tests/org.eclipse.swt.tests.gtk/ManualTests/org/eclipse/swt/tests/manualJUnit/MJ_Tree.java - platform/eclipse.platform.swt - Git at Google

 /*******************************************************************************
  * Copyright (c) 2018 Red Hat and others. All rights reserved.
  * The contents of this file are made available under the terms
  * of the GNU Lesser General Public License (LGPL) Version 2.1 that
  * accompanies this distribution (lgpl-v21.txt).  The LGPL is also
  * available at http://www.gnu.org/licenses/lgpl.html.  If the version
  * of the LGPL at http://www.gnu.org is different to the version of
  * the LGPL accompanying this distribution and there is any conflict
  * between the two license versions, the terms of the LGPL accompanying
  * this distribution shall govern.
  *
  * Contributors:
  *     Red Hat - initial API and implementation
  */
 package org.eclipse.swt.tests.manualJUnit;

 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.ControlAdapter;
 import org.eclipse.swt.events.ControlEvent;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.layout.FillLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.Tree;
 import org.eclipse.swt.widgets.TreeColumn;
 import org.eclipse.swt.widgets.TreeItem;
 import org.junit.FixMethodOrder;
 import org.junit.Test;
 import org.junit.runners.MethodSorters;

 /** Convienience class for easy copy & paste */
 @FixMethodOrder(MethodSorters.JVM)
 public class MJ_Tree extends MJ_root {


 	// Shared elements:
 		final Listener ownerDrawnListener = event -> {
 			final TreeItem item = (TreeItem)event.item;
 			Tree tree = item.getParent();
 			AtomicBoolean packpending = (AtomicBoolean) tree.getData();

 			if (event.type == SWT.EraseItem) {
 			}

 			if (event.type == SWT.PaintItem) {
 				final String text1 = (String)item.getData() + " (gc)";
 				if (event.index == 0) {
 					event.gc.drawText(text1, event.x, event.y, true);
 				}
 			}
 			if (event.type == SWT.MeasureItem) {
 				event.height = 50;
 				event.width =  100;
 			}
 			if (event.type == SWT.SetData) {
 				final int index = tree.indexOf(item);
 				final String data = "Virtual item:" + index;
 				item.setData(data);
 				item.setText("VirtItem " + index);
 				if (tree.getColumnCount() > 1) {
 					for (int i = 1; i <= tree.getColumnCount(); i++) {
 						item.setText(i, " Col: " + i + "   " + data);
 					}
 				}

 				if (packpending.get()) {
 					packpending.set(false);
 					display.asyncExec(() -> {
 						tree.setRedraw(false);
 						for (TreeColumn column : tree.getColumns()) {
 							column.pack();
 						}
 						tree.setRedraw(true);
 					});
 				}
 			}
 		};

 	/**
 	 *  <a href="https://bugs.eclipse.org/bugs/attachment.cgi?id=272647">Screenshot </a>
 	 */
 	@Test
 	public void ownerDrawn_cheese_single_col () {
 		knownToBeBrokenGtk3("Cheese on gtk3"); // z for warning
 		Shell shell = mkShell("Expected: There should be no cheese in the items. Move over shouldn't cheese out. See javadoc for screenshot");
 		shell.setLayout(new FillLayout(SWT.VERTICAL));

 		final Tree tree = new Tree(shell, SWT.VIRTUAL | SWT.BORDER |  SWT.H_SCROLL | SWT.V_SCROLL);

 		AtomicBoolean packpending = new AtomicBoolean(true);
 		tree.setData(packpending);

 		tree.addListener(SWT.EraseItem, 	ownerDrawnListener); // Not relevant.
 		tree.addListener(SWT.SetData, 		ownerDrawnListener);
 		tree.addListener(SWT.MeasureItem,  ownerDrawnListener);
 		tree.addListener(SWT.PaintItem, 	ownerDrawnListener);

 		final TreeColumn treeColumn = new TreeColumn(tree, SWT.LEFT);
 		treeColumn.setText("First Left Column");
 		treeColumn.setMoveable(true);

 		tree.setItemCount(100);

 		shell.setSize(800, 600); // Shell size seems to have a little bit of an initial impact. (may show proper with some shell sizes, incorrectly for others).
 		shell.open();
 		mainLoop(shell);
 	}

