Redundant margins when adding ImageView to ScrollView in Android.
- by Shmuel Meymann
Hi..
I have been trying to use a ScrollView on a single ImageView with a JPG (~770 x 1024) over an AVD that's 600x800.
My main.xml is:
<?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"
>
<ScrollView
android:id="@+id/scroller"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
Now, I add a single ImageView with
setContentView(R.layout.main);
ScrollView sv = (ScrollView)findViewById( R.id.scroller );
ImageView iv = new ImageView(this);
iv.setImageDrawable( new BitmapDrawable( "/sdcard/770x1024.jpg" ) ); // same happens with ScaleDrawable.
iv.setScaleType( ScaleType.CENTER_INSIDE );
sv.addView( sv ); // and it does not go any better if I use Linear Layout between the ScrollView and the ImageView.
The result is
The image was displayed in a middle of a ScrollView, wrapped with background area on top and bottom as following:
#####
#####
image
.
.
.
#####
#####
Where ##### stands for background area
I tried to set the background of the ImageView red, and it verified that the blank margins were ImageView background.
iv.setBackgroundColor( color.Red );
Where I would expect the image to take no more than its size (scaled to the AVD size) and I expect the ScrollView to let me scroll over the remainder (if any).
For some reason, I see that the drawable size is 600x1024.
Moreover
I tried to add a LinearLayout with a dummy text view such as the linear layout is a parent to the ImageView and the TextView, and the ScrollView is a parent to the LinearLayout.
LinearLayout dummy = new LinearLayout( this );
dummy.addView(iv);
TextView someTextView = new TextView( this );
someTextView.setLayoutParams(new LayoutParams( LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT ));
dummy.addView( someTextView );
sv.addView( dummy );
The result was very peculiar:
The entire layout was set into the width of a text-less text view (19).
It is important for me to avoid stretching the image.
What is the recommended way to implement a display of a page that can be potentially scrolled?
Do I have to do it manually with a plain layout and scrolling upon OnMove events?
Thanks
Shmuel
