCODE_BUTTON_L1, // Button 4
+        KeyEvent.KEYCODE_BUTTON_R1, // Button 5
+        KeyEvent.KEYCODE_BUTTON_L2, // Button 6
+        KeyEvent.KEYCODE_BUTTON_R2, // Button 7
+        KeyEvent.KEYCODE_BUTTON_SELECT, // Button 8
+        KeyEvent.KEYCODE_BUTTON_START, // Button 9
+        KeyEvent.KEYCODE_BUTTON_THUMBL, // Button 10
+        KeyEvent.KEYCODE_BUTTON_THUMBR, // Button 11
+        KeyEvent.KEYCODE_DPAD_UP, // Button 12
+        KeyEvent.KEYCODE_DPAD_DOWN, // Button 13
+        KeyEvent.KEYCODE_DPAD_LEFT, // Button 14
+        KeyEvent.KEYCODE_DPAD_RIGHT, // Button 15
+        KeyEvent.KEYCODE_BUTTON_MODE, // Button 16??
+    };
+
+    // Standard gamepad buttons.
+    private static class StandardButtons {
+        public static final int BUTTON_A = 0;
+        public static final int BUTTON_B = 1;
+        public static final int BUTTON_X = 2;
+        public static final int BUTTON_Y = 3;
+        public static final int LEFT_TRIGGER = 4;
+        public static final int RIGHT_TRIGGER = 5;
+        public static final int BOTTOM_LEFT_TRIGGER = 6;
+        public static final int BOTTOM_RIGHT_TRIGGER = 7;
+        public static final int SELECT = 8;
+        public static final int START = 9;
+        public static final int LEFT_THUMB = 10;
+        public static final int RIGHT_THUMB = 11;
+        public static final int DPAD_UP = 12;
+        public static final int DPAD_DOWN = 13;
+        public static final int DPAD_LEFT = 14;
+        public static final int DPAD_RIGHT = 15;
+        public static final int MODE = 16;
+        public static final int MAX_BUTTONS = 17;
+    }
+
+    // Standard gamepad axes.
+    private static class StandardAxes {
+        public static final int AXIS_0 = 0;
+        public static final int AXIS_1 = 1;
+        public static final int AXIS_2 = 2;
+        public static final int AXIS_3 = 3;
+        public static final int MAX_AXES = 4;
+    }
+
+    // We guess the gamepad inputDevice type from its name and then map it to the
+    // standard gamepad if it is one of the known gamepads.
+    protected enum GamepadType {
+        Shield,
+        XBox360,
+        Unknown
+    }
+    protected GamepadType mGamepadType;
+
+    // Following values should be changed if the gamepad layout changes

[xwang, 2014/01/14 03:03:22]

Will it better to separate the device specific stuff to another file/classes? 
Such as DeviceMappings.java.

[SaurabhK, 2014/01/15 16:57:08]

Will add another class in next patch set.

+    // or frameworks exposes different axes / buttons for a particular gamepad.
+    // mRawShieldAxes is the total raw axes on known shield gamepad.
+    private static final int mRawShieldAxes = 10;
+    // mRawShieldButtons is the total raw buttons on known shield gamepad.
+    private static final int mRawShieldButtons = 10;
+    // mRawXBoxAxes is the total raw axes on known XBox gamepad.
+    private static final int mRawXBoxAxes = 10;
+    // mRawXBoxButtons is the total raw buttons on known XBox gamepad.
+    private static final int mRawXBoxButtons = 9;
+
+    // Hash map of supported keycodes and their current value linearly
+    // normalized to the range [0.0 .. 1.0].
+    // 0.0 must mean fully unpressed, and 1.0 must mean fully pressed.
+    protected LinkedHashMap<Integer, Float> mKeyCodeValueMap = new LinkedHashMap<Integer, Float>();
+
+    GamepadDevice(int index, InputDevice inputDevice) {
+        mDeviceIndex = index;
+        mDeviceId = inputDevice.getId();
+        mDeviceName = inputDevice.getName();
+        mTimestamp = SystemClock.uptimeMillis();
+        // Get the total number of axes supported by gamepad.
