Categories
android android-layout android-ui android-widget android-xml

Android getMeasuredHeight returns wrong values !

I’m trying to determine the real dimension in pixels of some UI elements !

Those elements are inflated from a .xml file and are initialized with dip width and height so that the GUI will eventually support multiple screen size and dpi (as recommended by android specs).

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="150dip"
android:orientation="vertical">

<ImageView
android:id="@+id/TlFrame"
android:layout_width="110dip"
android:layout_height="90dip"
android:src="@drawable/timeline_nodrawing"
android:layout_margin="0dip"
android:padding="0dip"/></LinearLayout>

This previous xml represent one frame. But I do add many dynamically inside a horizontal layout describe here :

<HorizontalScrollView 
android:id="@+id/TlScroller"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_margin="0dip"
android:padding="0dip"
android:scrollbars="none"
android:fillViewport="false"
android:scrollbarFadeDuration="0"
android:scrollbarDefaultDelayBeforeFade="0"
android:fadingEdgeLength="0dip"
android:scaleType="centerInside">

<!-- HorizontalScrollView can only host one direct child -->
<LinearLayout
android:id="@+id/TimelineContent"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_margin="0dip"
android:padding="0dip"
android:scaleType="centerInside"/>

</HorizontalScrollView >

The method defined to add one frame inside my java code :

private void addNewFrame()
{
LayoutInflater inflater = (LayoutInflater) _parent.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
ViewGroup root = (ViewGroup) inflater.inflate(R.layout.tl_frame, null);
TextView frameNumber = (TextView) root.findViewById(R.id.FrameNumber);
Integer val = new Integer(_nFramesDisplayed+1); //+1 to display ids starting from one on the user side
frameNumber.setText(val.toString());

++_nFramesDisplayed;
_content.addView(root);
// _content variable is initialized like this in c_tor
// _content = (LinearLayout) _parent.findViewById(R.id.TimelineContent);
}

Then inside my code, I try to get the actual real size in pixel because I need this to draw some opengl stuff over it.

LayoutInflater inflater     = (LayoutInflater) _parent.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
ViewGroup root = (ViewGroup) inflater.inflate(R.layout.tl_frame, null);
ImageView frame = (ImageView) root.findViewById(R.id.TlFrame);

frame.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
frame.measure(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
final int w = frame.getMeasuredWidth();
final int h = frame.getMeasuredHeight();

Everything seems to work fine except that those values are way bigger than the actual pixel size of the ImageView.

Reported infos from getWindowManager().getDefaultDisplay().getMetrics(metrics);
are the following :
density = 1,5
densityDpi = 240
widthPixel = 600
heightPixel = 1024

Now, I know the rule from android is : pixel = dip * (dpi /160). But nothing makes any sense with the value returned. For that ImageView of (90dip X 110dip), the returned values of the measure() method is (270 x 218) which I assumed is in pixel !

Anyone has any idea why ?
Is the value returned in pixel ?

By the way : I’ve been testing the same code but with a TextView instead than an ImageView and everything seems to be working fine ! Why !?!?