 	@Test
 	public void ownerDrawn_cheese_multiple_col() {
 		final Shell shell = mkShell("Expected: No cheese in multiple column, also mouse move over no cheese.");
 		shell.setLayout(new FillLayout(SWT.VERTICAL));
 		final Tree tree = new Tree(shell, SWT.VIRTUAL | SWT.BORDER |  SWT.H_SCROLL | SWT.V_SCROLL);

 		AtomicBoolean packpending = new AtomicBoolean(true);
 		tree.setData(packpending);

 		tree.addListener(SWT.EraseItem, ownerDrawnListener);
 		tree.addListener(SWT.SetData, ownerDrawnListener);
 		tree.addListener(SWT.MeasureItem, ownerDrawnListener);
 		tree.addListener(SWT.PaintItem, ownerDrawnListener);

 		BiConsumer<Integer, String> createColCons = (colStyle, colName) -> {
 			final TreeColumn treeColumn = new TreeColumn(tree, colStyle);
 			treeColumn.setText(colName);
 			treeColumn.setMoveable(true);
 		};

 		createColCons.accept(SWT.LEFT, "LEFT");
 		createColCons.accept(SWT.CENTER, "CENTER");
 		createColCons.accept(SWT.RIGHT, "RIGHT");

 		int ItemCount = 1000;
 		tree.setItemCount(ItemCount);
 		tree.setHeaderVisible(true);

 		shell.setSize(SWIDTH, SHEIGHT);
 		shell.open();
 		mainLoop(shell);
 	}

 		/**
 		 * <a href="http://www.eclipse.org/articles/Article-CustomDrawingTreeAndTreeItems/customDraw.htm#_example4"> Screenshot </a>
 		 */
 		@Test
 		public void ownerDrawn_eraseItem_Snippet273() {
 			knownToBeBrokenGtk3("Test currently broken on Gtk3. See Comment#1 of Bug 531551");

 			final String[] MONTHS = {
 					"Jan", "Feb", "Mar", "Apr", "May", "Jun",
 					"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 				};
 			final int[] HIGHS = {-7, -4, 1, 11, 18, 24, 26, 25, 20, 13, 5, -4};
 			final int[] LOWS = {-15, -13, -7, 1, 7, 13, 15, 14, 10, 4, -2, -11};
 			final int SCALE_MIN = -30; final int SCALE_MAX = 30;
 			final int SCALE_RANGE = Math.abs(SCALE_MIN - SCALE_MAX);

 			Shell shell = mkShell(" Gtk3:broken, no erasing (1st March 2018)   Gtk2: Background is used as bar-chart of sort. See screenshot.");
 			final Color blue = display.getSystemColor(SWT.COLOR_BLUE);
 			final Color white = display.getSystemColor(SWT.COLOR_WHITE);
 			final Color red = display.getSystemColor(SWT.COLOR_RED);
 	//			 final Image parliamentImage = new Image(display, "./parliament.jpg");
 			final Tree tree = new Tree(shell, SWT.NONE);
 			tree.setBounds(10,10,350,300);
 	//			 tree.setBackgroundImage(parliamentImage);
 			for (int i = 0; i < 12; i++) {
 				TreeItem item = new TreeItem(tree, SWT.NONE);
 				item.setText(MONTHS[i] + " (" + LOWS[i] + "C..." + HIGHS[i] + "C)");
 			}
 			final int clientWidth = tree.getClientArea().width;

