How to refresh item in a popup menu? - refresh

i have a popup menu (that comes out when the user uses right click on specified elements), wich items are readed from a list.
I want that when an item is selected, that item is disabled in the popupMenu (then if some action happen it will return enabled).
I have implemented the popupMenu, but i cannot implement this enable/disable JMenuItem element. Anyone can help me? Thanks
class PopupTriggerListener extends MouseAdapter {
public void mousePressed(MouseEvent ev) {
if (ev.isPopupTrigger()) {
menu.show(ev.getComponent(), ev.getX(), ev.getY());
x = ev.getX();
y = ev.getY();
}
}
public void mouseReleased(MouseEvent ev) {
if (ev.isPopupTrigger()) {
menu.show(ev.getComponent(), ev.getX(), ev.getY());
x = ev.getX();
y = ev.getY();
}
}
public void mouseClicked(MouseEvent ev) {
}
}
}
JLabel label = new MyLabel("right-click");
public Test() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JMenuItem item = new JMenuItem("Test1");
item.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("Menu item Test1");
JLabel newLabel = new JLabel("test");
label.add(newLabel);
newLabel.setBounds(x, y, 40, 10);
}
});
menu.add(item);
item = new JMenuItem("Test2");
item.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
System.out.println("Menu item Test2");
}
});
menu.add(item);
getContentPane().add(label);
pack();
setSize(300, 100);
}
public static void main(String[] args) {
new Test().setVisible(true);
}

The way this is mostly done is using Actions. Actions are extensions of the ActionListener interface. You can set the Action of, for example, a JMenuItem and in the Action you can set enabled to false. This will automatically disable the JMenuItem. Alternately you can enable it by setting enabled to true on the Action.
Here is the Action API #Oracle: Action API JAVA
And here is a discourse on how to use Actions: How to use Actions JAVA

Related

ActionBar back button crash my app

I have problem with my school project when I want to back to my CurentCourseActivity using back button form action bar I have NE
Attempt to invoke virtual method 'java.util.List `com.example.pingu.mylanguages.Language.getList()' on a null object reference at
com.example.pingu.mylanguages.CurentCourseActivity.onCreate(CurentCourseActivity.java:37)`
While I use normal back button problem is not appear.
When we choose Lesson from GridView that makes a new activity. When we choose the back button from ActionBar then I have NE.
CourentCourseActivity:
public class CurentCourseActivity extends AppCompatActivity {
private Language language;
#Override
protected void onCreate(Bundle savedInstanceState) {
Log.d("s","onCreate");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_curent_course);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
if (savedInstanceState!=null){
language = (Language) savedInstanceState.getSerializable("Lang");
Log.d("xx","Coś ma");
}
if (getIntent().getExtras() != null) {
language = (Language) getIntent().getSerializableExtra("Lang"); //Obtaining data
}
GridView grid = (GridView) findViewById(R.id.grid);
CurrentCourseAdapter adapter = new CurrentCourseAdapter(this, R.layout.grid_item_curent_course, language.getList());
grid.setAdapter(adapter);
grid.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Intent intent = new Intent(CurentCourseActivity.this,LessonActivity.class);
intent.putExtra("Lesson",(Lesson)language.getList().get(i));
startActivity(intent);
}
});
getSupportActionBar().setTitle(language.getName());
}
}
LessonActivity:
public class LessonActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lesson);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
if(getIntent().getExtras()!=null){
Lesson lesson = (Lesson) getIntent().getSerializableExtra("Lesson");
getSupportActionBar().setTitle(lesson.getNamel());
}
}
}
The answer is simplest then I expect. So I need to overide this button and do it as normal back button because ActrionBar back button destroy parent activity.
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}

