There is a listener code.
Method onCreate:
rssListView.getViewTreeObserver().addOnGlobalLayoutListener(
new ViewTreeObserver.OnGlobalLayoutListener() {
public void onGlobalLayout() {
//Then it stops
rssListView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
}
);
I want to run it again, when the button clicked:
b1.setOnClickListener(
new View.OnClickListener() {
// #Override
public void onClick(View v) {
// ...
}
}
);
Tell me how I can activate the listener on the button?
I think you talking about Pull-to-Refresh functionality. If yes - look at this article.
What is it you want to run again.
If you want the function to be called on button click then do the function call in the onClick method of the listener. Once a listener is added to a UI Widget it keeps on listening to any UI Events on that object till the application is running.
Related
I have successfully implemented a custom Dialog box that appears when the user tries to leave an activity via a back button or by using onBackPressed(). They can simply cancel the dialog box or continue, and leave the activity. This function has been implemented in multiple activities, however its making my code a lot longer than it needs to be. I wanted to know how to create a util that can be referenced in different activities, without the need for the chunk of code to copy pasted multiple times. Please note that I am retrieving the dialog title and description from string.xml
This is my code:
Dialog customDialog;
Button button_one, button_two;
TextView dialog_title, dialog_description;
customDialog = new Dialog(this);
//Back button will close app
#Override
public void onBackPressed() {
customDialog.setContentView(R.layout.custom_dialog_box);
dialog_title = customDialog.findViewById(R.id.dialog_title);
dialog_title.setText(getString(R.string.leaving_activity_warning_title));
dialog_description = customDialog.findViewById(R.id.dialog_description); dialog_description.setText(getString(R.string.leaving_activity_warning_description));
button_one = customDialog.findViewById(R.id.button_one);
button_one.setText(getString(R.string.cancel));
button_two = customDialog.findViewById(R.id.button_two);
button_two.setText(getString(R.string.leave_anyway));
button_one.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
customDialog.dismiss();
}
});
button_two.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
customDialog.dismiss();
finish();
overridePendingTransition(R.anim.slide_in_left, R.anim.slide_out_right);
}
});
Objects.requireNonNull(customDialog.getWindow()).setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
customDialog.show();
}
UPDATE
Created a Java file called "DialogBoxMessage"
DialogBoxMessage Code:
class DialogBoxMessage {
private Dialog customDialog;
private TextView dialog_title, dialog_description;
private Button button_one, button_two;
//Custom Dialog Box Initialization
DialogBoxMessage(Button myButtonOne, TextView myDialogTitle, TextView myDialogDescription, Dialog myCustomDialog) {
customDialog = myCustomDialog;
button_one = myButtonOne;
button_two = myButtonOne;
dialog_title = myDialogTitle;
dialog_description = myDialogDescription;
}
void leaveActivity() {
customDialog.setContentView(R.layout.custom_dialog_box);
dialog_title = customDialog.findViewById(R.id.dialog_title);
dialog_title.setText(Resources.getSystem().getString(R.string.leaving_activity_warning_title));
dialog_description = customDialog.findViewById(R.id.dialog_description);
dialog_description.setText(Resources.getSystem().getString(R.string.leaving_activity_warning_description));
button_one = customDialog.findViewById(R.id.button_one);
button_one.setText(Resources.getSystem().getString(R.string.cancel));
button_two = customDialog.findViewById(R.id.button_two);
button_two.setText(Resources.getSystem().getString(R.string.leave_anyway));
button_one.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
customDialog.dismiss();
}
});
button_two.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
customDialog.dismiss();
}
});
Objects.requireNonNull(customDialog.getWindow()).setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
customDialog.show();
}
}
I input the following code in another activity
Other activity code:
//Reusable exit dialog message
DialogBoxMessage dialogBoxMessage;
//Back button will close app
#Override
public void onBackPressed() {
dialogBoxMessage.leaveActivity();
finish();
}
But it doesn't seem to work, I think there are a lot of issues... please help :(
I assume customDialog is a seperate class you wrote - therefore i would suggest you put main information like contentview, title, message or type in the constructor when you initialize ur Dialog.
For your onClick Method I suggest you create an Interface to handle Button Clicks in your
customDialog class.
This could be implemented as a static method in a utilities class. The method would require 'this' as a parameter, which contains the activity context. The method should return the result of the button press. The activity can use this response to determine if finish() should be called or not.
