How to destroy a Layout? - android

I'm developing an Android app in which I use LayoutInflator to generate new layout. What the app does basically is - Its has one imageview. When I click on a button, I change the layout to display multiple ImageViews (like 2x2 or 4x4). I am successful in displaying these layouts using the LayoutInflator. However, the previous Layout stays intact and the new Layout is displayed over the old Layout which, kind of, messes the whole layout. My question is - is there anyway to destroy the old layout before displaying the new one?
Edit:
Here is the code (on the onClick event that I'm using)
public void oneby1onClick(View view){
RelativeLayout main = (RelativeLayout)findViewById(R.id.main_layout);
view = getLayoutInflater().inflate(R.layout.activity_main, main,false);
main.removeView(main);
main.addView(view);
}
public void twoby2onClick(View view){
RelativeLayout main = (RelativeLayout)findViewById(R.id.main_layout);
view = getLayoutInflater().inflate(R.layout.twoby2, main,false);
main.removeView(main);
main.addView(view);
}
public void fourby4onClick(View view){
RelativeLayout main = (RelativeLayout)findViewById(R.id.main_layout);
view = getLayoutInflater().inflate(R.layout.fourby4, main,false);
main.removeView(main);
main.addView(view);
}

Maybe you could just make your layout invisible if that is the case.
This can be done quite easily programmaticaly:
layout.setVisibility(View.GONE);

According to #ookami.kb's suggestion I should use main.removeAllViews(); instead of main.removeView(main);, that helped me.

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Animating a TextView appearing on activity creation

I want to show an animation of a TextView appearing when an activity is created. What I want is to show the activity without the TextView and then the TextView appearing (ideally, flying from outside) in its final position without user interaction.
I've tried to use the transition framework from API level 19 by having the TextView with visibility gone in the XML layout and setting it to visible in onCreate() with this code:
ViewGroup layout = (ViewGroup) findViewById(R.id.main_layout);
TransitionManager.beginDelayedTransition(layout, new ChangeBounds());
textView.setVisibility(View.VISIBLE);
This doesn't work. However, if I don't do this in onCreate() but as a response to a button click, it works. I think that the problem is that the layout is not created yet, so when I set the visibility to visible in the onCreate(), the layout is created with the final state and there aren't two scenes for the TransitionManager to work.
I've tried putting the code in onPause() but the result was the same. Any ideas how this should be done?
Try onWindowFocusChanged() like this
#Override
public void onWindowFocusChanged(boolean hasFocus) {
if(hasFocus){
// start your animation here
}
}
You should do this in onResume() after the layout has been created. Initially the visibility would be Invisible and then the view will animate.
try like this:
ViewGroup layout = (ViewGroup) findViewById(R.id.main_layout);
layout.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
TransitionManager.beginDelayedTransition(layout, new ChangeBounds());
textView.setVisibility(View.VISIBLE);
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because your view should be able to animate only after it's creation

Adding form components to a custom android view

I have a custom view (extends View) and I would like to add controls (buttons/text boxes etc) in the OnCreate function to add these components to the view at runtime:
public Section(Context context) {
super(context);
this.setBackgroundColor(Color.argb(255, 242, 242, 242));
this.setOnTouchListener(mSectionOnTouch);
LinearLayout l = new LinearLayout(this.getContext());
l.setOrientation(LinearLayout.VERTICAL);
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btn.setId(1);
btn.setText("btn1");
l.addView(btn);
Button btn2 = new Button(this.getContext());
btn2.setId(2);
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but this does not seem to do anything... Could someone tell me what im doing wrong?
Many thanks
FR
You never add l to your view. It should look like this:
public Section(Context context)
{
// setup linear layout
addView(l);
}
A slightly simpler way to do this would be to have your custom view extend LinearLayout. Then you can just add the views directly to your custom view and you don't have to nest another container, which is better for performance.

Set background of android activity without using XML file

I want to develop an application in which I want to set the background image which is in my drawable folder. I want when my activity will run, the back ground will be that image.And also no XML is to be used.
Thanks.
Without XML file,
Create an ImageView and set drawable to it. Now use setContentView(View view) of Activity..
Simple...
Dynamically,
//pseudo code only.. Implement in your way..
OnCreate()
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Try to use setBackgroundDrawable(R.drawable.yourImage) method for your layout.Suppose your main layout is LinearLayout
LinearLayout ll = (LinearLayout) findViewById(R.id.lineaLayout);
ll.setBackgroundDrawable(R.drawable.yourImage); // like this you can set image for your layout
Another Simple solution..
Use this in your onCreate() method of Activity.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getWindow().setBackgroundDrawableResource(R.drawable.background);
}
Get a handle to the root layout used, then set the background color or drawable on that. The root layout is whatever you called setContentView with.
setContentView(R.layout.main);
// Now get a handle to any View contained
// within the main layout you are using
View someView = findViewById(R.id.randomViewInMainLayout);
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View root = someView.getRootView()
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I am trying to add a View to a RelativeLayout in my OnClickListener.
montrolButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// myParent is a relative layout
// newChild is an ImageView
myParent.addView(newChild);
requestLayout();
}
});
I have looked at the HierarchyViewer, I don' see my new child being added.
Can you please tell me if I miss anything?
I just tried the very same code and it works as it should. There could be an issue with your variable myParent which is not the element you expect it to be.
Also I did not have to call requestLayout() for the added view to appear on the screen.
Possibly try to just explicitly get another part of your view and add it there to see what is happening. Also just to try, you may do this:
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ProgressBar iv = new ProgressBar(this);
rv.addView(iv);
to see if there is anything wrong with your image view instead of myParent
In any case it works if both elements are OK - there is nothing else to do in an activity.
Do you set the layout attributes of the new view (image view)?

Adding View to Relative Layout behind an existing view causes screen flicker

I'm trying to insert a View behind another view that is taking up the full screen and then later removing the view in the front to reveal the only remaining view. Functionally, everything is working as expected but the problem is that when I call View.addView() to add the second view, specifying to add it at index 0 so it is behind the first view, the screen flickers. It's almost as if the view is actually getting added in front of the first view for a fraction of a second and then it is hidden again as it is moved behind it.
Here's what I'm doing:
When the Activity is created I add an ImageView to a RelativeLayout and make the RelativeLayout instance the Activity's content view:
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
m_layout = new RelativeLayout(this);
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m_splashImage = new ImageView(this);
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m_layout.addView(m_splashImage,
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RelativeLayout.LayoutParams.FILL_PARENT));
setContentView(m_layout);
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protected void onStart() {
super.onStart();
m_layout.addView(new MyGLSurfaceView(), 0,
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Later, after all of the loading is done and the GLSurfaceView is ready to continuously render,
the splash ImageView is removed and cleaned up.
public void hideSplashScreen() {
if (m_splashImage != null) {
m_layout.removeView(m_splashImage);
m_splashImage = null;
}
}
Is there a better way to do this that doesn't require creating the GLSurfaceView before the onStart() is called?
Have you tried using view.setVisibility(View.GONE) on of the view that you adding behind? Of course before you are adding it.

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