Add some depth to your Android scrolling.

Use Gradle to grab the dependency from Maven Central:

compile 'com.prolificinteractive:parallaxpager:0.8.0'

There are 3 important steps:

1. Use a ParallaxContainer in layout XML

2. Create a layout XML file for each page

3. Add the attachment code to onCreate of your Activity

4. Use a ParallaxContainer in layout XML

Use the class com.prolificinteractive.parallaxpager.ParallaxContainer in your layout XML, sizing it however you like.

Ex:

<com.prolificinteractive.parallaxpager.ParallaxContainer
      android:id="@+id/parallax_container_1"
      android:layout_width="match_parent"
      android:layout_height="match_parent"/>

2. Create a layout XML file for each page

Each page must have its own layout XML file. Use whichever Layouts or Views you like, as usual.

Ensure this line is added to the Root Element:

xmlns:app="http://schemas.android.com/apk/res-auto"

Assign any combination of the following attributes (all floats):

• x_in: as the View enters the screen, it will translate in the horizontal direction along with user swiping, at a rate multiplied by this value. Default is 0.

• x_out: as the View leaves the screen, it will translate in the horizontal direction along with user swiping, at a rate multiplied by this value. Default is 0.

• y_in: as the View enters the screen, it will translate downward as the user swipes right to left, at a rate multiplied by this value. Default is 0.

• y_out: as the View leaves the screen, it will translate upward as the user swipes right to left, at a rate multiplied by this value. Default is 0.

• a_in: as the View enters the screen, it will fade in as the user swipes right to left, at a rate multiplied by this value. Default is 0.

• a_out: as the View leaves the screen, it will fade out as the user swipes right to left, at a rate multiplied by this value. Default is 0.

Ex:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical">

  <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      app:x_in="@dimen/parallax_speed_medium"
      app:x_out="@dimen/parallax_speed_fast"
      app:y_in="@dimen/parallax_speed_medium_rev"
      app:y_out="@dimen/parallax_speed_fast"
      app:a_in="@dimen/parallax_speed_very_fast"
      app:a_out="@dimen/parallax_speed_very_fast"
      android:text="@string/text_1"
      />

  <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      app:x_in="@dimen/parallax_speed_medium_rev"
      app:x_out="@dimen/parallax_speed_fast"
      app:y_in="@dimen/parallax_speed_medium"
      app:y_out="@dimen/parallax_speed_fast_rev"
      app:a_in="@dimen/parallax_speed_very_fast"
      app:a_out="@dimen/parallax_speed_very_fast"
      android:text="@string/text_2"
      />
</LinearLayout>

Keep in mind that negative values mean a change in direction for translation effects, and have no effect for alpha. For translation effects, values between 0 and 1 will result in a high level of funkiness.

3. Add the attachment code to onCreate of your Activity

Important steps in onCreate:

• Find the parallax container by ID

• Specify whether the pager should loop (true means it will loop)

• Submit a Layout Inflater and list the layouts for each page (in order). Currently there must be at least 2 in this list (repeats allowed).

Ex:

// find the parallax container
ParallaxContainer parallaxContainer = (ParallaxContainer) findViewById(R.id.parallax_container);

if (parallaxContainer != null) {

  // specify whether pager will loop
  parallaxContainer.setLooping(true);

  // wrap the inflater and inflate children with custom attributes
  parallaxContainer.setupChildren(getLayoutInflater(),
      R.layout.parallax_view_1,
      R.layout.parallax_view_2,
      R.layout.parallax_view_3,
      R.layout.parallax_view_4);
}

See the text of this pull request for an example using a page indicator.

Copyright 2014 Prolific Interactive

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.