 			/*
 			 * NOTE: MeasureItem and EraseItem are called repeatedly. Therefore it is
 			 * critical for performance that these methods be as efficient as possible.
 			 */
 			tree.addListener(SWT.MeasureItem, event -> {
 				int itemIndex = tree.indexOf((TreeItem)event.item);
 				int rightX = (HIGHS[itemIndex] - SCALE_MIN) * clientWidth / SCALE_RANGE;
 				event.width = rightX;
 			});
 			tree.addListener(SWT.EraseItem, event -> {
 				int itemIndex = tree.indexOf((TreeItem)event.item);
 				int leftX = (LOWS[itemIndex] - SCALE_MIN) * clientWidth / SCALE_RANGE;
 				int rightX = (HIGHS[itemIndex] - SCALE_MIN) * clientWidth / SCALE_RANGE;
 				GC gc = event.gc;
 				Rectangle clipping = gc.getClipping();
 				clipping.x = leftX;
 				clipping.width = rightX - leftX;
 				gc.setClipping(clipping);
 				Color oldForeground = gc.getForeground();
 				Color oldBackground = gc.getBackground();
 				gc.setForeground(blue);
 				gc.setBackground(white);
 				gc.fillGradientRectangle(event.x, event.y, event.width / 2, event.height, false);
 				gc.setForeground(white);
 				gc.setBackground(red);
 				gc.fillGradientRectangle(
 					event.x + event.width / 2, event.y, event.width / 2, event.height, false);
 				gc.setForeground(oldForeground);
 				gc.setBackground(oldBackground);
 				event.detail &= ~SWT.BACKGROUND;
 				event.detail &= ~SWT.HOT;
 			});
 			shell.setSize(SWIDTH, SHEIGHT);
 			shell.open();
 			mainLoop(shell);
 		}

 	/**
 		 * On Windows/Mac, if columnWidth is not set via setWidth or pack, then items are not visible.
 		 */
 		@Test
 		public void column_noWidth_bug399522 () {
 			Shell shell = mkShell("Expected : You shouldn't see the column/item as column width not set yet.");

 			final Tree tree = new Tree(shell, SWT.BORDER);
 			tree.setHeaderVisible(true);

 			new TreeItem(tree, SWT.NONE).setText("Item1");
 			TreeColumn column1 = new TreeColumn(tree, SWT.NONE);
 	//		column1.setWidth(10);	// Setting column width (or packing) makes items visible.

 			tree.setSize(200, 200);
 			System.out.println(column1.handle);

 			shell.setSize(SWIDTH, SHEIGHT);
 			shell.open();
 			mainLoop(shell);
 		}

 	@Test
 	public void ownerDrawn_multiColumn_gc_snippet239 () {
 		Shell shell = mkShell("Verify that text is correctly drawn across 2 columns. 4 columns in total.");
 		shell.setText("Text spans two columns in a TreeItem");
 		shell.setLayout (new FillLayout());
 		final Tree tree = new Tree(shell, SWT.MULTI | SWT.FULL_SELECTION);
 		tree.setHeaderVisible(true);
 		int columnCount = 4;
 		for (int i=0; i<columnCount; i++) {
 			TreeColumn column = new TreeColumn(tree, SWT.NONE);
 			System.out.println("Column " + i);
 			column.setText("Column " + i);
 		}
 		int itemCount = 8;
 		for (int i = 0; i < itemCount; i++) {
 			TreeItem item = new TreeItem(tree, SWT.NONE);
 			item.setText(0, "item "+i+" a");
 			item.setText(3, "item "+i+" d");
 		}
 		/*
 		 * NOTE: MeasureItem, PaintItem and EraseItem are called repeatedly.
 		 * Therefore, it is critical for performance that these methods be
 		 * as efficient as possible.
 		 */
 		final String string = "text that spans two columns";
 		GC gc = new GC(tree);
 		final Point extent = gc.stringExtent(string);
 		gc.dispose();
 		final Color red = display.getSystemColor(SWT.COLOR_RED);
 		Listener paintListener = event -> {
 			switch(event.type) {
 				case SWT.MeasureItem: {
 					if (event.index == 1 || event.index == 2) {
 						event.width = extent.x/2;
 						event.height = Math.max(event.height, extent.y + 2);
 					}
 					break;
 				}
 				case SWT.PaintItem: {
 					if (event.index == 1 || event.index == 2) {
 						int offset = 0;
 						if (event.index == 2) {
 							TreeColumn column1 = tree.getColumn(1);
 							offset = column1.getWidth();
 						}
 						event.gc.setForeground(red);
 						int y = event.y + (event.height - extent.y)/2;
 						event.gc.drawString(string, event.x - offset, y, true);
 					}
 					break;
 				}
 			}
 		};
 		tree.addListener(SWT.MeasureItem, paintListener);
 		tree.addListener(SWT.PaintItem, paintListener);
 		for (int i = 0; i < columnCount; i++) {
 			tree.getColumn(i).pack();
 		}
 		shell.setSize(SWIDTH, SHEIGHT);
 		shell.open();
 		mainLoop(shell);
 	}

