Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/pakerfeldt/android-viewflow

A horizontal view scroller library for Android
https://github.com/pakerfeldt/android-viewflow

Last synced: about 1 month ago
JSON representation

A horizontal view scroller library for Android

Awesome Lists containing this project

README 

        
# View Flow for Android



ViewFlow is an Android UI widget providing a horizontally scrollable [ViewGroup](http://developer.android.com/reference/android/view/ViewGroup.html) with items populated from an [Adapter](http://developer.android.com/reference/android/widget/Adapter.html). Scroll down to the bottom of the page for a screen shot.



The component is a [Library Project](http://developer.android.com/guide/developing/eclipse-adt.html#libraryProject). This means that there's no need to copy-paste resources into your own project, simply add the viewflow component as a reference to any project.



## When to use

This library might be suitable if you have an indeterminate number of views in your viewflow, if instead you have a static numbers of views you ought to look at Fragments and the ViewPager in the Compatibility Library instead.



## Usage



### In your layout



    



The use of `app:sidebuffer` is optional. It defines the number of Views to buffer on each side of the currently shown View. The default sidebuffer is 3, making up a grand total of 7 (3 * 2 + 1) Views loaded at a time (at max).

To be able to use the more convenient `app:sidebuffer` attribute, the application namespace must be included in the same manner as the android namespace is. Please refer to the layout main.xml in the example project for a full example. Again, note that it's the application namespace and *not* the viewflow namespace that must be referred like `xmlns:app="http://schemas.android.com/apk/res/your.application.package.here"`.



### In your activity



    ViewFlow viewFlow = (ViewFlow) findViewById(R.id.viewflow);

    viewFlow.setAdapter(myAdapter);

    

Setting a different initial position (0 being default) is as easy as:



    viewFlow.setAdapter(myAdapter, 8);

    

Although possible, you should not call `setSelection(...)` immediately after calling `setAdapter(myAdapter)` as that might load unnecessary views giving you a decrease in performance.



### Listen on screen change events



If you need to listen to screen change events you would want to implement your own `ViewFlow.ViewSwitchListener` and pass it to the `setOnViewSwitchListener()` method.



    viewFlow.setOnViewSwitchListener(new ViewSwitchListener() {

        public void onSwitched(View v, int position) {

            // Your code here

        }

    });



### Listen on initialize view events



If you need a lazy View initialization you would want to implement your own `ViewFlow.ViewLazyInitializeListener` and pass it to the `setOnViewLazyInitializeListener()` method.



    viewFlow.setOnViewLazyInitializeListener(new ViewLazyInitializeListener() {

        public void onViewLazyInitialize(View view, int position) {

            // Your code here e.g.

            ((MyAdapter)((AbsListView)view).getAdapter()).initializeData();

        }

    });



### Flow Indicator

It is also possible to add a flow view indicator to your layout. The purpose of a `FlowIndicator` is to present a visual representation of where in the item list focus is at. You may either implement a `FlowIndicator` yourself or use an implementation provided by the View Flow library. The View Flow library currently supports the following indicators:



#### Circle Flow Indicator ####

This indicator shows a circle for each `View` in the adapter with a special circle representing the currently selected view (see screenshot below).



	



And then you'll need to connect your `ViewFlow` with the `FlowIndicator`:



	CircleFlowIndicator indic = (CircleFlowIndicator) findViewById(R.id.viewflowindic);

	viewFlow.setFlowIndicator(indic);



By default, the 'active' indicator moves smoothly from one 'inactive' indicator

to the next, as the user scrolls. If you set the `snap` attribute to `true`, it

will instead jump to the next position when the flow settles at the next page.



The following attributes are supported: `activeColor`, `inactiveColor`,

`activeType` (either fill or stroke), `inactiveType` (either fill or stroke),

`fadeOut` (time in ms until indicator fades out, 0 = never), `radius`, `sync`

(see above).



#### Title Flow Indicator ####

This indicator presents the title of the previous, current and next `View` in the adapter (see screenshot below).



		



And then you'll need to connect your `ViewFlow` with the `FlowIndicator`:



		TitleFlowIndicator indicator = (TitleFlowIndicator) findViewById(R.id.viewflowindic);

		indicator.setTitleProvider(myTitleProvider);

		viewFlow.setFlowIndicator(indicator);



## Building a jar file

If you rather want a jar file instead of a including the project as an android library, run `ant jar` in the `android-viewflow/viewflow` folder, to build a jar file.



## Caveats ##

The manifest states a min sdk version of 4, which is true. But in any case you want to support an api level < 8 you will have to forward an `onConfigurationChanged` event to the `ViewFlow` from your `Activity`. I know this isn't a very nice solution, feel free to propose better ones!



		@Override

		public void onConfigurationChanged(Configuration newConfig) {

			super.onConfigurationChanged(newConfig);

			viewFlow.onConfigurationChanged(newConfig);

		}



## Contributions

The following persons deserves a mention for their contributions:



* Eric Taix

* Marc Reichelt, 



### Want to contribute?



GitHub has some great articles on [how to get started with Git and GitHub](http://help.github.com/) and how to [fork a project](http://help.github.com/forking/).



Contributers are recommended to fork the app on GitHub (but don't have too). Create a feature branch, push the branch to git hub, press Pull Request and write a simple explanation.



One fix per commit. If let's say a commit closes the open issue 12. Just add `closes #12` in your commit message to close that issue automagically.



If you still feel uncomfortable contributing the project github-wise, don't hesistate to send a regular patch.



All code that is contributed must be compliant with [Apache License 2.0](http://www.apache.org/licenses/LICENSE-2.0.html).



## License

Copyright (c) 2011 [Patrik Åkerfeldt](http://about.me/pakerfeldt)



Licensed under the [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0.html)



![ViewFlow for Android](https://github.com/pakerfeldt/android-viewflow/raw/master/viewflow-example/screen.png "ViewFlow for Android")    ![ViewFlow for Android](https://github.com/pakerfeldt/android-viewflow/raw/master/viewflow-example/screen2.png "ViewFlow for Android")