Develop Reference

Android - Implement security in WallpaperService

I am using the WallpaperService class to set a live wallpaper on the device.
I want to implement security on the system screen (to prevent screenshot or recording) where the 'Set Wallpaper' button shows up by the android system.
So far, I have found one method of SurfaceView class - surfaceview.setSecure(boolean value)
But, I am not able to get the instance of the SurfaceView inside my class.
Please suggest some workaround to get the instance of this class.
My Code-
public class LiveWallpaperService extends WallpaperService {
private int mDeviceWidth, mDeviceHeight;
private int mAnimationWidth, mAnimationHeight;
#Override
public Engine onCreateEngine() {
Movie movie = null;
// Some Code here
return new GIFWallpaperEngine(movie);
}
private class GIFWallpaperEngine extends Engine {
private final int frameDuration = 24;
private SurfaceHolder holder;
private final Movie movie;
private boolean visible;
private final Handler handler;
private final Runnable drawGIF = new Runnable() {
public void run() {
draw();
}
};
public SurfaceView getSurfaceView(){
// How to find the SurfaceView object here?
}
GIFWallpaperEngine(Movie movie) {
this.movie = movie;
handler = new Handler();
}
#Override
public void onCreate(SurfaceHolder surfaceHolder) {
super.onCreate(surfaceHolder);
this.holder = surfaceHolder;
}
#Override
public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
super.onSurfaceChanged(holder, format, width, height);
mDeviceWidth = width;
mDeviceHeight = height;
}
private void draw() {
if (movie != null) {
try {
if (visible) {
Canvas canvas = holder.lockCanvas();
canvas.save();
final float scaleFactorX = mDeviceWidth / (mAnimationWidth * 1.f); //608 is image width
final float scaleFactorY = mDeviceHeight / (mAnimationHeight * 1.f);
// Adjust size and position to fit animation on the screen
canvas.scale(scaleFactorX, scaleFactorY); // w,h Size of displaying Item
movie.draw(canvas, 0, 0); // position on x,y
canvas.restore();
holder.unlockCanvasAndPost(canvas);
movie.setTime((int) (System.currentTimeMillis() % movie.duration()));
handler.removeCallbacks(drawGIF);
handler.postDelayed(drawGIF, frameDuration);
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
#Override
public void onVisibilityChanged(boolean visible) {
this.visible = visible;
if (visible) {
handler.post(drawGIF);
} else {
handler.removeCallbacks(drawGIF);
}
}
#Override
public void onDestroy() {
super.onDestroy();
handler.removeCallbacks(drawGIF);
}
}
}

