java - Android: align_left aligns to the center -

i have fragment contains google map:

<com.google.android.gms.maps.mapview     android:id="@+id/mapview"     android:layout_width="match_parent"     android:layout_height="match_parent"     map:camerazoom="13"     map:maptype="normal"     map:uizoomcontrols="false"     map:uirotategestures="true"     map:uiscrollgestures="true"     map:uizoomgestures="true" map:uitiltgestures="false" /> 

the map takes entire screen , has mylocation enabled:

 map.setmylocationenabled(true); 

the following code should align mylocation button top-left of screen:

 // mylocation button view                     view locationbutton = ((view) mapview.findviewbyid(integer.parseint("1")).getparent()).findviewbyid(integer.parseint("2"));                  relativelayout.layoutparams rlp = (relativelayout.layoutparams) locationbutton.getlayoutparams();                  rlp.addrule(relativelayout.align_parent_top);                 rlp.addrule(relativelayout.align_parent_left); 

however - aligns button top center of screen. however, if add this:

if (build.version.sdk_int >= 17) {                                rlp.addrule(relativelayout.align_parent_start);                         } 

then aligns left properly. problem align_parent_start can't used programmatically before api 17 , need support lower api level. why isn't align_parent_left working on it's own align button left?

here's implementation of moving location button:

<linearlayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <framelayout     android:layout_width="match_parent"     android:layout_height="match_parent"     android:layout_weight="3">     <fragment xmlns:android="http://schemas.android.com/apk/res/android"         android:id="@+id/map"         android:layout_height="match_parent"         android:layout_width="match_parent"         android:layout_weight="1"         android:name="com.google.android.gms.maps.supportmapfragment">     </fragment>       .       .       . 

on activity:

mapfragment = ((supportmapfragment) getsupportfragmentmanager()             .findfragmentbyid(r.id.mymap));   //if you're using fragment use:    //mapfragment = ((supportmapfragment) getchildfragmentmanager() .findfragmentbyid(r.id.mymap));       mapfragment.getmapasync(new onmapreadycallback() {         @override         public void onmapready(googlemap googlemap) {            //add map adjustments here//              //then move location button        view locationbutton = ((view) mapfragment.getview().findviewbyid(integer.parseint("1")).             getparent()).findviewbyid(integer.parseint("2"));      // , next place it, exemple, on bottom right (as google maps app)     relativelayout.layoutparams rlp = (relativelayout.layoutparams) locationbutton.getlayoutparams();     // position on right bottom     rlp.addrule(relativelayout.align_parent_top, 0);     rlp.addrule(relativelayout.align_parent_bottom, relativelayout.true);     rlp.setmargins(0, 0, 30, 30);           }     });