I have a program where I want to add two views in one activity, like
public class AnimationActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new GraphicsViewForBitmap(this));
setContentView(new GraphicsView(this));
}
}
where GraphicsViewForBitmap & GraphicsView are two classes extends view.
so I want at a time two views should set to an activity.
Is it possible?
Plz give me answer.
Thanks
setContentView() will display only the view that you have set . If you want to display more than one view then you can add both the view in your layout XML file inside any Layout like LinearLayout,RelativeLayout etc. Then you can use setContentView(R.layout.yourXML).
Here is how you can do it in your XML...
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<com.yourpkg.GraphicsView
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
<com.yourpkg.GraphicsViewForBitmap
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
</LinearLayout>
Yes but first you have to put them inside a ViewGroup, for example a LinearLayout, and then set that ViewGroup with setContentView. Because with the existing code you're not just appending the second view with the first, but you are setting another content.
Add the second view to the first view.
LinearLayout childLayout = new LinearLayout(this);
childLayout.setOrientation(LinearLayout.HORIZONTAL);
childLayout.addView(graphicsView);
parentLayout.add(childLayout);
Another way is to create a 2nd layout XML, say main2.xml (the 1st being main.xml). Then you can swap from one to another via, e.g. an ActionBar button, etc. as follows:
setContentView(R.layout.main2); // Pass from layout #1 to layout #2
setContentView(R.layout.main); // Pass from layout #2 back to layout #1
(You can create as many views as you like ...)
Related
I have an XML layout having a single TextView
Now I want to add 50 buttons which I want to add dynamically in my java file !.
Is it possible to add attributes to an XML file via java code ??
Or can an activity have 2 layouts at a time ??
for eg,
public class Options extends Activity
{
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.options);
Button but=new Button(this);
but.setText("Wassup");
// How do I add this button to the layout ?
}
}
Is it possible to add attributes to an XML file via java code ??
No, but you can add properties to Views and Layouts as you are doing with setText(). resource files themselves cannot be changed after compiled.
Or can an activity have 2 layouts at a time ??
The simple answer is no but you can inflate another layout and add it to the current layout.
Example of what you can do to add a Button
Inflate your root layout and add the Buttons to it with addView(). Something like
Layoutinflater inflater = (LayoutInflater) getSystemService
(Context.LAYOUT_INFLATER_SERVICE);
LinearLayout ll = (LinearLayout) inflater.inflate(R.layout.layout_file);
Button but=new Button(this);
but.setText("Wassup");
// How do I add this button to the layout ?
ll.addView(but);
LayoutInflater
Or if you want to add it to a layout in the current file you can just use findViewById() and use addView() on that to add your Buttons to.
Considering you have an xml layout as below:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#id/mainlayout"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
</TextView>
</LinearLayout>
In your java code after setContentView(R.layout.options); you can do the following:
LinearLayout linearLayout=(LinearLayout)findViewById(R.id.mainlayout);
Button button=new Button(this);
linearLayout.addView(button);
Now you can add as many buttons you like into the linear layout as seen above.
Yes it is possible. After setContentView(R.layout.options); get your buttons container with findViewById(). You will have a reference to a LinearLayout, RelativeLayout or something else. After that use Layout inflater and programmatically you can add other layouts or components.
Hope it helps!
just use layout.addView() where layout is a ViewGroup that you get by calling findViewById(R.id.layoutId)
I have a LinearLayout that contains a TextView, and always will. There will also always be at least one button located below the TextView, but there might be more than one under certain circumstances.
I can successfully create and add as many buttons as I need programmatically. I can also successfully set whatever appearance related parameters/options that I require for these buttons programmatically.
The problem is that I don't know how to tell a programmatically created button that it should use a XML resource file, which contains the appearance and layout parameters, instead of setting these parameters programmatically.
I've looked at similarly named questions and spent time messing with the API itself, to no avail.
