I'm aware or the Thread.sleep() and postDelayed() function in java/androidStudio.
But here is the issue, I'm creating a replicate of Simon says game.
I created a generateSequence() function that puts number of 1-9 randomly into an array called sequence. After that, I need to display these sequence, which basically changes the background of a textView for a second and then back to its original background using the postDelayed() function.
Here is my code:
private void displaySequence(){
for(int i = 0; i < sequence.size(); i++) {
if(sequence.get(i) == 1) {
viewCard11.setBackgroundResource(R.drawable.text_view_circle4);
proceed = false;
handler.postDelayed(() -> {
viewCard11.setBackgroundResource(R.drawable.text_view_circle3);
proceed = true;
}, 1000);
}
else if(sequence.get(i) == 2) {}
else if(sequence.get(i) == 3) {}
else if(sequence.get(i) == 4) {}
else if(sequence.get(i) == 5) {}
else if(sequence.get(i) == 6) {}
else if(sequence.get(i) == 7) {}
else if(sequence.get(i) == 8) {}
else if(sequence.get(i) == 9) {}
while(!proceed) {}
}
}
But the problem with postDelayed() is that only whatever is inside the function is delayed. Meaning if this sequence had 2 element, it will simultaneously blink the background. The for loop doesn't wait for the postDelayed to finish whatever it is suppose to do, but instead it increments and proceed to put the next postDelayed.
To solve this issue, I tried to use a proceed boolean variable as a delay. What I do is that, before we call the postDelayed, I set proceed as false. Since it will not wait for postDelayed(), it will go to the next line of code which is the while loop.
By setting the proceed as false, I use it to create a infinite loop. But this infinite loop will be broken by the completed postDelayed() as proceed will be set to true in it, then the code can continues the for loop.
But I not sure why it simply doesn't work. When I run the code, it just displayed a blank screen. It seemed like the problem resides within the infitine while loop and postDelayed() can't update the proceed variable.
I tried using Thread.sleep(1000) as a replacement of postDelayed, but during startup, the program simply shows a white background for however long the parameter is passed to Thread.sleep()
I have exhausted my option and I hope someone has a better idea.
Thank you.
The loop does not wait for the postDelayed because what's inside the postDelayed happens async. This means that it works independently from the UI thread, on a second thread. What you want to accomplish is to make the UIthread wait for a period of time, and not start another thread after a specific period.
You could try to use the handler in this way:
Handler handler=new Handler()
{
public void handleMessage(Message msg)
{
if(msg.what==0)
{
viewCard11.setBackgroundResource(R.drawable.text_view_circle3);
proceed = true;
}
}
};
and then you may use the handler like this:
handler.postDelayed(() ->
{
//does nothing just waits 1 second and then send empty message
handler.sendEmptyMessage(0)
}, 1000);
Related
I want to make a loop, the times the user wants but with a delay of 3 seconds.
This is the code:
for (i = 0;i < n1; i++){
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
Toast.makeText(KeyMapCreator.this, "Try number " + i,Toast.LENGTH_SHORT).show(); ActionIwantToDo();
}
},3000);
}
The variable i is the one that the user sets.
The problem is that the toast doesn't show up every 3 seconds, it just do like a normal loop without delay. I thought it was because of the time of the toast but if i set the time to 20 secs still being the same.
Someone knows how to make a proper delay inside a loop???
The problem you have is that your loop creates many handlers at once that delay for 3 seconds and then show a toast. They do not wait for each other, and because they are created within milliseconds of each other they will show the toast at the same time.
I'm not sure what you are trying to accomplish, and a loop is probably not what you want. However this is a way to get the toast to display after 3 seconds and every 3 seconds after for a number of times.
For this we will use recursion because it will make it so that you are not blocked on the main thread.
Call doSomething (the recursive function) from where you need the function to start (remember that the second variable is the number of times you want it to run, and 0 is just required as a counter)
doSomething(0, 3)
create doSomething
private void doSomething(int i, int n) {
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
if (i < n) {
Toast.makeText(KeyMapCreator.this, "Try number " + i,Toast.LENGTH_SHORT).show();
actionIWantToDo();
doSomething(i+1, n);
}
}
}, 3000);
}
A Handler just schedules some work for later execution. It doesn't actually block the current thread. All you're doing is scheduling n1 items of work to execute three seconds later, which will all execute in sequence on that exact delay.
You don't really ever want to write code to block the main thread. Ever. It will make your app appear to be unresponsive.
