Tree view in android

Android TreeView Examples

In this piece we want to look at TreeView examples in android. TreeView isn’t built into the android sdk but developers have created a few libraries that allow us implement a treeview with most of the features that you would expect in such a widget.

Example 1: Android DraggableTreeView – Drag and Nest TreeNodes

This is an android draggabletreeview tutorial. This is a custom adapter view that can render items in a tree manner. The nodes in the tree can then be dragged and nested infinitely.

It’s quite easy to use, once we’ve added dragtreeview component in our xml layout, we then reference it inside our mainactivity. We then instantiate as many treenodes as we like.

We can nest the items by adding them as children to specific treenodes. Of course we can do this programmatically in code or at runtime.

Views are nestable even at runtime. This is an adapterview, so we have SimpleTreeViewAdapter class. We instantiate it passing in the context as well as our root treenode. We this set adapter to our draggabletreeview.

It’s that simple. We use a DraggableTreeView library by Jake Bonk. The library is hosted in jitpack.io. You can find more details about the library here.

Screenshot

• Here’s the screenshot of the project.

Android DraggableTreeView Example

Common Questions this example explores

• Android DraggableTreeView Example.
• Android TreeView example tutorial java.
• How to drag and drop item views in a treeview in android.
• Android nesting views with draggabletreeview.
• Android Drag tree tutorial and example.
• Android SimpleTreeview adapter

Tools Used

This example was written with the following tools:

• Windows 8
• AndroidStudio IDE
• Genymotion Emulator
• Language : Java
• Topic : DraggableTreeView, TreeView Adapter, Drag Drop treenodes

Libaries Used

Let’s go.

1. Build.Gradle(Project)

Lets jump directly to the source code. Build.Gradle(Project)

• Project-level build.gradle.
• We specify the repository where our draggabletreeview library will be fetched from, in this jitpack.io.

2. Build.Gradle(App)

• App-level build.gradle.
• We add dependencies here. Add the dependency for draggabletreeview as shown below.
• Normally in android projects, there are two build.gradle files. One is the app level build.gradle, the other is project level build.gradle. The app level belongs inside the app folder and its where we normally add our dependencies and specify the compile and target sdks.
• Also Add dependencies for AppCompat and Design support libraries.
• Our MainActivity shall derive from AppCompatActivity while we shall also use Floating action button from design support libraries.

3. MainActivity.java

• Launcher activity.
• ActivityMain.xml inflated as the contentview for this activity.
• We initialize views and widgets inside this activity.
• We use DraggableTreeView as our adapterview and SimpleTreeViewAdapter as our adapter.
• We instantiate and add nodes here.

4. ActivityMain.xml

• Template layout.
• Contains our ContentMain.xml.
• Also defines the appbarlayout, toolbar as well as floatingaction buttton.

5. ContentMain.xml

• Content Layout.
• Defines the views and widgets to be displayed inside the MainActivity.
• In this case its a simple draggabletreeview.

How To Run

1. Download the project.
2. You’ll get a zipped file,extract it.
3. Open the Android Studio.
4. Now close, already open project.
5. From the Menu bar click on File >New> Import Project.
6. Now Choose a Destination Folder, from where you want to import project.
7. Choose an Android Project.
8. Now Click on “OK“.
9. Done, your done importing the project,now edit it.

Conclusion.

This was a simple android draggabletreeview example. How to bind data using simpletreeadapter, add treenodes and nest them both programmatically and at runtime.

More Resources

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GitHub Browse	Browse
GitHub Download Link	Download
Video	YouTube Video

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TreeView in Android with Example

If you are looking for the new UI designs for the representation of huge data, then there are so many ways for the representation of this type of data. You can use pie charts, graphs, and many more view types for the implementation of these views. For displaying such huge data then we can prefer using a TreeView. TreeView is similar to that of a tree in which it is having a parent node and inside that parent node, you can create multiple nodes according to requirement. In this example, we can take a look at creating a TreeView in your Android application. Now we will move towards the implementation of Tree View. Note that we are going to implement this project using the Java language.

What is TreeView and How it looks?

TreeView is a pattern for the representation of data in the form of the tree so that it becomes easier for users to understand the organization of data in our app. A sample image is given below to get an idea of how TreeView looks like.

Example

Step 1: Create a New Project

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.

Step 2: Add dependency to build.gradle(Module:app)

Navigate to the Gradle Scripts > build.gradle(Module:app) and add the below dependency in the dependencies section.

After adding this dependency sync your project and now we will move towards its implementation.

Источник

AndroidTreeView. TreeView implementation for android

Related tags

Overview

2D scrolling mode added, keep in mind this comes with few limitations: you won’t be able not place views on right side like alignParentRight. Everything should be align left. Is not enabled by default

Tree view implementation for android

• 1. N — level expandable/collapsable tree
• 1. Custom values, views, styles for nodes
• 1. Save state after rotation
• 1. Selection mode for nodes
• 1. Dynamic add/remove node

• For Android 4.0 (+/- nearest version) if you have too deep view hierarchy and with tree its easily possible, your app may crash

1) Add library as a dependency to your project

2) Create your tree starting from root element. TreeNode.root() element will not be displayed so it doesn’t require anything to be set.

