Develop Reference

While loop: Change Background color

I am trying to create a small animation which changes smoothly the background color. My problem is that it only shows the last value (100, that means it directly goes to a red background). I don't know why my created while-loop doesn't actualize every value (so that it would show a smoothly color animation)
New code (which almost works, but Idk how to stop the animation)
imageButton_info.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v){
final Handler handler = new Handler();
Runnable ChangeBackgroundRunnable = new Runnable() {
#Override
public void run() {
number++;
float[] hsvColor = {0, 1, 1};
hsvColor[0] = 360f * number / 100;
color.setBackgroundColor(Color.HSVToColor(hsvColor));
handler.postDelayed(this, 80);
if (number >=100)
number = 1;
}
};
number = 0;
handler.removeCallbacks(ChangeBackgroundRunnable);
handler.postDelayed(ChangeBackgroundRunnable, 0);
}
});
Code:
public void onClick(View v){
try {
while (number<=100) {
number=number+1;
float[] hsvColor = {0, 1, 1};
hsvColor[0] = 360f * number / 100;
color.setBackgroundColor(Color.HSVToColor(hsvColor));
Thread.sleep(10);
}
}catch(Exception e){
//New exception
Log.e("Camera Error!",e.getMessage());
}
Thank you for your answer in advance...

When you change something in the UI, it doesn't happen immediately. Instead, it posts a message to the Looper on the UI thread. When control returns to the looper (when you're done with whatever function the framework called), it will process all the messages on the Looper, until it eventually processes the redraw request. Then it will draw. So if you're looping in onClick, you will not get any updates to the screen. If you want something to happen in 10ms, post a delayed message to a Handler and update the UI in that thread.
Side note: NEVER EVER sleep on the UI thread. The reason is that no input or draw commands can be processed if you're not returning control to the Looper. So your app becomes unresponsive. If you do it long enough, it can even cause the framework to kill your app for being unresponsive.

A better way to do this would be to use an Android animation. I stole the code for this from here
int colorFrom = getResources().getColor(R.color.red);
int colorTo = getResources().getColor(R.color.blue);
ValueAnimator colorAnimation = ValueAnimator.ofObject(new ArgbEvaluator(), colorFrom, colorTo);
colorAnimation.setDuration(250); // milliseconds
colorAnimation.addUpdateListener(new AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator animator) {
textView.setBackgroundColor((int) animator.getAnimatedValue());
}
});
colorAnimation.start();

Wrapped the answers posted by #gabe-sechan and #jesse-buss
ValueAnimator support from devices SDK above HONEYCOMB. So below that SDK level we'll use #gabe-sechan suggestion. Check the below code.
private void executeBackgroundChange() {
// Handler and runnable to run the animation in devices sdk below honeycomb.
mHandler = new Handler();
mChangeBackgroundRunnable = new Runnable() {
#Override
public void run() {
number++;
float[] hsvColor = {0, 1, 1};
hsvColor[0] = 360f * number / 100;
mContainer.setBackgroundColor(Color.HSVToColor(hsvColor));
mHandler.postDelayed(this, 500);
if (number == 100)
number = 0;
}
};
number = 0;
mHandler.removeCallbacks(mChangeBackgroundRunnable);
mHandler.postDelayed(mChangeBackgroundRunnable, 0);
}
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
private void executeBackgroundChangeUsingValueAnimator() {
colorAnimation = ValueAnimator.ofObject(new ArgbEvaluator(), getResources().getColor(R.color.red), getResources().getColor(R.color.blue));
colorAnimation.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(final ValueAnimator animator) {
mContainer.setBackgroundColor((Integer) animator.getAnimatedValue());
}
});
colorAnimation.setRepeatCount(ValueAnimator.INFINITE);
colorAnimation.setDuration(10 * 1000);
colorAnimation.start();
}
Add the below method and to stop the animation on click of something call the below method.
private void stopBackgroundChangeAnimation() {
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB) {
if (colorAnimation != null && colorAnimation.isRunning())
colorAnimation.end();
} else {
if (mHandler != null && mChangeBackgroundRunnable != null)
mHandler.removeCallbacks(mChangeBackgroundRunnable);
}
}
Check the github project for reference.