I am making a game where the player can throw up to three projectiles at a time. I'm having trouble with the reloading. Here is the code:
public class AmmoManager {
public void tick(){
if(Player.ammo <= 0){
for(int t = 0; t < 10; t ++){
}
Player.ammo = 3;
}
}
}
It's supposed to wait a bit and then set the ammo to 3, but as soon as the ammo becomes 0, it is set to 3 instantly. What am I doing wrong?
I've tried using sleep, but the entire application would stop.
The problem is that your main program waits for tick() to return something.
Think about it like this; if you have this method
public boolean isOne(int num){
Thread.sleep(1000);
if(num==1){return true;}
return false;
}
and
boolean result = isOne(1);
if(result){ //can't be ran until isOne(1) returns the boolean
//do something
}
You can't continue with you main class when you call isOne() because you dont have the value of the boolean it returns. you have to wait for it to return the value, and then you can continue with the main method
The solution is threading. I'm not an expert on it, so you will need to consult someone else or an online resource, but I think it would look something like this:
public void tick(){
new Thread({ new Runnable(){
#Override
public void run(){
if(Player.ammo <= 0){
Thread.sleep(*seconds* times 1000);
Player.ammo = 3;
}
}).start();
}
There are two problems here.
as soon as the ammo becomes 0, it is set to 3 instantly. What am I doing wrong?
That's because the for loop does nothing. When you enter tick() and Player.ammo is 0, you instantly set it to 3.
I've tried using sleep, but the entire application would stop.
If you only have one thread, that is what Thread.sleep does.
I suspect that what you are attempting is more difficult than you think...
You need a main loop that controls the pace of the game. I might sleep() to ensure that the game does not run too fast.
Each pass, it must instruct every player, or whatever constructs you use, to update themselves. As one of the comments noted, that might involve incrementing a counter to replenish ammo.
My program is coded in Java. I have an IF() check in run() method (in a Thread). In the IF check, if the condition is satisfied, it shows a Window dialog (using JOptionPane.showMessageDialog) with OK button. However, it shows infinitely. When I click OK it pops up again and again. How can I end the if check after the user click OK. Or when the condition is met, it only shows once ?
This is my method()
public void danhHoiWumpus()
{
if ((GameScreen.bg[x[0] + 1][y[0]] == 2) || (GameScreen.bg[x[0] + 2][y[0]] == 2) || (GameScreen.bg[x[0] + 3][y[0]] == 2) || (GameScreen.bg[x[0]][y[0]+1] == 2) || (GameScreen.bg[x[0]][y[0]+2] == 2) || (GameScreen.bg[x[0]][y[0]+3] == 2))
{
JOptionPane.showMessageDialog(this, "Có mùi wumpus ! \n Bạn được học bổng 40%");
}
}
This is my run() method
public void run()
{
while(true)
{
hunter.update();
hunter.danhHoiWumpus();
// i++;
repaint();
// System.out.println("Gia tri cua y la " +i);
try {
thread.sleep(20);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
The idea of this action is. When the RED square is going near the YELLOW square, it will pop up a dialog "I smell Wumpus". When the user click OK. They will choose to shot the wumpus (I will do this later).
And here is my full source code (for reference):
https://www.mediafire.com/?wkp6hyq32nq23mp
Thank you in advance.
Your code is executing in an infinite while loop
while(true)
// I am infinite
}
The term you are looking for is hit detection. There are a myriad of ways to achieve it. Look up hit detection in Java for some pointers.
What you have isn't necessarily wrong though.
while (true) // I'm not always bad!
is used in a lot of applications. However, while your code isn't completely posted, I don't see anywhere you break from this. You may be interested in the
java.util.Timer
and the
java.util.TimerTask
Both of those have wide application in Java game development
Your sleep time is too low (20 nanoseconds). Increase the time, otherwise it will happen too quick for you to understand it.
You are potentially triggering this if condition many many times.
