i'm new to android programming. I have the following code happening on a button click
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button button = (Button) findViewById(R.id.morse_btn);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
loopCode();
}
});
}
which calls this:
public void loopCode()
{
String code = "Hello There";
TextView view = (TextView) findViewById(R.id.code_txt);
String s = "";
for(int i = 0; i < code.length(); i++)
{
s+=code.charAt(i);
view.setText(s);
try {
TimeUnit.SECONDS.sleep(1);
} catch(InterruptedException ex) {
Thread.currentThread().interrupt();
}
}
}
but when i run it on my phone, the text does not get appended until after the for loop has gone through, i.e i press the button, and after a few seconds, the whole string "Hello There" appears.
How can I make it write the text one character at a time, like a typewriter style.
Thanks
You need to use view.append("") which will append new text to the existing one.
Try this code:
int i = 0; //declare this globally
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
if(i != 10) {
text.append(" " + i);
i++;
handler.postDelayed(this, 1000);
}
}
}, 1000);
}
This code will append a new number to the TextView every one second until it has reached the count 10. You can apply the same logic.
I had provided this solution to a question here -
[EDIT]
Try this:
String code = "Hello There"; //declare variable globally
int i = 0; //declare globally
TextView view; //declare globally
public void loopCode()
{
view = (TextView) findViewById(R.id.code_txt);
//String s = "";
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
if(i != code.length()) {
view.append(" " + code.charAt(i));
i++;
handler.postDelayed(this, 1000);
}
}
}, 1000);
}
}
Don't forget to declare int i = 0 and String code = "Hello There" globally.
Exist 2 different method setText in TextView.
public final void setText (int resid)
public final void setText (CharSequence text)
when you put variable int in setText, the android try find String in classe R variable in same code.
To resolve this you then cast int to string using String.valueOF(...)
see more in;
http://developer.android.com/reference/android/widget/TextView.html#setText(java.lang.CharSequence)
http://docs.oracle.com/javase/6/docs/api/java/lang/String.html#valueOf(int)
try
public void loopCode()
{
String code = "Hello There";
TextView view = (TextView) findViewById(R.id.code_txt);
String s = "";
for(int i = 0; i < code.length(); i++)
{
view.setText(String.valueOf(i));
try {
TimeUnit.SECONDS.sleep(1);
} catch(InterruptedException ex) {
Thread.currentThread().interrupt();
}
}
}
Related
I'm working on a tank-game and I have a TextView which represents the shot. Now I want to display the TextView at the specific point and remove it after a second that it looks like the shot goes further step by step. But when I add a countdown or a Thread.sleep the program stops for a second but the TextView doesn't disappear. i want to move the TextView over the screen and after every iteration of my for loop i want to wait a second and then rearrange it again?
Here is the code :
public void shot(float power, float winkel, Button button) {
if(winkel>90) {
winkel = winkel - 10;
}else if(winkel<90){
winkel = winkel +10;
}
for (double i = 0; i<100;i = i+ 1) {
final TextView textView = new TextView(context);
textView.setText(".");
double x = tanks.get(currentTank).getxPos()+(i*power*Math.cos(winkel *(Math.PI/180)));
double y = tanks.get(currentTank).getyPos()+(-1*(i*power*Math.sin(winkel *(Math.PI/180))));
double gravity = (-1*((9.81/2)*Math.pow(i,2)));
y = (y-gravity);
textView.setX((float) x);
textView.setY((float) y);
layout.addView(textView);
for (int j = 0;j<tanks.size();j++){
if(textView.getX()>tanks.get(j).getxPos()&&textView.getX()<tanks.get(j).getxPos()+100){
if(textView.getY()>tanks.get(j).getyPos()&&textView.getY()<tanks.get(j).getyPos()+100){
float k = tanks.get(j).getxPos()-textView.getX();
if(k<0){
k = k*-1;
}
makeDamage(k,tanks.get(j));
}
}
}
new CountDownTimer(2000,1000){
#Override
public void onTick(long millisUntilFinished) {
}
#Override
public void onFinish() {
layout.removeView(textView);
}
}.start();
}
newTurn();
}
I want to pause the program after adding the TextView for one second and the remove it. The program stops but the TextView doesn't disappear till the for-loop finished. Then all TextViews disappear.
Problem solved:
i've added all positions in a array and then this
public void drawShot(final Button firework, final ArrayList<TextView> toDraw){
final int[] i = {0};
final Handler mHandler = new Handler();
firework.setOnClickListener(new View.OnClickListener() {
#RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN)
#Override
public void onClick(View v) {
firework(firework,toDraw.get(i[0]).getX(),toDraw.get(i[0]).getY());
}
});
Runnable runnable = new Runnable() {
#Override
public void run() {
layout.addView(toDraw.get(i[0]));
if(!check(toDraw.get(i[0]))) {
mHandler.postDelayed(this, (long) 1);
}
i[0]++;
}
};
// start it with:
mHandler.post(runnable);
}
probably need to run the remove command on main thread
Handler mainHandler = new Handler(context.getMainLooper());
Runnable myRunnable = new Runnable() {
#Override
public void run() {
layout.removeView(textView);
}
};
mainHandler.post(myRunnable);
I am trying to display values inside ArrayList on single line textView one by one after some interval. How to achieve this without blocking the main thread?
