android - FrameLayout child view not updating correctly on resize -

i have android application in root view framelayout on rotation kept , resized rather recreated.

among children of frameview 1 custom view (the main view) takes entire space, , custom view want display narrow band along bottom edge (in portrait mode) or right edge (in landscape mode).

to end run following code main view's onsizechanged() method:

boolean isbandshowing = ...;    // whether band should shown boolean isportrait = ...;       // whether in portrait mode, controls band displayed int horizontalbandheight = ...; // default height band in portrait mode int verticalbandwidth = ...;    // default width band in landscape mode  bandview.setvisibility(isbandshowing ? view.visible : view.gone); layoutparams bandlayoutparams = new framelayout.layoutparams(     isportrait ? layoutparams.match_parent : verticalbandwidth,  // x     isportrait ? horizontalbandheight : layoutparams.match_parent, // y     gravity.bottom | gravity.right); bandview.setlayoutparams(bandlayoutparams); 

upon creation, onsizechanged() gets called once (visible in log output) , sets band supposed to.

when display rotated, however, position of band not updated properly. after first rotation portrait landscape, band still displays @ bottom. when rotate portrait, band moves right – consistently lagging behind.

adding log output, can see following:

• onsizechanged() gets called on every rotation
• the 4 variables @ top have correct value (portrait/landscape correctly reflects new orientation)
• if query width , height newly created layoutparams, have expected values
• if query dimensions of bandview right after call setlayoutparams(), have old values (as displayed before rotation).

i've tried few things, no avail:

• calling requestlayout() on both framelayout , band view
• calling invalidate() on both
• calling postinvalidate() on both
• removing bandview framelayout before setting new layoutparams, re-adding it

what gives?

as had suspected based on log output, in guts of ui has not been updated time onsizechanged() gets called. haven't figured out what, takeaway layoutparams stuff needs deferred until else has finished. can done wrapping code runnable , post()ing framelayout:

static boolean isbandshowing = ...;    // whether band should shown static boolean isportrait = ...;       // whether in portrait mode, controls band displayed static int horizontalbandheight = ...; // default height band in portrait mode static int verticalbandwidth = ...;    // default width band in landscape mode  framelayout.post(new runnable() {     @override     public void run() {         bandview.setvisibility(isbandshowing ? view.visible : view.gone);         layoutparams bandlayoutparams = new framelayout.layoutparams(             isportrait ? layoutparams.match_parent : verticalbandwidth,  // x             isportrait ? horizontalbandheight : layoutparams.match_parent, // y             gravity.bottom | gravity.right);         bandview.setlayoutparams(bandlayoutparams);     } }); 

that solved it.