 	@Test
 	public void bug73812_treeColumn_getWidth_0 () {
 		Shell shell = mkShell("Verify that all columns are of same width. (100).");
 		shell.setSize(SWIDTH, SHEIGHT);
 		shell.setLayout(new FillLayout());

 		final Tree tt = new Tree(shell, SWT.FULL_SELECTION | SWT.MULTI | SWT.VIRTUAL);
 		tt.setLinesVisible(true);
 		tt.setHeaderVisible(true);

 		for (int i = 0; i < 10; i++) {
 			TreeColumn tc = new TreeColumn(tt, SWT.NONE);
 			tc.setWidth(100);
 			System.out.println(tc.getWidth());
 			tc.setWidth(tc.getWidth());
 			tc.setText("Column " + i);
 		}

 		for (int i = 0; i < 100; i++) {
 			new TreeItem(tt, SWT.NONE);
 		}

 		shell.open();
 		mainLoop(shell);
 	}

 	/**
 	 * Last column should be big enough so that text inside it can be read.
 	 * Notion that getWidth() when called after setWidth() returns a different size.
 	 */
 	@Test
 	public void bug51079_setWidth_getWidth() {
 		Shell shell = mkShell("column SetGet Width : Make shell smaller and bigger. If you don't see COL_SIZE_ERROR in console, all is well.");
 		shell.setSize(SWIDTH, SHEIGHT);
 		shell.setLayout(new FillLayout());
 		StringBuilder sbBuffer = new StringBuilder();

 		final Composite comp = new Composite(shell, SWT.NONE);
 		final Tree tree = new Tree(comp, SWT.BORDER | SWT.V_SCROLL | SWT.H_SCROLL | SWT.SINGLE | SWT.FULL_SELECTION);
 		tree.setHeaderVisible(true);
 		tree.setLinesVisible(true);
 		final TreeColumn column1 = new TreeColumn(tree, SWT.NONE);
 		column1.setText("Column 1");
 		column1.setResizable(false);
 		final TreeColumn column2 = new TreeColumn(tree, SWT.NONE);
 		column2.setText("Column 2");
 		column2.setResizable(false);
 		for (int i = 0; i < 60; i++) {
 			TreeItem item = new TreeItem(tree, SWT.NONE);
 			sbBuffer.append("M");
 			item.setText(new String[] { "item 0 " + sbBuffer.toString() + " " + i, "item 1 " + i });
 		}

 		Consumer<Integer> setColumnWidths = (width) -> {
 			int c1w = (int)(width * 0.9);
 			column1.setWidth(c1w);
 			int c1wPost = column1.getWidth();
 			if (c1w != c1wPost)
 				System.err.println("COL_SIZE_ERROR 1 Expected:" + c1w + " actual:" + c1wPost);

 			int c2w = width - column1.getWidth();
 			column2.setWidth(c2w);
 			int c2wPost = column2.getWidth();
 			if (c2w != c2wPost)
 				System.err.println("COL_SIZE_ERROR 2 Expected:" + c2w + " actual:" + column2.getWidth());
 		};

