Develop Reference

I want to do a TransitionDrawable transition multiple times using xml transition

Here my transition and reverse transition happens only once not 10 times, Can u tell me where I'm wrong ??
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
for(int i=0;i<10;i++)
{
Resources res = getApplicationContext().getResources();
Drawable background[] = new Drawable[2];
background[0] = res.getDrawable(R.drawable.shapes);
background[1] = res.getDrawable(R.drawable.large_shape);
final TransitionDrawable transition = new TransitionDrawable(background);
ImageView imgview = findViewById(R.id.transitimage);
imgview.setImageDrawable(transition);
Runnable r1 = new Runnable() {
#Override
public void run() {
transition.startTransition(2000);
}
};
Runnable r2 = new Runnable() {
#Override
public void run() {
transition.reverseTransition(2000);
}
};
Handler h = new Handler();
h.postDelayed(r1, 0);
h.postDelayed(r2, 2000);
}
}
}

public void repeat() {
new CountDownTimer(2000, 1000) {
public void onTick(long millisUntilFinished) {
if (i>9) { // i is a field,its initial value equals 0
cancel(); // stop timer
}
if (flag) {
transition.startTransition(2000);
} else {
transition.reverseTransition(2000);
}
flag = !flag;
i += 1;
}
public void onFinish() {
repeat();
}
}.start();
}
Call above function in some place.

Android update ProgressBar with Handler

I would like to update the progressBar with Handler and for loop but without success.
Code:
public void increase_splash_bar (int from, int to)
{
Handler handler1 = new Handler(Looper.getMainLooper());
for (progress_k = from; progress_k<=to ;progress_k++)
{
handler1.postDelayed(new Runnable()
{
#Override
public void run()
{
FrontLayout.update_splash_progress_bar(progress_k, 100);
}
}, 2000);
}
}
Question:
The progress bar increase immediately to the end value instead of progressively.
Why?

Try this:
public void increase_splash_bar (int from, int to)
{
Handler handler1 = new Handler(Looper.getMainLooper());
for (progress_k = from; progress_k<=to ;progress_k++)
{
final int curr_progress_k = progress_k;
handler1.postDelayed(new Runnable()
{
#Override
public void run()
{
FrontLayout.update_splash_progress_bar(curr_progress_k, 100);
}
}, progress_k * 100); // adjust "100" value to adjust speed
}
}

Repeat a task with a time delay?
#inazaruk
private ProgressBar progressBar;
private Handler mHandler;
private int progressInt = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.test);
progressBar = (ProgressBar) findViewById(R.id.pb);
progressBar.setProgress(0);
mHandler = new Handler();
runnable.run();
}
Runnable runnable = new Runnable() {
#Override
public void run() {
try {
updateProgress();
} catch (Exception ignored) {
} finally {
mHandler.postDelayed(runnable, progressInt);
}
}
};
private void updateProgress() {
progressInt += 1;
if (progressInt > 100) {
mHandler.removeCallbacks(runnable);
} else {
progressBar.setProgress(progressInt);
}
}

try this code:
Solution 1
public void increase_splash_bar (int from, int to)
{
Handler handler1 = new Handler();
class Task implements Runnable {
int start,end;
Task(int a,int b) { start = a; end = b;}
#Override
public void run() {
for (int i =start ; i <= end; i++) {
final int value = i;
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
handler1.post(new Runnable() {
#Override
public void run() {
progressBar.setProgress(value);
}
});
}
}
}
Thread t = new Thread(new Task(from, to)); //call it
t.start();
}
Solution 2: More Simple
If thread is too much to ask for this problem..
you can use the following solution to use a single Handler to update progressbar:
code
public class HandlerDemo extends Activity
{
ProgressBar bar;
Handler handler = new Handler()
{
#Override
public void handleMessage(Message msg)
{
bar.incrementProgressBy(5);
}
};
boolean isRunning = false;
#Override
public void onCreate(Bundle icicle)
{
super.onCreate(icicle);
setContentView(R.layout.main);
bar = (ProgressBar) findViewById(R.id.progress);
}
public void onStart()
{
super.onStart();
bar.setProgress(0);
Thread background = new Thread(new Runnable()
{
public void run()
{
try
{
for (int i = 0; i < 20 && isRunning; i++)
{
Thread.sleep(1000);
handler.sendMessage(handler.obtainMessage());
}
}
catch (Throwable t)
{
// just end the background thread
}
}
});
isRunning = true;
background.start();
}
public void onStop()
{
super.onStop();
isRunning = false;
}
}
Hope it helps..

