Gamepad API support for chrome on android

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

Index: content/public/android/java/src/org/chromium/content/browser/input/GamepadDevice.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/input/GamepadDevice.java b/content/public/android/java/src/org/chromium/content/browser/input/GamepadDevice.java
new file mode 100644
index 0000000000000000000000000000000000000000..3e9ab5ec9ba9e9d527e3fc13cce04e4f1d78a784
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+++ b/content/public/android/java/src/org/chromium/content/browser/input/GamepadDevice.java
@@ -0,0 +1,166 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.content.browser.input;
+
+import android.os.SystemClock;
+import android.view.InputDevice;
+import android.view.InputDevice.MotionRange;
+import android.view.KeyEvent;
+import android.view.MotionEvent;
+
+import java.util.Arrays;
+
+/**
+ * Manages information related to each connected gamepad device.
+ */
+class GamepadDevice {
+    // An id for the gamepad.
+    private int mDeviceId;
+    // The index of the gamepad in the Navigator.
+    private int mDeviceIndex;
+    // Last time the data for this gamepad was updated.
+    private long mTimestamp;
+    // If this gamepad is mapped to standard gamepad?
+    private boolean mIsStandardGamepad;
+
+    // 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".
+    private float[] mAxisValues;
+
+    private float[] mButtonsValues;
+
+    // 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. Therefore we must
+    // pass the raw Button and raw Axis values.
+    private float[] mRawButtons;
+    private float[] mRawAxes;
+
+    // An identification string for the gamepad.
+    private String mDeviceName;
+
+    // Array of axes ids.
+    private int[] mAxes;
+
+    GamepadDevice(int index, InputDevice inputDevice) {
+        mDeviceIndex = index;
+        mDeviceId = inputDevice.getId();
+        mDeviceName = inputDevice.getName();
+        mTimestamp = SystemClock.uptimeMillis();
+        mButtonsValues = new float[CanonicalButtonIndex.NUM_CANONICAL_BUTTONS];
+        mAxisValues = new float[CanonicalAxisIndex.NUM_CANONICAL_AXES];
+        mRawButtons = new float[256];
+        // 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];
+        mRawAxes = new float[totalAxes];
+        int i = 0;
+        for (MotionRange range : inputDevice.getMotionRanges()) {
+            if ((range.getSource() & InputDevice.SOURCE_CLASS_JOYSTICK) != 0) {
+                mAxes[i] = range.getAxis();
+                mRawAxes[i] = 0.0f;
+                i++;
+            }
+        }
+    }
+
+    /**
+     * Updates the axes and buttons maping of a gamepad device to a standard gamepad format.
+     */
+    public void updateButtonsAndAxesMapping() {
+        mIsStandardGamepad = GamepadMappings.mapToStandardGamepad(
+                mAxisValues, mButtonsValues, mRawAxes, mRawButtons, mDeviceName);
+    }
+
+    /**
+     * @return Device Id of the gamepad device.
+     */
+    public int getId() { return mDeviceId; }
+
+    /**
+     * @return Mapping status of the gamepad device.
+     */
+    public boolean isStandardGamepad() { return mIsStandardGamepad; }
+
+    /**
+     * @return Device name of the gamepad device.
+     */
+    public String getName() { return mDeviceName; }
+
+    /**
+     * @return Device index of the gamepad device.
+     */
+    public int getIndex() { return mDeviceIndex; }
+
+    /**
+     * @return The timestamp when the gamepad device was last interacted.
+     */
+    public long getTimestamp() { return mTimestamp; }
+
+    /**
+     * @return The axes state of the gamepad device.
+     */
+    public float[] getAxes() { return mAxisValues; }
+
+    /**
+     * @return The buttons state of the gamepad device.
+     */
+    public float[] getButtons() { return mButtonsValues; }
+
+    /**
+     * Reset the axes and buttons data of the gamepad device everytime gamepad data access is
+     * paused.
+     */
+    public void clearData() {
+        Arrays.fill(mAxisValues, 0);
+        Arrays.fill(mRawAxes, 0);
+        Arrays.fill(mButtonsValues, 0);
+        Arrays.fill(mRawButtons, 0);
+    }
+
+    /**
+     * Handles key event from the gamepad device.
+     * @return True if the key event from the gamepad device has been consumed.
+     */
+    public boolean handleKeyEvent(KeyEvent event) {
+        // Ignore event if it is not for standard gamepad key.
+        if (!GamepadList.isGamepadEvent(event)) return false;
+        int keyCode = event.getKeyCode();
+        assert keyCode < 256;
+        // Button value 0.0 must mean fully unpressed, and 1.0 must mean fully pressed.
+        if (event.getAction() == KeyEvent.ACTION_DOWN) {
+            mRawButtons[keyCode] = 1.0f;
+        } else if (event.getAction() == KeyEvent.ACTION_UP) {
+            mRawButtons[keyCode] = 0.0f;
+        }
+        mTimestamp = event.getEventTime();
+
+        return true;
+    }
+
+    /**
+     * Handles motion event from the gamepad device.
+     * @return True if the motion event from the gamepad device has been consumed.
+     */
+    public boolean handleMotionEvent(MotionEvent event) {
+        // Ignore event if it is not a standard gamepad motion event.
+        if (!GamepadList.isGamepadEvent(event)) return false;
+        // Update axes values.
+        for (int i = 0; i < mAxes.length; i++) {
+            mRawAxes[i] = event.getAxisValue(mAxes[i]);
+        }
+        mTimestamp = event.getEventTime();
+        return true;
+    }
+
+}