+        int totalAxes = 0;
+        for (MotionRange range : inputDevice.getMotionRanges()) {
+            if ((range.getSource() & InputDevice.SOURCE_CLASS_JOYSTICK) != 0) {
+                totalAxes++;
+            }
+        }
+        // Get axis ids and initialize axes values.
+        mAxes = new int[totalAxes];
+        mAxisValues = new float[totalAxes];
+        int i = 0;
+        for (MotionRange range : inputDevice.getMotionRanges()) {
+            if ((range.getSource() & InputDevice.SOURCE_CLASS_JOYSTICK) != 0) {
+                mAxes[i] = range.getAxis();
+                mAxisValues[i] = 0.0f;
+                i++;
+            }
+        }
+        // Update supported buttons list.
+        KeyCharacterMap kcm = inputDevice.getKeyCharacterMap();
+        boolean[] deviceKeys = kcm.deviceHasKeys(standardGamepadKeyCodes);
+        int j;
+        for (j = 0; j < standardGamepadKeyCodes.length; ++j) {
+            if (deviceKeys[j]) {
+                mKeyCodeValueMap.put(standardGamepadKeyCodes[j], 0.0f);
+            }
+        }
+
+        // When the user agent recognizes the attached inputDevice, it is recommended
+        // that it be remapped to a canonical ordering when possible. Devices
+        // that are not recognized should still be exposed in their raw form.
+        setGamepadType();
+    }
+
+    GamepadDevice() {}
+
+    public int getId() { return mDeviceId; }
+
+    public String getName() { return mDeviceName; }
+
+    public int getIndex() { return mDeviceIndex; }
+
+    public long getTimestamp() { return mTimestamp; }
+
+    public float[] getAxes() {
+        if ( mGamepadType != GamepadType.Unknown) {
+            return mapToStandardGamepadAxes(mAxisValues);
+        }
+        return mAxisValues;
+    }
+
+    public float[] getButtons() {
+        int size = mKeyCodeValueMap.size();
+        float[] values = new float[size];
+        int i = 0;
+        Iterator itr = mKeyCodeValueMap.values().iterator();
+        while (itr.hasNext()) {
+            values[i++] = (Float)itr.next();
+        }
+        if ( mGamepadType != GamepadType.Unknown) {
+            return mapToStandardGamepadButtons(values, mAxisValues);
+        }
+        return values;
+    }
+
+    public boolean updateForEvent(KeyEvent event) {
+        mTimestamp = SystemClock.uptimeMillis();
+        // Ignore event if it is not for standard gamepad key.
+        int keyCode = event.getKeyCode();
+        if (mKeyCodeValueMap.get(keyCode) == null) {
+            return true;
+        }
+        // Button value 0.0 must mean fully unpressed, and 1.0 must mean fully pressed.
+        if (event.getAction() == KeyEvent.ACTION_DOWN) {
+            mKeyCodeValueMap.put(keyCode, 1.0f);
+        } else if (event.getAction() == KeyEvent.ACTION_UP) {
+            mKeyCodeValueMap.put(keyCode, 0.0f);
+        }
+
+        return true;
+    }
+
+    public boolean updateForEvent(MotionEvent event) {
+        mTimestamp = SystemClock.uptimeMillis();
+        // Update axes values.
+        for (int i = 0; i < mAxes.length; ++i) {
+            mAxisValues[i] = event.getAxisValue(mAxes[i]);
+        }
+        return true;
+    }
+
+    public boolean isKnownGamepadLayout() {
+        return mGamepadType != GamepadType.Unknown;
+    }
+
+    protected void setGamepadType() {
+        if (isKnownShieldGamepad()) {
+            mGamepadType = GamepadType.Shield;
+        } else if (isKnownXBoxGamepad()) {
+            mGamepadType = GamepadType.XBox360;
+        } else {
+            // TODO: Add support for mapping other common gamepads to the standard gamepads.
