Android view dynamic size

Question

I have a layout with several views and one of these views have to be scaled based on screen size. As of now I have it set to 250dp as it looks good on a 5.1 inch device, but when used on smaller devices it isnt as good any more. I can't use wrap content as it will make the looks of it very bad and the size of buttons too small, so it has to be 1/3rd of the width of the screen. Is it possible to do that in the layout code, or does it have to be doen in java code?

Answer 1

Is it possible to do that in the layout code

Yes it is. It is pretty simple by using android:layout_weight and android:weightSum attributes of LinearLayout :

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
   android:layout_width="match_parent" 
   android:layout_height="match_parent" 
   android:weightSum="3"
   android:orientation="horizontal"> 

   <View 
      android:id="@+id/thirdView" 
      android:layout_height="wrap_content" 
      android:layout_width="0dp" 
      android:layout_weight="1" />

</LinearLayout>

Answer 2

You need to override onMeasure(...) then do your view resizing login inside this function. Here is the perfect explanation and solution. Some reference code from this link goes below...

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

    int desiredWidth = 100;
    int desiredHeight = 100;

    int widthMode = MeasureSpec.getMode(widthMeasureSpec);
    int widthSize = MeasureSpec.getSize(widthMeasureSpec);
    int heightMode = MeasureSpec.getMode(heightMeasureSpec);
    int heightSize = MeasureSpec.getSize(heightMeasureSpec);

    int width;
    int height;

    //Measure Width
    if (widthMode == MeasureSpec.EXACTLY) {
        //Must be this size
        width = widthSize;
    } else if (widthMode == MeasureSpec.AT_MOST) {
        //Can't be bigger than...
        width = Math.min(desiredWidth, widthSize);
    } else {
        //Be whatever you want
        width = desiredWidth;
    }

    //Measure Height
    if (heightMode == MeasureSpec.EXACTLY) {
        //Must be this size
        height = heightSize;
    } else if (heightMode == MeasureSpec.AT_MOST) {
        //Can't be bigger than...
        height = Math.min(desiredHeight, heightSize);
    } else {
        //Be whatever you want
        height = desiredHeight;
    }

    //MUST CALL THIS
    setMeasuredDimension(width, height);
}

Answer 3

You could have a look at the PercentRelativeLayout from the Percent Support Library. This is a RelativeLayout in which you can specify it's Views sizes in percentages, e.g. set its width to 33%.

<android.support.percent.PercentRelativeLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="match_parent">

     <Button
         app:layout_widthPercent="33%"
         app:layout_heightPercent="33%"
         app:layout_marginTopPercent="25%"
         app:layout_marginLeftPercent="25%" />

</android.support.percent.PercentRelativeLayout>