Gamepad: Add support for the Amazon Fire Game Controller

Manual verification of the mapping was done using:
http://www.html5rocks.com/en/tutorials/doodles/gamepad/gamepad-tester/tester.html

This also adds tests to check for mapping regressions for all gamepads.

BUG=453178,373942
TEST=GamepadMappingsTest

Review URL: https://codereview.chromium.org/875813003

Cr-Commit-Position: refs/heads/master@{#313994}

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

@@ -10,6 +10,8 @@ import android.view.InputDevice.MotionRange;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
 
+import org.chromium.base.VisibleForTesting;
+
 import java.util.Arrays;
 import java.util.List;
 
@@ -17,6 +19,16 @@ import java.util.List;
  * Manages information related to each connected gamepad device.
  */
 class GamepadDevice {
+    // Axis ids are used as indices which are empirically always smaller than 256 so this allows
+    // us to create cheap associative arrays.
+    @VisibleForTesting
+    static final int MAX_RAW_AXIS_VALUES = 256;
+
+    // Keycodes are used as indices which are empirically always smaller than 256 so this allows
+    // us to create cheap associative arrays.
+    @VisibleForTesting
+    static final int MAX_RAW_BUTTON_VALUES = 256;
+
     // An id for the gamepad.
     private int mDeviceId;
     // The index of the gamepad in the Navigator.
@@ -38,8 +50,8 @@ class GamepadDevice {
     // 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 final float[] mRawButtons = new float[256];
-    private final float[] mRawAxes = new float[256];
+    private final float[] mRawButtons = new float[MAX_RAW_BUTTON_VALUES];
+    private final float[] mRawAxes = new float[MAX_RAW_AXIS_VALUES];
 
     // An identification string for the gamepad.
     private String mDeviceName;
@@ -59,7 +71,7 @@ class GamepadDevice {
         for (MotionRange range : ranges) {
             if ((range.getSource() & InputDevice.SOURCE_CLASS_JOYSTICK) != 0) {
                 int axis = range.getAxis();
-                assert axis < 256;
+                assert axis < MAX_RAW_AXIS_VALUES;
                 mAxes[i++] = axis;
             }
         }
@@ -141,7 +153,7 @@ class GamepadDevice {
         // Ignore event if it is not for standard gamepad key.
         if (!GamepadList.isGamepadEvent(event)) return false;
         int keyCode = event.getKeyCode();
-        assert keyCode < 256;
+        assert keyCode < MAX_RAW_BUTTON_VALUES;
         // 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;

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

-// Copyright 2014 The Chromium Authors. All rights reserved.
+// Copyright 2015 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.
 
@@ -8,17 +8,23 @@ import android.view.KeyEvent;
 import android.view.MotionEvent;
 
 import org.chromium.base.JNINamespace;
+import org.chromium.base.VisibleForTesting;
 
 /**
  * Class to manage mapping information related to each supported gamepad controller device.
  */
 @JNINamespace("content")
 class GamepadMappings {
-    private static final String NVIDIA_SHIELD_DEVICE_NAME_PREFIX =
-            "NVIDIA Corporation NVIDIA Controller";
-    private static final String MICROSOFT_XBOX_PAD_DEVICE_NAME = "Microsoft X-Box 360 pad";
-    private static final String PS3_SIXAXIS_DEVICE_NAME = "Sony PLAYSTATION(R)3 Controller";
-    private static final String SAMSUNG_EI_GP20_DEVICE_NAME = "Samsung Game Pad EI-GP20";
+    @VisibleForTesting
+    static final String NVIDIA_SHIELD_DEVICE_NAME_PREFIX = "NVIDIA Corporation NVIDIA Controller";
+    @VisibleForTesting
+    static final String MICROSOFT_XBOX_PAD_DEVICE_NAME = "Microsoft X-Box 360 pad";
+    @VisibleForTesting
+    static final String PS3_SIXAXIS_DEVICE_NAME = "Sony PLAYSTATION(R)3 Controller";
+    @VisibleForTesting
+    static final String SAMSUNG_EI_GP20_DEVICE_NAME = "Samsung Game Pad EI-GP20";
+    @VisibleForTesting
+    static final String AMAZON_FIRE_DEVICE_NAME = "Amazon Fire Game Controller";
 
