In my app,I wanted to show the number of taps to be made to accomplish a task, for this purpose i used Toast class , I used Toast.makeText to show the text. problem is that I couldn’t change the text or make it hide quickly if new text was to be shown. Android would queue all the makeText requests.
I wanted to have a solution to be able to change the text or be able to cancel the previous toast without waiting for it to finish. While Looking for solution I found this class called Boast by a StackOverFlow user Richard Le Mesurier. The Boast class accomplishes exactly what I needed.
The trick is to keep track of the last Toast that was shown, and to cancel that one.
What Richard Le Mesurier have done is to create a Toast wrapper, that contains a static reference to the last Toast displayed.
When I need to show a new one, I first cancel the static reference, before showing the new one (and saving it in the static).
Here’s full code of the Boast wrapper Richard Le Mesurier made – it mimics enough of the Toast methods for me to use it.
By default the
Boastwill cancel the previous one, so you don’t build up a queue of Toasts waiting to be displayed.
This should be a direct drop-in replacement for Toast in most use cases. for example
mBoast.makeText(this,"your text",Duration).show();
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.Resources;
import android.widget.Toast;
/**
* {@link Toast} decorator allowing for easy cancellation of notifications. Use
* this class if you want subsequent Toast notifications to overwrite current
* ones. </p>
*
* By default, a current {@link Boast} notification will be cancelled by a
* subsequent notification. This default behaviour can be changed by calling
* certain methods like {@link #show(boolean)}.
*/
public class Boast
{
/**
* Keeps track of certain {@link Boast} notifications that may need to be cancelled.
* This functionality is only offered by some of the methods in this class.
*/
private volatile static Boast globalBoast = null;
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Internal reference to the {@link Toast} object that will be displayed.
*/
private Toast internalToast;
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Private constructor creates a new {@link Boast} from a given
* {@link Toast}.
*
* @throws NullPointerException
* if the parameter is <code>null</code>.
*/
private Boast(Toast toast)
{
// null check
if (toast == null)
{
throw new NullPointerException(
"Boast.Boast(Toast) requires a non-null parameter.");
}
internalToast = toast;
}
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Make a standard {@link Boast} that just contains a text view.
*
* @param context
* The context to use. Usually your {@link android.app.Application}
* or {@link android.app.Activity} object.
* @param text
* The text to show. Can be formatted text.
* @param duration
* How long to display the message. Either {@link #LENGTH_SHORT} or
* {@link #LENGTH_LONG}
*/
@SuppressLint("ShowToast")
public static Boast makeText(Context context, CharSequence text,
int duration)
{
return new Boast(Toast.makeText(context, text, duration));
}
/**
* Make a standard {@link Boast} that just contains a text view with the
* text from a resource.
*
* @param context
* The context to use. Usually your {@link android.app.Application}
* or {@link android.app.Activity} object.
* @param resId
* The resource id of the string resource to use. Can be formatted
* text.
* @param duration
* How long to display the message. Either {@link #LENGTH_SHORT} or
* {@link #LENGTH_LONG}
*
* @throws Resources.NotFoundException
* if the resource can't be found.
*/
@SuppressLint("ShowToast")
public static Boast makeText(Context context, int resId, int duration)
throws Resources.NotFoundException
{
return new Boast(Toast.makeText(context, resId, duration));
}
/**
* Make a standard {@link Boast} that just contains a text view. Duration
* defaults to {@link #LENGTH_SHORT}.
*
* @param context
* The context to use. Usually your {@link android.app.Application}
* or {@link android.app.Activity} object.
* @param text
* The text to show. Can be formatted text.
*/
@SuppressLint("ShowToast")
public static Boast makeText(Context context, CharSequence text)
{
return new Boast(Toast.makeText(context, text, Toast.LENGTH_SHORT));
}
/**
* Make a standard {@link Boast} that just contains a text view with the
* text from a resource. Duration defaults to {@link #LENGTH_SHORT}.
*
* @param context
* The context to use. Usually your {@link android.app.Application}
* or {@link android.app.Activity} object.
* @param resId
* The resource id of the string resource to use. Can be formatted
* text.
*
* @throws Resources.NotFoundException
* if the resource can't be found.
*/
@SuppressLint("ShowToast")
public static Boast makeText(Context context, int resId)
throws Resources.NotFoundException
{
return new Boast(Toast.makeText(context, resId, Toast.LENGTH_SHORT));
}
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Show a standard {@link Boast} that just contains a text view.
*
* @param context
* The context to use. Usually your {@link android.app.Application}
* or {@link android.app.Activity} object.
* @param text
* The text to show. Can be formatted text.
* @param duration
* How long to display the message. Either {@link #LENGTH_SHORT} or
* {@link #LENGTH_LONG}
*/
public static void showText(Context context, CharSequence text, int duration)
{
Boast.makeText(context, text, duration).show();
}
/**
* Show a standard {@link Boast} that just contains a text view with the
* text from a resource.
*
* @param context
* The context to use. Usually your {@link android.app.Application}
* or {@link android.app.Activity} object.
* @param resId
* The resource id of the string resource to use. Can be formatted
* text.
* @param duration
* How long to display the message. Either {@link #LENGTH_SHORT} or
* {@link #LENGTH_LONG}
*
* @throws Resources.NotFoundException
* if the resource can't be found.
*/
public static void showText(Context context, int resId, int duration)
throws Resources.NotFoundException
{
Boast.makeText(context, resId, duration).show();
}
/**
* Show a standard {@link Boast} that just contains a text view. Duration
* defaults to {@link #LENGTH_SHORT}.
*
* @param context
* The context to use. Usually your {@link android.app.Application}
* or {@link android.app.Activity} object.
* @param text
* The text to show. Can be formatted text.
*/
public static void showText(Context context, CharSequence text)
{
Boast.makeText(context, text, Toast.LENGTH_SHORT).show();
}
/**
* Show a standard {@link Boast} that just contains a text view with the
* text from a resource. Duration defaults to {@link #LENGTH_SHORT}.
*
* @param context
* The context to use. Usually your {@link android.app.Application}
* or {@link android.app.Activity} object.
* @param resId
* The resource id of the string resource to use. Can be formatted
* text.
*
* @throws Resources.NotFoundException
* if the resource can't be found.
*/
public static void showText(Context context, int resId)
throws Resources.NotFoundException
{
Boast.makeText(context, resId, Toast.LENGTH_SHORT).show();
}
// ////////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Close the view if it's showing, or don't show it if it isn't showing yet.
* You do not normally have to call this. Normally view will disappear on
* its own after the appropriate duration.
*/
public void cancel()
{
internalToast.cancel();
}
/**
* Show the view for the specified duration. By default, this method cancels
* any current notification to immediately display the new one. For
* conventional {@link Toast#show()} queueing behaviour, use method
* {@link #show(boolean)}.
*
* @see #show(boolean)
*/
public void show()
{
show(true);
}
/**
* Show the view for the specified duration. This method can be used to
* cancel the current notification, or to queue up notifications.
*
* @param cancelCurrent
* <code>true</code> to cancel any current notification and replace
* it with this new one
*
* @see #show()
*/
public void show(boolean cancelCurrent)
{
// cancel current
if (cancelCurrent && (globalBoast != null))
{
globalBoast.cancel();
}
// save an instance of this current notification
globalBoast = this;
internalToast.show();
}
}