Android ImageView sized by weight not centering in parent LinearLayout

I realize this is probably a trivial layout question, but I can't seem to get it working the way I want without layering in what I feel is too many container layouts. What I am trying to do is setup an ImageView such that the following conditions are satisfied: - The width of the ImageView is some given percentage of the width of its parent (the screen width for now). - The ImageView is centered horizontally within the screen. I have created a test case using an XML layout, but in practice I will be creating these layouts and views programmatically; I don't think this matters for the purposes of figuring out the correct layout though. I am somewhat familiar with weights in Android layouts and how they are typically used to layout multiple views with relative weighting factors. In order to satisfy condition 1, I create a container LinearLayout (horizontal orientation), set its weightSum = 1, then embed my ImageView with a weight of whatever percentage I want, say 0.5. This works! Next, I would like the ImageView to end up being centered in the screen horizontally. So I set the gravity to "center"/"centerHorizontal". This is where I am stuck, because no matter what gravity/layout_gravity settings I choose it seems to always align to the left side. Layout file: ``` <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="#FFFFFF"> <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:weightSum="1.0"> <ImageView android:src="@drawable/earth" android:adjustViewBounds="true" android:layout_width="0" android:layout_height="wrap_content" android:layout_weight="0.5" android:layout_gravity="center_horizontal" android:id="@+id/imageView1" /> </LinearLayout> </LinearLayout> ``` Result: What I really want to achieve is something like this: But in order to achieve that, I had to insert two dummy LinearLayouts with weights 0.25 on either side of my ImageView like so: ``` <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="#FFFFFF"> <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:weightSum="1.0"> <LinearLayout android:orientation="horizontal" android:layout_width="0" android:layout_height="wrap_content" android:layout_weight="0.25"/> <ImageView android:src="@drawable/earth" android:adjustViewBounds="true" android:layout_width="0" android:layout_height="wrap_content" android:layout_weight="0.5" android:layout_gravity="center_horizontal" android:id="@+id/imageView1" /> <LinearLayout android:orientation="horizontal" android:layout_width="0" android:layout_height="wrap_content" android:layout_weight="0.25"/> </LinearLayout> </LinearLayout> ``` This is an ugly and awkward layout in my opinion, not only because I am now having to use 3 additional LinearLayouts aside from my top-level LinearLayout just to size and position my view, but also because I want to do all of the layout programmatically and dynamically. I might decide to right or left align my views at runtime, or change their scaling factor relative to the screen width, which in this solution requires potentially adding/removing dummy layout views and setting all the weights appropriately. I am hoping that someone better at layouts than I will have a better solution! Ideally something where I can just set the "gravity" (although I haven't been able to get that to work), or some alternative way to set the width without needing the horizontal LinearLayout container and weights, since without that container I can center horizontally in my top-level vertical LinearLayout. Thanks! EDIT: I just realized that in my second layout attempt using dummy padding LinearLayouts that I can do away with the second padding LinearLayout (set to weight of 0.25) and just use one dummy padding LinearLayout before my ImageView, since they are relative to a predetermined weightSum in the parent. E.g.: ``` <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:weightSum="1.0"> <LinearLayout android:orientation="horizontal" android:layout_width="0" android:layout_height="wrap_content" android:layout_weight="0.25"/> <ImageView android:src="@drawable/earth" android:adjustViewBounds="true" android:layout_width="0" android:layout_height="wrap_content" android:layout_weight="0.5" android:layout_gravity="center_horizontal" android:id="@+id/imageView1" /> </LinearLayout> ``` Still not the ideal solution I was hoping for.