How can I use action item as a button in android programming? - java

I have a menu upside my page and it has an action item. like this:
action item
I set app:showAsAction="always" for it.
I have invisible view (in UI) in my page too.
I want to if I click on it, my invisible view appears. so I set a boolean parameter for that.
My boolean set true but my object doesn't appear at all. How can I fix it?
here is my code:
public static boolean myBoolean=false;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//this if doesn't check after change parameter
if(myBoolean)
findViewById(R.id.checkBox).setVisibility(View.VISIBLE);
}
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
switch (id) {
case R.id.action_setting: {
myBoolean=true;
return true;
}}}

What I am getting from this is you want to show a view based on the click of some menu item in action bar right?. if this is true then do like this.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.action_setting:
if(myBoolean){
findViewById(R.id.checkBox).setVisibility(View.GONE);
myBoolean = false;
}else{
findViewById(R.id.checkBox).setVisibility(View.VISIBLE);
myBoolean = true;
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
you can't decide the visibility earlier in your code since click may happen sometime after onCreate() only.

Related

How can I fix the problem that a MenuItem takes on the ID of a previous one

At the beginning I have two items and the 2nd gets a listener with:
final View view = findViewById(R.id.list_item);
if (view != null) {
view.setOnLongClickListener(v -> {
Toast.makeText(getApplicationContext(), "Long pressed", Toast.LENGTH_SHORT).show();
return true;
});
}
}
But if I add a new item with menu.add("name"); the listener is on the newly added item and not on the old one (list_item)
I have already tested many other alternatives, but they don't work!
I just need help on how to keep the item ID or how the listener stays on the item.
When you add an item using ``menu.add(...)` it returns a reference to the newly added item. You can set the listener like this:
final MenuItem newItem = menu.add("New item");
newItem.setOnMenuItemClickListener(menuItem -> {
// Handle your click here!
return true;
});
However, you should add/remove menu items by overriding onPrepareOptionsMenu(Menu menu). When you use menu.add(...) use the overload that allows you to set the itemId:
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
menu.add(Menu.NONE, 314159, Menu.NONE, "New item");
return super.onPrepareOptionsMenu(menu);
}
Note that the above will be called each time the menu is going to be shown (very convenient).
Then you can handle the menu being selected from onOptionsItemSelected:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == 314159) {
// Handle menu selection here!
}
return super.onOptionsItemSelected(item);
}
Check the AppBar/Menu guide here: https://developer.android.com/training/appbar

Disable refresh icon on Menu while content is being refreshed

I have a refresh icon on my menu which when clicked will refresh the contents of the Activity. But the problem is that the refresh icon is still clickable while it is refreshing which I do not want. Here is my menu.xml file
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context=".MainActivity">
<item
android:id="#+id/action_refresh"
android:orderInCategory="100"
android:icon="#mipmap/ic_refresh"
android:enabled="true"
android:title="#string/action_settings"
app:showAsAction="always"/>
And here is where I handle the click event for the icon
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_refresh) {
// getData() fetches the data and updates the display
getData();
return true;
}
return super.onOptionsItemSelected(item);
}
Also, is there a way to maybe dim the icon so that the user knows that they have already clicked the icon?
When you click the icon, use the isEnabled() method of your Menuitem to check if it is currently enabled. If it is, then disable it until the data is loaded. Once the data loads successfully, then you can enable it again. Example:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if(item.isEnabled()) {
// "Dim" the icon like you said. You can use other alpha values if you like.
item.getIcon().setAlpha(130);
// Disable the menu icon
item.setEnabled(false);
}
getData();
return true;
}
return super.onOptionsItemSelected(item);
}
Now, you said that you have a getData() method which updates the display after it fetches the data. Once the data is fetched, check if the Menuitem is disabled. If it is disabled, then enable it again. Example:
if(item != null && item.isEnabled() == false) {
// "Undim" the icon
item.getIcon().setAlpha(255);
// Enable it again
item.setEnabled(true);
}
You can use setEnabled(true) method to enable/disable menu item
You could create a second menu.xml, that is used after the refresh button is clicked. To force a menu redraw call invalidateOptionsMenu();
In this second menu.xml, the refresh button could be disabled, or switched to a diffrent one, indicating the user, that the refresh is on going.
Easiest way to fix this is to hold on to the menu item in your activity.
private MenuItem mRefreshItem;
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater infl = new MenuInflater(this);
infl.inflate(R.menu.menu, menu);
mRefreshItem = menu.findItem(R.id.action_refresh);
return super.onCreateOptionsMenu(menu);
}
/** Call this when you begin or end loading */
private void setRefreshEnabled(boolean enabled) {
mRefreshItem.setEnabled(enabled);
}

How to avoid user clicking few times on the OptionsItemSelected button in Android?

In my Android project user is clicking few times at button so I want to block that button if it's pressed already. Now SaveOrder() method is fired few times which is not acceptable.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.order_save:
Log.d("Custom Synchronization", "Click!");
SaveOrder();
canQuit = true;
hasAcceptQuit = true;
onBackPressed(); // navigate to other acitivty
return true;
case R.id.order_adnotation:
setAdnotationOrder();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
You could use a boolean that starts with false like:
private static boolean hasPressed = false;
And then when calling the SaveOrder method you check for the boolean to be false and change it:
if(!hasPressed) {
SaveOrder();
hasPressed = true;
}
Then, after the execution of the method, you could change the boolean again so the user can call the method again. Be aware that the animation of click will still happen, so consider showing something like a Toast to the user to inform what's going on.