 		comp.addControlListener(new ControlAdapter()
 		{
 			@Override
 			public void controlResized(ControlEvent e)
 			{
 				Rectangle area = tree.getParent().getClientArea();
 				Point preferredSize = tree.computeSize(SWT.DEFAULT, SWT.DEFAULT);
 				int width = area.width - 2 * tree.getBorderWidth();
 				if (preferredSize.y > area.height)
 				{
 					// Subtract the scrollbar width from the total column width
 					// if a vertical scrollbar will be required
 					Point vBarSize = tree.getVerticalBar().getSize();
 					width -= vBarSize.x;
 				}
 				Point oldSize = tree.getSize();
 				if (oldSize.x > area.width)
 				{
 					// tree is getting smaller so make the columns
 					// smaller first and then resize the tree to
 					// match the client area width
 					setColumnWidths.accept(width);
 					tree.setSize(area.width, area.height);
 				}
 				else
 				{
 					// tree is getting bigger so make the tree
 					// bigger first and then make the columns wider
 					// to match the client area width
 					tree.setSize(area.width, area.height);
 					setColumnWidths.accept(width);
 				}
 			}
 			});
 			shell.open();
 			mainLoop(shell);
 	}

 	@Test
 	public void basicTree_Snippet35() {
 		// original was table, modified for tree.
 		Shell shell = mkShell("TREE: Basic Tree with a few items, no column, no headers");
 		shell.setLayout(new FillLayout());
 		Tree tree = new Tree (shell, SWT.BORDER | SWT.V_SCROLL | SWT.H_SCROLL);
 		for (int i=0; i<12; i++) {
 			TreeItem item = new TreeItem (tree, 0);
 			item.setText ("Item " + i);
 		}
 		shell.setSize (SWIDTH, SHEIGHT);
 		shell.open ();
 		mainLoop(shell);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2018 Red Hat and others. All rights reserved.
	* The contents of this file are made available under the terms
	* of the GNU Lesser General Public License (LGPL) Version 2.1 that
	* accompanies this distribution (lgpl-v21.txt). The LGPL is also
	* available at http://www.gnu.org/licenses/lgpl.html. If the version
	* of the LGPL at http://www.gnu.org is different to the version of
	* the LGPL accompanying this distribution and there is any conflict
	* between the two license versions, the terms of the LGPL accompanying
	* this distribution shall govern.
	*
	* Contributors:
	* Red Hat - initial API and implementation
	*/
	package org.eclipse.swt.tests.manualJUnit;

	import java.util.concurrent.atomic.AtomicBoolean;
	import java.util.function.BiConsumer;
	import java.util.function.Consumer;

	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.ControlAdapter;
	import org.eclipse.swt.events.ControlEvent;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.GC;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.layout.FillLayout;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Listener;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.swt.widgets.Tree;
	import org.eclipse.swt.widgets.TreeColumn;
	import org.eclipse.swt.widgets.TreeItem;
	import org.junit.FixMethodOrder;
	import org.junit.Test;
	import org.junit.runners.MethodSorters;

	/** Convienience class for easy copy & paste */
	@FixMethodOrder(MethodSorters.JVM)
	public class MJ_Tree extends MJ_root {


	// Shared elements:
	final Listener ownerDrawnListener = event -> {
	final TreeItem item = (TreeItem)event.item;
	Tree tree = item.getParent();
	AtomicBoolean packpending = (AtomicBoolean) tree.getData();

	if (event.type == SWT.EraseItem) {
	}

	if (event.type == SWT.PaintItem) {
	final String text1 = (String)item.getData() + " (gc)";
	if (event.index == 0) {
	event.gc.drawText(text1, event.x, event.y, true);
	}
	}
	if (event.type == SWT.MeasureItem) {
	event.height = 50;
	event.width = 100;
	}
	if (event.type == SWT.SetData) {
	final int index = tree.indexOf(item);
	final String data = "Virtual item:" + index;
	item.setData(data);
	item.setText("VirtItem " + index);
	if (tree.getColumnCount() > 1) {
	for (int i = 1; i <= tree.getColumnCount(); i++) {
	item.setText(i, " Col: " + i + " " + data);
	}
	}

	if (packpending.get()) {
	packpending.set(false);
	display.asyncExec(() -> {
	tree.setRedraw(false);
	for (TreeColumn column : tree.getColumns()) {
	column.pack();
	}
	tree.setRedraw(true);
	});
	}
	}
	};