Edit:
Here's an approximation of what I'm trying to do that will hopefully make explanations a bit clearer for me:
private TextView textView;
private SomeObject someObject;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View scrollView = inflater.inflate(R.layout.fragment_play_game, container, false);
textView = (TextView) scrollView.findViewById(R.id.game_data_text);
textView.setText(someObject.getTextForTextView());
LinearLayout layout = (LinearLayout) scrollView.findViewById(R.id.game_data_container);
for (String optionText : someObject.getTextForButtons()) {
layout.addView(createOptionButton(optionText, layout));
}
return scrollView;
}
private View createOptionButton(String optionText, LinearLayout layout) {
Button optionButton = new Button(this.getActivity());
// set button layout/options here, somehow??
optionButton.setText(optionText);
return optionButton;
}
My XML layout file for the fragment looks like this (It's this LinearLayout that I'm trying to add buttons to):
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/game_data_container"
etc... >
<TextView
android:id="#+id/game_data_text"
etc... />
</LinearLayout>
</ScrollView>
Also, if I'm to create an XML layout file for the button (lets call it custom_button.xml) should it look something like this?:
<?xml version="1.0" encoding="utf-8"?>
<Button xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/play_game_option_button"
etc... />
Update:
Just to expand a bit on what MrFox# is talking about, what I did to get it working was replace this line:
Button optionButton = new Button(this.getActivity());
with this one:
Button optionButton = (Button) inflater.inflate(R.layout.play_game_option_button, layout, false);
...which inflates an xml file containing only a Button layout (the button template). In this case, it returns the root view of that file, which is just the button because there's no parent above the button in the file.
However, if I had have set the last boolean value (attachToParent) to true, it would have returned the root container that the button will be in (which is just the 'layout' variable that was passed into the call).
I can now produce as many buttons as I want using this template.
Have you thought of making a layout that is just the button with the applied XML styles and then inflating it into your linear layout?
something like:
inflater.inflate(R.layout.StyledButton, MyLinearLayout, true);
xml for your button under /res/layout/my_button_layout.xml
<Button xmlns:android="http://schemas.android.com/apk/res/android"
... />
code in your activity
myButton = (Button)inflate.inflate(R.layout.my_button_layout, null);
myView.addView(myButton);
I am developing an Android 2.1 app.
I have defined a LinearLayout class:
public class MyTopBar extends LinearLayout {
...
}
Then, I have a layout xml file (content.xml):
<LinearLayout>
...
</LienarLayout>
I have a RootActivity.java , I would like to set MyTopBar as content in this RootActivity.
Then I have MyActivity which extends RootActivity:
public class MyActivity extends RootActivity{
//set xml layout as content here
}
I would like to set the content.xml as content of MyActivity.
As a whole, I would like to use the above way to achieve the layout that MyTopBar should be located on top of the screen always. The other Activities which extend RootActivity will have its content below MyTopBar. How to achieve this??
1 You could add your custom LinearLayout directly to the xml layout of the MyActivity class like this:
<LinearLayout>
<com.full.package.MyTopBar
attributes here like on any other xml views
/>
...
</LinearLayout>
or you could use the include tag to include the layout with the custom view:
<LinearLayout>
<include layout="#layout/xml_file_containing_mytopbar"
/>
...
</LinearLayout>
2 Use :
setContentView(R.layout.other_content);
Have a Layout vacant for the TopBar and add Your Topbar in it by using layout.addView(topbarObject);
Regarding your second question the setContentView can be called only once, as far as I know. You can however have those two xml files inflated using View.inflate(other_content.xml) and added in the parent xml layout whenever you need it. You can removeView() on parent layout and addView() with the new layout file.
Edit:
For the solution of both the question, you can have a parent Layout for eg. like the following:
//Omitting the obvious tags
//parent.xml
<RelativeLayout
android:id="#+id/parentLayout">
<RelativeLayout
android:id="#+id/topLayout">
</RelativeLayout>
<RelativeLayout
android:id="#+id/contentLayout">
</RelativeLayout>
</RelativeLayout>
Now in your code set the parent layout as content view,make an object of your TopBar layout and add it to the topLayout.
setContentView(R.layout.parent);
MyTopBar topBar=new MyTopBar(this);
RelativeLayout toplayout=(RelativeLayout)findViewByid(R.id.topLayout);
topLayout.addView(topBar); //or you can directly add it to the parentLayout, but it won't work for the first question. So better stick to it.
Now inflate the required xml layout. and add it to contentLayout.
RelativeLayout layout=(RelativeLayout)View.inflate(R.layout.content,null);
contentLayout.addView(layout);//Assuming you've done the findViewById on this.
and when you need to show the other content xml, just call the following code.
contentLayout.removeAllView();
RelativeLayout layout2=(RelativeLayout)View.inflate(R.layout.other_content,null);
contentLayout.addView(layout2);
I am preparing to do an android demonstration of sorts and one of the first apps that i would like to write would be a screen filled with different widgets(which of course are views) but would like to put them on the screen without any layout built to hold them. is this possible or do you have to use a layout to put more than one view(widget) on the screen at once?
