Develop Reference

Getting an android view button's width after setting it programatically

During my oncreate I have a button that is drawn. I come back and have it resized as part of the viewTreeObserver.OnGlobalLayoutListener() method. This works great. Within the same onGlobalLayouyListener method how can I come back and retrieve the width and height of the button. If I use btn.getwidth it returns the setting i have in my xml and not the value I just set. How can I retrieve the new width and height of the button.
mainlayout.getViewTreeObserver().addOnGlobalLayoutListener(
new ViewTreeObserver.OnGlobalLayoutListener() {
public void onGlobalLayout() {
Cyclebuttons(mainlayout);
getwidth();}
public void Cyclebuttons(ViewGroup parent) {
int btn2height= somenumber;
// set button width and height
ConstraintLayout.LayoutParams newLayoutParams = (ConstraintLayout.LayoutParams) btnx21.getLayoutParams();
newLayoutParams.width = btn2height;
newLayoutParams.height = btn2height;
btnx21.setLayoutParams(newLayoutParams);
}
public Void getwidth{
btnx21.getwidth();
}
thanks.

Didn't run the code, but the following might work:
public Void getwidth{
ConstraintLayout.LayoutParams newLayoutParams = (ConstraintLayout.LayoutParams) btnx21.getLayoutParams();
return newLayoutParams.width;
}

Custom Popupwindow for all screensize android

I am using a custom popup window. On Load I have to pass the height and width of the window. But I want to load the popup for all screensizes. I am using the below function to load my popup.
private void loadPopup() {
LayoutInflater inflater = this.getLayoutInflater();
final View layout = inflater.inflate(R.layout.activity_pop_up_ad, null);
final PopupWindow windows = new PopupWindow(layout , 300,500,true);
layout.post(new Runnable() {
public void run() {
windows.showAtLocation(layout,Gravity.CENTER, 0, 0);
}
});
ImageButton close = (ImageButton) layout.findViewById(R.id.close);
close.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
windows.dismiss();
}
});
}
I tried this one. But it completes the screen size. I don't want that much filled.
windows.setWindowLayoutMode(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
Any ideas?

Can't you just detect the screen height / width and then scale down by some factor so it does not fill the screen as much as you want?
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
The above code should get you your height and width of the screen and then you can just divide or subtract down the height and width to make the pop up fill as much of the screen as you want.
was this what you wanted? or did i misunderstand?

Auto Scroll to HorizontalScrollView

I am doing auto-horizontal scrolling. So i have 15 items. Now i want to access at 12 item so my index is 11. But i am unable to scroll it auto when a index occur.
horizontalScrollView.scrollTo(12, 0);
#Override
public void onPageSelected(int page) {
for(int i = 0; i < holeTitle.length; i++) {
if(i == page) {
title[i].setTextColor(0xffffffff);
horizontalScrollView.scrollTo(12, 0);
}
else {
title[i].setTextColor(0xffe0e0e0);
}
}
}
please expert make a look.