You need some 'rising edge trigger' logic in order to only trigger when the new value goes from false to true, instead of triggering whenever it's true.
currentValue = bigLongLogicCheck;
if(!oldvalue&¤tValue) {alert()}
oldvalue = currentValue
I am almost a beginner on android. I am sort of stuck at a point. In the following code I am running a while loop for 30 times and runnable post delay is 3 seconds, means loop will run for 90 seconds(which is not important yet). It does so, thats fine. But in the runnable, when I call rangeofRouter0() function,the value in the textView changes to "You have reached the turn" when it goes into "else if" condition of rangeofRouter0() function and it must remove the callbacks as defined and move to next activity, exitiing from the while loop whether it has completed 90 seconds or not but program doesn't reach in if(textView.getText.equals....) part. And if I put this condition directly into "else if", callbacks are (I think) not removed and next screen is called again and again. I want that when code goes into else if, it should simply move to next screen and previous activity(means this activity), should simply be forgotten
int i = 1;
while (i<30)
{
myRunnable =new Runnable() {
public void run() {
scanWifiList();
rangeofRouter0();
}
};
handler1.postDelayed(myRunnable, i * 3000);
i++;
if(textView.getText().toString.equals("You have reached the turn")){
///this text gets in textView in "else if" condition
handler1.removeCallbacks(myRunnable);
Intent intent = new Intent(getApplicationContext(), FrontScreen.class);
// finish();
startActivity(intent);
break;
}
}//While loop ended
private void scanWifiList() {
mainWifi.startScan();
wifiList = mainWifi.getScanResults();
textView5.setText("" + firstRouterDistance());
}
public void rangeofRouter0(){
if(firstRouterDistance() >= 30 &&
firstRouterDistance() <= 70 && ((degree>0 && degree <60)||(degree>300 && degree <360)))
{
textView.setText("Move left");
speakOut(textView.getText().toString());
}
else if(firstRouterDistance() >= 3 &&
firstRouterDistance() <= 20 &&
secondRouterDistance() >= 7 &&
secondRouterDistance() <= 60 && degree>220 && degree <250)
{
textView.setText("You have reached the turn");
counter++;
}
else{
textView.setText("Not before dining hall");
}
}
You first need to understand how postDelayed() works exactly.
When you assign a runnable to the Handler's postDelayed(), that means you are scheduling a task to get executed at a particular time interval from the current time.
Now what you are doing is running a while loop 29 times and each time scheduling the task - total 29 tasks to run at 3,6,9... seconds respectively.
At this point you only scheduled the task and it's not started running yet.
And you while loop finishes after iterating for 29 times.
Your rangeofRouter0() never gets called during the while loop iterations since it took only a few milliseconds and hence counter is never greater than 0.
Note - If you want the loop to run for 30 times you should change it to while (i<=30).
So, you need to change your logic to achieve what you want. If you want to read more about Handler. Check this.
I am using AndEngine to develop my game, though I'm thinking this problem is unrelated to AndEngine.
I have two possible dialogs that fire if:
User touches down in an incorrect area or
Users lifts up from an incorrect area.
Unfortunately, if a user touches down in an incorrect area, when they lift up they are also satisfying error 2--lifting up from an incorrect area.
Here's my code in a nutshell:
public boolean onSceneTouchEvent(Scene pScene, TouchEvent pSceneTouchEvent) {
float y = pSceneTouchEvent.getY();
int dialog_count = 0;
if (pSceneTouchEvent.isActionDown() && y < 1000) {
activity.runOnUiThread(new Runnable() {
#Override
public void run() {
AlertDialog Code
..............
}
}
dialog_count ++;
Log.d("Dialog Count", "Count is " + dialog_count);
} else if (dialog_count < 1 && pSceneTouchEvent.isActionUp() && y > 105) {
Log.d("Dialog Count", "Count is still " + dialog_count);
activity.runOnUiThread(new Runnable() {
#Override
public void run() {
Second AlertDialog Code
.................
}
}
}
return false;
}
Now, my first log for dialog_count shows a value of 1. However when I lift up the second log shows a value of 0. Somehow this value is either getting reset or my Else statement just can't see the updated value of dialog_count because I get the second dialog popping on top of my first.
Any ideas?
Your code initializes
int dialog_count = 0;
each time it runs.
To keep the value you saw the last time, make dialog_count an instance variable in the class.
Notice that you will be seeing two events, one for "down" and one for "up".
If you want to show only one then you need to use a flag to check if the user has touched down and then if you want not to show the touch up dialog just check from the flag. But the Touch down will always follow the Touch Up. You can use the Touch Move method if you want to show the dialog when the user has moved a bit.
If I understand correctly, what you are trying to do
dialogCount is function local (garbage collected, after you exit the method). So it will be 0 on each new run of the method. (Make it private class variable).
If you are referring to your dialogCount in multiple threads, dialogCount must be thread safe, so use concurrent primitives - AtomicInteger