Try to use runOnUiThread
public void onCreate(Bundle savedInstanceState) {
res = getResources();
super.onCreate(savedInstanceState);
setContentView(R.layout.xyz);//**Works**/
handler.postDelayed(runnable, 10);
}
private Runnable runnable = new Runnable() {
public void run() {
runOnUiThread(new Runnable() {
public void run()
{
try {
while (number<=100) {
number=number+1;
float[] hsvColor = {0, 1, 1};
hsvColor[0] = 360f * number / 100;
color.setBackgroundColor(Color.HSVToColor(hsvColor));
}
}catch(Exception e){
//New exception
}
}
});
}
}

How to animate multiple objects one by one after some intervals android

How to animate multiple objects one by one after some intervals android
i am using this code for animation
for (int y = 0; y < 10; y++) {
runOnUiThread(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
Toast.makeText(ProjectFirstActivity.this, y + "",
Toast.LENGTH_SHORT).show();
ObjectAnimator oa = ObjectAnimator.ofFloat(myimageview[y],
"translationY", 0, -200);
oa.setDuration(1000);
oa.start();
}
});
}
but it is animating all in one go but i want one by one animation of my imageview please help

No need to use Threads and Handlers. Instead of that use,
objectAnimator.setStartDelay(delay);
Using that you can stop that animation for the respective 'delay'
Try this code..
int delay = 1000;
for (int y = 0; y < 10; y++) {
Toast.makeText(ProjectFirstActivity.this, y + "",
Toast.LENGTH_SHORT).show();
ObjectAnimator oa = ObjectAnimator.ofFloat(myimageview[y],
"translationY", 0, -200);
oa.setDuration(1000);
oa.setStartDelay(delay);
oa.start();
delay = delay+1000;
}

You can use for loop to generate AnimatorSet and then play them sequentially using set.playSequentially(yourAnimatorSetListHere);
I haven't used list in below mentioned snippet.
AnimatorSet decSet = new AnimatorSet();
decSet.playTogether(
ObjectAnimator.ofArgb(mTextSlidetoCancel, "visibility", View.GONE, View.VISIBLE),
ObjectAnimator.ofArgb(mBtnMicActive, "visibility", View.GONE, View.VISIBLE),
ObjectAnimator.ofArgb(mChronometer, "visibility", View.GONE, View.VISIBLE));
decSet.setDuration(125);
AnimatorSet decSet2 = new AnimatorSet();
decSet2.playTogether(
ObjectAnimator.ofArgb(mBtnAttach, "visibility", View.VISIBLE, View.GONE),
ObjectAnimator.ofArgb(mBtnEmoji, "visibility", View.VISIBLE, View.GONE),
ObjectAnimator.ofArgb(mEditTExt, "visibility", View.VISIBLE, View.GONE)
);
decSet2.setDuration(125);
AnimatorSet set = new AnimatorSet();
set.playSequentially(decSet2,decSet);
set.start();

Try out this way!
public Integer[] Imgid = {R.drawable.anim2, R.drawable.anim3,
R.drawable.anim4, R.drawable.anim5}; // your image array.
Animation anim;
Handler handler;
ImageView iv;
int count;
Runnable galleryAnimRunnable;
Inside onCreate
iv= (ImageView)findViewById(R.id.imagetype);
handler = new Handler();
galleryAnimRunnable = new Runnable() {
public void run() {
if(count==Imgid.length){
//do any action
}
else{
anim = AnimationUtils.loadAnimation(AnimationScreen.this, R.anim.fade_out); // load your desire animation.
iv.setBackgroundResource(Imgid[count]);
iv.setAnimation(anim);
count++;
handler.postDelayed(galleryAnimRunnable, 300); //set your desire delay time.
}
}
};

Your sleep call isn't helping because when one posted UI job goes to sleep, then next one starts and goes to sleep immediately following that, and so on. Then the first job wakes up and runs, followed closely by the second job awakening and running, etc.
If you want the sleep to help you need to wait before posting each job, which could be as simple as something like the following:
for (int y = 0; y < 10; y++) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(ProjectFirstActivity.this, y + "",
Toast.LENGTH_SHORT).show();
ObjectAnimator oa = ObjectAnimator.ofFloat(myimageview[y],
"translationY", 0, -200);
oa.setDuration(1000);
oa.start();
}
});
}
EDIT: Although the above explains why you were having problems, I would recommend going with something like the answer posted by Jgdsh Seerm using setStartDelay().

Try this way!
ImageView image1;
public int currentimageindex1=0;
Timer timer;
TimerTask task;
private Animation animation1;
private Animation animation2;
int img[] = {R.drawable.aa, R.drawable.bb,
R.drawable.cc,R.drawable.dd,R.drawable.ee,R.drawable.ff,R.drawable.gg,
R.drawable.hh};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Handler mHandler = new Handler();
// Create runnable for posting
final Runnable mUpdateResults = new Runnable() {
public void run() {
AnimateandSlideShow();
}
};
int delay = 1000; // delay for 1 sec.
int period = 4000; // repeat every 4 sec.
Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
public void run() {
mHandler.post(mUpdateResults);
}
}, delay, period);
}
public void onClick(View v) {
finish();
android.os.Process.killProcess(android.os.Process.myPid());
}
/**
* Helper method to start the animation on the splash screen
*/
private void AnimateandSlideShow() {
image1 = (ImageView)findViewById(R.id.imageView1);
image1.setImageResource(img[currentimageindex1%img.length]);
currentimageindex1++;
}

