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androidlayoutlayoutparams

Android: Check if view is aligned to parent bottom/top programmatically


How can I check if my view is aligned to it's parent bottom (or top).

If the view is aligned to the parent bottom, I want to align it to the parent top, and vice versa. I am able to align the view as I want but I don't know how to check it first.

My XML:

< RelativeLayout
    android:layout_width="20dp"
    android:layout_height="200dp">
        < Button 
            android:id="@+id/mybutton"     
            android:layout_height="25dp"       
            android:layout_alignParentBottom="true"
            android:layout_width="match_parent">
        < / Button>
< / RelativeLayout >

My code:

Button mybutton = (Button) findViewById(R.id.mybutton);
LayoutParams params1 = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, 25);
params1.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, 0);
params1.addRule(RelativeLayout.ALIGN_PARENT_TOP);
button.setLayoutParams(params1);

I can't use getRule() since that is only valid for API23 and above, and I'm using since API16.

Any help on what I can do to find this? Thanks.


Solution

  • Its Simple, You can use one flag variable to achive this as below :

        int isTopAligned=0;
        int isBottomAligned=0;
        Button mybutton = (Button) findViewById(R.id.mybutton);
        LayoutParams params1 = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, 25);
        if(isTopAligned==0){
           params1.addRule(RelativeLayout.ALIGN_PARENT_TOP);
           params1.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM,0);
           isTopAligned=1;
           isBottomAligned=0;
         }
         else{
           params1.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
           params1.addRule(RelativeLayout.ALIGN_PARENT_TOP,0);
           isTopAligned=0;
           isBottomAligned=1;
         }
         button.setLayoutParams(params1);
    

    I think there is no more elaboration required, as the code is simple to understand.

    Note: isBottomAligned flag is not needed, since checking for isTopAligned is enough.