DmRomantsov's answer is the right way to scroll to the 12th button. However, getLeft() and getRight() methods return 0 because the layout is not displayed yet on the screen. It is too early to calculate the width of the layout parent and children. To achieve it, you need to do your auto-scroll inside onWindowFocusChanged.
#Override
public void onWindowFocusChanged(boolean hasFocus){
super.onWindowFocusChanged(hasFocus);
if(hasFocus){
// do smoothScrollTo(...);
}
}
However, inside a Fragment, this method above will not work. I just wrote it to give a clue, to understand the concept. To have the same behaviour in Fragment, you just need to do a Runnable which lets the time to your UI to be displayed. Then, do this with a LinearLayout oriented to horizontal:
// Init variables
HorizontalScrollView mHS;
LinearLayout mLL;
// onCreateView method
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.layout_container, container, false);
// Find your views
mHS = (HorizontalScrollView)view.findViewById(R.id.hscrollview);
mLL = (LinearLayout)view.findViewById(R.id.hscrollview_container);
// Do a Runnable on the inflated view
view.post(new Runnable() {
#Override
public void run() {
Log.v("","Left position of 12th child = "+mLL.getChildAt(11).getLeft());
mHS.smoothScrollTo(mLL.getChildAt(11).getLeft(), 0);
}
});
return view;
}
Middle HorizontalScrollView:
Your question was to auto-scroll until your 12th child. However, in the comments below, you ask me to auto-scroll at the middle of the HorizontalScrollView, I assume on every device. You need to calculate the width of the screen, the total width of the container and how many children are displayed inside the device width. Here is a simple code:
// Auto scroll to the middle (regardless of the width screen)
view.post(new Runnable() {
#Override
public void run() {
// Width of the screen
DisplayMetrics metrics = getActivity().getResources()
.getDisplayMetrics();
int widthScreen = metrics.widthPixels;
Log.v("","Width screen total = " + widthScreen);
// Width of the container (LinearLayout)
int widthContainer = mLL.getWidth();
Log.v("","Width container total = " + widthContainer );
// Width of one child (Button)
int widthChild = mLL.getChildAt(0).getWidth();
Log.v("","Width child = " + widthChild);
// Nb children in screen
int nbChildInScreen = widthScreen / widthChild;
Log.v("","Width screen total / Width child = " + nbChildInScreen);
// Width total of the space outside the screen / 2 (= left position)
int positionLeftWidth = (widthContainer
- (widthChild * nbChildInScreen))/2;
Log.v("","Position left to the middle = " + positionLeftWidth);
// Auto scroll to the middle
mHS.smoothScrollTo(positionLeftWidth, 0);
}
});
/**
* Your value might be resumed by:
*
* int positionLeftWidth =
* ( mLL.getWidth() - ( mLL.getChildAt(0).getWidth() *
* ( metrics.widthPixels / mLL.getChildAt(0).getWidth() ) ) ) / 2;
*
**/
Middle HorizontalScrollView with chosen Value:
I have a bit misunderstand the real request. Actually, you wanted to auto-scroll until a chosen child view, and display this view at the middle of the screen.
Then, I changed the last int positionLeftWidth which refers now to the left position of the chosen view relative to its parent, the number of children contained in one screen, and the half width of the chosen view. So, the code is the same as above, except positionLeftWidth:
// For example the chosen value is 7
// 7th Child position left
int positionChildAt = mLL.getChildAt(6).getLeft();
// Width total of the auto-scroll (positionLeftWidth)
int positionLeftWidth = positionChildAt - // position 7th child from left less
( ( nbChildInScreen // ( how many child contained in screen
* widthChild ) / 2 ) // multiplied by their width ) divide by 2
+ ( widthChild / 2 ); // plus ( the child view divide by 2 )
// Auto-scroll to the 7th child
mHS.smoothScrollTo(positionLeftWidth, 0);
Then, whatever the value in getChildAt() method, and whatever the width screen, you will always have the chosen (in your case) button at the middle of the screen.

Try
horizontalScrollView.smoothScrollTo(horizontalScrollView.getChildAt(11).getRight(),0);
first patameter - X coord, second - Y.
Offset:
public final void smoothScrollBy (int dx, int dy)
Absolute:
public final void smoothScrollTo (int x, int y)

Try horizontalScrollView.smoothScrollBy(12, 0);

Try this is working code. position will be where you want to scroll
final HorizontalScrollView mHorizontalScrollView = (HorizontalScrollView) .findViewById(R.id.horizontalScrollView);
mHorizontalScrollView.postDelayed(new Runnable() {
#Override
public void run() {
mHorizontalScrollView.scrollTo(position, 0);
mHorizontalScrollView.smoothScrollBy(1200, 0);
}
},100);

Getting the width/height of a layout in Android

I'm wondering how to measure the dimensions of a view. In my case it is aan Absolute Layout. I've read the answers concerning those questions but I still don't get it.
This is my code:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
AbsoluteLayout layoutbase = (AbsoluteLayout) findViewById(R.id.layoutbase);
drawOval();
}
public void drawOval(){ //, int screenWidth, int screenHeight){
AbsoluteLayout layoutbase = (AbsoluteLayout) findViewById(R.id.layoutbase);
int screenWidth = layoutbase.getWidth();
int screenHeight = layoutbase.getHeight();
Log.i("MyActivity", "screenWidth: " + screenWidth + ", screenHeight: " +screenHeight);
Coordinates c = new Coordinates(BUTTONSIZE,screenWidth,screenHeight);
...some code ...
((ViewGroup) layoutbase ).addView(mybutton, new AbsoluteLayout.LayoutParams(BUTTONSIZE, BUTTONSIZE, c.mX, c.mY));
mybutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
showText(mybutton);
}
});
}
public void showText(View button){
int x = findViewById(LAYOUT).getWidth();
int y = findViewById(LAYOUT).getHeight();
Toast message = Toast.makeText(this, "x: " + x , Toast.LENGTH_SHORT);
message.show();
}
The getWidth() command works great in showText() but it does not in drawOval(). I know it looks a bit different there but I also used the int x = findViewById(LAYOUT).getWidth(); version in drawOval(), and x/y are always 0. I don't really understand why there seems to be no width/height at that earlier point. Even if I actually draw a Button on the Absolute Layout, getWidth() returns 0. Oviously I want to measure the sizes in drawOval().

