I'm new to so and fairly new to android development too, and have already developed some bad habits.
Basically I've coded up an app, using an old learning source as a reference which did not cover fragments. As such I have several standard activities which I am in the process of converting to fragments.
One thing that I have not been able to find information on is the best practices for the action bar; is it best to define the action bar in the activity, or in the fragment?
I notice that calling onCreateOptionsMenu(Menu menu, MenuInflater inflater) results in subtle changes from calling the same method in the activity, would it be possible to have advice on where it is best to call this and what benefits it provides?
Thanks
Yep, this method is a little bit different for fragment:
void onCreateOptionsMenu(Menu menu, MenuInflater inflater)
and activity:
boolean onCreateOptionsMenu(Menu menu)
The logic is quite simple: if you are going to have the same Action Bar (the same number of actions) across all the fragments, it's better to define it in the activity. If Action Bar layout depends on fragment, it's better to define it there.
Related
How to hide 3 dots from Navigation header which comes in the right of header? This could be repeated question. I found few similar questions and their answers but they were for older version of Android. I am using Android sdk 21.
Any idea how to hide that 3 dot button?
Just Remove Override Method like this
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.search_and_add, menu);
return true;
}
This Override Method is responsible to for creating three dote as you mention it's really OptionMenu. If you don't want it, don't override onCreateOptionsMenumethod.
Alternative
Don't Inflate the menu xml. Just block the line like this
//getMenuInflater().inflate(R.menu.search_and_add, menu);
other code can remain same. No problem at all..
Those "3 Dots" are the "Overflow" menu, and is created when you establish a menu using a file in the menu resources directory.
If you have buttons or functionality you are wanting to expose via you action bar, you will need to have the overflow buttons (or instead, you can choose to have your buttons exposed at the top level inside the Action bar.
If you really don't want a menu, get rid of the menu.xml file describing this menu, and then get rid of the onCreateOptionsMenu() from your Activity.
Here are the official docs, which describe how this works.
I think you are speaking about the options menu, to get rid of it remove the override of the method onCreateOptionsMenu
In your menu folder the xmlfile that is used by your activity, change the app:showAsAction="never" to app:showAsAction="always" or some other you can see the options that are availabe by pressing ctrl+space.
Or else to get rid of it completely just remove the whole code and it's corresponding usages.
I'm currently developing an android application, whose target is API19 (min sdk version is set to API14). This app will not run in a mobile phone, but on a custom device.
The screen is not a touch screen, so user interaction will rely on a keyboard, and also I have to mention that this app won't have action bar implemented (I'm currently hidding it).
I'm trying to implement the old style menu behaviour, where you could bring up the menu by pressing the menu button on your device (deprecated since API10), like this:
So, things get complicated when I try to inflate the menu, as android will automatically inflate my menu in the action bar (since API11):
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
QUESTION:
I know it's deprecated, but still I want to implement the menu that way, therefore, is there any way I can force android to inflate this menu "the old way", without lowering my target API ?
Before I ask the question let me give some additional info:
I have a Fragment which adds a MenuItem in the onCreateOptionsMenu. The added MenuItem also has a custom ActionProvider added to it.
The custom ActionProvider doesn't use a ActionView but instead prepares a SubMenu with certain items to choose from. For this reason I've setup the ActionProvider as follows:
I return null in the onCreateActionView method
hasSubMenu() returns true
In onPrepareSubMenu(SubMenu Menu) I first clear the current menu, afterwards add the needed items
I correctly handle the onMenuItemClick in the ActionProvider
Since I'm using ActionBarSherlock, my ActionProvider extends com.actionbarsherlock.view.ActionProvider rather then android.support.v4.view.ActionProvider (don't know if it should make any difference, but at this point I don't know what does)
This all goes well on devices with Android versions higher then 3.0. I see the added MenuItem, it has the correct SubMenu (from the bound ActionProvider) and the correct actions take place for each menu option. But with devices running Android versions below 3.0 (I could only test this on a device running 2.3.6) something weird happens; hence the following question.
Google clearly states:
"onPerformDefaultAction()
The system calls this when the menu item is selected from the action overflow and the action provider should perform a default action for the menu item.
However, if your action provider provides a submenu, through the onPrepareSubMenu() callback, then the submenu appears even when the action provider is placed in the action overflow. Thus, onPerformDefaultAction() is never called when there is a submenu."