     public static boolean mapToStandardGamepad(float[] mappedAxes, float[] mappedButtons,
             float[] rawAxes, float[] rawButtons, String deviceName) {
@@ -34,6 +40,9 @@ class GamepadMappings {
         } else if (deviceName.equals(SAMSUNG_EI_GP20_DEVICE_NAME)) {
             mapSamsungEIGP20Gamepad(mappedButtons, rawButtons, mappedAxes, rawAxes);
             return true;
+        } else if (deviceName.equals(AMAZON_FIRE_DEVICE_NAME)) {
+            mapAmazonFireGamepad(mappedButtons, rawButtons, mappedAxes, rawAxes);
+            return true;
         }
 
         mapUnknownGamepad(mappedButtons, rawButtons, mappedAxes, rawAxes);
@@ -115,6 +124,13 @@ class GamepadMappings {
         mappedButtons[CanonicalButtonIndex.RIGHT_SHOULDER] = rTrigger;
     }
 
+    private static void mapPedalAxesToBottomShoulder(float[] mappedButtons, float[] rawAxes) {
+        float lTrigger = rawAxes[MotionEvent.AXIS_BRAKE];
+        float rTrigger = rawAxes[MotionEvent.AXIS_GAS];
+        mappedButtons[CanonicalButtonIndex.LEFT_TRIGGER] = lTrigger;
+        mappedButtons[CanonicalButtonIndex.RIGHT_TRIGGER] = rTrigger;
+    }
+
     private static void mapTriggerAxesToBottomShoulder(float[] mappedButtons, float[] rawAxes) {
         float lTrigger = rawAxes[MotionEvent.AXIS_LTRIGGER];
         float rTrigger = rawAxes[MotionEvent.AXIS_RTRIGGER];
@@ -122,11 +138,13 @@ class GamepadMappings {
         mappedButtons[CanonicalButtonIndex.RIGHT_TRIGGER] = rTrigger;
     }
 
-    private static float negativeAxisValueAsButton(float input) {
+    @VisibleForTesting
+    static float negativeAxisValueAsButton(float input) {
         return (input < -0.5f) ? 1.f : 0.f;
     }
 
-    private static float positiveAxisValueAsButton(float input) {
+    @VisibleForTesting
+    static float positiveAxisValueAsButton(float input) {
         return (input > 0.5f) ? 1.f : 0.f;
     }
 
@@ -139,6 +157,23 @@ class GamepadMappings {
         mappedButtons[CanonicalButtonIndex.DPAD_DOWN] = positiveAxisValueAsButton(hatY);
     }
 
+    /**
+     * Method for mapping Amazon Fire gamepad axis and button values
+     * to standard gamepad button and axes values.
+     */
+    private static void mapAmazonFireGamepad(
+            float[] mappedButtons, float[] rawButtons, float[] mappedAxes, float[] rawAxes) {
+        mapCommonXYABButtons(mappedButtons, rawButtons);
+        mapTriggerButtonsToTopShoulder(mappedButtons, rawButtons);
+        mapCommonThumbstickButtons(mappedButtons, rawButtons);
+        mapCommonStartSelectMetaButtons(mappedButtons, rawButtons);
+        mapPedalAxesToBottomShoulder(mappedButtons, rawAxes);
+        mapHatAxisToDpadButtons(mappedButtons, rawAxes);
+
+        mapXYAxes(mappedAxes, rawAxes);
+        mapZAndRZAxesToRightStick(mappedAxes, rawAxes);
+    }
+
     /**
      * Method for mapping Nvidia gamepad axis and button values
      * to standard gamepad button and axes values.