Develop Reference

Getting the size of an inner layout in pixels

With the following Java and XML code, I was wondering how to retrieve the dimensions in pixels of an inner/child layout (LinearLayout, whereas the parent is RelativeLayout with paddings of 20dp) properly:
Java code:
public class TestActivity extends Activity {
private LinearLayout linLay;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
linLay = (LinearLayout)findViewById(R.id.linLay);
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT,
RelativeLayout.LayoutParams.MATCH_PARENT);
linLay.setLayoutParams(lp);
getDimensions();
}
private void getDimensions() {
System.out.println(linLay.getHeight());
System.out.println(linLay.getWidth());
}
}
XML:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="20dp" >
<LinearLayout
android:id="#+id/linLay"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerVertical="true"
android:layout_centerHorizontal="true">
</LinearLayout>
</RelativeLayout>
... Since I get outputs of 0 for the dimensions, I am aware that the LinearLayout needs to be set first on the screen before I could retrieve the dimensions... But what am I doing wrong here?

It didn't get its dimensions at the time you try to output them.You can just add a delay or just use method below.
private void getDimensions() {
ViewTreeObserver vto = linLay.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener(){
#Override
public voidonGlobalLayout() {
linLay.getViewTreeObserver().removeGlobalOnLayoutListener(this);
int height =linLay.getMeasuredHeight();
int width =linLay.getMeasuredWidth();
System.out.println(height);
System.out.println(width);
}
});
}

RelativeLayout getWidth returns zero

First, I know this is a duplicate of other question but I couldn't manage to fix it so I created my own question for help. I am trying to get the RelativeLayout width, it was successful at first but I don't know what I changed and the code returns only zero.
Here is my code:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ImageView[] imageViewArray = new ImageView[20];
ArrayList<Float> xarray = new ArrayList<>();
ArrayList<Float> yarray = new ArrayList<>();
rlt = (RelativeLayout) findViewById(R.id.layout);
imageView = (ImageView) findViewById(R.id.imageView);
rlt.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
rlt.getViewTreeObserver().removeOnGlobalLayoutListener(this);
Toast.makeText(MainActivity.this, "right" + rlt.getWidth(), Toast.LENGTH_SHORT).
show();
layoutwidth = rlt.getWidth();
layoutheight = rlt.getHeight();
}
});
}
Here is my activity_main xml file:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:id="#+id/layout"
android:background="#android:color/black"
android:paddingBottom="#dimen/activity_vertical_margin" tools:context=".MainActivity">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/imageView"
android:src="#mipmap/you"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>
Simple one, but yet not working, any help please?

It's because your layout's width isn't set yet
You should override onLayout() method
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
height = bottom - top;
width = right - left;
}

Usually you would extend whatever View you're interested in (here RelativeLayout) and override onSizeChanged():
https://developer.android.com/reference/android/view/View.html#onSizeChanged(int,%20int,%20int,%20int)
Whether that is useful in your scenario or not is hard to tell, since your question is fairly generic.

Try
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run()
{
//get width here
}
}, 10);

Maybe try to put the code for the views into the "onPostCreate" Method

Android: how to set the height of view?

I have been created a button and use addView() to draw some chart in onClickListener(). But it will not extend the height of view automatically if the chart out of bound.So I want to add the height of view when all chart have been drawn. I try to use getLayoutParams().height to modify the height but it doesn't work.
public class MainActivity extends Activity {
private TableLayout layout;
private Button btnDraw;
public void onCreate(Bundle savedInstanceState){
layout=findViewById((TableLayout) findViewById(R.id.tableLayout));
btnDraw=findViewById((Button) findViewById(R.id.btnDraw));
btnDraw.setOnClickListener(new OnClickListener(){
public void onClick(View arg0) {
layout.addView(new Chart(MainActivity.this)
}
});
}
class Chart extends View {
public void onDraw(Canvas c) {
int addHeight=0;
for(...){ //draw several chart
...
addHeight+=500;
}
FrameLayout.LayoutParams params = (FrameLayout.LayoutParams) layout.getLayoutParams();
params.height += addHeight;
layout.setLayoutParams(params);
}
}
}
here is xml code
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
<TableLayout
android:id="#+id/tableLayout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:stretchColumns="1">
<TableRow>
<Button
android:id="#+id/btnDraw"
android:layout_span="2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Draw" />
</TableRow>
...
</TableLayout>
</ScrollView>
I also try to call onMeasure(getWidth(),addHeight) outside the for loop but it still not work.
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(widthMeasureSpec, widthMeasureSpec);
}

