added jtree support

src/mdlaf/MaterialColors.java

@@ -13,4 +13,6 @@ public static Color bleach (Color color, float amount) {
 		int blue = (int) ((color.getBlue () * (1 - amount) / 255 + amount) * 255);
 		return new Color (red, green, blue);
 	}
+
+	private MaterialColors () {}
 }

src/mdlaf/MaterialImages.java

@@ -0,0 +1,24 @@
+package mdlaf;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.io.InputStream;
+
+public class MaterialImages {
+
+	public static final BufferedImage RIGHT_ARROW = loadImg ("/imgs/right_arrow.png");
+	public static final BufferedImage DOWN_ARROW = loadImg ("/imgs/down_arrow.png");
+
+	private static BufferedImage loadImg (String imgPath) {
+		try (InputStream inputStream = MaterialImages.class.getResourceAsStream (imgPath)) {
+			return ImageIO.read (inputStream);
+		}
+		catch (IOException e) {
+			e.printStackTrace ();
+			throw new RuntimeException ("Image " + imgPath + " wasn't loaded");
+		}
+	}
+
+	private MaterialImages () {}
+}

src/mdlaf/MaterialLookAndFeel.java

@@ -5,6 +5,7 @@
 import mdlaf.table.MaterialTableHeaderUI;
 import mdlaf.table.MaterialTableUI;
 import mdlaf.textfield.MaterialTextFieldUI;
+import mdlaf.tree.MaterialTreeUI;
 
 import javax.swing.BorderFactory;
 import javax.swing.UIDefaults;
@@ -18,21 +19,22 @@ public class MaterialLookAndFeel extends BasicLookAndFeel {
 	private static final String passwordFieldUI = MaterialPasswordFieldUI.class.getCanonicalName ();
 	private static final String tableUI = MaterialTableUI.class.getCanonicalName ();
 	private static final String tableHeaderUI = MaterialTableHeaderUI.class.getCanonicalName ();
+	private static final String treeUI = MaterialTreeUI.class.getCanonicalName ();
 
 	@Override
 
 	public String getName () {
-		return "mdlaf.MaterialLookAndFeel";
+		return "Material Look And Feel";
 	}
 
 	@Override
 	public String getID () {
-		return "mdlaf.MaterialLookAndFeel";
+		return "MaterialLookAndFeel";
 	}
 
 	@Override
 	public String getDescription () {
-		return "A modern, Material Design UI for Java Swing";
+		return "A modern Material Design UI for Java Swing";
 	}
 
 	@Override
@@ -53,6 +55,7 @@ protected void initClassDefaults (UIDefaults table) {
 		table.put ("PasswordFieldUI", passwordFieldUI);
 		table.put ("TableUI", tableUI);
 		table.put ("TableHeaderUI", tableHeaderUI);
+		table.put ("TreeUI", treeUI);
 	}
 
 	@Override

src/mdlaf/button/MaterialButtonUI.java

@@ -47,4 +47,9 @@ private void paintBackground (final Graphics g, final JComponent c) {
 		g.setColor (c.getBackground ());
 		g.fillRoundRect (0, 0, c.getWidth (), c.getHeight (), 7, 7);
 	}
+
+	@Override
+	public String getPropertyPrefix () {
+		return "Button";
+	}
 }

src/mdlaf/password/MaterialPasswordFieldUI.java

@@ -146,12 +146,12 @@ public void paintBackground (final Graphics g) {
 
 	@Override
 	public void focusGained (FocusEvent e) {
-		getComponent ().setBackground (focusedBackground);
+		e.getComponent ().setBackground (focusedBackground);
 	}
 
 	@Override
 	public void focusLost (FocusEvent e) {
-		getComponent ().setBackground (unfocusedBackground);
+		e.getComponent ().setBackground (unfocusedBackground);
 	}
 
 	@Override

src/mdlaf/table/MaterialTableCellEditor.java

@@ -10,7 +10,7 @@ public class MaterialTableCellEditor extends DefaultCellEditor {
 	@Override
 	public Component getTableCellEditorComponent (JTable table, Object value, boolean isSelected, int rowIndex, int vColIndex) {
 		JTextField textField = (JTextField) super.getTableCellEditorComponent (table, value, isSelected, rowIndex, vColIndex);
-		textField.setText ((String) value);
+		textField.setText (value.toString ());
 
 		return textField;
 	}

src/mdlaf/textfield/MaterialTextFieldUI.java

@@ -147,12 +147,12 @@ public void paintBackground (final Graphics g) {
 
 	@Override
 	public void focusGained (FocusEvent e) {
-		getComponent ().setBackground (focusedBackground);
+		e.getComponent ().setBackground (focusedBackground);
 	}
 