how to get auto changing background image after few seconds?

i'm working on an Android application in which i want the background image to be changed after every 5 seconds. i have all the images in my drawable folder.
i am giving the code which i am using but i am not getting the output. As an output i am getting a still image which is not changing.
Please help
Thanks
[CODE]
public class Home extends Activity {
public static int count=0;
int[] drawablearray=new int[]{R.drawable.slider_1,R.drawable.slider_2,R.drawable.slider_3,R.drawable.slider_4,R.drawable.slider_5};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
new Handler().postDelayed(new Runnable() {
public void run() {
if(count<drawablearray.length){
Home.this.getWindow().
setBackgroundDrawableResource(drawablearray[count]);
count++; //<<< increment counter here
}
else{
// reset counter here
count=0;
}
}
}, 5000);
}
}

You can achieve this using Timer
public class Home extends Activity {
public static int count=0;
int[] drawablearray=new int[]{R.drawable.slider_1,R.drawable.slider_2,R.drawable.slider_3,R.drawable.slider_4,R.drawable.slider_5};
Timer _t;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
lnMain = (LinearLayout) findViewById(R.id.lnMain);
_t = new Timer();
_t.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
runOnUiThread(new Runnable() // run on ui thread
{
public void run() {
if (count < drawablearray.length) {
lnMain.setBackgroundDrawable(drawablearray[count]);
count = (count + 1) % drawablearray.length;
}
}
});
}
}, 5000, 5000);
}
}

Why don't you have a look at the ViewFlipper class
http://developer.android.com/reference/android/widget/ViewFlipper.html

final Handler h = new Handler();
Runnable r = new Runnable() {
public void run() {
Home.this.getWindow().setBackgroundDrawableResource(drawablearray[count]);
count += (count+1)%drawablearray.length; //<<< increment counter here
h.postDelayed(this, 5000);
}
};
now call like
h.postDelayed(r, 5000);

I think that would be easier to work with the xmls. You can change the background of the main layout of the activity.
Try something like this:
public class Home extends Activity {
public static int count=0;
int[] drawablearray=new int[]{R.drawable.slider_1,R.drawable.slider_2,R.drawable.slider_3,R.drawable.slider_4,R.drawable.slider_5};
LinearLayout ll;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
ll = (LinearLayout) findViewByID(R.id.mainlayout) //It depends of the name that you gave to it
new Handler().postDelayed(new Runnable() {
public void run() {
ll.setBackgroundDrawable(drawablearray[count]);
// or ll.setBackgroundResource(resid) if you want.
count += (count+1)%drawablearray.length;
}
}, 5000);
}
}

Make android screen change color once per second

I am a beginner to android, with some java under my belt. I have completed the make my first app tutorial only.
Next I want to make an app to use simple 2D graphics
To start, I want to find a way of flashing the screen between two colors (red and green) in an infinite loop
wait int seconds;
make screen red;
wait int seconds;
make screen green;
loop forever;
Could anyone please point me to a tutorial(s) or source code(s) that may help?
Many Thanks

How about you make a layout which fills the screen, lets call it llayout.
put this in the code:
static final int[] COLORS = {0xff0000, 0x00ff00};
static final int WAITTIME = 1000;
int currentColor = 0;
public void onCreate(Bundle b) {
setContentView(R.layout.mylayout);
final LinearLayout llayout = (LinearLayout) findViewById(R.id.llayout);
new Thread() {
public void run() {
while(true) {
Thread.sleep(WAITTIME);
currentColor++;
if (currentColor > COLORS.length)
currentColor = 0;
YourActivity.this.runOnUiThread(new Runnable() {
public void run() {
llayout.setBackgroundColor(COLORS[currentColor]);
}
});
}
}
}.start();
}
This should work. Using this code, you can add additional colors to the array COLORS.

