FractionalSizeView

FractionalSizeView is a simple Android View that allows children of a RelativeLayout to be arranged using ratios, similar to the layout_weight property of a LinearLayout. The FractionalSizeView acts as a strut, allowing other views to be aligned to it.

Inspired by this answer on Stack Overflow, by Ivan Volosyuk.

Setup

There is a sample app provided, although it is best viewed in the layout preview window. The instructions below are to include the library in your own project.

Clone the repository:
git clone [email protected]:Ter0/FractionalSizeView.git

Import the lib module into your current project. In Android Studio 0.5.8, this can be achieved by navigating to File > Import Module, and selecting the folder named lib in the downloaded project.

Add the newly imported lib module as a dependency on the module you wish to use it in. In Android Studio 0.5.8, this can be achieved by right clicking on the module name, and selecting Open Module Settings. Then select the Dependencies tab, click the small green '+' symbol on the right, choose the Module Dependency entry, and finally choose the lib module from the list.

Rebuild the project.

Usage

<RelativeLayout 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">

    <net.ter0.fractionalsizeview.FractionalSizeView
        android:id="@+id/fractional_size_view_horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:fractionalSize="1/3"
        app:orientation="horizontal" />

    <View
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/right_view"
        android:background="#ffab6a83"
        android:layout_below="@+id/fractional_size_view_horizontal"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignRight="@+id/fractional_size_view_horizontal"
        android:layout_alignEnd="@+id/fractional_size_view_horizontal" />
</RelativeLayout>

In this example, the strut occupies a third of the parents width, and the coloured view is aligned to its width.

Don't forget to include the namespace in the root element of the layout: xmlns:app="http://schemas.android.com/apk/res-auto"

You can then add the custom attributes to the FractionalSizeView.

Attribute	Definition	Possible values	Default
app:orientation	The orientation of the strut	vertical, horizontal	horizontal
app:fractionalSize	The fraction of the parents width or height to occupy	any valid fraction, eg. 1/2, 2/3, 33/67	1/1

License

Copyright 2014 Chris Johns

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.