android-project/app/src/main/java/org/libsdl/app/SDLControllerManager.java

package org.libsdl.app;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Objects;

import android.content.Context;
import android.os.*;
import android.view.*;
import android.util.Log;


public class SDLControllerManager 
{

    public static native int nativeSetupJNI();

    public static native int nativeAddJoystick(int device_id, String name, String desc,
                                               int is_accelerometer, int nbuttons,
                                               int naxes, int nhats, int nballs);
    public static native int nativeRemoveJoystick(int device_id);
    public static native int nativeAddHaptic(int device_id, String name);
    public static native int nativeRemoveHaptic(int device_id);
    public static native int onNativePadDown(int device_id, int keycode);
    public static native int onNativePadUp(int device_id, int keycode);
    public static native void onNativeJoy(int device_id, int axis,
                                          float value);
    public static native void onNativeHat(int device_id, int hat_id,
                                          int x, int y);

    protected static SDLJoystickHandler mJoystickHandler;
    protected static SDLHapticHandler mHapticHandler;

    private static final String TAG = "SDLControllerManager";

    public static void initialize() {
        mJoystickHandler = null;
        mHapticHandler = null;

        SDLControllerManager.setup();
    }

    public static void setup() {
        if (Build.VERSION.SDK_INT >= 16) {
            mJoystickHandler = new SDLJoystickHandler_API16();
        } else if (Build.VERSION.SDK_INT >= 12) {
            mJoystickHandler = new SDLJoystickHandler_API12();
        } else {
            mJoystickHandler = new SDLJoystickHandler();
        }
        mHapticHandler = new SDLHapticHandler();
    }

    // Joystick glue code, just a series of stubs that redirect to the SDLJoystickHandler instance
    public static boolean handleJoystickMotionEvent(MotionEvent event) {
        return mJoystickHandler.handleMotionEvent(event);
    }

    /**
     * This method is called by SDL using JNI.
     */
    public static void pollInputDevices() {
        mJoystickHandler.pollInputDevices();
    }

    /**
     * This method is called by SDL using JNI.
     */
    public static void pollHapticDevices() {
        mHapticHandler.pollHapticDevices();
    }

    /**
     * This method is called by SDL using JNI.
     */
    public static void hapticRun(int device_id, int length) {
        mHapticHandler.run(device_id, length);
    }

    // Check if a given device is considered a possible SDL joystick
    public static boolean isDeviceSDLJoystick(int deviceId) {
        InputDevice device = InputDevice.getDevice(deviceId);
        // We cannot use InputDevice.isVirtual before API 16, so let's accept
        // only nonnegative device ids (VIRTUAL_KEYBOARD equals -1)
        if ((device == null) || (deviceId < 0)) {
            return false;
        }
        int sources = device.getSources();

        if ((sources & InputDevice.SOURCE_CLASS_JOYSTICK) == InputDevice.SOURCE_CLASS_JOYSTICK) {
            Log.v(TAG, "Input device " + device.getName() + " is a joystick.");
        }
        if ((sources & InputDevice.SOURCE_DPAD) == InputDevice.SOURCE_DPAD) {
            Log.v(TAG, "Input device " + device.getName() + " is a dpad.");
        }
        if ((sources & InputDevice.SOURCE_GAMEPAD) == InputDevice.SOURCE_GAMEPAD) {
            Log.v(TAG, "Input device " + device.getName() + " is a gamepad.");
        }

        return (((sources & InputDevice.SOURCE_CLASS_JOYSTICK) == InputDevice.SOURCE_CLASS_JOYSTICK) ||
                ((sources & InputDevice.SOURCE_DPAD) == InputDevice.SOURCE_DPAD) ||
                ((sources & InputDevice.SOURCE_GAMEPAD) == InputDevice.SOURCE_GAMEPAD)
        );
    }

}

/* A null joystick handler for API level < 12 devices (the accelerometer is handled separately) */
class SDLJoystickHandler {

    /**
     * Handles given MotionEvent.
     * @param event the event to be handled.
     * @return if given event was processed.
     */
    public boolean handleMotionEvent(MotionEvent event) {
        return false;
    }

    /**
     * Handles adding and removing of input devices.
     */
    public void pollInputDevices() {
    }
}