I think will help you.
LinearLayout headerLayout = (LinearLayout)findviewbyid(R.id.headerLayout);
ViewTreeObserver observer = headerLayout .getViewTreeObserver();
observer.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
// TODO Auto-generated method stub
int headerLayoutHeight= headerLayout.getHeight();
int headerLayoutWidth = headerLayout.getWidth();
headerLayout .getViewTreeObserver().removeGlobalOnLayoutListener(
this);
}
});
}

getWidth() is giving you 0 because onCreate is called before layout actually happens. Due to views being able to have dynamic positions and sizes based on attributes or other elements (fill_parent for example) there's not a fixed size for any given view or layout. At runtime there is a point in time (actually it can happen repeatedly depending on many factors) where everything is actually measured and laid out. If you really need the height and width, you'll have to get them later as you've discovered.

This specially deal with Dimensions so
Display display = getWindowManager().getDefaultDisplay();
int width = display.getWidth();
int height = display.getHeight();
This may help you in managing dimensions.
Note: This returns the display dimensions in pixels - as expected. But the getWidth() and getHeight() methods are deprecated. Instead you can use:
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
as also Martin Koubek suggested.

If your goal is to simply draw an oval on the screen, then consider creating your own custom View rather than messing around with AbsoluteLayout. Your custom View must override onDraw(android.graphics.Canvas), which will be called when the view should render its content.
Here is some extremely simple sample code that might help get you started:
public class MainActivity extends Activity {
private final Paint mPaint = new Paint();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SampleView(this));
}
// create a nested custom view class that can draw an oval. if the
// "SampleView" is not specific to the Activity, put the class in
// a new file called "SampleView.java" and make the class public
// and non-static so that other Activities can use it.
private static class SampleView extends View {
public SampleView(Context context) {
super(context);
setFocusable(true);
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.CYAN);
// smoothen edges
mPaint.setAntiAlias(true);
mPaint.setColor(Color.RED);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(4.5f);
// set alpha value (opacity)
mPaint.setAlpha(0x80);
// draw oval on canvas
canvas.drawOval(new RectF(50, 50, 20, 40), mPaint);
}
}
}

This give you screen resolution:
WindowManager wm = (WindowManager)context.getSystemService(context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
Point outSize = new Point();
display.getSize(outSize);

kabuko's answer is correct, but could be a little more clear, so let me clarify.
getWidth() and getHeight() are (correctly) giving you 0 because they have not been drawn in the layout when you call them. try calling the two methods on the button after addView() (after the view has been drawn and is present in the layout) and see if that gives you the expected result.
See this post for more information.

How to show PopupWindow at special location?

I need to show PopupWindow under one Views shown on the screen.
How can I calculate coordinates of needed View and place PopupWindow under it? Code example are more than welcome. Thanks.

Locating an already displayed view is fairly easy - here's what I use in my code:
public static Rect locateView(View v)
{
int[] loc_int = new int[2];
if (v == null) return null;
try
{
v.getLocationOnScreen(loc_int);
} catch (NullPointerException npe)
{
//Happens when the view doesn't exist on screen anymore.
return null;
}
Rect location = new Rect();
location.left = loc_int[0];
location.top = loc_int[1];
location.right = location.left + v.getWidth();
location.bottom = location.top + v.getHeight();
return location;
}
You could then use code similar to what Ernesta suggested to stick the popup in the relevant location:
popup.showAtLocation(parent, Gravity.TOP|Gravity.LEFT, location.left, location.bottom);
This would show the popup directly under the original view - no guarantee that there would be enough room to display the view though.

you have getLeft() and getBottom() to get the exact position of the view in the layout. You also have getWidth() and getHeight() to know the exact space occupied by the view. If you want to position your popup window below a view.
You setLeft() and setTop() methods of the view to position the new popup Window.

To get size of the main application screen without stuff like title and notification bars, override the following method in the class generating the screen in question (sizes are measured in pixels):
#Override
protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
}
To get the bottom coordinate of the view under which you want to show the popup:
View upperView = ...
int coordinate = upperView.getBottom();
Now as long as height - coordinate is large enough for your popup view, you can simply place the popup like this:
PopupWindow popup = new PopupWindow();
Button button = new Button(this);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
popup.showAtLocation(parent, Gravity.CENTER, 0, coordinate);
}
});
Here, showAtLocation() takes the parent view as an argument together with gravity and location offsets.