ProgressBar causing constant onDraw calls for all the UI

I have an activity which has a ProgressBar. This bar is used to show the elapsed time on the game level.
I'm updating this bar and a TextView with a CountdownTimer, called every 100ms. The problem is that every time I call setProgress, it seems to be causing an invalidate() that makes my whole UI to be redrawn. If I delete the line where the ProgressBar get updated everything works fine, even setText for the TextView that show the time left.
This is a problem for me because I also have a custom view which needs to be redrawn only when I need it, or at least a few times but not constantly because it'll affect performance.
This is a piece of my code:
private CountDownTimer timer;
private long ttime;
private long ctime;
private ProgressBar bar;
private TextView clock;
#Override
protected void onCreate(Bundle savedInstanceState) {
...
startTimer(500);
...
}
#Override
protected void onResume() {
super.onResume();
if(!checkFlags()){
startTimer(500);
}
}
#Override
protected void onPause() {
super.onPause();
if(!checkFlags()){
timer.cancel();
}
}
private void startTimer(long delay){
timer = new CountDownTimer(ctime,100){
public void onTick(long millisUntilFinished){
ctime = millisUntilFinished;
clock.setText(formatTime(millisUntilFinished));
bar.setProgress((int) (1000 - ((ctime * 1000)/ttime)));
}
public void onFinish(){
clock.setText("00:00");
gameOver(false);
}
};
if(delay > 0){
Handler handler = new Handler();
handler.postDelayed(new Runnable(){
public void run(){
timer.start();
}
},delay);
}else{
timer.start();
}
}
How could I prevent the ProgressBar to cause this onDraw calls for every element of the UI?

According to 'sources/android-18/android/widget/ProgressBar.java' in Android SDK the call of setProgress() will result in the call of invalidate().
private synchronized void doRefreshProgress(int id, int progress, boolean fromUser,
boolean callBackToApp) {
float scale = mMax > 0 ? (float) progress / (float) mMax : 0;
final Drawable d = mCurrentDrawable;
if (d != null) {
Drawable progressDrawable = null;
if (d instanceof LayerDrawable) {
progressDrawable = ((LayerDrawable) d).findDrawableByLayerId(id);
if (progressDrawable != null && canResolveLayoutDirection()) {
progressDrawable.setLayoutDirection(getLayoutDirection());
}
}
final int level = (int) (scale * MAX_LEVEL);
(progressDrawable != null ? progressDrawable : d).setLevel(level);
} else {
>>> invalidate();
}
if (callBackToApp && id == R.id.progress) {
onProgressRefresh(scale, fromUser);
}
}
Try to use setProgressDrawable(). It seems that invalidate() is not called in that case.

How to wait for Runnable finish?

I have a method named loadBalls(). In this method, I called another method named removeOldBalls().
In removeOldBalls(), I have a runnable to detach children on the scene.
Below are 2 methods :
public static void loadBalls() {
removeOldBalls();
for (int i = 0; i < MAX_BALL; i++) {
int x = MathUtils.random(0, CAMERA_WIDTH - BALL_SIZE);
int y = BALL_SIZE;
final Ball ball = new Ball(x, y, BALL_SIZE, BALL_SIZE, GraphicsManager.trBalloons[i]);
scene.registerTouchArea(ball);
balls.add(ball);
if (!balls.get(i).hasParent()) {
scene.attachChild(balls.get(i));
}
Log.e("test", "load");
}
}
public static void removeOldBalls() {
((BaseLiveWallpaperService) LWP.context).runOnUpdateThread(new Runnable() {
public void run() {
Log.e("test", "remove");
scene.detachChildren();
}
});
if (balls != null) {
int length = balls.size();
for (int i = 0; i < length; i++) {
fsw.destroyBody(balls.get(i).body);
}
balls.clear();
Log.e("test", "clear");
}
}
What I need is all children are removed before adding new ones. But when running above source code, the children are added first, then removed.
Please tell me how to wait for removing finish before adding.

I think look for the class android.os.Handler. Then you can create two threads: one to remove all the children and another to add the children. Then add those threads to the Handler like this:
handler.post(new Runnable(){
#Override
public void run() {
// Thread to remove children
}
});
handler.post(new Runnable(){
#Override
public void run() {
// Thread to add children
}
});
Once you add them one after another the Android SDK will execute them in the order they were added. So that will take care of your ordering issue.

