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
new file mode 100644
index 0000000000000000000000000000000000000000..d94dc016a4c4ebad9215d33ef9b8a6b67cb01ca8
--- /dev/null
+++ b/content/public/android/java/src/org/chromium/content/browser/GamepadDevice.java
@@ -0,0 +1,177 @@
+// 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;

[Ted C, 2014/04/04 18:52:18]

for all these gamepage files, can you move them into the input/ package?

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Done.

+
+import android.os.SystemClock;
+import android.view.InputDevice;
+import android.view.InputDevice.MotionRange;
+import android.view.KeyEvent;
+import android.view.MotionEvent;
+
+import org.chromium.content.browser.input.CanonicalAxisIndex;
+import org.chromium.content.browser.input.CanonicalButtonIndex;
+
+import java.util.Arrays;
+
+/*

[Ted C, 2014/04/04 18:52:18]

for javadocs, the starting token is /**

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Done.

+ * Class to manage information related to each connected gamepad device.
+ */
+

[Ted C, 2014/04/04 18:52:18]

remove blank line

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, 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 String mMapping;
+
+    // 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();
+        mMapping = " ";

[Ted C, 2014/04/04 18:52:18]

can you make " " and "standard" constants.

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Now i am keeping mMapping as boolean after review comment from Jdduke

+        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++;
+            }
+        }
+    }
+
+    GamepadDevice() {}

[Ted C, 2014/04/04 18:52:18]

why do you need the empty constructor?

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Removed it.

+
+    /**
+    * Map the axes and buttons of a gamepad device to a standard gamepad format.

[Ted C, 2014/04/04 18:52:18]

for these javadoc comments and below, the seond and third lines need to be
indented one more:

/**
 * ...
 */

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Done.

+    */
+    public void mapButtonsAndAxes() {
+        mMapping = GamepadMappings.mapToStandardGamepad(mAxisValues, mButtonsValues, mRawAxes,

[Ted C, 2014/04/04 18:52:18]

style nit

in java, the indenting is different than that of c++.  The following lines
should be indented 8 from the start of the previous line and not aligned with
the ( above.

Granted, if all params will fit on a line together, I try to use the following:
mMapping = GamepadMappings.mapToStandardGamepad(
        mAxisValues, mButtonsValues, mRawAxes, mRawButtons, mDeviceName) ?
"standard" : " ";

I don't know if that will be under 100 chars in this case though, so you might
need to do:
mMapping = GamepadMappings.mapToStandardGamepad(mAxisValues, mButtonsValues,
mRawAxes,
        mRawButtons, mDeviceName) ? "standard" : " ";

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Keeping all paramaeters in one line after indenting 8 from start of above line.

+                                                        mRawButtons,
+                                                        mDeviceName) ? "standard" : " ";
+    }
+
+    /**
+    * @return Device Id of the gamepad device.
+    */
+    public int getId() { return mDeviceId; }
+
+    /**
+    * @return Mapping status of the gamepad device.
+    */
+    public String 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() {

[Ted C, 2014/04/04 18:52:18]

for consistency with the ones above, these two should probably be one liners as
well.

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Done.

+        return mAxisValues;
+    }
+
+    /**
+    * @return The buttons state of the gamepad device.
+    */
+    public float[] getButtons() {
+        return mButtonsValues;
+

[Ted C, 2014/04/04 18:52:18]

remove extra blank line

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Done.

+    }
+
+    /**
+    * 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 updateForEvent(KeyEvent event) {

[Ted C, 2014/04/04 18:52:18]

for consistency with android, I would call this handleKeyEvent

and handleMotionEvent below.

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Done.

+        // 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 updateForEvent(MotionEvent event) {
+        // Update axes values.

[Ted C, 2014/04/04 18:52:18]

does this need a corresponding isGamepadEvent like the key event handler above?

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Added a check

+        for (int i = 0; i < mAxes.length; ++i) {

[Ted C, 2014/04/04 18:52:18]

i++ in java

[SaurabhK, 2014/04/11 14:41:42]

On 2014/04/04 18:52:18, Ted C wrote:

Done.

+            mRawAxes[i] = event.getAxisValue(mAxes[i]);
+        }
+        mTimestamp = event.getEventTime();
+        return true;
+    }
+
+}