TreeView

Additional

Language
Java
Version
v0.5.0 (Feb 1, 2019)
Created
Feb 21, 2018
Updated
Feb 4, 2019
Owner
Team-Blox
Contributors
block (DennisBlock)
GregorBlock
2
Activity
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Source code
APK file

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Note: This library is in an early stage of development. There will be breaking changes to the public API until the first stable version is released.

GraphView

Android GraphView is used to display data in graph structures.

Overview

The library is designed to support different graph layouts.

Download

dependencies {
    implementation 'de.blox:graphview:0.5.0'
}

Layouts

Tree

Uses Walker's algorithm with Buchheim's runtime improvements (BuchheimWalkerAlgorithm class). Supports different orientations. All you have to do is using the BuchheimWalkerConfiguration.Builder.setOrientation(int) with either ORIENTATION_LEFT_RIGHT, ORIENTATION_RIGHT_LEFT, ORIENTATION_TOP_BOTTOM and ORIENTATION_BOTTOM_TOP (default). Furthermore parameters like sibling-, level-, subtree separation can be set.

Directed graph

Directed graph drawing by simulating attraction/repulsion forces. For this the algorithm by Fruchterman and Reingold (FruchtermanReingoldAlgorithm class) was implemented (currently works only for small graphs).

Layered graph

Algorithm from Sugiyama et al. for drawing multilayer graphs, taking advantage of the hierarchical structure of the graph (SugiyamaAlgorithm class). You can also set the parameters for node and level separation using the SugiyamaConfiguration.Builder.

Usage

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <de.blox.graphview.GraphView
     android:id="@+id/graph"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
    </de.blox.graphview.GraphView>
</LinearLayout>

You can make the node Layout how you like. Just define a layout file, e.g. node.xml ...

<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
                                    xmlns:card_view="http://schemas.android.com/apk/res-auto"
                                    android:id="@+id/card_view"
                                    android:layout_width="match_parent"
                                    android:layout_height="wrap_content"
                                    android:layout_gravity="center"
                                    android:layout_margin="5dp"
                                    card_view:cardBackgroundColor="@android:color/holo_blue_dark"
                                    card_view:cardElevation="16dp"
                                    card_view:contentPadding="10dp">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <TextView
            android:id="@+id/textView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="@android:color/white"
            android:textStyle="bold"/>

    </LinearLayout>
</android.support.v7.widget.CardView>

... and use it with the adapter

public class MainActivity extends AppCompatActivity {
    private int nodeCount = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        GraphView graphView = findViewById(R.id.graph);

        // example tree
        final Graph graph = new Graph();
        final Node node1 = new Node(getNodeText());
        final Node node2 = new Node(getNodeText());
        final Node node3 = new Node(getNodeText());
        final Node node4 = new Node(getNodeText());
        final Node node5 = new Node(getNodeText());
        final Node node6 = new Node(getNodeText());
        final Node node8 = new Node(getNodeText());
        final Node node7 = new Node(getNodeText());
        final Node node9 = new Node(getNodeText());
        final Node node10 = new Node(getNodeText());
        final Node node11 = new Node(getNodeText());
        final Node node12 = new Node(getNodeText());

        graph.addEdge(node1, node2);
        graph.addEdge(node1, node3);
        graph.addEdge(node1, node4);
        graph.addEdge(node2, node5);
        graph.addEdge(node2, node6);
        graph.addEdge(node6, node7);
        graph.addEdge(node6, node8);
        graph.addEdge(node4, node9);
        graph.addEdge(node4, node10);
        graph.addEdge(node4, node11);
        graph.addEdge(node11, node12);

        // you can set the graph via the constructor or use the adapter.setGraph(Graph) method
        final BaseGraphAdapter<ViewHolder> adapter = new BaseGraphAdapter<ViewHolder>(this, R.layout.node, graph) {
            @NonNull
            @Override
            public ViewHolder onCreateViewHolder(View view) {
                return new ViewHolder(view);
            }

            @Override
            public void onBindViewHolder(ViewHolder viewHolder, Object data, int position) {
                viewHolder.mTextView.setText(data.toString());
            }
        };
        graphView.setAdapter(adapter);
        
        // set the algorithm here
        final BuchheimWalkerConfiguration configuration = new BuchheimWalkerConfiguration.Builder()
                .setSiblingSeparation(100)
                .setLevelSeparation(300)
                .setSubtreeSeparation(300)
                .setOrientation(BuchheimWalkerConfiguration.ORIENTATION_TOP_BOTTOM)
                .build();
        adapter.setAlgorithm(new BuchheimWalkerAlgorithm(configuration));
    }
    
    private String getNodeText() {
        return "Node " + nodeCount++;
    }
}

ViewHolder class:

    private class ViewHolder {
        TextView mTextView;
        ViewHolder(View view) {
            mTextView = view.findViewById(R.id.textView);
        }
    }

Customization

To use the custom attributes you have to add the namespace first: xmlns:app="http://schemas.android.com/apk/res-auto"

Attribute Format Example Explanation
lineThickness Dimension 10dp Set how thick the connection lines should be
lineColor Color "@android:color/holo_red_dark" Set the color of the connection lines
useMaxSize Boolean true Use the same size for each node

Each of the attributes has a corresponding setter in the GraphView class, if you want to use it programmatically.

GraphView internally uses ZoomLayout for its zoom feature. To change the zoom values just use the different attributes described in the ZoomLayout project site.

Examples

Rooted Tree

Directed Graph

Layered Graph

License

Copyright 2019 Team-Blox

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.