Thanks for the input,
This code seems to work OK
package biz.consett.mydraw;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
/* Flash the screen between red and green each second */
public class MainActivity extends Activity {
final static int INTERVAL = 1000; // 1000=1sec
private static View myView = null;
boolean whichColor = true;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myView = (View) findViewById(R.id.my_view);
myView.setBackgroundColor(Color.RED);// set initial colour
new Thread(new Runnable() {
public void run() {
while (true) {
try {
Thread.sleep(INTERVAL);
}
catch (InterruptedException e) {
e.printStackTrace();
}
updateColor();
whichColor = !whichColor;
}
}
}).start();
}
private void updateColor() {
runOnUiThread(new Runnable() {
#Override
public void run() {
if (whichColor)
myView.setBackgroundColor(Color.RED);
else
myView.setBackgroundColor(Color.GREEN);
}
});
}
}
Layout, activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<View
android:id="#+id/my_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
</View>
</RelativeLayout>

You already got a lot of solutions but just adding my own...
You will need a timer
#Override
protected void onCreate(Bundle bundle)
{
...
Timer timer = new Timer();
TimerTask updateColor = new SwitchColorTask();
timer.scheduleAtFixedRate(updateColor, 100, 100);
...
}
A timer task.
private boolean colorSwitched;
class SwitchColorTask extends TimerTask {
public void run() {
LinearLayout main = (LinearLayout)findViewById(R.id.main);
if(colorSwitched){
main.setBackgroundColor (Color.GREEN)
}
else{
main.setBackgroundColor (Color.RED)
}
colorSwitched=!colorSwitched
}
}

Taken from this post and edited for your case:
private int m_interval = 1000; // 1 second by default, can be changed later
private Handler m_handler;
private Layout mYourMainLayout //dont know what type of layout you use
private boolean which;
#Override
protected void onCreate(Bundle bundle)
{
...
mYourMainLayout = (Layout) this.findViewById(R.id.yourMainLayout);
m_handler = new Handler();
}
Runnable m_colorChanger = new Runnable()
{
#Override
public void run() {
if(which){
mYourMainLayout.setBackgroundColor(Color.GREEN)
}
else {
mYourMainLayout.setBackgroundColor(Color.RED)
}
which=!which
m_handler.postDelayed( m_colorChanger, m_interval);
}
};

This code implements the array of colors and works fine - many thanks.
(uses same manifest and layout)
package biz.consett.mydraw;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
/*
* Simple use of Android Thread
* Flash the screen between an array of colours at an interval
*
*/
public class MainActivity extends Activity
static final int[] COLORS =
{AColor.RED, AColor.BLUE, AColor.GREEN};// colour array
// Colour Red Green Blue
// Index [0] [1] [2]
private int currentColor = 0;
private View MYVIEW = null;
//boolean whichColor = true;
final int interval = 100; // 0.6 second static final?
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MYVIEW = (View) findViewById(R.id.my_view);
MYVIEW.setBackgroundColor(Color.RED);// set initial colour
new Thread(new Runnable()
{
// #Override
public void run()
{
while (true)
{
try
{
Thread.sleep(interval); // sleep for interval
}
catch (InterruptedException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
updateColor();
} // end of while true loop
}// end of run
}).start(); // end of runnable
} // end of onCreate bundle
private void updateColor()
{
runOnUiThread(new Runnable()
{
#Override
public void run()
{
if (currentColor > COLORS.length - 1)
{
currentColor = 0;
}
MYVIEW.setBackgroundColor(COLORS[currentColor]);
currentColor++;
}// end of run
});
}
}// -------------END OF MainActivity extends Activity-----------------------
package biz.consett.mydraw;
public class AColor
{
final static int RED = 0xFFFF0000; // hex alpha_R_G_B
final static int GREEN = 0xFF00FF00;
final static int BLUE = 0xFF0000FF;
final static int PURPLE = 0xFFAA00AA;
}