UPDATE
I had suggested a simple static method, but you've gone down the object-oriented route. That's fine.
However, your constructor requires passing in several views, which wouldn't appear to achieve the code efficiency you are after.
Your constructor should just require the Activity context; everything else is encapsulated in your new class.
In each Activity's onBackPressed method you will need to create the object with
dialogBoxMessage = new DialogBoxMessage(this);
before you can call any of that object's methods.
I wanted to know if its possible to have two onclick methods for one buttton..Im trying to have a button that can open a new activity and send a id token to the server for firebase purposes, if possible how do i go about it on android studio
I think you are getting the underlying concept wrong.
Buttons react to clicks.
The "ActionListener" that gets triggered on that click ... can do whatever it wants. There is nothing (conceptually) that prevents you in your code to just trigger various things. Of course, you have to understand what you are doing (things like: not blocking the UI thread for too long; or how to kick of things in background threads, and so on).
No. There is only one onClick method for a Button. But you can still perform two different purposes by one button.
I am using a button to hide and show a linear layout. The code is given below :
final int[] count = {2};
//here startTopics is the button....
startTopics.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(count[0] %2==0)
{
topicLin.setVisibility(View.VISIBLE);
count[0]++;
}
else
{
topicLin.setVisibility(View.GONE);
//here topicLin is the linear layout
count[0]++;
}
}
});
It is one button and so you should apply only one onClick listener which performs the buttons job.
In your onClick-method you can just call another (private) method if you want to do multiple things without sacrificing code management.
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
sendTokenToServer();
// Include your code to open the activity here or outsource it again into another private method
}
});
And your method to send the token to the server:
private void sendTokenToServer() {
// Your code here.
}
I've found numerous tutorials on how to accomplish this when you can grab the textview from the xml but nothing on how to implement such a function when you have multiple edit texts created programmatically that all need the same functionality.
After you create the EditText, you would add a click listener the same way you would to any other view. You may also need to disable the focusable attribute to prevent clicks from activating the keyboard:
editText.setFocusable(false);
editText.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
// Open dialog here
}
});
If you have all EditText's, simply create one OnClickListener, call setOnClickListener on every EditText and pass the OnClickListener Object.
View.OnClickListener listener = new View.OnClickListener() {
#Override
public void onClick(View v) {
//open dialog here;
}
};
editText1.setOnClickListener(listener);
editText2.setOnClickListener(listener);
You should maybe store the EditText's in an array, so that you can just loop through all of them.
I am trying to implement simple back button on activity to go to previous activity, but some weird behavior is happening when I am calling method finish() - the problem is I have to press back button TWO times? Why is this happening? In the back method i have only finish(). What is the other way to go to previous saved activity without instantiate a completely new Intent?
public void back1 (View view){
this.finish();
}
This is second try with the same result:
ImageButton buttonback = (ImageButton) findViewById(R.id.imageButton6);
buttonback.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
onBackPressed();
}
});
You are most likely starting the activity twice.
When pressing back you are finishing one, and the other one is coming forward. Check your onCreate and onResume for anything that may be using intents or starting any activity
#Override
public void onBackPressed() {
super.onBackPressed();
}
add that to your code the super call closes the activity no need to call finish()
If you just want the devices back button to function, you dont need to override the onBackPressed method in Activity.
If you want to place a custom button in view and set back action to that button, then you need to write button clicklistener to the same
backbutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
finish();
}
});
I don't know whether this question get minus points, but I searched every where and my last resort is stackoverflow.
I need to add five buttons to notification area in horizontally. And each button I need to add even listener. I know it is possible to do with RemoteViews. But I never seen anyone adding event listener to each element.
These are the references if anyone need to refer.
Notifications Documentation
How to create a custom notification on android
SlidingDrawer API
You can add 5 anonymous listeners, or a single named listener.
Anonymous:
Button b1 = new Button(...);
b1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// first listener's code goes here
}
});
Button b2 = new Button(...);
b2.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// second listener's code goes here
}
});
...
named is much the same, but contains a switch statement to differentiate what happens:
View.OnClickListener myListener = new View.OnClickListener() {
public void onClick(View v) {
String buttonTitle = ((Button)v).getText();
if ("title1".equals(buttonTitle)) {
// do things for the first button's click
} else if ("title2".equals(buttonTitle)) {
// do things for the second button's click
}
...
}
});
...