Create and add your nodes (use your custom object as constructor param)

3) Add tree view to layout

The simplest but not styled tree is ready. Now you can see parent node as root of your tree

4) Custom view for nodes

Extend TreeNode.BaseNodeViewHolder and overwrite createNodeView method to prepare custom view for node:

5) Connect view holder with node

6) Consider using

For more details use sample application as example

Let me know if i missed something, appreciate your support, thanks!

Projects using this library

Issues

Dynamic Add/Remove Node

I need dynamic creation of Nodes on Expanding the Parent.. So how can i achieve this ?

Remove the default listener and handle Node expansion manually

I have tried to do treeView.setDefaultNodeClickListener(null); and then do this code whenever I’m creating a new node:

But when I do this, both actions happen; The node expands/collapses and the item opens in a new activity, how can I disable the default node listener so that I can let the arrow button on the far right of my layout be responsible for expanding and collapsing items?

How to get name of selected nodes ?

How can I get the name of the selected nodes?

Strange treeView.getView() returns null

This code runs through my parent Task objects and for each one of its children, it gets the children and adds them to that parent, then to the root, then again for all the remaining parents. At the end, it makes a new AndroidTreeView and set its properties and then should add that TreeView to the containerView I have defined (RelativeLayout cast into ViewGroup), just as your code says. processTasks(allTasks) is called only once.

Seems strange that there would be an exception and I looked through all the issues, no one faced this..any help would be appreciated, thanks!

How do you know in the Activity or Fragment when a checkbox has been checked?

How do you know in the Activity or Fragment when a checkbox has been checked?

Crash when nodes more than 7 level

In Folder Structure Example application when nodes get more than 7 level app will crash.

Implement selectable background

I need to display a background when I select a node like select element of ListView , I’m trying to set a background in nodeClickListener but doesn’t work, any way to solve this? Thanks.

Child node layout doesn’t leave a gap on the left.

Right now, my tree view looks like a normal list. The children don’t move to the left. I had compared the project’s sample but there isn’t any different. What am I missing?

Padding Issue

No Space as in Image for Folder Structure before icon.

[Question] TreeView in fragment

I used to have my TreeView created in the main Activity. I move it to a Fragment but now nothing show up. I followed your samples but i can’t find my mistake. I hope you can help me.

Here is my Fragment creation:

And here is my fragment layout:

The fragment is added in the actvity xml layout.

Источник

Tree view in android

2D scrolling mode added, keep in mind this comes with few limitations: you won’t be able not place views on right side like alignParentRight. Everything should be align left. Is not enabled by default

Tree view implementation for android

• 1. N — level expandable/collapsable tree
• 1. Custom values, views, styles for nodes
• 1. Save state after rotation
• 1. Selection mode for nodes
• 1. Dynamic add/remove node

• For Android 4.0 (+/- nearest version) if you have too deep view hierarchy and with tree its easily possible, your app may crash

1) Add library as a dependency to your project

2) Create your tree starting from root element. TreeNode.root() element will not be displayed so it doesn’t require anything to be set.

Create and add your nodes (use your custom object as constructor param)

3) Add tree view to layout

The simplest but not styled tree is ready. Now you can see parent node as root of your tree

4) Custom view for nodes

Extend TreeNode.BaseNodeViewHolder and overwrite createNodeView method to prepare custom view for node:

5) Connect view holder with node

6) Consider using

For more details use sample application as example

Let me know if i missed something, appreciate your support, thanks!

Источник

Tree view in android

Provide configurable tree view list for android devices

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README.md

This is a small widget that provides quite configurable tree view list. It is based on standard android list view.

Note that using generic tree is probably not the best approach for Android (or any other mobile) UI. See http://developer.android.com/design/index.html for all the control that it makes sense to use. Thus tree view should be considered as deprecated.

The widget is fully configurable — with your custom adapter you can provide your own implementation of the item views — even completely different implementation of item views depending on the tree level you are at. Implementation follows best approach of Adapters from android so views at the same tree level are reusable.

The whole project can be included as external android library. After unsetting the «isLibrary?» flag, the project can also be compiled and installed on its own — providing demo application that presents capability of the widget. It shows how the tree behaves dynamically including explanding and collapsing nodes for many/all node, providing context menu for the tree, custom tree view with checkboxes only available for leaf nodes, custom colouring and different text sizes for text for different levels of the tree (albeit ugly) of the tree. The activity handling it is TreeViewListDemo.java, adapters used are SimpleStandardAdapter.java and extending it, colorful FancyColouredVariousSizesAdapter.java. Layout for tree items is defined in demo_list_item.xml. You can learn from the demo how to use the widget. The tree can be configured through XML layout file (attributes are defined in attrs.xml ).

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Provide configurable tree view list for android devices

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