[android-beginners] Re: Assistance with understanding LunarLander code
Hi,
At what point does the surfaceCreated() method fire? I presume its
after we add the callback interface with addCallback?
On Dec 12, 5:19 pm, RichardS richardswingw...@googlemail.com wrote:
Steve,
This is my understanding of it:
The file res/layout/lunar_layout.xml describes the layout of the view.
The src/R.java file is auto generated: it equates object ids to names.
setContentView(R.layout.lunar_layout)
'reads' lunar_layout.xml file and creates and instance of the
LunarView class and hence the View itself.
If you look in the XML file it contains an Id string @+id/lunar:
this is one of the ids that R.java
defines a name for - in this case R.id.lunar.
mLunarView = (LunarView) findViewById(R.id.lunar)
searches all view for the one identified by R.id.lunar ( == @+id/
lunar). This returns a reference to
the LunaView instance created above which we store in a member
variable.
The constructor for LunarView created a private LunarThread object so
doing:
mLunarThread = mLunarView.getThread()
enables us to retrieve a reference to the thread object.
Hope that's correct and helpful!
richard.
On 12 Dec, 15:49, steve_macleod steven_macl...@hotmail.com wrote:
Hi,
I have been working through the lunarlander example application, in
an
attempt to understand the source code. I have run into a couple of
problems, and would really appreciate if someone could space a couple
of minutes to assist in may understanding.
The onCreate method contains the following:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// turn off the window's title bar
requestWindowFeature(Window.FEATURE_NO_TITLE);
// tell system to use the layout defined in our XML file
setContentView(R.layout.lunar_layout);
// get handles to the LunarView from XML, and its LunarThread
mLunarView = (LunarView) findViewById(R.id.lunar);
mLunarThread = mLunarView.getThread();
// give the LunarView a handle to the TextView used for
messages
mLunarView.setTextView((TextView) findViewById(R.id.text));
if (savedInstanceState == null) {
// we were just launched: set up a new game
mLunarThread.setState(LunarThread.STATE_READY);
Log.w(this.getClass().getName(), SIS is null);
} else {
// we are being restored: resume a previous game
mLunarThread.restoreState(savedInstanceState);
Log.w(this.getClass().getName(), SIS is nonnull);
}
}
I can see that we are performing the following:
Turn off the title bar in the window
Set the activity content to the lunar_layour layout file
gets a reference to the 'lunar' layout
gets a reference to the thread member of the LunarView class
give the LunarView a reference to the textview for game
messages
we then set the state of the lunar thread to STATE_READY,
which also
outputs a bunch of status messages
The problem is that after executution of setState, the code seems to
end. I can see no sections of code that actually creates the
LunarView
or LunarThread objects, which are required to start the game proper.
Obviously I am missing something here, I was wondering if anyone
could
assist! Thanks lots!- Hide quoted text -
- Show quoted text -
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[android-beginners] Re: Assistance with understanding LunarLander code
RichardS wrote: Steve, I'm sure the instance is created by setContentView(R.layout.lunar_layout) so the constructor will have been run by the time we do mLunarView = (LunarView) findViewById(R.id.lunar) Correct. If you look in res/layout/lunar_layout.xml, you will see the declaration: com.example.android.lunarlander.LunarView android:id=@+id/lunar android:layout_width=fill_parent android:layout_height=fill_parent/ When the layout is inflated via setContentView(), the constructors for each widget and container are called. For built-in widgets like FrameLayout, Android knows they are in the package android.widget; for custom ones, the full namespace is spelled out in the layout (com.example.android.lunarlander.LunarView). -- Mark Murphy (a Commons Guy) http://commonsware.com _The Busy Coder's Guide to Android Development_ Version 1.9 Available! --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Android Beginners group. To post to this group, send email to android-beginners@googlegroups.com To unsubscribe from this group, send email to android-beginners-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en -~--~~~~--~~--~--~---
[android-beginners] Re: Assistance with understanding LunarLander code
Cheers, that makes sense. I didnt notice the reference to the class in the lunar_layour xml. On Dec 13, 3:58 pm, Mark Murphy mmur...@commonsware.com wrote: RichardS wrote: Steve, I'm sure the instance is created by setContentView(R.layout.lunar_layout) so the constructor will have been run by the time we do mLunarView = (LunarView) findViewById(R.id.lunar) Correct. If you look in res/layout/lunar_layout.xml, you will see the declaration: com.example.android.lunarlander.LunarView android:id=@+id/lunar android:layout_width=fill_parent android:layout_height=fill_parent/ When the layout is inflated via setContentView(), the constructors for each widget and container are called. For built-in widgets like FrameLayout, Android knows they are in the package android.widget; for custom ones, the full namespace is spelled out in the layout (com.example.android.lunarlander.LunarView). -- Mark Murphy (a Commons Guy)http://commonsware.com _The Busy Coder's Guide to Android Development_ Version 1.9 Available! --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups Android Beginners group. To post to this group, send email to android-beginners@googlegroups.com To unsubscribe from this group, send email to android-beginners-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-beginners?hl=en -~--~~~~--~~--~--~---
[android-beginners] Re: Assistance with understanding LunarLander code
Steve,
This is my understanding of it:
The file res/layout/lunar_layout.xml describes the layout of the view.
The src/R.java file is auto generated: it equates object ids to names.
setContentView(R.layout.lunar_layout)
'reads' lunar_layout.xml file and creates and instance of the
LunarView class and hence the View itself.
If you look in the XML file it contains an Id string @+id/lunar:
this is one of the ids that R.java
defines a name for - in this case R.id.lunar.
mLunarView = (LunarView) findViewById(R.id.lunar)
searches all view for the one identified by R.id.lunar ( == @+id/
lunar). This returns a reference to
the LunaView instance created above which we store in a member
variable.
The constructor for LunarView created a private LunarThread object so
doing:
mLunarThread = mLunarView.getThread()
enables us to retrieve a reference to the thread object.
Hope that's correct and helpful!
richard.
On 12 Dec, 15:49, steve_macleod steven_macl...@hotmail.com wrote:
Hi,
I have been working through the lunarlander example application, in
an
attempt to understand the source code. I have run into a couple of
problems, and would really appreciate if someone could space a couple
of minutes to assist in may understanding.
The onCreate method contains the following:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// turn off the window's title bar
requestWindowFeature(Window.FEATURE_NO_TITLE);
// tell system to use the layout defined in our XML file
setContentView(R.layout.lunar_layout);
// get handles to the LunarView from XML, and its LunarThread
mLunarView = (LunarView) findViewById(R.id.lunar);
mLunarThread = mLunarView.getThread();
// give the LunarView a handle to the TextView used for
messages
mLunarView.setTextView((TextView) findViewById(R.id.text));
if (savedInstanceState == null) {
// we were just launched: set up a new game
mLunarThread.setState(LunarThread.STATE_READY);
Log.w(this.getClass().getName(), SIS is null);
} else {
// we are being restored: resume a previous game
mLunarThread.restoreState(savedInstanceState);
Log.w(this.getClass().getName(), SIS is nonnull);
}
}
I can see that we are performing the following:
Turn off the title bar in the window
Set the activity content to the lunar_layour layout file
gets a reference to the 'lunar' layout
gets a reference to the thread member of the LunarView class
give the LunarView a reference to the textview for game
messages
we then set the state of the lunar thread to STATE_READY,
which also
outputs a bunch of status messages
The problem is that after executution of setState, the code seems to
end. I can see no sections of code that actually creates the
LunarView
or LunarThread objects, which are required to start the game proper.
Obviously I am missing something here, I was wondering if anyone
could
assist! Thanks lots!
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