Avoiding a toast if one toast is shown

Question

I have several SeekBar and onSeekBarProgressStop() , I want to show a Toast message.

But if I execute the action quickly on the SeekBar , then the UI thread is somehow blocked, and the Toast message waits until the UI thread is free.

Now I am worried about avoiding the appearance of a new Toast message if the Toast message is already displayed. Or is there any condition under which we check that the user interface thread is currently free, then I will Toast message.

I tried this in both directions using runOnUIThread() , and also creating a new Handler .

Answer 1

I tried different things to do this. At first I tried to use cancel() , which did not affect me (see also this answer ).

With setDuration(n) I didn't go anywhere either. It turned out that he writes getDuration() , that it carries a value of 0 (if the makeText() parameter was Toast.LENGTH_SHORT ) or 1 (if the makeText() parameter was Toast.LENGTH_LONG ).

Finally, I tried to check if there is isShown() toast isShown() . Of course, this is not so if there is no toast, but even more, it returns a fatal error in this case. Therefore, I needed to try to catch a mistake. Now isShown() returns true if a toast is displayed. Using isShown() , I came up with a method:

  /** * <strong>public void showAToast (String st)</strong></br> * this little method displays a toast on the screen.</br> * it checks if a toast is currently visible</br> * if so </br> * ... it "sets" the new text</br> * else</br> * ... it "makes" the new text</br> * and "shows" either or * @param st the string to be toasted */ public void showAToast (String st){ //"Toast toast" is declared in the class try{ toast.getView().isShown(); // true if visible toast.setText(st); } catch (Exception e) { // invisible if exception toast = Toast.makeText(theContext, st, toastDuration); } toast.show(); //finally display it } 

Answer 2

Below is an alternative solution to the most popular answer without try / catch.

 public void showAToast (String message){ if (mToast != null) { mToast.cancel(); } mToast = Toast.makeText(this, message, Toast.LENGTH_SHORT); mToast.show(); } 

Answer 3

A clean solution that works out of the box. Define this in your activity:

 private Toast toast; /** * Use this to prevent multiple Toasts from spamming the UI for a long time. */ public void showToast(CharSequence text, int duration) { if (toast == null) toast = Toast.makeText(this, text, duration); else toast.setText(text); toast.show(); } public void showToast(int resId, int duration) { showToast(getResources().getText(resId), duration); } 

Answer 4

An enhanced function from the aforementioned stream that will show a toast only if not displayed with the same text message:

  public void showSingleToast(){ try{ if(!toast.getView().isShown()) { toast.show(); } } catch (Exception exception) { exception.printStackTrace(); Log.d(TAG,"Toast Exception is "+exception.getLocalizedMessage()); toast = Toast.makeText(this.getActivity(), getContext().getString(R.string.no_search_result_fou'enter code here'nd), Toast.LENGTH_SHORT); toast.show(); } } 

Answer 5

track the last time you showed a toast, and re-show it without-op if it falls within a certain interval.

 public class RepeatSafeToast { private static final int DURATION = 4000; private static final Map<Object, Long> lastShown = new HashMap<Object, Long>(); private static boolean isRecent(Object obj) { Long last = lastShown.get(obj); if (last == null) { return false; } long now = System.currentTimeMillis(); if (last + DURATION < now) { return false; } return true; } public static synchronized void show(Context context, int resId) { if (isRecent(resId)) { return; } Toast.makeText(context, resId, Toast.LENGTH_LONG).show(); lastShown.put(resId, System.currentTimeMillis()); } public static synchronized void show(Context context, String msg) { if (isRecent(msg)) { return; } Toast.makeText(context, msg, Toast.LENGTH_LONG).show(); lastShown.put(msg, System.currentTimeMillis()); } } 

and then

 RepeatSafeToast.show(this, "Hello, toast."); RepeatSafeToast.show(this, "Hello, toast."); // won't be shown RepeatSafeToast.show(this, "Hello, toast."); // won't be shown RepeatSafeToast.show(this, "Hello, toast."); // won't be shown 

this is not ideal since the lengths of LENGTH_SHORT and LENGTH_LONG undefined, but in practice it works well. it takes precedence over other solutions that you don’t need to hold onto the Toast object, and the call syntax remains concise.

Answer 6

Combined solution

In my case, I needed to cancel the current toast, if it is shown, and display another.

This was supposed to solve the scenario when a user requests a service while it is still loading or unavailable. I need to show a toast (maybe I will be different if the requested service is different). Otherwise, the toasts will be displayed in order, and it will take a lot of time to automatically hide them.

So basically I save the toast instance that I create and the following code: how to safely cancel it

 synchronized public void cancel() { if(toast == null) { Log.d(TAG, "cancel: toast is null (occurs first time only)" ); return; } final View view = toast.getView(); if(view == null){ Log.d(TAG, "cancel: view is null"); return; } if (view.isShown()) { toast.cancel(); }else{ Log.d(TAG, "cancel: view is already dismissed"); } } 

And to use it, now I can not worry about canceling, as in:

 if (toastSingleton != null ) { toastSingleton.cancel(); toastSingleton.showToast(messageText); }else{ Log.e(TAG, "setMessageText: toastSingleton is null"); } 

showToast is up to you how to implement it, since I need a custom look for my toast.

Answer 7

Good for stopping styling, for example. Click running toast. Based on @Addi's answer.

 public Toast toast = null; //.... public void favsDisplay(MenuItem item) { if(toast == null) // first time around { Context context = getApplicationContext(); CharSequence text = "Some text..."; int duration = Toast.LENGTH_SHORT; toast = Toast.makeText(context, text, duration); } try { if(toast.getView().isShown() == false) // if false not showing anymore, then show it toast.show(); } catch (Exception e) {} } 

Answer 8

Check if the toast message is displayed on the screen, whether it is displayed or not. To display a toast message, make a separate class. And use the method of this class that displays the toast message after checking the visibility of the toast message. Use this piece of code:

 public class AppToast { private static Toast toast; public static void showToast(Context context, String message) { try { if (!toast.getView().isShown()) { toast=Toast.makeText(context, message, Toast.LENGTH_SHORT); toast.show(); } } catch (Exception ex) { toast=Toast.makeText(context,message,Toast.LENGTH_SHORT); toast.show(); } } } 

I hope this solution helps you.

thank

Answer 9

Added timer to remove toast after 2 seconds.

 private Toast toast; public void showToast(String text){ try { toast.getView().isShown(); toast.setText(text); }catch (Exception e){ toast = Toast.makeText(mContext, text, Toast.LENGTH_SHORT); } if(toast.getView().isShown()){ new Timer().schedule(new TimerTask() { @Override public void run() { toast.cancel(); } }, 2000); }else{ toast.show(); } } showToast("Please wait"); 

Answer 10

My decision:

 public class Utils { public static Toast showToast(Context context, Toast toast, String str) { if (toast != null) toast.cancel(); Toast t = Toast.makeText(context, str, Toast.LENGTH_SHORT); t.show(); return t; } } 

and the caller must have a Toast member for this method parameter, or

 class EasyToast { Toast toast; Context context; public EasyToast(Context context) { this.context = context; } public Toast show(String str) { if (toast != null) toast.cancel(); Toast t = Toast.makeText(context, str, Toast.LENGTH_SHORT); t.show(); return t; } } 

there is a helper class like this.