	/**
	* <a href="https://bugs.eclipse.org/bugs/attachment.cgi?id=272647">Screenshot </a>
	*/
	@Test
	public void ownerDrawn_cheese_single_col () {
	knownToBeBrokenGtk3("Cheese on gtk3"); // z for warning
	Shell shell = mkShell("Expected: There should be no cheese in the items. Move over shouldn't cheese out. See javadoc for screenshot");
	shell.setLayout(new FillLayout(SWT.VERTICAL));

	final Tree tree = new Tree(shell, SWT.VIRTUAL \| SWT.BORDER \| SWT.H_SCROLL \| SWT.V_SCROLL);

	AtomicBoolean packpending = new AtomicBoolean(true);
	tree.setData(packpending);

	tree.addListener(SWT.EraseItem, ownerDrawnListener); // Not relevant.
	tree.addListener(SWT.SetData, ownerDrawnListener);
	tree.addListener(SWT.MeasureItem, ownerDrawnListener);
	tree.addListener(SWT.PaintItem, ownerDrawnListener);

	final TreeColumn treeColumn = new TreeColumn(tree, SWT.LEFT);
	treeColumn.setText("First Left Column");
	treeColumn.setMoveable(true);

	tree.setItemCount(100);

	shell.setSize(800, 600); // Shell size seems to have a little bit of an initial impact. (may show proper with some shell sizes, incorrectly for others).
	shell.open();
	mainLoop(shell);
	}

	@Test
	public void ownerDrawn_cheese_multiple_col() {
	final Shell shell = mkShell("Expected: No cheese in multiple column, also mouse move over no cheese.");
	shell.setLayout(new FillLayout(SWT.VERTICAL));
	final Tree tree = new Tree(shell, SWT.VIRTUAL \| SWT.BORDER \| SWT.H_SCROLL \| SWT.V_SCROLL);

	AtomicBoolean packpending = new AtomicBoolean(true);
	tree.setData(packpending);

	tree.addListener(SWT.EraseItem, ownerDrawnListener);
	tree.addListener(SWT.SetData, ownerDrawnListener);
	tree.addListener(SWT.MeasureItem, ownerDrawnListener);
	tree.addListener(SWT.PaintItem, ownerDrawnListener);

	BiConsumer<Integer, String> createColCons = (colStyle, colName) -> {
	final TreeColumn treeColumn = new TreeColumn(tree, colStyle);
	treeColumn.setText(colName);
	treeColumn.setMoveable(true);
	};

	createColCons.accept(SWT.LEFT, "LEFT");
	createColCons.accept(SWT.CENTER, "CENTER");
	createColCons.accept(SWT.RIGHT, "RIGHT");

	int ItemCount = 1000;
	tree.setItemCount(ItemCount);
	tree.setHeaderVisible(true);

	shell.setSize(SWIDTH, SHEIGHT);
	shell.open();
	mainLoop(shell);
	}

	/**
	* <a href="http://www.eclipse.org/articles/Article-CustomDrawingTreeAndTreeItems/customDraw.htm#_example4"> Screenshot </a>
	*/
	@Test
	public void ownerDrawn_eraseItem_Snippet273() {
	knownToBeBrokenGtk3("Test currently broken on Gtk3. See Comment#1 of Bug 531551");

	final String[] MONTHS = {
	"Jan", "Feb", "Mar", "Apr", "May", "Jun",
	"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
	};
	final int[] HIGHS = {-7, -4, 1, 11, 18, 24, 26, 25, 20, 13, 5, -4};
	final int[] LOWS = {-15, -13, -7, 1, 7, 13, 15, 14, 10, 4, -2, -11};
	final int SCALE_MIN = -30; final int SCALE_MAX = 30;
	final int SCALE_RANGE = Math.abs(SCALE_MIN - SCALE_MAX);