+            mGamepadType = GamepadType.Unknown;
+        }
+    }
+
+    private boolean isKnownShieldGamepad() {
+        if (mDeviceName.contains("NVIDIA") && mDeviceName.contains("Controller")) {
+            // Known shield gamepad should have mRawShieldAxes and mRawShieldButtons.
+            if (mAxisValues.length == mRawShieldAxes &&
+                        mKeyCodeValueMap.size() == mRawShieldButtons) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean isKnownXBoxGamepad() {
+        if (mDeviceName.contains("Microsoft") && mDeviceName.contains("X-Box") &&
+            mDeviceName.contains("360") && mDeviceName.contains("pad")) {
+            // Known XBox gamepad should have mRawXBoxAxes and mRawXBoxButtons.
+            if (mAxisValues.length == mRawXBoxAxes && mKeyCodeValueMap.size() == mRawXBoxButtons) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private float[] mapToStandardGamepadAxes(float[] rawAxes) {
+        switch (mGamepadType) {
+            case Shield:
+                return mapShieldAxes(rawAxes);
+            case XBox360:
+                return mapXBox360Axes(rawAxes);
+        }
+        return rawAxes;
+    }
+
+    private float[] mapToStandardGamepadButtons(float[] rawButtons, float[] rawAxes) {
+        switch (mGamepadType) {
+            case Shield:
+                return mapShieldButtons(rawButtons, rawAxes);
+            case XBox360:
+                return mapXBox360Buttons(rawButtons, rawAxes);
+        }
+        return rawAxes;
+    }
+
+    private float negativeAxisValueAsButton(float input) {
+        return (input < -0.5f) ? 1.f : 0.f;
+    }
+
+    private float positiveAxisValueAsButton(float input) {
+        return (input > 0.5f) ? 1.f : 0.f;
+    }
+
+    /**
+     * Method for mapping Nvidia gamepad axis values to
+     * standard gamepad axis values.
+     */
+    private float[] mapShieldAxes(float[] rawAxes) {
+        float[] values = new float[StandardAxes.MAX_AXES];
+        // Standard gamepad can have only four axes.
+        values[StandardAxes.AXIS_0] = rawAxes[0];
+        values[StandardAxes.AXIS_1] = rawAxes[1];
+        values[StandardAxes.AXIS_2] = rawAxes[4];
+        values[StandardAxes.AXIS_3] = rawAxes[5];
+        return values;
+    }
+
+    /**
+     * Method for mapping Nvidia gamepad axis and button values
+     * to standard gamepad button values.
+     */
+    public float[] mapShieldButtons(float[] rawButtons, float[] rawAxes) {
+        float[] values = new float[StandardButtons.MAX_BUTTONS];
+        // First four buttons on Nvidia gamepad appear in correct order so no mapping is required.
+        values[StandardButtons.BUTTON_A] = rawButtons[0];
+        values[StandardButtons.BUTTON_B] = rawButtons[1];
+        values[StandardButtons.BUTTON_X] = rawButtons[2];
+        values[StandardButtons.BUTTON_Y] = rawButtons[3];
+        // Third axis on Nvidia gamepad acts as a bottom left trigger button.
+        values[StandardButtons.BOTTOM_LEFT_TRIGGER] = rawAxes[2];
+        values[StandardButtons.LEFT_TRIGGER] = rawButtons[4];
+        values[StandardButtons.RIGHT_TRIGGER] = rawButtons[5];
+        values[StandardButtons.SELECT] = rawButtons[6];
+        values[StandardButtons.START] = rawButtons[7];
+        values[StandardButtons.LEFT_THUMB] = rawButtons[8];
+        values[StandardButtons.RIGHT_THUMB] = rawButtons[9];
+        // Seventh axis on Nvidia gamepad acts as a bottom right trigger button.
+        values[StandardButtons.BOTTOM_RIGHT_TRIGGER] = rawAxes[6];
+        // Ninth axis on Nvidia gamepad acts as directional pad right and left button.
+        // Positive axis value indicates dpad right.