I have written code which is able to do this with Thread.sleep but, after a few seconds of running, activity is getting crashed. I have used For Loop & Thread.sleep to iterate every ArrayList value after some interval.
When activity crashes, I am getting IndexOutOfBondException after a few seconds of running.
public void errorRepeater() {
Thread t = new Thread() {
#Override
public void run() {
// !isInterrupted()
while (!isInterrupted()) {
for (xz = 0; xz < errorList.size(); xz++) {
try {
Thread.sleep(2000); //1000ms = 1 sec
runOnUiThread(new Runnable() {
#Override
public void run() {
String sErrorList = errorList.get(xz);
String sErrorListOkBox = errorListOkBox.get(xz);
Log.i("MQTT sErrorList", sErrorList);
TextView tvC1HPLP = findViewById(R.id.errormsg);
tvC1HPLP.setText(sErrorList);
TextView tvok = findViewById(R.id.ok);
tvok.setText(sErrorListOkBox);
rl.setBackgroundResource(R.drawable.errorred);
tvC1HPLP.setTextColor(Color.RED);
}
});
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
};
t.start();
}
textView should display values inside ArrayList one by one without crashing activity.
Just for reference, you can try something like this.
// You can define those both textview globally.
TextView tvC1HPLP = findViewById(R.id.errormsg);
TextView tvok = findViewById(R.id.ok);
Handler mHandler = new Handler();
final Runnable runnable = new Runnable() {
int count = 0;
#Override
public void run() {
String sErrorList = errorList.get(count%errorList.size);
String sErrorListOkBox = errorListOkBox.get(count%errorListOkBox.size);
tvC1HPLP.setText(sErrorList);
tvok.setText(sErrorListOkBox);
rl.setBackgroundResource(R.drawable.errorred);
tvC1HPLP.setTextColor(Color.RED);
count++;
mHandler.postDelayed(this, 4000); // four second in ms
}
};
mHandler.postDelayed(runnable, 1000);
currently developing an app where I need to take a number of wifi measurements, take an average of these measurements and store the averages. However I've found that I have to implement a delay between measurements otherwise there's not enough time to see any variation between measurements.
In the Handler.postDelayed() method I've tried to implement a 2000ms delay, however when I view the timestamp of the logs generated by TAKEWIFI, there appears to be no delay at all.
Any help would be greatly appreciated :)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_takewifi);
final String[] strArr = new String[60];
for (int i=0;i<60;i++)
{
strArr[i] = "EMPTY";
}
WifiManager wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
final int state = wifi.getWifiState();
if(state == WifiManager.WIFI_STATE_ENABLED) {
RawData rD = new RawData();
Toast.makeText(TakeWifi.this,
"Taking RSS measurement, hold still!",
Toast.LENGTH_SHORT).show();
for(int a=0;a<30;a++)
{
wifi.startScan();
final Handler handler = new Handler();
handler.post(new Runnable() {
#Override
public void run() {
handler.postDelayed(this, 2000);
}
});
List<ScanResult> results = wifi.getScanResults();
String index = (String) results.toString();
int forCount = 0;
int ifCount = 0;
for (String retval: index.split(",")){
if (((forCount%5==1)||(forCount%5==3))&&(ifCount<60)){
strArr[ifCount] = retval;
strArr[ifCount] = strArr[ifCount].replace(" BSSID:", "BSSID:");
strArr[ifCount] = strArr[ifCount].replace(" level:", "level:");
ifCount++;
}
forCount++;
}
for(int check=0;check<60;check++)
{
Log.d("TAKEWIFI","strArr[" + check + "]: " + strArr[check]);
}
rD.setStrArr(strArr,rD);
}
final String[] temp = rD.getStrArr(rD);
for(int b=0;b<20;b++)
{
strArr[b]=temp[b];
}
for(int i=0;i<20;i++)
{Log.d("STRARR",strArr[i]);}
List<String> stringList = Arrays.asList(temp);
for (int i = 0; i < 20; i++) {
Log.d("STRLIST",stringList.get(i));
}
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, stringList);
ListView listview = (ListView) findViewById(R.id.listview);
if (listview==null)
{
Log.d("LISTVIEW","NULL");
}listview.setAdapter(adapter);
Toast.makeText(TakeWifi.this,"RSS measurement complete",Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(TakeWifi.this,"Wifi Not Enabled",Toast.LENGTH_SHORT).show();
}
final Button commitBut=(Button)findViewById(R.id.button4);
commitBut.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
if(state == WifiManager.WIFI_STATE_ENABLED){
commit(strArr);
}
else
{
Toast.makeText(TakeWifi.this,"Wifi Not Enabled",Toast.LENGTH_SHORT).show();
}
}
});
}
Replace your handle with this and put everything you want delayed into it.
