Class Tree

java.lang.Object
com.codename1.ui.Component
com.codename1.ui.Container
com.codename1.ui.tree.Tree
All Implemented Interfaces:
Animation, Editable, StyleListener, Iterable<Component>
Direct Known Subclasses:
FileTree
public class Tree extends Container

The Tree component allows constructing simple tree component hierarchies that can be expanded seamlessly with no limit. The tree is bound to a model that can provide data with free form depth such as file system or similarly structured data.

To customize the look of the tree the component can be derived and component creation can be replaced.

class StringArrayTreeModel implements TreeModel {
    String[][] arr = new String[][] {
            {"Colors", "Letters", "Numbers"},
            {"Red", "Green", "Blue"},
            {"A", "B", "C"},
            {"1", "2", "3"}
        };

    public Vector getChildren(Object parent) {
        if(parent == null) {
            Vector v = new Vector();
            for(int iter = 0 ; iter  iter + 1 && arr[iter + 1] != null) {
                    for(int i = 0 ; i

And heres a more "real world" example showing an XML hierarchy in a `Tree`:

```java
class XMLTreeModel implements TreeModel {
private Element root;
public XMLTreeModel(Element e) {
root = e;
}

public Vector getChildren(Object parent) {
if(parent == null) {
Vector c = new Vector();
c.addElement(root);
return c;
}
Vector result = new Vector();
Element e = (Element)parent;
for(int iter = 0 ; iter

Another real world example showing the `com.codename1.io.FileSystemStorage` as a tree:

```java
Form hi = new Form("FileSystemTree", new BorderLayout());
TreeModel tm = new TreeModel() {
@Override
    public Vector getChildren(Object parent) {
        String[] files;
        if(parent == null) {
            files = FileSystemStorage.getInstance().getRoots();
            return new Vector(Arrays.asList(files));
        } else {
            try {
                files = FileSystemStorage.getInstance().listFiles((String)parent);
            } catch(IOException err) {
                Log.e(err);
                files = new String[0];
            }
        }
        String p = (String)parent;
        Vector result = new Vector();
        for(String s : files) {
            result.add(p + s);
        }
        return result;
    }
@Override
    public boolean isLeaf(Object node) {
        return !FileSystemStorage.getInstance().isDirectory((String)node);
    }
};
Tree t = new Tree(tm) {
@Override
    protected String childToDisplayLabel(Object child) {
        String n = (String)child;
        int pos = n.lastIndexOf("/");
        if(pos
@author Shai Almog

  • Constructor Details

    • Tree

      public Tree()
      Constructor for usage by GUI builder and automated tools, normally one should use the version that accepts the model

    • Tree

      public Tree(TreeModel model)

      Construct a tree with the given tree model

      Parameters
      • model: represents the contents of the tree

  • Method Details

    • setFolderIcon

      public static void setFolderIcon(Image folderIcon)

      Sets the icon for a tree folder

      Parameters
      • folderIcon: the icon for a folder within the tree

    • setFolderOpenIcon

      public static void setFolderOpenIcon(Image folderIcon)

      Sets the icon for a tree folder in its expanded state

      Parameters
      • folderIcon: the icon for a folder within the tree

    • setNodeIcon

      public static void setNodeIcon(Image nodeIcon)

      Sets the icon for a tree node

      Parameters
      • nodeIcon: the icon for a node within the tree

    • getTreeState

      public Tree.TreeState getTreeState()

      Gets the state of the tree in a format that can be restored later by either the same tree or a different tree whose model includes the same nodes.

      Returns

      A TreeState object that can be passed to #setTreeState(com.codename1.ui.tree.Tree.TreeState)

    • setTreeState

      public void setTreeState(Tree.TreeState state)

      Sets the tree state.

      Parameters
      • state: The state, which was returned from the #getTreeState() method.

    • isMultilineMode

      public boolean isMultilineMode()

      Toggles a mode where rows in the tree can be broken since span buttons will be used instead of plain buttons.

      Returns

      the multilineMode

    • setMultilineMode

      public void setMultilineMode(boolean multilineMode)

      Toggles a mode where rows in the tree can be broken since span buttons will be used instead of plain buttons.

      Parameters
      • multilineMode: the multilineMode to set

    • getPropertyNames

      public String[] getPropertyNames()

      A component may expose mutable property names for a UI designer to manipulate, this API is designed for usage internally by the GUI builder code

      Returns

      the property names allowing mutation

      Overrides:
      getPropertyNames in class Component

    • getPropertyTypes

      public Class[] getPropertyTypes()

      Matches the property names method (see that method for further details).

      Returns

      the types of the properties

      Overrides:
      getPropertyTypes in class Component

    • getPropertyTypeNames

      public String[] getPropertyTypeNames()

      This method is here to workaround an XMLVM array type bug where property types aren't identified properly, it returns the names of the types using the following type names: String,int,double,long,byte,short,char,String[],String[][],byte[],Image,Image[],Object[],ListModel,ListCellRenderer

      Returns

      Array of type names

      Overrides:
      getPropertyTypeNames in class Component

    • getPropertyValue

      public Object getPropertyValue(String name)

      Returns the current value of the property name, this method is used by the GUI builder

      Parameters
      • name: the name of the property
      Returns

      the value of said property

      Overrides:
      getPropertyValue in class Component

    • setPropertyValue

      public String setPropertyValue(String name, Object value)

      Sets a new value to the given property, returns an error message if failed and null if successful. Notice that some builtin properties such as "$designMode" might be sent to components to indicate application state.