Receiving touch events on CardScrollView

I have a CardScrollView that has multiple items in it and I would like to be able to pull up a menu on an item, similar to the built in Timeline.
I know Card cannot have a specific menu attached to it so I have the menu prepared at the Activity level.
However, something seems to be swallowing all onKeyDown events.
public class HostsView extends CardScrollView {
private String TAG = "HostsView";
private HostsCardScrollAdapter cards;
private Activity parent;
public HostsView(Activity parent, HostDatabase hostDb) {
super(parent);
cards = new HostsCardScrollAdapter(parent);
//populates the cards and what not
this.setAdapter(cards);
this.activate();
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
//I never see this log
Log.d(TAG, "Key event " + event.toString());
if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
parent.openOptionsMenu();
return true;
}
return super.onKeyDown(keyCode, event);
}
}
If you only need to handle a simple tap on a card in a CardScrollView, you can call setOnItemClickListener to attach an AdapterView.OnItemClickListener, just as you would with a standard Android ListView. This is typically much simpler than working with GestureDetector for this basic use case.
yesterday I came across the same problem. I solved it with a GestureDetector, as the GDK documentation recommends. Here is the code I used:
private GestureDetector mGestureDetector;
#Override
public void onCreate(Bundle savedInstanceState) {
mGestureDetector = createGestureDetector(this);
}
private GestureDetector createGestureDetector(Context context) {
GestureDetector gestureDetector = new GestureDetector(context);
gestureDetector.setBaseListener( new GestureDetector.BaseListener() {
#Override
public boolean onGesture(Gesture gesture) {
if (gesture == Gesture.LONG_PRESS || gesture == Gesture.TAP) {
Log.d(MainActivity.TAG, "Tap"); //When I tap the touch panel, I only get LONG_PRESS
openOptionsMenu();
return true;
} else if (gesture == Gesture.TWO_TAP) {
return true;
} else if (gesture == Gesture.SWIPE_RIGHT) {
return true;
} else if (gesture == Gesture.SWIPE_LEFT) {
return true;
}
return false;
}
});
return gestureDetector;
}
#Override
public boolean onGenericMotionEvent(MotionEvent event) {
if (mGestureDetector != null) {
return mGestureDetector.onMotionEvent(event);
}
return false;
}
Your menu should open now!

On every button click data is added to listview but in an unexpected manner . Data is repeated in the listview

[Activity]
public class MainActivity : Activity
{
public string[] items = new string[100]; // string to store data from editText
int i =0;
ArrayAdapter<string > adapter;
protected override void OnCreate(Bundle savedInstance)
{
base.OnCreate(savedInstance);
SetContentView(R.Layouts.MainLayout);
var btn1= FindViewById <Button> (R.Ids.btn1);
btn1.Click += AddItem; // calls a function on button click to add data to listview
}
public void AddItem(object sender,EventArgs eventargs)
{
try
{
var et1 = FindViewById <EditText>(R.Ids.et1);
items[i] = et1.Text.ToString();
i++;
view(); //to add data to listview
}
catch(Exception ex)
{
error(ex.ToString());
}
}
public void view ()
{
adapter = new ArrayAdapter<string>(GetApplicationContext(),Android.R.Layout.Simple_list_item_1,items);
ListView listview = FindViewById<ListView>(R.Ids.listview1);
listview.SetAdapter(adapter);
listview.SetTextFilterEnabled(true);
}
}
You should not call view() from AddItem because all code in view is initialization code. Rename it initList or so and call it from OnCreate.
You also don't need items (or i). Just add the string to adapter.
-- EDIT
[Activity]
public class MainActivity : Activity
{
private ArrayAdapter<string> adapter;
protected override void OnCreate(Bundle savedInstance)
{
base.OnCreate(savedInstance);
SetContentView(R.Layouts.MainLayout);
ListView list = FindViewById<ListView>(R.Ids.list);
adapter = new ArrayAdapter<string>(this, Android.R.Layout.Simple_list_item_1);
list.SetAdapter(adapter);
Button button = FindViewById<Button>(R.Ids.button);
button.Click += button_Click;
}
void button_Click(object sender, EventArgs e)
{
EditText text = FindViewById<EditText>(R.Ids.text);
adapter.Add(text.Text.ToString());
}
}