Taken from: http://developer.android.com/guide/topics/ui/actionbar.html#CreatingActionProvider
From the excerpt I take it onPerformDefaultAction() should NEVER be called in my custom ActionProvider. Yet on devices running Android version 2.3.6 the onPerformDefaultAction() DOES get called, which also prevents the SubMenu from showing.
My question is; why does the onPerformDefaultAction() gets called instead of the onPrepareSubMenu(SubMenu Menu)? I need a submenu on devices running Android 2.3.6 as well..
EDIT:
I managed to fix my problem using the same technique from the SubMenus.java from the ActionbarSherlock demo-code. This involves adding a SubMenu instead of a custom ActionProvider to the menu in onCreateOptionsMenu(Menu menu), and attaching OnMenuItemClickListener to each MenuItem there.
The workaround is nice and simple. Still, this does not answer my question as to why custom ActionProviders do not work.
I want to make Option Menu for Android, I have visit this site. In their script, I found onPrepareOptionsMenu, I try to compile and run using Android 2.3.3 compiler with and without onPrepareOptionsMenu, both works, but I didn't see any difference.
public boolean onCreateOptionsMenu(Menu menu){
//code here
}
public boolean onOptionsItemSelected(MenuItem item){
//code here
}
public boolean onPrepareOptionsMenu(Menu menu){
//code here
}
What is actually onPrepareOptionsMenu method do? Is that method important? Could I just delete the method?
Addition
Oh, I also hear about Action Bar in Android 3.0, it says that Action Bar is the alternative way for make Option Menu, and it using onPrepareOptionsMenu. Is that right?
Thank you...
Take a look in the API:
Prepare the Screen's standard options menu to be displayed. This is called right before the menu is shown, every time it is shown. You can use this method to efficiently enable/disable items or otherwise dynamically modify the contents.
If you want to alter the menu before it's shown to the user, you can put code to do that into onPrepareOptionsMenu. I've used that dynamically to disable some menu options in some circumstances.
As an example of when one might want to disable a menu option, I had an app where there was a way of specifying a destination. One of my menu options was to calculate a route to the destination. However, if a destination wasn't specified, that option didn't apply, so I used onPrepareOptionsMenu to disable that menu option when it wasn't applicable.
From Android 3.0 and beyond, there's the ActionBar, which is a menu bar. The most important items go into the ActionBar itself, but then there's an overflow for when there's not enough room on the action bar. One can specify that menu items should always be in the overflow menu and never on the action bar itself. On some devices, the action bar overflow corresponds to the permanent menu button on the device, whereas on other devices which don't have a menu button the overflow menu is seen on the right hand side of the action bar as three vertical dots.
onCreateOptionsMenu is called once, when your activity is first created. If it returns false, no option menu is shown and onPrepareOptionsMenu is never called.
If onCreateOptionsMenu returns true, onPrepareOptionsMenu is also called before the activity is displayed, and also every time the options menu is invalidated. Use onPrepareOptionsMenu if you need to enable/disable, show/hide, or add/remove items after creating it.
If your menu does not change, use onCreateOptionsMenu.
example
#Override
public void onPrepareOptionsMenu(#NonNull Menu menu) {
super.onPrepareOptionsMenu(menu);
if(!URLUtil.isValidUrl(news.geturl())){
menu.findItem(R.id.share).setVisible(false);
}
}
I'm having Sherlock Action Bar to show several icons in the Action Bar, like sharing, info, etc.
The thing is that I want to delete, for certain activities/fragments one of the buttons (sharing), but I can't do it.
My activity (StartActivity) extends from InfoActivity, which is the one that implements the onCreateOptionsMenu.
I tried to override the onCreateOptionsMenu method and do a clear() but it doesn't work:
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
}
Any ideas on how to do this?
Thanks a lot in advance.
Find the menu item in question and disable or hide it. Something like this in onCreateOptionsMenu() or onPrepareOptionsMenu() if you want to make it dynamic:
menu.findItem(R.id.menu_share).setVisible(false);
What I did in the end, was creating different classes: one with the Sharing button in the menu as a button, and one without, and just making the proper activity extend from the appropriate class.
For example, StartActivity, I don't want it to have sharing capabilities, so I made it extend from an Activity without the sharing button.
Thanks #NikolayElenkov for your help!