Android SurfaceView with drawBitmap(Matrix) leaves blinking ghost image

To preface, I'm probably going to work with Views instead of SurfaceView given this weird interaction, but my curiosity is getting the better of me and I want to know what's going on.
So I have a matrix class variable. I run matrix.setTranslate() once, and every other frame I say matrix.setTranslate(). After this I call canvas.drawBitmap(, matrix, null). After 100 frames, I stop drawing the bitmap.
Here's the code:
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
// matrix = new Matrix(); //Doesn't matter if I add this.
// matrix.reset(); //This doesn't matter either.
if (!once) {
matrix.setTranslate(100, 100);
} else {
matrix.setTranslate(800,800);
}
once = true;
if (++timer < 100) {
canvas.drawBitmap(ball, matrix, null);
}
}
What I expect to happen: Three possibilities.
Only the bottom right bitmap is visible since the entire screen was invalidated
Both bitmaps are visible because SurfaceView was smart with the dirty rectangle
Nothing is shown because nothing was drawn.
What actually happens: The top left bitmap blinks, bottom right bitmap displays solidly.
I'm pretty sure I have all of my bases covered:
All class variables are properly set in the constructor.
SurfaceView.onDraw() is called every 33 millis in its own thread.
Thread calls lockCanvas, then onDraw, then unlockCanvasAndPost
So, what's going on here? And bonus question, do these ghost images consume any extra resources and how can I clear them?
Rest of the code, mostly boilerplate:
public class FullscreenActivity extends Activity {
GameSurface ball;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ball = new GameSurface(this);
setContentView(ball);
}
}
class GameSurface extends SurfaceView implements SurfaceHolder.Callback {
GameThread thread;
boolean once = false;
Bitmap ball;
Matrix matrix;
int timer = 0;
public GameSurface(Context context) {
super(context);
ball = BitmapFactory.decodeResource(getResources(),R.drawable.football);
matrix = new Matrix();
getHolder().addCallback(this);
setFocusable(true);
}
#Override
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
// matrix = new Matrix(); //Doesn't matter if I add this.
// matrix.reset(); //This doesn't matter either.
if (!once) {
matrix.setTranslate(100, 100);
} else {
matrix.setTranslate(800,800);
}
//matrix.postRotate(timer); //For even more weirdness...
once = true;
if (++timer < 100) {
canvas.drawBitmap(ball, matrix, null);
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
thread = new GameThread(getHolder(), this);
thread.setRunning(true);
thread.start();
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
class GameThread extends Thread {
private SurfaceHolder surfaceHolder;
private GameSurface gameView;
private boolean run = false;
public GameThread(SurfaceHolder surfaceHolder, GameSurface gameView) {
this.surfaceHolder = surfaceHolder;
this.gameView = gameView;
}
public void setRunning(boolean run) {
this.run = run;
}
#Override
public void run() {
Canvas c;
while (run) {
c = null;
try {
Thread.sleep(33);
}
catch(InterruptedException e) {}
try {
c = surfaceHolder.lockCanvas();
synchronized (surfaceHolder) {
gameView.onDraw(c);
}
} finally {
if (c != null) {
surfaceHolder.unlockCanvasAndPost(c);
}
}
}
}
}
}

Android app crashes upon attempt to switch to a different Activity

I am running into an issue in my app. When my game ends (when life == 0) I am attempting to switch to a game over screen by using a different activity. When the game ends, the app simply crashes. I have included the XML for the activity I am trying to switch from as well as indicating where the app crashes. If anyone could help out, that would be great! Thanks.
activity_game.XML:
SurfaceView I am trying to switch from once game ends:
public class SVGameView extends SurfaceView implements Runnable {
private SurfaceHolder holder;
Thread thread = null;
volatile boolean running = false;
static final long FPS = 30;
private Sprite sprite;
private long lastClick;
private Bitmap ball, gameOver;
//private int x = 200, y = 200;
private int scorePosX = 100;
private int scorePosY = 100;
private int countScore = 0;
private int life = 1;
public SVGameView(Context context) {
super(context);
thread = new Thread(this);
holder = getHolder();
holder.addCallback(new SurfaceHolder.Callback() {
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
boolean retry = true;
running = false;
while (retry) {
try {
thread.join();
retry = false;
} catch (InterruptedException e) {
}
}
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
running = true;
thread.start();
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format,
int width, int height) {
}
});
ball = BitmapFactory.decodeResource(getResources(), R.drawable.ball2);
gameOver = BitmapFactory.decodeResource(getResources(),R.drawable.endscreen);
sprite = new Sprite(this, ball);
}
#Override
public void run() {
long ticksPS = 1000 / FPS;
long startTime;
long sleepTime;
while (running) {
Canvas c = null;
startTime = System.currentTimeMillis();
try {
c = getHolder().lockCanvas();
synchronized (getHolder()) {
update();
draw(c);
}
} finally {
if (c != null) {
getHolder().unlockCanvasAndPost(c);
}
}
sleepTime = ticksPS-(System.currentTimeMillis() - startTime);
try {
if (sleepTime > 0)
thread.sleep(sleepTime);
else
thread.sleep(10);
} catch (Exception e) {}
}
}
private void update(){
sprite.update();
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
Paint paint = new Paint();
canvas.drawPaint(paint);
paint.setColor(Color.WHITE);
paint.setTextSize(48);
canvas.drawText("Score: " + countScore, scorePosX, scorePosY, paint);
canvas.drawText("Lives: " + life, 500, 100, paint);
sprite.onDraw(canvas);
//Crashes here
if(life == 0) {
getContext().startActivity(new Intent(getContext(), SVGameOver.class));
}
}
#Override
public boolean onTouchEvent(MotionEvent event) {
if(System.currentTimeMillis()-lastClick > 300){
lastClick = System.currentTimeMillis();
}
synchronized (getHolder()){
if(sprite.isHit(event.getX(), event.getY())){
countScore += 1;
sprite.increase();
}else{
life --;
}
}
return super.onTouchEvent(event);
}
}
Activity I am trying to reach once the game ends:
public class SVGameOver extends Activity {
private Bitmap gameOverScreen;
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game);
gameOverScreen = BitmapFactory.decodeResource(getResources(), R.drawable.endscreen);
}
protected void onDraw(Canvas canvas){
canvas.drawBitmap(gameOverScreen, 0,0,null);
}
}