So right now i can do something like:
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.main);
TextView view1 = new TextView(this);
view1.setText("I am view one");
setContentView(view1);
}
}
In this case i really havent specified a layout but there doesnt seem to be a way to position multiple widgets on the screen without setting a layout. The purpose of this would be to show why you would want to use layouts. perhaps there is a way to display widgets on the screen without having to call the setContentView method.
You can only add multiple widgets/views to something called a ViewGroup. If you take a look at the documentation you'll see - not surprisingly - that basically all layouts extend this class. Similarly, if you look up the documentation on e.g. a TextView, you'll find that it doesn't extend ViewGroup (it does inherit from View, just like ViewGroup, which means it's on a different branch in the hierarchy tree).
In other words: you will need some sort of a layout in order to display more than a single widget/view at a time. You will also always need an explicit call to setContentView(), unless you use something like a ListActivity or ListFragment that by default creates a layout with a ListView as root.
That being said, your example is actually just a programmatical way of setting the following layout on the activity:
<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="I am view one" />
You can do it like this:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FrameLayout frameLayout = new FrameLayout(this);
TextView view1 = new TextView(this);
view1.setText("I am view one");
frameLayout.addView(view1);
// add more widgets into ViewGroup as you want
// then set the viewgroup as content view
setContentView(frameLayout);
}
want to make an Android app that starts with a main layout and when you push a button (called stateButton) that is in this layout the layout changes to a main2 layout containing another button (called boton2), and when you push this one you get back to the first main.
I want to do this in the same activity without creating or starting another one.
Here I show you part of the code:
public class NuevoshActivity extends Activity
implements SensorEventListener, OnClickListener {
private Button stateButton;
private Button boton2;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.stateButton = (Button) this.findViewById(R.id.boton);
this.boton2 = (Button) this.findViewById(R.id.boton2);
stateButton.setOnClickListener(this);
boton2.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if(v==stateButton) {
setContentView(R.layout.main2);
}
else if(v==boton2) {
setContentView(R.layout.main);
}
}
}
The mains only have some images, text views and the buttons.
But I've some troubles. Can't it just be as simple as that or what am I missing or what is wrong?
When you use findViewById, you are actually trying to find a view inside the layout you specified by the setContentView. So using setContentView again and again might bring problems when you are trying to check for buttons.
Instead of using a setContentView, I would add the 2 layouts for the screen as child's for a view-flipper which only shows one child at a time. And you can specify the index of which child to show. The benefit of using a view flipper is that you can easily specify a 'in' and 'out' animation for the view if you need an animation when you switch between views. This is a lot cleaner method then recalling setContentView again and again.
The FrameLayout handles this wonderfully... Use this with the <include... contstruct to load multiple other layouts, then you can switch back and forth between them by using setvisibility(View.VISIBLE); and setVisibility(View.INVISIBLE); on the individual layouts.
For example:
Main XML including two other layouts:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout android:id="#+id/frameLayout1" android:layout_width="fill_parent" android:layout_height="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android">
<include android:id="#+id/buildinvoice_step1_layout" layout="#layout/buildinvoice_step1" android:layout_width="fill_parent" android:layout_height="fill_parent"></include>
<include android:id="#+id/buildinvoice_step2_layout" android:layout_width="fill_parent" layout="#layout/buildinvoice_step2" android:layout_height="fill_parent"></include>
</FrameLayout>
Code to switch between layouts:
findViewById(R.id.buildinvoice_step1_layout).setVisibility(View.VISIBLE);
findViewById(R.id.buildinvoice_step2_layout).setVisibility(View.INVISIBLE);
You will also need to set the visibility of the individual layouts when the activity starts (or in XML) otherwise you will see them both - one on top of the other.
Your boton2 button will be NULL because the definition of the button is in main2.xml.
The only views you will be able to find are the views which are defined in main.xml.
Thanks!!! All the info was usefull to understand a lot of things and as C0deAttack commented I've got troubles with the button on the main2. What I've done is to set View.VISIBLE and View.GONE to the TextViews and Buttons that I wanted in each layout. Thank you very much.