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..ae5a188d47264aaa8d9b68cd8f4b0c98b4018ccd
--- /dev/null
+++ 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;
+
+/**
+ * Class to manage information related to each connected gamepad device.

[Ted C, 2014/04/16 23:36:53]

No need for "Class to", this can just be "Manages"

[SaurabhK, 2014/04/18 14:51:57]

On 2014/04/16 23:36:53, Ted C wrote:

Done.

+ */
+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 mMapping;

[Ted C, 2014/04/16 23:36:53]

now that this is a boolean, I think mIsStandardGamepad is easier to understand.

although "standard" is somewhat confusing to me as well, but it looks like that
is
what native uses and expects.

update the getter as well.

[SaurabhK, 2014/04/18 14:51:57]

On 2014/04/16 23:36:53, Ted C wrote:

Done.

+
+    // 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++;
+            }
+        }
+    }
+
+    /**
+     * Map the axes and buttons of a gamepad device to a standard gamepad format.
+     */
+    public void mapButtonsAndAxes() {
+        mMapping = 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 getMapping() { return mMapping; }
+
+    /**
+     * @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;
+    }
+
+}