Develop Reference

Not able to create buttons dynamically

I have an overlay on my screen which will show some buttons to control the feature. This overlay will have a dynamic list of buttons which will be created based on the number of steps. Example if steps are 3 then 3 button will get created. I have created a LinearLayout inside this buttons will get created. I have created a method which will set all the button attributes, but somehow it's giving me null pointer exception.
In onCreateView I have initialize the buttonArray.
Here is my fragment:
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
mContext = getActivity();
gc = GlobalClass.getInstance(mContext);
db = DataBaseHelper.getInstance(mContext);
sectionButtons = new Button[3];
/*if(savedInstanceState!=null)
mVisible = savedInstanceState.getBoolean("visible",false);*/
manager = SharedPreferenceManager.getInstance(mContext);
//check wether to play video in cover mode or another mode
inflater.inflate(R.layout.fragment_video_side_by_side, container, false);
}
and onViewCreated() I am calling my method addSections():
// show overlay with buttons in onTouch
parentLayout.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
if (!mVisible) {
overLay.setVisibility(View.VISIBLE);
addSections(3);
mVisible = true;
} else {
overLay.setVisibility(View.GONE);
mVisible = false;
}
}
return true;
}
});
Method:
public void addSections(int numOfSection){
if(numOfSection==0)
return;
else {
for (int i = 0; i < numOfSection; i++) {
//set the properties for button
sectionButtons[i].setLayoutParams(new LinearLayout.LayoutParams(50, 50));
sectionButtons[i].setBackgroundResource(R.drawable.round_button);
sectionButtons[i].setText("Section "+i+"");
sectionButtons[i].setId(i);
//add button to the layout
mSectionLayout.addView(sectionButtons[i]);
}
}
}
mSectionLayout is my parent LinearLayout. While debugging I found my sectionButtons is not showing null but while setting the attributes it's throwing nullPointer exception.

Create Dynamic Buttons and attach with the Layout
You can easily create the dynamic button by the following way:
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout layout = (LinearLayout) findViewById(R.id.layout);
TextView textView = new TextView(this);
textView.setText("Text View ");
LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT
);
layout.addView(textView, p);
Button buttonView = new Button(this);
buttonView.setText("Button");
buttonView.setOnClickListener(mThisButtonListener);
layout.addView(buttonView, p);
}
private OnClickListener mThisButtonListener = new OnClickListener() {
public void onClick(View v) {
Toast.makeText(MainActivity.this, "Hello !",
Toast.LENGTH_LONG).show();
}
};
}
Using this code, you easily generate a list of buttons on the layout.
Happy coding

Android - Popup window is not closing

I want to close the popup window when I click a button, but it seems dismiss function doesn't work and the window is not closing. What did I wrong?
(I'm a beginner, so codes might be 'weird'. Please understand...)
public class AlarmPopup extends Activity {
private PopupWindow popup;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
onShowPopup();
}
public void onShowPopup(){
LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View view = inflater.inflate(R.layout.alarm_popup, null, false);
final PopupWindow popup = new PopupWindow(view, 400, 300, true);
setContentView(R.layout.alarm_popup);
view.findViewById(R.id.button).post(new Runnable() {
#Override
public void run() {
popup.showAtLocation(view, Gravity.CENTER, 0, 0);
}
});
findViewById(R.id.button).setOnClickListener(mClickListener);
}
Button.OnClickListener mClickListener = new View.OnClickListener() {
#Override
public void onClick(View v) { // dismiss and stop the alarm function on other class
Intent i = new Intent(AlarmPopup.this, AlarmService.class);
stopService(i); // this function is working...
popup.dismiss();
}
};
}

You have declared popup as global and inside your onShowPopup you are creating new object for popup so that local popup will never be accessible from listener so make the changes as below:
public void onShowPopup(){
LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
final View view = inflater.inflate(R.layout.alarm_popup, null, false);
popup = new PopupWindow(view, 400, 300, true);
setContentView(R.layout.alarm_popup);
view.findViewById(R.id.button).post(new Runnable() {
#Override
public void run() {
popup.showAtLocation(view, Gravity.CENTER, 0, 0);
}
});
view.findViewById(R.id.button).setOnClickListener(mClickListener);
}

Popup variable that you are using to dismiss your popup window has not been initialized in the code that you have posted. Your final variable that you have created inside method is local and will not be accessible outside that method.
So initialize your variable or use same variable inside method too.

