Develop Reference

android scrollview scroll to top direction when new view added

In scrollview, if I add any view in middle, normally all the views below the added view scrolls downside. But I want to scroll the top views of added view to upside without disturbing the bottom views. Is it possible in scrollview , please help me ?
In the figure , If view 4 was added , then view 1 has to be scrolled upwards , without changing the positions of view 2 and view 3.

You can probably get the height of the view you are adding with and then scroll the scrollview manually that many pixels
scrollView.scrollBy(0, viewAdded.getHeight())

I've been wanting to try this question for quite some time, I finally got the chance today. The method is pretty simple (in fact, #dweebo already mentioned it earlier) - we move the ScrollView up as we add the view. For getting precise (and valid) dimensions when adding, we use a ViewTreeObserver. Here's the code you can get hints from:
// Getting reference to ScrollView
final ScrollView scrollView = (ScrollView) findViewById(R.id.scrollView);
// Assuming a LinearLayout container within ScrollView
final LinearLayout parent = (LinearLayout) findViewById(R.id.parent);
// The child we are adding
final View view = new View(ScaleActivity.this);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 100);
view.setLayoutParams(params);
// Finally, adding the child
parent.addView(view, 2); // at index 2
// This is what we need for the dimensions when adding
ViewTreeObserver viewTreeObserver = parent.getViewTreeObserver();
viewTreeObserver.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
parent.getViewTreeObserver().removeOnPreDrawListener(this);
scrollView.scrollBy(0, view.getHeight());
// For smooth scrolling, run below line instead
// scrollView.smoothScrollBy(0, view.getHeight())
return false;
}
});

How to dynamically wrap root layout in a ScrollView

I want to add a scroll view to all the layouts that I have. But dynamically. Because the app will run in different screen sizes, and when I will get a screen size smaller than a specific size, then I want to show the layout in a scroll view.
So I made this method, it will be called on the check that the screen is small. I will pass my activity and I want to change the root layout to scroll view or just add a ScrollView as the root layout. So if the root layout is a LinearLayout, then I want to put that layout in the ScrollView. And I have not named all the layouts, meaning that I didn't give an ID to the layout, so I cannot use findViewById.
public static void SetActivityRoot(Activity c) {
View v = c.getWindow().getDecorView();
// View v = v.getRootView();
ScrollView sv = new ScrollView(c);
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT);
sv.setLayoutParams(lp);
((ViewGroup)v.getParent()).removeView(v);
sv.addView((View) v);
((ViewGroup)v.getParent()).addView(sv);
}
It's giving me an error saying that "you cannot remove view from null" etc. Or that "you cannot add view to layout as it already has parent view". How can I make this work?

Finally solved my problem.
public static void SetActivityRoot(Activity c) {
View v = ((ViewGroup)c.findViewById(android.R.id.content)).getChildAt(0);
ScrollView sv = new ScrollView(c);
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT);
sv.setLayoutParams(lp);
((ViewGroup) v.getParent()).removeAllViews();
sv.addView((View) v);
c.addContentView(sv, lp);
}

Set framelayout margin and its children width, height and position

I am currently having a programatically created framelayout with a imageview and a text view. By original layout is relative layout.
RelativeLayout layout = (RelativeLayout) findViewById(R.id.rel);
FrameLayout fr = new FrameLayout(this);
fr.setBackgroundResource(R.drawable.question_bar_icon);
ImageView b1 = new ImageView(this);
TextView b2 = new TextView(this);
b1.setBackgroundResource(R.drawable.mcq);
fr.addView(b1);
fr.addView(b2);
layout.addView(fr);
Now i am unable to resize the imageview and the button, also m unable to position them, in the sence textview in the center and imageview in the verticle center and left positioned.
I tried layout params, but not working, any help would be greatly appreciated!

Try using the overloaded version of addView that takes a LayoutParameter as well in every case you are programatically adding a view, otherwise it is inserted to the ViewGroup with default layout parameters. (P.S. you can also control the order of insertion).
For example for the ImageView you wanted to be in the center of the frame layout:
int width = FrameLayout.LayoutParams.WRAP_CONTENT; //or whatever you want
int height= FrameLayout.LayoutParams.WRAP_CONTENT; //or whatever you want
FrameLayout.LayoutParams lp = new FrameLayout.LayoutParams(width, height, Gravity.CENTER);
fr.addView(b1,lp);
Do the same for the other view, and most importantly, do the same, using RelativeLayout.LayoutParams for inserting the frame element itself into your RelativeLayout.