Long click on a list item in GWT

Is there a way in gwt for a long click on a list-item like in a native app for a mobile device.
That is the intuitive click on a smartphone beside the simple click.
I would like to offer a possibility for the user to delete the item.
Something like a longclicklistener...
This has worked for me:
final Timer longpress = new Timer(){
#Override
public void run() {
Window.alert("long press!");
}};
marker.addMouseDownListener(new Marker.MouseDownHandler() {
#Override
public void handle(MouseEvent event) {
longpress.schedule(TIME_LONG_PRESS);
}
});
marker.addMouseUpListener(new Marker.MouseUpHandler() {
#Override
public void handle(MouseEvent event) {
longpress.cancel();
}
});
There is no LongPressListener per se , but you can implement a MouseListener ( http://google-web-toolkit.googlecode.com/svn/javadoc/1.5/com/google/gwt/user/client/ui/MouseListener.html ) and onMouseDown , start a timer , cancel it in onMouseUp(). If the timer expires before it is cancelled , then you have a long click.
Timer t = new Timer() {
public void run() {
//fire long press event.
}
};
new MouseListener(){
public void onMouseDown(Widget sender,int x,int y){
timer.cancel();
timer.schedule(1000);
}
public void onMouseUp(Widget sender,int x,int y){
timer.cancel();
}
}
Take a look at m-gwt ( its a mobile UI Framework for GWT) and it has different GestureRecognizers.
see: http://www.m-gwt.com

how to refresh the linear layout view after deleting an element

I have a simple app, in one activity I take name and date of birth. I store it in the database. and in the main activity I have linearlayout which will show all the names.
When I click on any of the name in the main activity, it should delete that name from the database and also refresh the view.
I am able to delete the entry from database, but my linear layout view is not being updated. Can some one pls help.
public class child extends Activity {
private Intent intent;
private LinearLayout layout;
private LayoutInflater linflater;
private int i =0;
private Cursor cr;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.child);
layout = (LinearLayout)findViewById(R.id.layout);
Button addBtn = (Button)findViewById(R.id.AddButton);
Button remBtn = (Button)findViewById(R.id.RemoveButton);
intent = new Intent(this,login.class);
layout = (LinearLayout) findViewById(R.id.mylayout1);
linflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
//Check the database if there are any entries available. If available, then
//list them on the main screen
final myDBAdapter mydb = new myDBAdapter(getApplicationContext());
mydb.open();
cr = mydb.GetMyData();
if(cr.getCount()>0)
{
cr.moveToFirst();
for (int i=0;i<cr.getCount();i++)
{
cr.moveToPosition(i);
buildList(cr.getString(1),cr.getString(2));
}
}
//Start the login activity which will return the newly added baby name
addBtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
startActivityForResult(intent, 1001);
}
});
//Remove all the entries from Database
remBtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if(cr.getCount()>0)
{
cr.moveToFirst();
for (int i=0;i<cr.getCount();i++)
{
Toast.makeText(getApplicationContext(), cr.getString(1),
Toast.LENGTH_LONG).show();
mydb.RemoveEntry(cr.getString(1));
cr.moveToPosition(i);
}
}
}
});
mydb.close();
}
private void buildList(final String bname,String bsex)
{
final View customView = linflater.inflate(R.layout.child_view,
null);
TextView tv = (TextView) customView.findViewById(R.id.TextView01);
//tv.setId(i);
tv.setText(bname);
tv.setTextColor(getResources().getColor(R.color.black));
tv.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
myDBAdapter mydb = new myDBAdapter(getApplicationContext());
mydb.open();
if (mydb.RemoveEntry(bname)>0)
{
Toast.makeText(getApplicationContext(), "Row deleted",
Toast.LENGTH_LONG).show();
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
WHAT IS REQUIRED HERE TO UPDATE THE VIEW???
//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
}
else
{
Toast.makeText(getApplicationContext(), "Row not deleted",
Toast.LENGTH_LONG).show();
}
}
});
layout.addView(customView);
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data){
if(requestCode == 1001)
{
if(resultCode == RESULT_OK)
{
Bundle extras = data.getExtras();
buildList(extras.getString("bname"),extras.getString("bsex"));
}
}
}
}
Hmm I'm also trying to get this to work, Have you tried looking at maybe refreshing the LinearLayout every say 5 seconds using a game loop? This may prove to be useful as it helped me with my problem http://aubykhan.wordpress.com/2010/04/25/android-game-programming-the-game-loop/
You may also be able to call onCreate(Bundle) function again while this is a terrible terrible way to do this it will work.