I think logcat is asking you the right question: "have you declared this activity in your AndroidManifest.xml" ?
If you think you did it, It's highly probable you did it in a wrong way, most of the times that you think you added an Activity to the manifest but you are receiving this kind of crash, 99,9% of the time you declared it with a wrong namespace

Declare SVGameOver activity in your AndroidManifest.xml:
<activity
android:name="com.example.welcome.assignment2.SVGameOver">
...
</activity>

android: collision of two bitmaps

good day... im a new programmer in android... and actually its my first time doing so...
but i have basic knowledge about java...
so here goes.. my game will have an icon that can be controlled by a joystick... and another icon that goes up and down the screen(non controllable) i want the speed to increase a little..... i have started the code but dont know where and how to start the collision.. another one is that the icon that is controllabe always passes the screen and pop out the opposite direction...
public class GameSurface1 extends SurfaceView implements SurfaceHolder.Callback {
private Context _context;
private GameThread1 _thread;
private GameControl _controls;
private GameJoystick1 _joystick;
private int y = 0;
private int xSpeed = 1;
private Bitmap _pointer, bmp;
public GameSurface1(Context context) {
super(context);
// TODO Auto-generated constructor stub
_context = context;
init();
}
private void init(){
//initialize our screen holder
SurfaceHolder holder = getHolder();
holder.addCallback( this);
//initialize our game engine
//initialize our Thread class. A call will be made to start it later
_thread = new GameThread1(holder, _context, new Handler(),this);
setFocusable(true);
_joystick = new GameJoystick1(getContext().getResources());
_pointer = (Bitmap)BitmapFactory.decodeResource(getResources(), R.drawable.icon1);
bmp = (Bitmap)BitmapFactory.decodeResource(getResources(), R.drawable.bad1);
//contols
_controls = new GameControl();
setOnTouchListener(_controls);
}
public void doDraw(Canvas canvas){
if (y == getHeight() - bmp.getHeight()) {
xSpeed = -1;
}
if (y == 0) {
xSpeed = 1;
}
y = y + xSpeed;
//update the pointer
_controls.update(null);
//draw the pointer
canvas.drawBitmap(_pointer, _controls._pointerPosition.x, _controls._pointerPosition.y, null);
//draw the joystick background
canvas.drawBitmap(_joystick.get_joystickBg(), 15,215, null);
//draw the dragable joystick
canvas.drawBitmap(_joystick.get_joystick(),_controls._touchingPoint.x - 26, _controls._touchingPoint.y - 26, null);
canvas.drawBitmap(bmp, 280, y, null);
}
//these methods are overridden from the SurfaceView super class. They are automatically called
//when a SurfaceView is created, resumed or suspended.
#Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {}
private boolean retry;
#Override
public void surfaceDestroyed(SurfaceHolder arg0) {
retry = true;
//code to end gameloop
_thread.state = GameThread1.STOPED;
while (retry) {
try {
//code to kill Thread
_thread.join();
retry = false;
} catch (InterruptedException e) {
}
}
}
#Override
public void surfaceCreated(SurfaceHolder arg0) {
if(_thread.state==GameThread1.PAUSED){
//When game is opened again in the Android OS
_thread = new GameThread1(getHolder(), _context, new Handler(),this);
_thread.start();
}else{
//creating the game Thread for the first time
_thread.start();
}
}
ill appreciate all the help you can give...
thank you