Non responding app in "Recent Apps" when PopUpMenu and Edit Text Present

Context
I'm working with popupwindows to allow a user to quickly rename a cardview in an activity.
I do this by using a ViewSwitcher to swap the TextView (original name) for an EditText(new name).
Problem
When the EditText and PopUpWindow to confirm are present an the user presses "RECENT APPS", you cannot for some reason get back into the app. ie. when you click it, it won't respond.
Diagnosis
I think it's an issue with Window Focus. I've tried EditText.clearFocus() from ET and dismissing all PopUps onPause, no luck.
Is there a way to use onFocusChangeListener to remove this issue?
Code (I've tried to remove as much superfluous items as possible)
TheHubActivity.java
public class TheHubActivity extends AppCompatActivity implements RecyclerViewAdapter.onCardClickListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
// KEYBOARD
imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
//... Set up recycle view
rvContent = new ArrayList<>();
}
#Override
public void onCardLongClick(Flow longClickedFlow, int cardPosition, View cardViewClicked) {
showLongClickPopUpMenu(longClickedFlow,cardPosition, cardViewClicked);
}
private void showLongClickPopUpMenu(final Flow longClickedFlow, final int cardPosition, final View cardViewClicked) {
LayoutInflater layoutInflater = (LayoutInflater) this
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = layoutInflater.inflate(R.layout.popup_window_longclick, null);
LinearLayout viewGroup = (LinearLayout) layout.findViewById(R.id.popup_longclick);
// Creating the PopupWindow
final PopupWindow popup = new PopupWindow(layout, RecyclerView.LayoutParams.WRAP_CONTENT,
RecyclerView.LayoutParams.WRAP_CONTENT);
popup.setFocusable(true);
// Getting a reference to Close button, and close the popup when clicked.
ImageView delete = (ImageView) layout.findViewById(R.id.popup_delete_item);
delete.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
/*.... Delete current Flow from internal file and UI */
popup.dismiss();
}
});
ImageView edit = (ImageView) layout.findViewById(R.id.popup_edit_item);
edit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
popup.dismiss();
renameFlow(cardPosition, cardViewClicked);
}
});
// Displaying the popup at the specified location, + offsets.
popup.showAsDropDown(cardViewClicked, cardViewClicked.getMeasuredWidth(),popupDisplayHeight, Gravity.TOP);
longClickPopup = popup;
}
private void renameFlow(final int cardPosition, final View cardViewClicked) {
final ViewSwitcher switcher = (ViewSwitcher) cardViewClicked.findViewById(R.id.rename_switcher);
final EditText rename = (EditText) switcher.findViewById(R.id.item_flow_rename);
rename.setOnFocusChangeListener(new View.OnFocusChangeListener() {
#Override
public void onFocusChange(View v, boolean hasFocus) {
if (rename.hasFocus()) {
showEditPopupWindow(rename, cardViewClicked, switcher, cardPosition);
} else {
imm.hideSoftInputFromWindow(rename.getWindowToken(), 0);
}
}
});
switcher.showNext();
rename.requestFocus();
imm.toggleSoftInput(InputMethodManager.SHOW_IMPLICIT, InputMethodManager.HIDE_IMPLICIT_ONLY);
/* Forces keyboard */
}
private void showEditPopupWindow(final EditText newName, View cardViewClicked, final ViewSwitcher switcher, final int cardPosition) {
LayoutInflater layoutInflater = (LayoutInflater) this
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View layout = layoutInflater.inflate(R.layout.popup_window_editing, null);
LinearLayout viewGroup = (LinearLayout) layout.findViewById(R.id.popup_editing);
// Creating the PopupWindow
final PopupWindow popup = new PopupWindow(layout, RecyclerView.LayoutParams.WRAP_CONTENT,
RecyclerView.LayoutParams.WRAP_CONTENT);
popup.setFocusable(false); // So that user can edit text
// Getting a reference to Close button, and close the popup when clicked.
ImageView confirmEdit = (ImageView) layout.findViewById(R.id.popup_confirm_item_changes);
confirmEdit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
/* .. Changes name of cardview through edit text */
switcher.showNext();
popup.dismiss();
newName.clearFocus();
}
}
});
ImageView cancelEdit = (ImageView) layout.findViewById(R.id.popup_cancel_item_changes);
cancelEdit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
switcher.showNext();
popup.dismiss();
}
});
popup.showAsDropDown(cardViewClicked, cardViewClicked.getMeasuredWidth(),popupDisplayHeight, Gravity.TOP);
editingPopup = popup;
}
#Override
protected void onPause() {
dismissPopups();
super.onPause();
}
private void dismissPopups() {
if (longClickPopup!=null && longClickPopup.isShowing()) {
longClickPopup.dismiss();
}
if (editingPopup!=null && editingPopup.isShowing()) {
editingPopup.dismiss();
}
}
}
For Visual People