/* Actual joystick functionality available for API >= 12 devices */
class SDLJoystickHandler_API12 extends SDLJoystickHandler {

    static class SDLJoystick {
        public int device_id;
        public String name;
        public String desc;
        public ArrayList<InputDevice.MotionRange> axes;
        public ArrayList<InputDevice.MotionRange> hats;
    }
    static class RangeComparator implements Comparator<InputDevice.MotionRange> {
        @Override
        public int compare(InputDevice.MotionRange arg0, InputDevice.MotionRange arg1) {
            return arg0.getAxis() - arg1.getAxis();
        }
    }

    private ArrayList<SDLJoystick> mJoysticks;

    public SDLJoystickHandler_API12() {

        mJoysticks = new ArrayList<SDLJoystick>();
    }

    @Override
    public void pollInputDevices() {
        int[] deviceIds = InputDevice.getDeviceIds();
        // It helps processing the device ids in reverse order
        // For example, in the case of the XBox 360 wireless dongle,
        // so the first controller seen by SDL matches what the receiver
        // considers to be the first controller

        for(int i=deviceIds.length-1; i>-1; i--) {
            SDLJoystick joystick = getJoystick(deviceIds[i]);
            if (joystick == null) {
                joystick = new SDLJoystick();
                InputDevice joystickDevice = InputDevice.getDevice(deviceIds[i]);
                if (SDLControllerManager.isDeviceSDLJoystick(deviceIds[i])) {
                    joystick.device_id = deviceIds[i];
                    joystick.name = joystickDevice.getName();
                    joystick.desc = getJoystickDescriptor(joystickDevice);
                    joystick.axes = new ArrayList<InputDevice.MotionRange>();
                    joystick.hats = new ArrayList<InputDevice.MotionRange>();

                    List<InputDevice.MotionRange> ranges = joystickDevice.getMotionRanges();
                    Collections.sort(ranges, new RangeComparator());
                    for (InputDevice.MotionRange range : ranges ) {
                        if ((range.getSource() & InputDevice.SOURCE_CLASS_JOYSTICK) != 0) {
                            if (range.getAxis() == MotionEvent.AXIS_HAT_X ||
                                range.getAxis() == MotionEvent.AXIS_HAT_Y) {
                                joystick.hats.add(range);
                            }
                            else {
                                joystick.axes.add(range);
                            }
                        }
                    }

                    mJoysticks.add(joystick);
                    SDLControllerManager.nativeAddJoystick(joystick.device_id, joystick.name, joystick.desc, 0, -1,
                                                           joystick.axes.size(), joystick.hats.size()/2, 0);
                }
            }
        }

        /* Check removed devices */
        ArrayList<Integer> removedDevices = new ArrayList<Integer>();
        for(int i=0; i < mJoysticks.size(); i++) {
            int device_id = mJoysticks.get(i).device_id;
            int j;
            for (j=0; j < deviceIds.length; j++) {
                if (device_id == deviceIds[j]) break;
            }
            if (j == deviceIds.length) {
                removedDevices.add(Integer.valueOf(device_id));
            }
        }

        for(int i=0; i < removedDevices.size(); i++) {
            int device_id = removedDevices.get(i).intValue();
            SDLControllerManager.nativeRemoveJoystick(device_id);
            for (int j=0; j < mJoysticks.size(); j++) {
                if (mJoysticks.get(j).device_id == device_id) {
                    mJoysticks.remove(j);
                    break;
                }
            }
        }
    }

    protected SDLJoystick getJoystick(int device_id) {
        for(int i=0; i < mJoysticks.size(); i++) {
            if (mJoysticks.get(i).device_id == device_id) {
                return mJoysticks.get(i);
            }
        }
        return null;
    }

    @Override
    public boolean handleMotionEvent(MotionEvent event) {
        if ((event.getSource() & InputDevice.SOURCE_JOYSTICK) != 0) {
            int actionPointerIndex = event.getActionIndex();
            int action = event.getActionMasked();
            switch(action) {
                case MotionEvent.ACTION_MOVE:
                    SDLJoystick joystick = getJoystick(event.getDeviceId());
                    if ( joystick != null ) {
                        for (int i = 0; i < joystick.axes.size(); i++) {
                            InputDevice.MotionRange range = joystick.axes.get(i);
                            /* Normalize the value to -1...1 */
                            float value = ( event.getAxisValue( range.getAxis(), actionPointerIndex) - range.getMin() ) / range.getRange() * 2.0f - 1.0f;
                            SDLControllerManager.onNativeJoy(joystick.device_id, i, value );
                        }
                        for (int i = 0; i < joystick.hats.size(); i+=2) {
                            int hatX = Math.round(event.getAxisValue( joystick.hats.get(i).getAxis(), actionPointerIndex ) );
                            int hatY = Math.round(event.getAxisValue( joystick.hats.get(i+1).getAxis(), actionPointerIndex ) );
                            SDLControllerManager.onNativeHat(joystick.device_id, i/2, hatX, hatY );
                        }
                    }
                    break;
                default:
                    break;
            }
        }
        return true;
    }

    public String getJoystickDescriptor(InputDevice joystickDevice) {
        return joystickDevice.getName();
    }
}


class SDLJoystickHandler_API16 extends SDLJoystickHandler_API12 {

    @Override
    public String getJoystickDescriptor(InputDevice joystickDevice) {
        String desc = joystickDevice.getDescriptor();

        if (desc != null && desc != "") {
            return desc;
        }

        return super.getJoystickDescriptor(joystickDevice);
    }
}

class SDLHapticHandler {

    class SDLHaptic {
        public int device_id;
        public String name;
        public Vibrator vib;
    }