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
// Everything you want to be delayed needs to go inside this runnable
}
}, 2000);
You are waiting in another thread (hence the run() method in your handler) :) Try removing that whole handler magic and call Thread.sleep directly.
I have a simple app that updates a TextView from a values generated in a loop when i click on a button.
But when i run the app, it only shows the last number in the TextView. I added a Thread.sleep() to slow down the loop but it did not work, Still the same result. What am i doing wrong here? Thanks in advace
public class MainThread extends ActionBarActivity {
Button btnShow;
TextView txtSee;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_thread);
btnShow = (Button) findViewById(R.id.btnShow);
txtSee = (TextView) findViewById(R.id.txtSee);
btnShow.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
try {
for (int i = 0; i <= 5; i++) {
String text1 = "Iteration No " + i + " occured";
txtSee.setText(text1);
Thread.sleep(2000);
}
} catch (InterruptedException e) {
}
}
});
}
....
}
use
txtSee.append(text1);
instead of
txtSee.setText(text1);
your loop is executing too fast to let you observe the changes
Call another function inside loop and use
txtSee.setText(text1); inside that function.
or (int i = 0; i <= 5; i++) {
String text1 = "Iteration No " + i + " occured";
call_function(text1,txtSee);
}
call_function:-
call_function(String text1,TextView txtSee;){
txtSee.setText(text1);
Thread.sleep(2000);
}
I want the Text in a TextView to be displayed word after word or even letter after letter, just like in most rpgs and adventures with textboxes. A good example how the textflow should look like is the game phoenix wright ( http://youtu.be/2OOX2Gv0768?t=1m7s )
What i have tried until now is this:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String text = "test test test test";
String[] split = text.split(" ");
Deque<String> words = new LinkedList<String>();
for (int i = 0; i<split.length; i++)
{
words.addLast(split[i]);
}
showNextWord(words);
}
public void showNextWord(final Deque<String> words)
{
Handler handler = new Handler();
handler.postDelayed(new Runnable()
{
public void run()
{
TextView t = (TextView) findViewById(R.id.textBox);
t.append(words.pollFirst()+" ");
if (words.size()>0)
showNextWord(words);
}
}, 500);
}
I tested on an emulator and it seems to be with low performance, even more if i would start a delay after displaying each letter. The delay isn´t consistent.
In addition to that I hope there is a more elegant solution to that. Maybe some way to be more flexible with the delays? E.g. a bigger delay after a sentence and so on.
Thank you very much!
public class Typewriter extends TextView {
private CharSequence mText;
private int mIndex;
private long mDelay = 500; //Default 500ms delay
public Typewriter(Context context) {
super(context);
}
public Typewriter(Context context, AttributeSet attrs) {
super(context, attrs);
}
private Handler mHandler = new Handler();
private Runnable characterAdder = new Runnable() {
#Override
public void run() {
setText(mText.subSequence(0, mIndex++));
if(mIndex <= mText.length()) {
mHandler.postDelayed(characterAdder, mDelay);
}
}
};
public void animateText(CharSequence text) {
mText = text;
mIndex = 0;
setText("");
mHandler.removeCallbacks(characterAdder);
mHandler.postDelayed(characterAdder, mDelay);
}
public void setCharacterDelay(long millis) {
mDelay = millis;
}
}
And use above class in your activity like this:
Typewriter writer = new Typewriter(this);
//Add a character every 200ms
writer.setCharacterDelay(200);
writer.animateText("Sample String");
Try this:
Handler handler = new Handler();
handler.postDelayed(new Runnable()
{
public void run()
{
if (words.size()>0)
showNextWord(words);
}
}, 500);
public void showNextWord(words)
{
TextView t = (TextView) findViewById(R.id.textBox);
t.append(words.pollFirst()+" ");
}
Alright here is what I came up with!
public static void main(String[] args) {
printWord("Sup dude!", 150);
}
public static void printWord(String word, int time){
for(int i = 0; i < word.length(); i++){
double start = System.currentTimeMillis();
double end = System.currentTimeMillis();
while(end - start <= time){
end = System.currentTimeMillis();
}
System.out.print(word.charAt(i));
}
}
I bet you can easily can the print to your textview by changing the syso to:
tv.setText(tv.getText() + word.charAt(i));
Hope that answers your question and helps! Good luck :)
Take a look at this Library: https://github.com/flavienlaurent/spans It has a feature called typewriter that might suit your needs. You can see it in action in this blog post: http://flavienlaurent.com/blog/2014/01/31/spans/