Animation in Live Wallpaper Android?

I am fairly new developer and trying to make a live wallpaper app. Among many animations, my first target is to show a rotating Bitmap which is actually a Black Hole.
public class Painting extends Thread {
/** Reference to the View and the context */
private SurfaceHolder surfaceHolder;
private Context context;
/** State */
private boolean wait;
private boolean run;
/** Dimensions */
private int width;
private int height;
/** Time tracking */
private long previousTime;
boolean first = true;
Bitmap hole;
int degree;
public Painting(Context con , SurfaceHolder surf)
{
context = con;
surfaceHolder = surf;
this.wait = true;
Log.i("Live Test","UnInitialized");
Drawable d = (con.getResources().getDrawable(R.drawable.vlack));
hole = ((BitmapDrawable)d).getBitmap();
hole.prepareToDraw();
if(hole != null)
Log.i("Live Test","Initialized");
run = true;wait = false;
degree = 0;
}
#Override
public void run()
{
while (run) {
this.run = true;
Canvas c = null;
Log.i("Live Test","Draw Color");
while (run) {
try {
c = this.surfaceHolder.lockCanvas();
synchronized (this.surfaceHolder) {
doDraw(c);
}
} finally {
if (c != null) {
this.surfaceHolder.unlockCanvasAndPost(c);
Log.i("Live Test","Unlocked And Posted");
}
}
// pause if no need to animate
synchronized (this) {
if (wait) {
try {
wait();
} catch (Exception e) {
Log.i("Live Test","Error wait");
}
}
}
}
}
}
public void setSurfaceSize(int width, int height) {
this.width = width;
this.height = height;
synchronized(this) {
this.notify();
}
}
/**
* Pauses the livewallpaper animation
*/
public void pausePainting() {
this.wait = true;
synchronized(this) {
this.notify();
}
}
/**
* Resume the livewallpaper animation
*/
public void resumePainting() {
this.wait = false;
synchronized(this) {
this.notify();
}
}
/**
* Stop the livewallpaper animation
*/
public void stopPainting() {
this.run = false;
synchronized(this) {
this.notify();
}
}
private void doDraw(Canvas canvas) {
if(first)
{
canvas.save();
canvas.drawColor(0x60444444);
canvas.drawBitmap(hole, 80,80,null);
canvas.restore();
first = false;
}
else
{
long currentTime = System.currentTimeMillis();
long elapsed = currentTime - previousTime;
if (elapsed > 20) {
canvas.save();
degree+= 5;
if(degree>359)degree = degree -358;
canvas.rotate((float) degree);
canvas.restore();
Log.i("Live Test","rotated");
}
previousTime = currentTime;
}
}
}
So I am trying to rotate the bitmap and show it again so it looks like its sucking stars and all.
Also I have removed Basic onPause onResume Functions so that you guys can understand the code easily. I know there is something basic I am missing, but What?

Hmmm. It would take more time than I have right now to puzzle this out, but I do have one suggestion: code your wallpaper using a simpler approach. Scrap the thread and do something more along the lines of the Cube example, that is to say make a runnable which schedules calls to itself using postDelayed. Hope this helps. George.