I solved the issue... and it was surprisingly larger and completely unrelated to the Focus/PopUps (tunnel vision does that I guess).
In my Manifest I was using android:launchMode="singleTop" which was creating weird behaviour when TheHubActivity was sent to recent apps because this was my entrance activity. From the Developer Docs singleTop functions like so:
Similarly, a new instance of a "singleTop" activity may also be created to handle a new intent. However, if the target task already has an existing instance of the activity at the top of its stack, that instance will receive the new intent (in an onNewIntent() call); a new instance is not created. In other circumstances — for example, if an existing instance of the "singleTop" activity is in the target task, but not at the top of the stack, or if it's at the top of a stack, but not in the target task — a new instance would be created and pushed on the stack.
<activity
android:name=".TheHubActivity"
android:label="#string/app_name"
~~~~~~android:launchMode="singleTop"~~~~~~~~
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

Dynamically add LinearLayout into LinearLayout

I have a issue trying to dynamically add some linear layout into a linearlayout container after user have clicked on a button.
private void AddView() {
MyView myView1 = new MyView("Name");
this.mainLinearLayout.addView(myView1);
}
This code works great in activity's onCreate method but not after handling user event.
Do you have any idea why it's not working ? (I mean nothing appears on UI)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
AddView(); => works great
}
playButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
AddView(); => not working
}
});
Thanks,

I think that AddView is wrong.
private void addView() {
LayoutParams lparams = new LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
MyView myView1 = new MyView("Name");
myView1.setLayoutParams(lparams);
this.mainLinearLayout.addView(myView1);
}

How to create a popup window (PopupWindow) in Android

To create a simple working PopupWindow, we need to do the following:
popup_example.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:padding="10dip"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dip"
android:text="Test Pop-Up" />
</LinearLayout>
Java code
LayoutInflater inflater = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
PopupWindow pw = new PopupWindow(inflater.inflate(R.layout.popup_example, null, false),100,100, true);
pw.showAtLocation(this.findViewById(R.id.main), Gravity.CENTER, 0, 0);
My requirement is that I need a
<TEXTVIEW android:layout_height="wrap_content" android:layout_width="fill_parent" />
and a
<BUTTON android:id="#+id/end_data_send_button" android:text="Cancel"/>
in my popup_example.xml. How can I handle these two components in my Java code?

How to make a simple Android popup window
This is a fuller example. It is a supplemental answer that deals with creating a popup window in general and not necessarily the specific details of the OP's problem. (The OP asks for a cancel button, but this is not necessary because the user can click anywhere on the screen to cancel it.) It will look like the following image.
Make a layout for the popup window
Add a layout file to res/layout that defines what the popup window will look like.
popup_window.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#62def8">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:layout_margin="30dp"
android:textSize="22sp"
android:text="This is a popup window."/>
</RelativeLayout>
Inflate and show the popup window
Here is the code for the main activity of our example. Whenever the button is clicked, the popup window is inflated and shown over the activity. Touching anywhere on the screen dismisses the popup window.
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void onButtonShowPopupWindowClick(View view) {
// inflate the layout of the popup window
LayoutInflater inflater = (LayoutInflater)
getSystemService(LAYOUT_INFLATER_SERVICE);
View popupView = inflater.inflate(R.layout.popup_window, null);
// create the popup window
int width = LinearLayout.LayoutParams.WRAP_CONTENT;
int height = LinearLayout.LayoutParams.WRAP_CONTENT;
boolean focusable = true; // lets taps outside the popup also dismiss it
final PopupWindow popupWindow = new PopupWindow(popupView, width, height, focusable);
// show the popup window
// which view you pass in doesn't matter, it is only used for the window tolken
popupWindow.showAtLocation(view, Gravity.CENTER, 0, 0);
// dismiss the popup window when touched
popupView.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
popupWindow.dismiss();
return true;
}
});
}
}
That's it. You're finished.
Going on
Check out how gravity values effect PopupWindow.
You can also add a shadow.
Further study
These were also helpful in learning how to make a popup window:
PopupWindow documentation
How To Create Pop Up Window In Android (YouTube video)
Android Popup Window Example

Here, I am giving you a demo example. See this and customize it according to your need.
public class ShowPopUp extends Activity {
