android layout - Why is my image clipped after scaling? -

i having strange problem. scale image and, while scaling works correctly, image gets clipped. tried different scale types - things changed never make work.

just clear, here's need solve: 1. have horizontalscrollview around imageview , scrollview around horizontalview. 2. scroll around (using scrollto of both scroll views) and, upon event, zoom in. 3. i'd happen imageview scale around current scroll position.

here's layout:

<?xml version="1.0" encoding="utf-8"?> <framelayout xmlns:android="http://schemas.android.com/apk/res/android"     android:orientation="vertical" android:layout_width="match_parent"     android:layout_height="match_parent">      <scrollview         android:layout_width="match_parent"         android:layout_height="match_parent"         android:scrollbars="none"         android:overscrollmode="never">          <horizontalscrollview             android:layout_width="match_parent"             android:layout_height="match_parent"             android:scrollbars="none"             android:overscrollmode="never">              <imageview                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:layout_margin="3dp"                 android:scaletype="fitcenter" />         </horizontalscrollview>     </scrollview> </framelayout> 

and here's scaling code (originalwidth/originalheight calculated @ scale of 1; targetview points imageview):

public synchronized void changescale(float newscalefactor) {     this.scalefactor = math.max(min_zoom, math.min(newscalefactor, max_zoom));     if (targetview != null && originalwidth > 0) {         int newwidth = (int)(originalwidth * scalefactor);         int newheight = (int)(originalheight * scalefactor);         onscalechanged(targetview, scalefactor, newwidth, newheight);     } }   public void onscalechanged(view targetview, float scalefactor, int newwidth, int newheight) {     viewgroup.layoutparams layoutparams = targetview.getlayoutparams();     layoutparams.width = newwidth;     layoutparams.height = newheight;      // needed increase pane size (rather zoom within initial layout)     targetview.setlayoutparams(layoutparams);     // tell system recalculate layout     targetview.requestlayout();      // needed specify center of scaling     horizontalscrollview horizontalscrollview = (horizontalscrollview)targetview.getparent();     scrollview vertscrollview = (scrollview)horizontalscrollview.getparent();     // ~~~ pivot points wrong      targetview.setpivotx(horizontalscrollview.getscrollx() * scalefactor);     targetview.setpivoty(vertscrollview.getscrolly() * scalefactor);      // needed actual zooming     targetview.setscalex(scalefactor);     targetview.setscaley(scalefactor); };   public void zoomin(float scaledelta) {     changescale(scalefactor + scaledelta); }  public void zoomout(float scaledelta) {     changescale(scalefactor - scaledelta); } 

question 1: how prevent clipping? can't find right combination of scaletype , layout resizing.

question 2: when use setscalex/setscaley, should pivot calculated after applying new scale factor or renderer take care of automatically?

after updating scale need invalidate(), , requestlayout() views.

targetview.invalidate(); targetview.requestlayout(); 

i calculate scale differently images. try scale image view using matrix scale type. need know size of bound dpi.

// scaled dpi int boundboxindp = getresources().getdisplaymetrics().densitydpi * scalefactor  // determine how scale: dimension requiring less scaling // closer side. way image stays inside // bound , either x/y axis touches bound neither go over. float xscale = ((float) boundboxindp) / newwidth; float yscale = ((float) boundboxindp) / newheight; float scale = (xscale <= yscale) ? xscale : yscale;  // scale using our calculated scale targetview.setscalex(scale); targetview.setscaley(scale); 

as second question pivot. need set center of visible scroll area. the scrollable area should increased when change image size since using fit_center;