 	@Override
 	public void focusLost (FocusEvent e) {
-		getComponent ().setBackground (unfocusedBackground);
+		e.getComponent ().setBackground (unfocusedBackground);
 	}
 
 	@Override

src/mdlaf/tree/MaterialTreeCellEditor.java

@@ -0,0 +1,48 @@
+package mdlaf.tree;
+
+import javax.swing.JTextField;
+import javax.swing.JTree;
+import javax.swing.tree.DefaultTreeCellEditor;
+import javax.swing.tree.DefaultTreeCellRenderer;
+import javax.swing.tree.TreeCellEditor;
+import java.awt.Component;
+import java.awt.event.KeyAdapter;
+import java.awt.event.KeyEvent;
+
+public class MaterialTreeCellEditor extends DefaultTreeCellEditor {
+
+	private JTextField textField;
+
+	private void init () {
+		textField = new JTextField ();
+
+		textField.addKeyListener (new KeyAdapter () {
+			@Override
+			public void keyTyped (KeyEvent e) {
+				if (e.getKeyChar () == KeyEvent.VK_ENTER)
+					stopCellEditing ();
+			}
+		});
+	}
+
+	@Override
+	public Component getTreeCellEditorComponent (JTree tree, Object value, boolean isSelected, boolean expanded, boolean leaf, int row) {
+		textField.setText (value.toString ());
+		return textField;
+	}
+
+	@Override
+	public Object getCellEditorValue () {
+		return textField.getText ();
+	}
+
+	public MaterialTreeCellEditor (JTree tree, DefaultTreeCellRenderer renderer) {
+		super (tree, renderer);
+		init ();
+	}
+
+	public MaterialTreeCellEditor (JTree tree, DefaultTreeCellRenderer renderer, TreeCellEditor editor) {
+		super (tree, renderer, editor);
+		init ();
+	}
+}

src/mdlaf/tree/MaterialTreeCellRenderer.java

@@ -0,0 +1,39 @@
+package mdlaf.tree;
+
+import mdlaf.MaterialColors;
+import mdlaf.MaterialFonts;
+import mdlaf.MaterialImages;
+
+import javax.swing.BorderFactory;
+import javax.swing.ImageIcon;
+import javax.swing.JComponent;
+import javax.swing.JTree;
+import javax.swing.tree.DefaultTreeCellRenderer;
+import java.awt.Color;
+import java.awt.Component;
+
+public class MaterialTreeCellRenderer extends DefaultTreeCellRenderer {
+
+	@Override
+	public Component getTreeCellRendererComponent (JTree tree, Object value, boolean isSelected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
+		JComponent component = (JComponent) super.getTreeCellRendererComponent (tree, value, isSelected, expanded, leaf, row, hasFocus);
+		component.setBorder (BorderFactory.createEmptyBorder (5, 2, 5, 2));
+
+		return component;
+	}
+
+	public MaterialTreeCellRenderer () {
+		setTextSelectionColor (Color.BLACK);
+		setTextNonSelectionColor (Color.BLACK);
+
+		setBackgroundSelectionColor (MaterialColors.LIGHT_GRAY);
+		setBackgroundNonSelectionColor (Color.WHITE);
+
+		setBorderSelectionColor (null);
+
+		setClosedIcon (new ImageIcon (MaterialImages.RIGHT_ARROW));
+		setOpenIcon (new ImageIcon (MaterialImages.DOWN_ARROW));
+
+		setFont (MaterialFonts.REGULAR);
+	}
+}

src/mdlaf/tree/MaterialTreeUI.java

@@ -0,0 +1,37 @@
+package mdlaf.tree;
+
+import mdlaf.MaterialFonts;
+
+import javax.swing.JComponent;
+import javax.swing.JTree;
+import javax.swing.plaf.ComponentUI;
+import javax.swing.plaf.basic.BasicTreeUI;
+import javax.swing.tree.DefaultTreeCellRenderer;
+import javax.swing.tree.TreeCellEditor;
+
+public class MaterialTreeUI extends BasicTreeUI {
+
+	public static ComponentUI createUI (final JComponent c) {
+		return new MaterialTreeUI ();
+	}
+
+	@Override
+	public void installUI (JComponent c) {
+		super.installUI (c);
+		JTree tree = (JTree) c;
+
+		DefaultTreeCellRenderer renderer = new MaterialTreeCellRenderer ();
+		TreeCellEditor editor = new MaterialTreeCellEditor (tree, renderer);
+
+		tree.setCellRenderer (renderer);
+		tree.setCellEditor (editor);
+
+		tree.setFont (MaterialFonts.REGULAR);
+		tree.setRowHeight (0);
+		tree.setInvokesStopCellEditing (true);
+
+		MaterialTreeUI ui = (MaterialTreeUI) tree.getUI ();
+		ui.setLeftChildIndent (10);
+		ui.setRightChildIndent (10);
+	}
+}