    private ArrayList<SDLHaptic> mHaptics;
    
    public SDLHapticHandler() {
        mHaptics = new ArrayList<SDLHaptic>();
    }

    public void run(int device_id, int length) {
        SDLHaptic haptic = getHaptic(device_id);
        if (haptic != null) {
            haptic.vib.vibrate (length);
        }
    }

    public void pollHapticDevices() {
        
        final int deviceId_VIBRATOR_SERVICE = 999999;
        boolean hasVibratorService = false;

        int[] deviceIds = InputDevice.getDeviceIds();
        // It helps processing the device ids in reverse order
        // For example, in the case of the XBox 360 wireless dongle,
        // so the first controller seen by SDL matches what the receiver
        // considers to be the first controller

        if (Build.VERSION.SDK_INT >= 16)
        {
            for (int i = deviceIds.length - 1; i > -1; i--) {
                SDLHaptic haptic = getHaptic(deviceIds[i]);
                if (haptic == null) {
                    InputDevice device = InputDevice.getDevice(deviceIds[i]);
                    Vibrator vib = device.getVibrator();
                    if (vib.hasVibrator()) {
                        haptic = new SDLHaptic();
                        haptic.device_id = deviceIds[i];
                        haptic.name = device.getName();
                        haptic.vib = vib;
                        mHaptics.add(haptic);
                        SDLControllerManager.nativeAddHaptic(haptic.device_id, haptic.name);
                    }
                }
            }
        }

        /* Check VIBRATOR_SERVICE */
        Vibrator vib = (Vibrator) SDL.getContext().getSystemService(Context.VIBRATOR_SERVICE);
        if (vib != null) {
            if (Build.VERSION.SDK_INT >= 11) {
                hasVibratorService = vib.hasVibrator();
            } else {
                hasVibratorService = true;
            }

            if (hasVibratorService) {
                SDLHaptic haptic = getHaptic(deviceId_VIBRATOR_SERVICE);
                if (haptic == null) {
                    haptic = new SDLHaptic();
                    haptic.device_id = deviceId_VIBRATOR_SERVICE;
                    haptic.name = "VIBRATOR_SERVICE";
                    haptic.vib = vib; 
                    mHaptics.add(haptic);
                    SDLControllerManager.nativeAddHaptic(haptic.device_id, haptic.name);
                }
            }
        }

        /* Check removed devices */
        ArrayList<Integer> removedDevices = new ArrayList<Integer>();
        for(int i=0; i < mHaptics.size(); i++) {
            int device_id = mHaptics.get(i).device_id;
            int j;
            for (j=0; j < deviceIds.length; j++) {
                if (device_id == deviceIds[j]) break;
            }

            if (device_id == deviceId_VIBRATOR_SERVICE && hasVibratorService) {
                // don't remove the vibrator if it is still present
            } else if (j == deviceIds.length) {
                removedDevices.add(device_id);
            }
        }

        for(int i=0; i < removedDevices.size(); i++) {
            int device_id = removedDevices.get(i);
            SDLControllerManager.nativeRemoveHaptic(device_id);
            for (int j=0; j < mHaptics.size(); j++) {
                if (mHaptics.get(j).device_id == device_id) {
                    mHaptics.remove(j);
                    break;
                }
            }
        }
    }

    protected SDLHaptic getHaptic(int device_id) {
        for(int i=0; i < mHaptics.size(); i++) {
            if (mHaptics.get(i).device_id == device_id) {
                return mHaptics.get(i);
            }
        }
        return null;
    }   
}

class SDLGenericMotionListener_API12 implements View.OnGenericMotionListener {
    // Generic Motion (mouse hover, joystick...) events go here
    @Override
    public boolean onGenericMotion(View v, MotionEvent event) {
        float x, y;
        int action;

        switch ( event.getSource() ) {
            case InputDevice.SOURCE_JOYSTICK:
            case InputDevice.SOURCE_GAMEPAD:
            case InputDevice.SOURCE_DPAD:
                return SDLControllerManager.handleJoystickMotionEvent(event);

            case InputDevice.SOURCE_MOUSE:
                if (!SDLActivity.mSeparateMouseAndTouch) {
                    break;
                }
                action = event.getActionMasked();
                switch (action) {
                    case MotionEvent.ACTION_SCROLL:
                        x = event.getAxisValue(MotionEvent.AXIS_HSCROLL, 0);
                        y = event.getAxisValue(MotionEvent.AXIS_VSCROLL, 0);
                        SDLActivity.onNativeMouse(0, action, x, y);
                        return true;

                    case MotionEvent.ACTION_HOVER_MOVE:
                        x = event.getX(0);
                        y = event.getY(0);

                        SDLActivity.onNativeMouse(0, action, x, y);
                        return true;

                    default:
                        break;
                }
                break;

            default:
                break;
        }

        // Event was not managed
        return false;
    }
}