Android Open Source - Steering-Wheel-Interface Button Actions

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Back to project page Steering-Wheel-Interface.

License

The source code is released under:

Copyright 2013 Kristoffer Smith and other contributors http://theksmith.com/ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation...

Java Source Code

/*
 * TODO: Re-do this class to allow end users to define the button's bus messages and map each to a predefined action
 * // w  w w . j  av a 2 s.c o  m
 * Currently the project is assumed to be only a template. A developer would need to override
 * this class with their own specific implementation. To make this a "real" app, we will
 * need to make the buttons and their associated actions definable via the settings screen.
 */

package com.theksmith.steeringwheelinterface;

import java.util.Date;
import java.util.HashMap;

import android.content.Context;
import android.media.AudioManager;
import android.util.Log;
import android.view.KeyEvent;


/**
 * Provides a central place to define which bus messages correspond to which buttons, and which buttons do what actions.
 * This class is a basic template that would most likely be overridden.
 * 
 * @author Kristoffer Smith <kristoffer@theksmith.com>
 */
public class ButtonActions {
  protected static final String TAG = ButtonActions.class.getSimpleName();
  
  protected static final int DEBOUNCE_THRESHOLD = 50;  //milliseconds
  
  protected Context mAppContext;
  protected HashMap<String, Long> mBusMessageDebounceTimes = new HashMap<String, Long>();
  
    //performAction() return status
  public static final int STATUS_ERROR_UNKNOWN = 0;
  public static final int STATUS_ERROR_UNKNOWNBUTTON = 1;
  public static final int STATUS_ERROR_ACTIONERROR = 2;
  public static final int STATUS_SUCCESS = 3;  

  //the known buttons and the beginning of their corresponding bus messages
  //TODO: allow wildcard or regex definitions
  public static final String BUTTON_LEFT_CENTER = "3D 11 00 80";
  public static final String BUTTON_LEFT_DOWN = "3D 11 10 00";
  public static final String BUTTON_LEFT_UP = "3D 11 20 00";
  public static final String BUTTON_RIGHT_CENTER = "3D 11 00 02";
  public static final String BUTTON_RIGHT_DOWN = "3D 11 02 00";
  public static final String BUTTON_RIGHT_UP = "3D 11 04 00";
  
  
  private ButtonActions() { 
    //exists only to prevent creation of class without passing required param
  }

  
  /**
   * Constructor.
   * 
   * @param appContext    The application context of the container app. 
   */
  public ButtonActions(Context appContext) {
    mAppContext = appContext.getApplicationContext();
  }
  

  /**
   * Executes a particular button's assigned action.
   * 
   * @param forBusMessage    A bus message, expected to correspond to a button (one of the ButtonActions.BUTTON_XYZ definitions).
   * @return           Returns one of the ButtonActions.STATUS_XYZ definitions.
   */
  public int performAction(String forBusMessage) {
    try {      
      if (forBusMessage.startsWith(BUTTON_LEFT_CENTER)) {
        if (!isHardwareBounce(forBusMessage)) {
          btnMediaPause();
        }
      } else if (forBusMessage.startsWith(BUTTON_LEFT_DOWN)) {
        if (!isHardwareBounce(forBusMessage)) {
          btnMediaTrackPrevious();
        }
      } else if (forBusMessage.startsWith(BUTTON_LEFT_UP)) {
        if (!isHardwareBounce(forBusMessage)) {
          btnMediaTrackNext();
        }
      } else if (forBusMessage.startsWith(BUTTON_RIGHT_CENTER)) {
        if (!isHardwareBounce(forBusMessage)) {
          btnHomeScreen();
        }
      } else if (forBusMessage.startsWith(BUTTON_RIGHT_DOWN)) {
        if (!isHardwareBounce(forBusMessage)) {
          btnVolumeDown();
        }
      } else if (forBusMessage.startsWith(BUTTON_RIGHT_UP)) {
        if (!isHardwareBounce(forBusMessage)) {
          btnVolumeUp();
        }
      } else {
        Log.i(TAG, "Unknown button: " + forBusMessage);
        return STATUS_ERROR_UNKNOWNBUTTON;
      }
    } catch (Exception ex) {
      Log.e(TAG, "Error performing action for button: " + forBusMessage, ex);
      return STATUS_ERROR_ACTIONERROR;
    }
    
    return STATUS_SUCCESS;
  }
  

  protected boolean isHardwareBounce(String busMessage) {
    Boolean isBounce = true;    
    
    long now = (new Date()).getTime();    
    Long last = mBusMessageDebounceTimes.get(busMessage);
    
    if (last == null) {
      isBounce = false;
    } else {    
      if (now - last > DEBOUNCE_THRESHOLD) {
        isBounce = false;
      }
    }
    
    mBusMessageDebounceTimes.put(busMessage, now);
    
    return isBounce;
  }
    
  
  //TODO: most of these require root, is there a better way? how does Tasker do it?
  

  protected void btnMediaPause() throws Exception {
    Runtime.getRuntime().exec("su -c input keyevent " + KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE);
    }
    

  protected void btnMediaTrackNext() throws Exception {
       Runtime.getRuntime().exec("su -c input keyevent " + KeyEvent.KEYCODE_MEDIA_NEXT);
    }
    
    
  protected void btnMediaTrackPrevious() throws Exception {
       Runtime.getRuntime().exec("su -c input keyevent " +  + KeyEvent.KEYCODE_MEDIA_PREVIOUS);
    }

  
  protected void btnHomeScreen() throws Exception {
    Runtime.getRuntime().exec("su -c input keyevent " + KeyEvent.KEYCODE_HOME);
    }

    
  protected void btnVolumeUp() throws Exception {
       AudioManager mAudioManager = (AudioManager)mAppContext.getSystemService(Context.AUDIO_SERVICE);        
       mAudioManager.adjustStreamVolume(AudioManager.STREAM_MUSIC, AudioManager.ADJUST_RAISE, AudioManager.FLAG_SHOW_UI);
    }
    
    
  protected void btnVolumeDown() throws Exception {
    AudioManager mAudioManager = (AudioManager)mAppContext.getSystemService(Context.AUDIO_SERVICE);        
    mAudioManager.adjustStreamVolume(AudioManager.STREAM_MUSIC, AudioManager.ADJUST_LOWER, AudioManager.FLAG_SHOW_UI);
    }    
}

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