+        // Negative value indicates dpad left.
+        values[StandardButtons.DPAD_RIGHT] = positiveAxisValueAsButton(rawAxes[8]);
+        values[StandardButtons.DPAD_LEFT] = negativeAxisValueAsButton(rawAxes[8]);
+        // Tenth axis on Nvidia gamepad acts as directional pad up and down button.
+        // Positive axis value indicates dpad down.
+        // Negative value indicates dpad up.
+        values[StandardButtons.DPAD_DOWN] = positiveAxisValueAsButton(rawAxes[9]);
+        values[StandardButtons.DPAD_UP] = negativeAxisValueAsButton(rawAxes[9]);
+        // Other standard buttons are either not present on the gamepad or not exposed to an
+        // application.
+        values[StandardButtons.MODE] = 0.0f;
+        return values;
+    }
+
+    /**
+     * Method for mapping Microsoft XBox 360 gamepad axis values to
+     * standard gamepad axis values.
+     */
+    private float[] mapXBox360Axes(float[] rawAxes) {
+        float[] values = new float[StandardAxes.MAX_AXES];
+        // Standard gamepad can have only four axes.
+        values[StandardAxes.AXIS_0] = rawAxes[0];
+        values[StandardAxes.AXIS_1] = rawAxes[1];
+        values[StandardAxes.AXIS_2] = rawAxes[4];
+        values[StandardAxes.AXIS_3] = rawAxes[5];
+        return values;
+    }
+
+    /**
+     * Method for mapping Microsoft XBox 360 gamepad axis and button values
+     * to standard gamepad button values.
+     */
+    private float[] mapXBox360Buttons(float[] rawButtons, float[] rawAxes) {
+        float[] values = new float[StandardButtons.MAX_BUTTONS];
+        // First four buttons on Microsoft XBox 360 gamepad appear in correct order so no mapping
+        // is required.
+        values[StandardButtons.BUTTON_A] = rawButtons[0];
+        values[StandardButtons.BUTTON_B] = rawButtons[1];
+        values[StandardButtons.BUTTON_X] = rawButtons[2];
+        values[StandardButtons.BUTTON_Y] = rawButtons[3];
+        // Third axis on Microsoft XBox 360 gamepad acts as a left bottom shoulder button.
+        values[StandardButtons.BOTTOM_LEFT_TRIGGER] = rawAxes[2];
+        values[StandardButtons.LEFT_TRIGGER] = rawButtons[4];
+        values[StandardButtons.RIGHT_TRIGGER] = rawButtons[5];
+        values[StandardButtons.START] = rawButtons[6];
+        values[StandardButtons.LEFT_THUMB] = rawButtons[7];
+        values[StandardButtons.RIGHT_THUMB] = rawButtons[8];
+        // Seventh axis on Microsoft XBox 360 gamepad acts as a right bottom shoulder button.
+        values[StandardButtons.BOTTOM_RIGHT_TRIGGER] = rawAxes[6];
+        // Ninth axis on Microsoft XBox 360 gamepad acts as directional pad right and left button.
+        // Positive axis value indicates dpad right.
+        // Negative value indicates dpad left.
+        values[StandardButtons.DPAD_RIGHT] = positiveAxisValueAsButton(rawAxes[8]);
+        values[StandardButtons.DPAD_LEFT] = negativeAxisValueAsButton(rawAxes[8]);
+        // Tenth axis on Microsoft XBox 360 gamepad acts as directional pad up and down button.
+        // Positive axis value indicates dpad down.
+        // Negative value indicates dpad up.
+        values[StandardButtons.DPAD_DOWN] = positiveAxisValueAsButton(rawAxes[9]);
+        values[StandardButtons.DPAD_UP] = negativeAxisValueAsButton(rawAxes[9]);
+        // Other standard buttons are either not present on the gamepad or not exposed to an
+        // application.
+        values[StandardButtons.SELECT] = 0.0f;
+        values[StandardButtons.MODE] = 0.0f;
+        return values;
+    }
+
+}