Giving right margin in button on being clicked in android

I have a screen where I display five buttons inside a Linearlayout vertically.
this linear layout is inside a relative layout and aligned to parent right.
Now I need that when any button is clicked it should shift leftwards while others remain at the original position.
I am trying to give left margin to the button on being clicked but the problem is all the buttons are shifting and not only that one.
Here is the code
final LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
layoutParams.rightMargin = 20;
mColorButton.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
fillDataList(1);
mIsClicked = true;
//[start] setting the colour of button
mColorButton.setBackgroundResource(R.drawable.yellow_stick) ;
mColorButton.setLayoutParams(layoutParams);
mPatternButton.setBackgroundResource(R.drawable.brown_stick);
mDistributionButton.setBackgroundResource(R.drawable.brown_stick);
mShapeButton.setBackgroundResource(R.drawable.brown_stick);
mLesionButton.setBackgroundResource(R.drawable.brown_stick);
//[end] setting the colour of button
}
});

May be this is the problem:
By default all Buttons are left aligned and when you give right margin to a Button it expands its parent layout size. The parent expands it self with its child. So all the Button shifted left side.
try to give android:layout_gravity="right" to all Button in XML or code.

Place view inside FrameLayout in Android

I want to add a view inside a FrameLayout programmatically and to place it in a specific point within the layout with a specific width and height. Does FrameLayout support this? If not, should I use an intermediate ViewGroup to achieve this?
int x; // Can be negative?
int y; // Can be negative?
int width;
int height;
View v = new View(context);
// v.setLayoutParams(?); // What do I put here?
frameLayout.addView(v);
My initial idea was to add an AbsoluteLayout to the FrameLayout and place the view inside the AbsoluteLayout. Unfortunately I just found out that AbsoluteLayout is deprecated.
Any pointers will be much appreciated. Thanks.

The following example (working code) shows how to place a view (EditText) inside of a FrameLayout. Also it shows how to set the position of the EditText using the setPadding setter of the FrameLayout (everytime the user clicks on the FrameLayout, the position of the EditText is set to the position of the click):
public class TextToolTestActivity extends Activity{
FrameLayout frmLayout;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
frmLayout = (FrameLayout)findViewById(R.id.frameLayout1);
frmLayout.setFocusable(true);
EditText et = new EditText(this);
frmLayout.addView(et,100,100);
frmLayout.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
Log.i("TESTING","touch x,y == " + event.getX() + "," + event.getY() );
frmLayout.setPadding(Math.round(event.getX()),Math.round(event.getY()) , 0, 0);
return true;
}
});
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="fill_parent"
android:layout_height="fill_parent">
<FrameLayout
android:id="#+id/frameLayout1"
android:layout_height="fill_parent" android:layout_width="fill_parent">
</FrameLayout>
</LinearLayout>

You can also add a margin around the newly added view to position it inside the FrameLayout.
FrameLayout frameLayout = (FrameLayout) findViewById(R.id.main); // or some other R.id.xxx
DisplayMetrics metrics = context.getResources().getDisplayMetrics();
LayoutParams params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.setMargins(0, metrics.heightPixels - 20, 0, 0);
View v = new View(context);
v.setLayoutParams(params);
frameLayout.addView(v);
This will position the FrameLayout 20 pixels from the bottom of the screen.
Edit: completed the example so it stands by itself. And oh, yes it does work.

It's true that with FrameLayout all children are pegged to the top left of the screen, but you still have some control with setting their padding. If you set different padding values to different children, they will show up at different places in the FrameLayout.

From the link Quinn1000 provided:
You can add multiple children to a FrameLayout, but all children are pegged to the top left of the screen.
This means you can't put your View at a specific point inside the FrameLayout (except you want it to be at the top left corner :-)).
If you need the absolute positioning of the View, try the AbsoluteLayout:
A layout that lets you specify exact locations (x/y coordinates) of its children. Absolute layouts are less flexible and harder to maintain than other types of layouts without absolute positioning.
As for setting the width and height of the View, also like Quinn1000 said, you supply the v.setLayoutParams() method a LayoutParams object, depending on the container you chose (AbsoluteLayout, LinearLayout, etc.)

The thread here on stackOverflow at
How do you setLayoutParams() for an ImageView?
covers it somewhat.
For instance:
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(30, 30);
yourImageView.setLayoutParams(layoutParams);
implies that you need to be defining a LinearLayout.LayoutParams (or in your case a FrameLayout.layoutParams) object to pass to the setLayoutParams method of your v object.
At
http://developer.android.com/reference/android/widget/FrameLayout.html
it almost makes it looks like you could ask your v to:
generateDefaultLayoutParams () via this method if you have not defined the parameters specifically.
But it's late, and those links are making my eyes bleed a little. Let me know if they nhelp any :-)