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POAndroid: ImageView loses transparency
 

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    <p>I have a list of blog posts from users with avatars. Cause of some design reasons I need to crop square avatar images into circle images.</p> <p>This is my ListView xml</p> <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/linearLayout1" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" &gt; &lt;ListView android:id="@+id/listViewBlogs" style="@style/CustomListView" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="1" android:divider="@drawable/divider" &gt; &lt;/ListView&gt; &lt;/LinearLayout&gt; &lt;style name="CustomListView"&gt; &lt;item name="android:fadingEdge"&gt;none&lt;/item&gt; &lt;item name="android:cacheColorHint"&gt;@android:color/transparent&lt;/item&gt; &lt;item name="android:divider"&gt;@null&lt;/item&gt; &lt;item name="android:listSelector"&gt;@android:color/transparent&lt;/item&gt; &lt;/style&gt; </code></pre> <p>This is my ListViewItem xml (blog post content is removed from example, only author name and avatar remains)</p> <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/linearLayout1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="vertical" android:padding="6dip"&gt; &lt;LinearLayout android:id="@+id/linearLayout1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal" &gt; &lt;ImageView android:id="@+id/imageAvatar" android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/avatar_default2" android:focusable="false" android:background="@color/transparent" android:layerType="hardware" /&gt; &lt;TextView android:id="@+id/textAuthor" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_weight="1" android:text="TextView" android:textColor="@color/text_dark_grey" android:textSize="20dip" android:textStyle="bold" /&gt; &lt;/LinearLayout&gt; &lt;/LinearLayout&gt; </code></pre> <p>Here is fragment from my adapter. Images are downloaded via Internet and cached into local storage. Then cropped pixels are filled with transparent</p> <pre><code>class BlogsAdapter extends ArrayAdapter&lt;BlogItem&gt;{ //... @Override public View getView(int position, View convertView, ViewGroup parent) { View v = convertView; if(v == null){ LayoutInflater inf = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = inf.inflate(R.layout.blogs_list_item_1, null); } BlogItem item = getItem(position); if(item != null){ TextView textAuthor = (TextView)v.findViewById(R.id.textAuthor); if(textAuthor != null){ textAuthor.setText(item.author_name); } ImageView imageAvatar = (ImageView)v.findViewById(R.id.imageAvatar); if(imageAvatar != null){ //Load image from cache BitmapFactory.Options op = new Options(); op.inPreferredConfig = Bitmap.Config.ARGB_8888; Bitmap imageFromCache = BitmapFactory.decodeFile(item.imagepath, op); //Crop round. This is not quickest one solution to do it here, but it is here to make test case clear Bitmap bmp2 = imageFromCache.copy(Bitmap.Config.ARGB_8888, true); int mw = bmp2.getWidth(); int mh = bmp2.getHeight(); int wc = mw/2; int hc = mh/2; for(int i=0; i&lt;mw;i++){ for(int j=0; j&lt;mh;j++){ if( Math.sqrt( (i-wc)*(i-wc) + (j-hc)*(j-hc) ) &gt;=(wc-2) ){ bmp2.setPixel(i, j, Color.TRANSPARENT); } } } //Set cropped image into view imageView.setBackgroundColor(0); imageView.setImageBitmap(bmp2); } return v; } } </code></pre> <p>It works good enougth</p> <p><img src="https://i.stack.imgur.com/m6Ijs.png" alt="Good screenshot"></p> <p>But when I scroll listview, transparency looses</p> <p><img src="https://i.stack.imgur.com/UQQSF.png" alt="Not so good one"></p> <p>I tried:</p> <ul> <li>android:cacheColorHint=@android:color/transparent is setted into ListViewStyle</li> <li>imageView.setBackgroundColor(0);</li> </ul> <p>Any ideas?</p>
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