displaying progressbar using threading

I am trying to display a progress bar using threading .. I accept that I do not have that much concept of threading.
Here is the code
public class Progress extends Activity {
static String[] display;
private static final int Progress = 0;
private ProgressBar mProgress;
private int mProgressStatus = 0;
private Handler mHandler = new Handler();
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.progress);
mProgress = (ProgressBar) findViewById(R.id.progressBar);
// Start lengthy operation in a background thread
new Thread(new Runnable() {
public void run() {
while (mProgressStatus < 100) {
mProgressStatus = doWork();
// Update the progress bar
mHandler.post(new Runnable() {
public void run() {
mProgress.setProgress(mProgressStatus);
}
});
}
}
private int doWork() {
display = new Logic().finaldata();
// TODO Auto-generated method stub
return 100;
}
}).start();
}
}
On running, the logcat message is
java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
What is the mistake that I am doing here?

So your problem will be elsewhere. I tried your example with Handler and it works for me.
package com.sajmon.threadsDemo;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.widget.ProgressBar;
import android.widget.TextView;
public class ThreadsDemoActivity extends Activity {
ProgressBar bar;
TextView label;
Handler handler = new Handler();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
bar = (ProgressBar) findViewById(R.id.progBar);
new Thread(new Runnable() {
int i = 0;
int progressStatus = 0;
public void run() {
while (progressStatus < 100) {
progressStatus += doWork();
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
// Update the progress bar
handler.post(new Runnable() {
public void run() {
bar.setProgress(progressStatus);
i++;
}
});
}
}
private int doWork() {
return i * 3;
}
}).start();
}
}
And XML:
<ProgressBar
android:id="#+id/progBar" style="?android:attr/progressBarStyleHorizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
So look at this and edit your code similar with this.

Find the below example code for progress bar update using threads
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.TextView;
public class ThreadDemo1ProgressBar extends Activity
{
ProgressBar bar;
TextView msgWorking;
boolean isRunning = false;
Handler handler = new Handler(){
#Override
public void handleMessage(Message msg) {
bar.incrementProgressBy(5);
if (bar.getProgress() == bar.getMax()) {
msgWorking.setText("Done");
bar.setVisibility(View.INVISIBLE);
} else {
msgWorking.setText("Working..." +
bar.getProgress());
}
}// handleMessage
};
#Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
setContentView(R.layout.main);
bar = (ProgressBar) findViewById(R.id.progress);
bar.setMax(100);
msgWorking = (TextView) findViewById(R.id.TextView01);
}
public void onStart() {
super.onStart();
bar.setProgress(0);
Thread background = new Thread(new Runnable() {
public void run() {
try
{
for (int i = 0; i < 20 && isRunning; i++) {
Thread.sleep(1000);
handler.sendMessage(handler.obtainMessage());
}
}
catch(Throwable t) {
// just end the background thread
}
}
});
isRunning = true;
background.start();
}// onStart
public void onStop() {
super.onStop();
isRunning = false;
}
}// ThreadDemo1ProgressBar
The about example updating the progress bar for every 5 seconds.

I actually just create a thread instance once and it works anyway. This code was written in the Startup Activity. All you need to do is call showSpinner1() method to show/hide the spinner.
Ensure to do this
getWindow().requestFeature(Window.FEATURE_INDETERMINATE_PROGRESS); in your onCreate() method and use this code for toggling the spinner ON and OFF.
// Spinner related code - The thread is created just once and is used multiple times (works!!)
boolean toShow = false;
Thread spinner1Thread = new Thread("Show/Hide Spinner Thread") {
#Override
public void run() {
setProgressBarIndeterminateVisibility(toShow);
}
};
/**
* Shows and hides the spinner
* #param pShow
*/
public void showSpinner1(boolean pShow) {
toShow = pShow;
runOnUiThread(spinner1Thread);
}