Change Android Action Bar Menu Item's Icon on Click

I'm using sherlock action bar.
I have 2 items on the action bar. When the item is chosen (active), I want to change the icon's image.
This is my code on Java
#Override
public boolean onPrepareOptionsMenu (Menu menu){
MenuInflater inflater = getSupportMenuInflater();
inflater.inflate(R.menu.menutes, menu);
todaySched=menu.findItem(R.id.todaySched);
if(todaySched.isEnabled()){
todaySched.setIcon(R.drawable.calendarselected);
}
return true;
}
but when I do this the icon become double, and the icon won't change neither.
Can someone help?
Use the on onOptionsItemSelected method
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.todaySched:
// put your code here to change the icon
return true;
default:
return super.onOptionsItemSelected(item);
}
}
you may need to include the correct namespace for the ActionBar Sherlock library to ensure it Overrides the correct menu item. So the start of the method will look like this:
#Override
public boolean onOptionsItemSelected(com.actionbarsherlock.view.MenuItem item)

how to override action bar back button in android?

I want to customize the activity back button in action bar, not in hard key back button. I have overriden the onBackPressed() method. It works with my emulator back button, but not with action bar back button.
I want it to happen with action bar. How can I do this?
Here is my code:
#Override
public void onBackPressed() {
Toast.makeText(getApplicationContext(),"Back button clicked", Toast.LENGTH_SHORT).show();
return;
}
I have used this toast whether back pressed is working or not but the actual implementation changes like to move back to previous activity. But this is not working with the button present on top of action bar (besides title of the activity).
Please any one could specify me the problem.
I think you want to override the click operation of home button. You can override this functionality like this in your activity.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
Toast.makeText(getApplicationContext(),"Back button clicked", Toast.LENGTH_SHORT).show();
break;
}
return true;
}
If you want ActionBar back button behave same way as hardware back button:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == android.R.id.home) {
onBackPressed();
return true;
}
return false;
}
Two things to keep in mind that the user can either press back button or press the actionbar home button.
So, if you want to redirect him to the same destination then you can do this.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
}
return false;
}
#Override
public void onBackPressed() {
super.onBackPressed();
Intent intent = new Intent(CurrentActivity.this, NextActivity.class);
startActivity(intent);
finish();
}
This will take the user to the intent pressing either key or the action bar button.
Sorry mine is a late answer, but for anyone else arriving at this page with the same question, I had tried the above:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
...
if (item.getItemId() == android.R.id.home) {
....
}
....
}
but this failed to catch the "Back" button press.
Eventually I found a method that worked for me on https://stackoverflow.com/a/37185334/3697478 which is to override the "onSupportNavigateUp()" as I am using the actionbar from the "AppCompatActivity" support library. (There is an equivalent "onNavigateUp()" for the newer actionbar/toolbar library.)
#Override
public boolean onSupportNavigateUp(){
finish();
return true;
}
and I removed the "android:parentActivityName=".MainActivity" section from the manifest file.
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
finish();
break;
}
return true;
}
(1) Add Parent activity for your child activity (AndroidManifest.xml)
<activity
android:name=".ParentActivity" />
(2) override the onSupportNavigateUp method inside the child activity
#Override
public boolean onSupportNavigateUp() {
onBackPressed();
return false;
}
I have achieved this, by using simply two steps,
Step 1: Go to AndroidManifest.xml and in the add the parameter in tag - android:parentActivityName=".home.HomeActivity"
example :
<activity
android:name=".home.ActivityDetail"
android:parentActivityName=".home.HomeActivity"
android:screenOrientation="portrait" />
Step 2: in ActivityDetail add your action for previous page/activity
example :
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
onBackPressed();
return true;
}
return super.onOptionsItemSelected(item);
}
If you want to return to the previous instance of an Activity by pressing of ActionBar home button, without recreating it, you can override getParentActivityIntent method to use the one from the back stack:
#TargetApi(Build.VERSION_CODES.JELLY_BEAN)
#Override
public Intent getParentActivityIntent() {
return super.getParentActivityIntent().addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
}
EDIT:
Also you can achieve the same result by
setting the launchMode of your parent activity to singleTop.
So setandroid:launchMode="singleTop" to parent activity in your manifest.
Or you can use flag FLAG_ACTIVITY_CLEAR_TOP with the UP intent.
reference: Providing Up Navigation
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == android.R.id.home) {
onBackPressed();
return true;
}
//noinspection SimplifiableIfStatement
if (id == R.id.signIn) {
return true;
}
return super.onOptionsItemSelected(item);
}
///////////////////
#Override
public void onBackPressed() {
super.onBackPressed();
finish();
}
There are several ways how to set up back button in bar:
1) method .setDisplayHomeAsUpEnabled(true); will do it, and then you can simply override android.R.id.home
2) adding <meta-data android:name="android.support.PARENT_ACTIVITY" android:value="my.package.parrent" /> in Android Manifest, but in this case you can not override android.R.id.home in OnOptionsMenuSelected.
.. for those who wonder why it doesn't work for them...

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