on android phones there is a button at the bottom left. this usually opens up a menu. what is the code for this. Its okay to lead me to another post instead of posting a long answer here. sorry Im asking. I understand if there are other posts like this one. I just couldnt seem to find one. ill delete this one when done. Thanks.
Check out the developer guide on menu :) http://developer.android.com/guide/topics/ui/menus.html
To specify the options menu for an activity, override onCreateOptionsMenu() (fragments provide their own onCreateOptionsMenu() callback). In this method, you can inflate your menu resource (defined in XML) into the Menu provided in the callback. For example:
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.game_menu, menu);
return true;
}
To handle click events:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.new_game:
newGame();
return true;
case R.id.help:
showHelp();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
Related
i have three menu items "enable, diable, exit". what i want to do is, when the R.id.menu_enable_bt is chosen, i want to disable it using
menu.findItem(R.id.menu_enable_bt).setVisible(false);
but i can not call
menu.findItem(R.id.menu_enable_bt).setVisible(false);
from inside the onOptionsItemSelected(..) method.
how can i change the visibility of a menu item inside onOptionsItemSelected(..)
CODE:
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
Log.w(TAG, SubTag.msg("onCreateOptionsMenu"));
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
if (this.mBTAdapter.isEnabled()) {
menu.findItem(R.id.menu_enable_bt).setVisible(false);
menu.findItem(R.id.menu_disable_bt).setVisible(true);
} else {
menu.findItem(R.id.menu_enable_bt).setVisible(true);
menu.findItem(R.id.menu_disable_bt).setVisible(false);
}
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
Log.w(TAG, SubTag.msg("onOptionsItemSelected"));
switch (item.getItemId()) {
case R.id.menu_enable_bt:
Log.d(TAG, SubTag.bullet("onOptionsItemSelected", "menu_enable_bt"));
//menu.findItem(R.id.menu_enable_bt).setVisible(false); **how to do this**
this.mATEnableBT = new ATEnableBT();
this.mATEnableBT.execute();
break;
case R.id.menu_disable_bt:
Log.d(TAG, SubTag.bullet("onOptionsItemSelected", "menu_disable_bt"));
break;
case R.id.menu_exit:
Log.d(TAG,SubTag.bullet("onOptionsItemSelected", "menu_exit"));
finish();
break;
}
return super.onOptionsItemSelected(item);
}
you can use invalidateOptionsMenu() which will forse onCreateOptionsMenu to be called again.
From the documentation
Declare that the options menu has changed, so should be recreated. The
onCreateOptionsMenu(Menu) method will be called the next time it needs
to be displayed.
There you can check your conditions and undertake the needed actions
See the javadoc for onPrepareOptionsMenu. This is your opportunity to make changes to a menu just before it becomes visible to the user. So you should maintain some member variables describing what should be visible and use that to modify the menu items here.
I have the below code and I can't understand why my code doesn't show up menu. If the activity containing data, condition_true = true otherwise condition_true = false. I can clearly see the control going to menutag and the condition is true too. Even I am getting Inflated string too in log. But still menu doesn't show up. I have seen lot of posts on these like link 1, link2 etc., but that didn't solve my problem. Can someone please help me on this issue?
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
menu.clear(); //Clear view of previous menu
MenuInflater inflater = getSupportMenuInflater();
Log.d("menutag", condition_true);
if(condition_true)
{
inflater.inflate(R.layout.menu, menu);
Log.d("menutag","Inflated");
}
return super.onPrepareOptionsMenu(menu); // replaced this with true, but no use.
}
You have to add the options attributes in xml.. Otherwise you can do it programmatically like this:
public boolean onCreateOptionsMenu(Menu menu){
getMenuInflater().inflate(R.menu.yourmenuxmlfilename, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item){
switch(item.getItemId){
case R.id.item1:
// what you want to do with first button
break;
case .....
break;
}
return true;
}
Maybe you're overriding onKeyDown and it always returns true? This can cause the problem, because it will catch the menu button pressed event too.