Move the code which adds the children to another method, for example addBalls:
private void addBalls() {
for (int i = 0; i < MAX_BALL; i++) {
int x = MathUtils.random(0, CAMERA_WIDTH - BALL_SIZE);
int y = BALL_SIZE;
final Ball ball = new Ball(x, y, BALL_SIZE, BALL_SIZE, GraphicsManager.trBalloons[i]);
scene.registerTouchArea(ball);
balls.add(ball);
if (!balls.get(i).hasParent()) {
scene.attachChild(balls.get(i));
}
Log.e("test", "load");
}
}
And call this method fron the run method of the Runnable after you call scene.detachChildren:
public void run() {
Log.e("test", "remove");
scene.detachChildren();
addBalls();
}

Displaying a sequence of images with a time delay

I wanted to display 9 images one after the other. I have included the 9 images as an array:
imageHolders = new ArrayList<ImageView>();
imageHolders.add((ImageView) view.findViewById(R.id.imgOne));
imageHolders.add((ImageView) view.findViewById(R.id.imgTwo));
imageHolders.add((ImageView) view.findViewById(R.id.imgThree));
imageHolders.add((ImageView) view.findViewById(R.id.imgFour));
imageHolders.add((ImageView) view.findViewById(R.id.imgFive));
imageHolders.add((ImageView) view.findViewById(R.id.imgSix));
imageHolders.add((ImageView) view.findViewById(R.id.imgSeven));
imageHolders.add((ImageView) view.findViewById(R.id.imgEight));
imageHolders.add((ImageView) view.findViewById(R.id.imgNine));
This is what I have tried:
public void handleMessage(Message msg) {
int currentImage = 0;
int nextImage = 0;
// Logic to change the images
for (final ImageView imageView : imageHolders) {
currentImage = Integer.parseInt(imageView.getTag().toString());
if (currentImage > 1) {
nextImage = currentImage - 1;
} else {
nextImage = 9;
}
imageView.setTag(""+nextImage);
new CountDownTimer(10000, 1000) {
public void onTick(long millisUntilFinished) {
}
public void onFinish() {
imageView.setVisibility(VISIBLE);
}
}.start();
}
super.handleMessage(msg);
}
}
There is a delay between the first and the second images. I am not able to introduce a delay between the rest. I have no clue about introducing the delay. Any suggestions would be appreciated.

you could just use AnimationDrawable which does this for you , and allows you to set a duration of time (in milliseconds) using android:duration attribute .

The AnimationDrawable is probably the best answer, but for another solution you can look at AsyncTask.
http://developer.android.com/reference/android/os/AsyncTask.html
Then, you can in the background just sleep for some set amount of time, then display the next image.
You may want an event though to handle when this task is done, and in the listener you call the next one.

If you want to make just a simple static animation (all images at the same position) you can use AnimationDrawable but you can't easly change it dynamically - like change speed or something.
I just wrote a simple class for this so I can set multiple animations for one ImageView and change speed.
public class ImageSequence extends ImageView {
ArrayList<Drawable> draws = new ArrayList<Drawable>();
ArrayList<Integer> bnds = new ArrayList<Integer>(); //bounds of sequences - index of first and last frame.
ArrayList<String> names = new ArrayList<String>(); //sequences names.
Timer timer = new Timer(true);
TimerTask task;
int p = -1; //current playback position.
int cS = -1; //current sequence.
public ImageSequence(Context context) {
super(context);
createTask();
}
public void addSequence(String name, int[] res){
names.add(name);
bnds.add(draws.size());
bnds.add(draws.size() + res.length - 1);
for (int i = 0; i < res.length; i++){
draws.add(getContext().getResources().getDrawable(res[i]));
}
}
public void play(String sequence, float speed){
cS = -1;
for(int i = 0; i < names.size(); i++){
if(names.get(i) == sequence){ cS = i; break;}
}
if(cS<0) return;
p = -1;
task.run();
task.cancel();
if(speed <= 0) return;
createTask();
timer.schedule(task, (long) (1000/speed), (long) (1000/speed));
}
public void stop(){
task.cancel();
}
public void cancelTimer(){
timer.cancel();
}
private void createTask() {
task = new TimerTask(){
public void run() {
p++;
mHandler.obtainMessage(1).sendToTarget();
}
};
}
public Handler mHandler = new Handler() {
public void handleMessage(Message msg) {
int l = p;
if(l > bnds.get(cS*2+1) || l < bnds.get(cS*2)) l = bnds.get(cS*2);
p = l;
ImageSequence.this.setImageDrawable(draws.get(l));
}
};
}
From outside you can use it like this:
seq.addSequence("orange", new int[]{R.drawable.ic_oval_diode_orange, R.drawable.ic_oval_diode_off});
seq.addSequence("green", new int[]{R.drawable.ic_oval_diode_green, R.drawable.ic_oval_diode_off});
seq.addSequence("red", new int[]{R.drawable.ic_oval_diode_red, R.drawable.ic_oval_diode_off});
seq.play("red", 4);
I'm not really experienced in Android and Java but it works and it do the job for me. Hope it will help someone.