      Parameters

      • name: the name of the property

      • value: new value for the property

      Returns

      error message or null

      Overrides:
      setPropertyValue in class Component

    • getModel

      public TreeModel getModel()

      Returns the tree model instance

      Returns

      the tree model

    • setModel

      public void setModel(TreeModel model)

      Sets the tree model to a new value

      Parameters
      • model: the model of the tree

    • isExpanded

      protected boolean isExpanded(Component node)

      This method returns true if the given node is expanded.

      Parameters
      • node: a Component that represents a tree node.
      Returns

      true if this tree node is expanded

    • findNodeComponent

      public Component findNodeComponent(Object node)

      Finds the component for a model node.

      Parameters
      • node: The node from the model.
      Returns

      The corresponding component in the UI or null if not found.

      Since

      7.0

    • findNodeComponent

      public Component findNodeComponent(Object node, Component root)

      Finds the component for a model node.

      Parameters

      • node: Model node whose view we seek.

      • root: A root component - we check root and its descendents.

      Returns

      The corresponding UI component for node, or null if not found.

      Since

      7.0

    • expandPath

      public void expandPath(Object... path)

      Expands the tree path

      Parameters
      • path: the path to expand

    • expandPath

      public void expandPath(boolean animate, Object... path)

      Expands the tree path

      Parameters

      • path: the path to expand

      • animate: whether to animate expansion

    • collapsePath

      public void collapsePath(Object... path)

      Collapses the last element in the path

      Parameters
      • path: the path to the element that should be collapsed

    • getSelectedItem

      public Object getSelectedItem()

      Returns the currently selected item in the tree

      Returns

      the object selected within the tree

    • getParentNode

      public Object getParentNode(Component nodeComponent)

      Gets the parent model node for a component.

      Parameters
      • nodeComponent: The UI for a node.
      Returns

      The model node's parent, or null if not found.

    • getParentComponent

      public Component getParentComponent(Component nodeComponent)

      Gets the UI component corresponding to the parent model mode of the node corresponding with the given UI component.

      Parameters
      • nodeComponent: UI component, whose node we seek the parent.
      Returns

      UI component for the given node's parent.

      Since

      7.0

    • refreshNode

      public void refreshNode(Component nodeComponent)

      Refreshes a node of the tree.

      Parameters
      • nodeComponent: The node component.
      Since

      7.0

    • createNodeComponent

      protected Button createNodeComponent(Object node, int depth)

      Creates a node within the tree, this method is protected allowing tree to be subclassed to replace the rendering logic of individual tree buttons.

      Parameters

      • node: the node object from the model to display on the button

      • depth: the depth within the tree (normally represented by indenting the entry)

      Returns

      a button representing the node within the tree

      Deprecated

      replaced with createNode, bindNodeListener and setNodeIcon

    • bindNodeListener

      protected void bindNodeListener(ActionListener l, Component node)

      Since a node may be any component type developers should override this method to add support for binding the click listener to the given component.

      Parameters

      • l: listener interface

      • node: node component returned by createNode

    • setNodeIcon

      protected void setNodeIcon(Image icon, Component node)

      Sets the icon for the given node similar in scope to bindNodeListener

      Parameters

      • icon: the icon for the node

      • node: the node instance

    • setNodeMaterialIcon

      protected void setNodeMaterialIcon(char c, Component node, float size)

      Sets material icon for the node.

      Parameters

      • c: Material icon code. See FontImage

      • node: The node to set the icon for.

      • size: The size in millimetres for the icon.

      Since

      7.0

    • createNode

      protected Component createNode(Object node, int depth)

      Creates a node within the tree, this method is protected allowing tree to be subclassed to replace the rendering logic of individual tree buttons.

      Parameters

      • node: the node object from the model to display on the button

      • depth: the depth within the tree (normally represented by indenting the entry)

      Returns

      a button representing the node within the tree

    • childToDisplayLabel

      protected String childToDisplayLabel(Object child)

      Converts a tree child to a label, this method can be overriden for simple rendering effects

      Returns

      a string representing the given tree node

    • addLeafListener

      public void addLeafListener(ActionListener l)

      A listener that fires when a leaf is clicked

      Parameters
      • l: listener to fire when the leaf is clicked

    • removeLeafListener

      public void removeLeafListener(ActionListener l)

      Removes the listener that fires when a leaf is clicked

      Parameters
      • l: listener to remove

    • getModel

      protected Object getModel(Component node)

      Gets the model for a component in the tree.

      Parameters
      • node: The component whose model we want to obtain.
      Returns

      The model.

      Since

      7.0

    • calcPreferredSize

      protected Dimension calcPreferredSize()

      Calculates the preferred size based on component content. This method is invoked lazily by getPreferred size.

      Returns

      the calculated preferred size based on component content

      Overrides:
      calcPreferredSize in class Container