I have the following in my activity (sorry new to Java/Android):
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.options, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch(item.getItemId()) {
case R.id.selectItem:
// menu.add(...) --> how to get the menu instance?
return true;
default:
return super.onOptionsItemSelected(item);
}
}
I am wondering, how can I access a menu object in onOptionsItemSelected? For example, how would I go about adding a new view to the options menu based on the selection of an existing menu item? Is the answer related to "onPrepareOptionsMenu"?
you should use SubMenu for such things ... remeber that you cant add submenu to another submenu ... so only Menu->Submenu is possible you can't do stuff like this Menu->Submenu->Submenu (while Submenu is Dialog with choices)
I am trying to get my webView to move back and forward by calling up the menu. Thus far I have the menu working fine and opening, and the refresh button will refresh the browser. However, I cannot find documentation anywhere about the methods for forward of back. If the default internet browser has them by just pressing the menu key there must be out there. I just can't find them/don't know how to implement them. Any help would be beneficial, thank you.
Here is what I am trying to do:
WebView.Java:
#Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_navigation, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.back_button:
"???"
case R.id.forward_button:
"???"
case R.id.refresh_button:
refreshBrowser();
return true;
}
return false;
}
The part that I'm missing is marked by the three question marks "???". Let me know if you need more information to get some help, and thanks again.
Use webView.canGoBack and webView.canGoForward to check if there is history data to go back / forward and then load that url.
I need to enable a MenuItem when a previous screen (Activity) returns.
I tried this code:
...
((MenuItem)findViewById(R.id.menu_how)).setEnabled(true);
...
but a null pointer exception is launched.
BTW, the menu_how is set to false in xml; and the code is part of onActivityResult(int requestCode, int resultCode, Intent data) call.
Try using menu.findItem(R.id.menu_how) in onCreateOptionsMenu and save a reference for later use.
This should work fine with enabled, however, I've found that setting a menu item to invisible in the XML means you can't show/hide it programmatically.
I found something at the android dev site that might be helpful (look for the section "Changing menu items at runtime")
It said that the onCreateOptionsMenu() method fired only when the the menu for the activity is created, and it happens when this activity starts. So if you want to change the menu items after the menu/activity was created, you need to override the onPrepareOptionsMenu() method instead. search the link for full details.
EDIT:
Just made it and it's working fine. I'm using one boolean var per menuItem which represents if this item should be enabled or not. This is my code:
/*************************************Game Menu**************************************/
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.game_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId())
{
case R.id.gm_new_game:
//newGame();
return true;
case R.id.gm_stand_up:
//some code when "gm_stand_up" button clicked..
return true;
case R.id.gm_forfeit:
//some code when "gm_forfeit" button clicked..
return true;
case R.id.gm_surrender:
//some code when "gm_surrender" button clicked..
return true;
case R.id.gm_exit_table:
exitTableCommand();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
public boolean onPrepareOptionsMenu(Menu menu)
{
menu.findItem(R.id.gm_forfeit).setEnabled(forfeitMenuButtonIsEnabled);
menu.findItem(R.id.gm_surrender).setEnabled(surrenderMenuButtonIsEnabled);
menu.findItem(R.id.gm_new_game).setEnabled(newGameMenuButtonIsEnabled);
menu.findItem(R.id.gm_stand_up).setEnabled(standUpMenuButtonIsEnabled);
return super.onPrepareOptionsMenu(menu);
}
where are you calling this? (Sorry, didn't read carefully) I think you need to call it after the menu is inflated (usually in OnCreateOptionsMenu). To do this, you can set a variable to true when the other Activity returns, then do ((MenuItem)findViewById(R.id.menu_how)).setEnabled(mMyBooleanField) in OnCreateOptionsMenu after the call to inflater.inflate.
Edit: To accomplish this in code, it might look something like this:
At the top of the class (along with all the other class members):
Boolean mEnableMenuItem = false;
In OnCreateOptionsMenu:
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.options_main, menu);
((MenuItem)findViewById(R.id.menu_how)).setEnabled(mEnableMenuItem );
In OnActivityResult:
mEnableMenuItem = true;
Keep a reference to Menu in your activity:
private Menu mMenu;
Then:
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_note, menu);
mMenu = menu;
return true;
}
Now, to access menu items anywhere in your activity use similar code to this:
mMenu.findItem(R.id.menu_how).setVisible(false);
or
mMenu.findItem(R.id.menu_how).setEnabled(true);