PopupWindow popUp;
boolean click = true;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
popUp = new PopupWindow(this);
LinearLayout layout = new LinearLayout(this);
LinearLayout mainLayout = new LinearLayout(this);
TextView tv = new TextView(this);
Button but = new Button(this);
but.setText("Click Me");
but.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if (click) {
popUp.showAtLocation(layout, Gravity.BOTTOM, 10, 10);
popUp.update(50, 50, 300, 80);
click = false;
} else {
popUp.dismiss();
click = true;
}
}
});
LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT,
LayoutParams.WRAP_CONTENT);
layout.setOrientation(LinearLayout.VERTICAL);
tv.setText("Hi this is a sample text for popup window");
layout.addView(tv, params);
popUp.setContentView(layout);
// popUp.showAtLocation(layout, Gravity.BOTTOM, 10, 10);
mainLayout.addView(but, params);
setContentView(mainLayout);
}
}
Hope this will solve your issue.

are you done with the layout inflating? maybe you can try this!!
View myPoppyView = pw.getContentView();
Button myBelovedButton = (Button)myPoppyView.findViewById(R.id.my_beloved_button);
//do something with my beloved button? :p

I construct my own class, and then call it from my activity, overriding small methods like showAtLocation. I've found its easier when I have 4 to 5 popups in my activity to do this.
public class ToggleValues implements OnClickListener{
private View pView;
private LayoutInflater inflater;
private PopupWindow pop;
private Button one, two, three, four, five, six, seven, eight, nine, blank;
private ImageButton eraser;
private int selected = 1;
private Animation appear;
public ToggleValues(int id, Context c, int screenHeight){
inflater = (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
pop = new PopupWindow(inflater.inflate(id, null, false), 265, (int)(screenHeight * 0.45), true);
pop.setBackgroundDrawable(c.getResources().getDrawable(R.drawable.alpha_0));
pView = pop.getContentView();
appear = AnimationUtils.loadAnimation(c, R.anim.appear);
one = (Button) pView.findViewById(R.id.one);
one.setOnClickListener(this);
two = (Button) pView.findViewById(R.id.two);
two.setOnClickListener(this);
three = (Button) pView.findViewById(R.id.three);
three.setOnClickListener(this);
four = (Button) pView.findViewById(R.id.four);
four.setOnClickListener(this);
five = (Button) pView.findViewById(R.id.five);
five.setOnClickListener(this);
six = (Button) pView.findViewById(R.id.six);
six.setOnClickListener(this);
seven = (Button) pView.findViewById(R.id.seven);
seven.setOnClickListener(this);
eight = (Button) pView.findViewById(R.id.eight);
eight.setOnClickListener(this);
nine = (Button) pView.findViewById(R.id.nine);
nine.setOnClickListener(this);
blank = (Button) pView.findViewById(R.id.blank_Selection);
blank.setOnClickListener(this);
eraser = (ImageButton) pView.findViewById(R.id.eraser);
eraser.setOnClickListener(this);
}
public void showAtLocation(View v) {
pop.showAtLocation(v, Gravity.BOTTOM | Gravity.LEFT, 40, 40);
pView.startAnimation(appear);
}
public void dismiss(){
pop.dismiss();
}
public boolean isShowing() {
if(pop.isShowing()){
return true;
}else{
return false;
}
}
public int getSelected(){
return selected;
}
public void onClick(View arg0) {
if(arg0 == one){
Sudo.setToggleNum(1);
}else if(arg0 == two){
Sudo.setToggleNum(2);
}else if(arg0 == three){
Sudo.setToggleNum(3);
}else if(arg0 == four){
Sudo.setToggleNum(4);
}else if(arg0 == five){
Sudo.setToggleNum(5);
}else if(arg0 == six){
Sudo.setToggleNum(6);
}else if(arg0 == seven){
Sudo.setToggleNum(7);
}else if(arg0 == eight){
Sudo.setToggleNum(8);
}else if(arg0 == nine){
Sudo.setToggleNum(9);
}else if(arg0 == blank){
Sudo.setToggleNum(0);
}else if(arg0 == eraser){
Sudo.setToggleNum(-1);
}
this.dismiss();
}
}

Button endDataSendButton = (Button)findViewById(R.id.end_data_send_button);
Similarly you can get the text view by adding a id to it.

LayoutInflater inflater = (LayoutInflater) SettingActivity.this.getSystemService(SettingActivity.LAYOUT_INFLATER_SERVICE);
PopupWindow pw = new PopupWindow(inflater.inflate(R.layout.gd_quick_action_slide_fontsize, null),LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT, true);
pw.showAtLocation(SettingActivity.this.findViewById(R.id.setting_fontsize), Gravity.CENTER, 0, 0);
View v= pw.getContentView();
TextView tv=v.findViewById(R.id.....);

This an example from my code how to address a widget(button) in popupwindow
View v=LayoutInflater.from(getContext()).inflate(R.layout.popupwindow, null, false);
final PopupWindow pw = new PopupWindow(v,500,500, true);
final Button button = rootView.findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
pw.showAtLocation(rootView.findViewById(R.id.constraintLayout), Gravity.CENTER, 0, 0);
}
});
final Button popup_btn=v.findViewById(R.id.popupbutton);
popup_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
popup_btn.setBackgroundColor(Color.RED);
}
});
Hope this help you

Edit your style.xml with:
<style name="AppTheme" parent="Base.V21.Theme.AppCompat.Light.Dialog">
Base.V21.Theme.AppCompat.Light.Dialog provides a android poup-up theme