Your Chart class should implement onMeasure() if you want to do it the eight way. If it is just a hack you can use AbsoluteLayout. You can also play with setting the layout params, but you should call updateViewLayout() and possibly even requestLayout().

view.getWidth() in Dialog not working

I want to create square buttons, but because I can't get the width by XML to assign it to button's height, I'm doing it by Java. So I do this:
View body = inflater.inflate(R.layout.picker_numeric, null);
Button up = (Button) body.findViewById(R.id.picker_numeric_up);
Log.d(TAG, "" + up.getWidth());
int height = up.getWidth();
up.setHeight(height);
........................
AlertDialog.Builder builder = new AlertDialog.Builder(activity)
.setTitle(title)
.setView(body)
........................
I used Log.d to confirm that getWidth() returns 0.
Anyone knows why this happens? I'm out of options.
EDIT:
After what MKJParekh and Simon said my code is this:
dialogContent.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/picker_numeric_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:baselineAligned="false"
android:padding="#dimen/padding_small"
android:weightSum="3"
tools:ignore="HardcodedText,UselessParent" >
<LinearLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:orientation="vertical" >
<Button
android:id="#+id/picker_numeric_up"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="#dimen/padding_medium"
android:layout_marginRight="#dimen/padding_medium"
android:gravity="center"
android:text="+" />
<EditText
android:id="#+id/picker_numeric_value"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="#dimen/padding_medium"
android:layout_marginRight="#dimen/padding_medium"
android:gravity="center"
android:inputType="number" />
<Button
android:id="#+id/picker_numeric_down"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="#dimen/padding_medium"
android:layout_marginRight="#dimen/padding_medium"
android:gravity="center"
android:text="-" />
</LinearLayout>
</LinearLayout>
Method in dialog's creator class:
public void equalDimens() {
up.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int height = up.getMeasuredWidth();
android.util.Log.d("dd", ""+height);
up.setLayoutParams(new LinearLayout.LayoutParams(height, height));
down.setLayoutParams(new LinearLayout.LayoutParams(height, height));
}
Then in Activity's Class:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
createMyDialog();
LinearLayout mainLayout = (LinearLayout ) this.getLayoutInflater().inflate(R.layout.main, null);
mainLayout.getViewTreeObserver().addOnGlobalLayoutListener(
new ViewTreeObserver.OnGlobalLayoutListener() {
public void onGlobalLayout() {
myDialogClass.equalDimens();
}
});
setContentView(mainLayout);
}
Without calling myDialogClass.equalDimens() I obtain this:
And calling the method I obtain this:

You need to measure your view before you can get height and width of the view.
You can do it like this,here ll2 is your any view object
ll2.measure(
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int height = ll2.getMeasuredHeight();
int width = ll2.getMeasuredWidth();
And after getting the height and width you will need to set them as,
ll2.setLayoutParams(new LayoutParams(width, height));

You view is measured and inflated but not yet drawn in onCreate.
You can use (amongst other solutions):
#Override
public void onWindowFocusChanged(boolean hasFocus) {
super.onWindowFocusChanged(hasFocus);
// get width here
}
If you can't use this, e.g. you have dialog boxes spawned from your activity, try a global layout listener.
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// inflate your main layout here (use RelativeLayout or whatever your root ViewGroup type is
LinearLayout mainLayout = (LinearLayout ) this.getLayoutInflater().inflate(R.layout.main, null);
// set a global layout listener which will be called when the layout pass is completed and the view is drawn
mainLayout.getViewTreeObserver().addOnGlobalLayoutListener(
new ViewTreeObserver.OnGlobalLayoutListener() {
public void onGlobalLayout() {
// measure your views here
}
}
);
setContentView(mainLayout);
}

How to set a FrameLayout fill_parent in width and always have a fixed ratio in height?

I see some questions about "ImageView"s, but I need a FrameLayout.
I have a FrameLayout, which I need its width:height = 2:1, and the width is fill_parent. There are many image views inside the frame layout, I can just set them width=fill_parent and height=fill_parent.
I don't find a way to do this, please help .
My xml code is:
<FrameLayout
android:id="#+id/cardView"
android:layout_width="fill_parent" android:layout_height="fill_parent"
android:layout_centerInParent="true">
<ImageView
android:id="#+id/frameView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="fitXY"
android:src="#drawable/card_style1"
/>
</FrameLayout>

See if this is what you want:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.your_layout);
final FrameLayout target = (FrameLayout) findViewById(R.id.frame_id);
target.post(new Runnable() {
#Override
public void run() {
int width = target.getWidth();
int height = width / 2;
LayoutParams lp = target.getLayoutParams();
lp.height = height;
target.setLayoutParams(lp);
}
});
}