Determining the Size of an Android View At Runtime

Determining the size of an Android view at runtime

Based on @mbaird's advice, I found a workable solution by subclassing the ImageView class and overriding onLayout(). I then created an observer interface which my activity implemented and passed a reference to itself to the class, which allowed it to tell the activity when it was actually finished sizing.

I'm not 100% convinced that this is the best solution (hence my not marking this answer as correct just yet), but it does work and according to the documentation is the first time when one can find the actual size of a view.

Get height and width of a layout programmatically

The view itself, has it's own life cycle which is basically as follows:

• Attached

• Measured

• Layout

• Draw

So, depending on when are you trying to get the width/height you might not see what you expect to see, for example, if you are doing it during onCreate, the view might not even been measured by that time, on the other hand if you do so during onClick method of a button, chances are that by far that view has been attached, measured, layout, and drawn, so, you will see the expected value, you should implement a ViewTreeObserver to make sure you are getting the values at the proper moment.

LinearLayout layout = (LinearLayout)findViewById(R.id.YOUR VIEW ID);
ViewTreeObserver vto = layout.getViewTreeObserver(); 
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() { 
    @Override 
    public void onGlobalLayout() { 
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
                this.layout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
            } else {
                this.layout.getViewTreeObserver().removeOnGlobalLayoutListener(this);
            } 
        int width  = layout.getMeasuredWidth();
        int height = layout.getMeasuredHeight(); 

    } 
});

When does a View know its own size in Android? (width & height)

A View doesn't know its own size until it is drawn on the screen. To get the values once they are drawn you can use an OnGlobalLayoutListener like so:

<yourView>.getViewTreeObserver().addOnGlobalLayoutListener(
    new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            //getWidth() and getHeight() now have values
            //you can remove this layout listener too if you don't need it anymore
        }
    }
);

Dynamically calculate size of View elements

To get height of layout you have to write the code in onWindowFocusChanged() method.
First get the layout in onCreate() method then write the following code.

@Override
public void onWindowFocusChanged(boolean hasFocus) {
    // TODO Auto-generated method stub
    super.onWindowFocusChanged(hasFocus);
    System.out.println("...111Height..."+mainLayout.getMeasuredHeight());
}

Thanks
Deepak

get layout height and width at run time android

Suppose I have to get a LinearLayout width defined in XML. I have to get reference of it by XML. Define LinearLayout l as instance.

 l = (LinearLayout)findviewbyid(R.id.l1);
ViewTreeObserver observer = l.getViewTreeObserver();
        observer.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

            @Override
            public void onGlobalLayout() {
                // TODO Auto-generated method stub
                init();
            l.getViewTreeObserver().removeGlobalOnLayoutListener(
                    this);
        }
    });

protected void init() {
        int a= l.getHeight();
            int b = l.getWidth();
Toast.makeText(getActivity,""+a+" "+b,3000).show();
    } 
    callfragment();
}  

How to get size of an image from xml in android

You can use getWidth and getHeight to get dimensions of any view (in this case constraint layout) at runtime.

But be carful, before using this two methods you have to make sure that the view (constraint layout) is already created, otherwise it gonna return 0, witch means you can't call them in onCreate.

So the correct way to do it is to wait for the view to be created then get its size.
Like this :

create this method

public static void runJustBeforeBeingDrawn(final View view, final Runnable runnable) {
final OnPreDrawListener preDrawListener = new OnPreDrawListener() {
    @Override
    public boolean onPreDraw() {
        view.getViewTreeObserver().removeOnPreDrawListener(this);
        runnable.run();
        return true;
    }
};
view.getViewTreeObserver().addOnPreDrawListener(preDrawListener); 
}

Then call it when u need to get the dimensions

runJustBeforeBeingDrawn(yourView, new Runnable() {
        @Override
        public void run() {
            //Here you can safely get the view size (use "getWidth" and "getHeight"), and do whatever you wish with it
        }
    });

Related to your question :

View's getWidth() and getHeight() returns 0

Determining the size of an Android view at runtime

Get screen width and height in Android

Using this code, you can get the runtime display's width & height:

DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
int height = displayMetrics.heightPixels;
int width = displayMetrics.widthPixels;

---

In a view you need to do something like this:

((Activity) getContext()).getWindowManager()
                         .getDefaultDisplay()
                         .getMetrics(displayMetrics);

---

In some scenarios, where devices have a navigation bar, you have to check at runtime:

public boolean showNavigationBar(Resources resources)
{
    int id = resources.getIdentifier("config_showNavigationBar", "bool", "android");
    return id > 0 && resources.getBoolean(id);
}

If the device has a navigation bar, then count its height:

private int getNavigationBarHeight() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
        DisplayMetrics metrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(metrics);
        int usableHeight = metrics.heightPixels;
        getWindowManager().getDefaultDisplay().getRealMetrics(metrics);
        int realHeight = metrics.heightPixels;
        if (realHeight > usableHeight)
            return realHeight - usableHeight;
        else
            return 0;
    }
    return 0;
}

So the final height of the device is:

int height = displayMetrics.heightPixels + getNavigationBarHeight();

---

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