	Shell shell = mkShell(" Gtk3:broken, no erasing (1st March 2018) Gtk2: Background is used as bar-chart of sort. See screenshot.");
	final Color blue = display.getSystemColor(SWT.COLOR_BLUE);
	final Color white = display.getSystemColor(SWT.COLOR_WHITE);
	final Color red = display.getSystemColor(SWT.COLOR_RED);
	// final Image parliamentImage = new Image(display, "./parliament.jpg");
	final Tree tree = new Tree(shell, SWT.NONE);
	tree.setBounds(10,10,350,300);
	// tree.setBackgroundImage(parliamentImage);
	for (int i = 0; i < 12; i++) {
	TreeItem item = new TreeItem(tree, SWT.NONE);
	item.setText(MONTHS[i] + " (" + LOWS[i] + "C..." + HIGHS[i] + "C)");
	}
	final int clientWidth = tree.getClientArea().width;

	/*
	* NOTE: MeasureItem and EraseItem are called repeatedly. Therefore it is
	* critical for performance that these methods be as efficient as possible.
	*/
	tree.addListener(SWT.MeasureItem, event -> {
	int itemIndex = tree.indexOf((TreeItem)event.item);
	int rightX = (HIGHS[itemIndex] - SCALE_MIN) * clientWidth / SCALE_RANGE;
	event.width = rightX;
	});
	tree.addListener(SWT.EraseItem, event -> {
	int itemIndex = tree.indexOf((TreeItem)event.item);
	int leftX = (LOWS[itemIndex] - SCALE_MIN) * clientWidth / SCALE_RANGE;
	int rightX = (HIGHS[itemIndex] - SCALE_MIN) * clientWidth / SCALE_RANGE;
	GC gc = event.gc;
	Rectangle clipping = gc.getClipping();
	clipping.x = leftX;
	clipping.width = rightX - leftX;
	gc.setClipping(clipping);
	Color oldForeground = gc.getForeground();
	Color oldBackground = gc.getBackground();
	gc.setForeground(blue);
	gc.setBackground(white);
	gc.fillGradientRectangle(event.x, event.y, event.width / 2, event.height, false);
	gc.setForeground(white);
	gc.setBackground(red);
	gc.fillGradientRectangle(
	event.x + event.width / 2, event.y, event.width / 2, event.height, false);
	gc.setForeground(oldForeground);
	gc.setBackground(oldBackground);
	event.detail &= ~SWT.BACKGROUND;
	event.detail &= ~SWT.HOT;
	});
	shell.setSize(SWIDTH, SHEIGHT);
	shell.open();
	mainLoop(shell);
	}

	/**
	* On Windows/Mac, if columnWidth is not set via setWidth or pack, then items are not visible.
	*/
	@Test
	public void column_noWidth_bug399522 () {
	Shell shell = mkShell("Expected : You shouldn't see the column/item as column width not set yet.");

	final Tree tree = new Tree(shell, SWT.BORDER);
	tree.setHeaderVisible(true);

	new TreeItem(tree, SWT.NONE).setText("Item1");
	TreeColumn column1 = new TreeColumn(tree, SWT.NONE);
	// column1.setWidth(10); // Setting column width (or packing) makes items visible.

	tree.setSize(200, 200);
	System.out.println(column1.handle);

	shell.setSize(SWIDTH, SHEIGHT);
	shell.open();
	mainLoop(shell);
	}

	@Test
	public void ownerDrawn_multiColumn_gc_snippet239 () {
	Shell shell = mkShell("Verify that text is correctly drawn across 2 columns. 4 columns in total.");
	shell.setText("Text spans two columns in a TreeItem");
	shell.setLayout (new FillLayout());
	final Tree tree = new Tree(shell, SWT.MULTI \| SWT.FULL_SELECTION);
	tree.setHeaderVisible(true);
	int columnCount = 4;
	for (int i=0; i<columnCount; i++) {
	TreeColumn column = new TreeColumn(tree, SWT.NONE);
	System.out.println("Column " + i);
	column.setText("Column " + i);
	}
	int itemCount = 8;
	for (int i = 0; i < itemCount; i++) {
	TreeItem item = new TreeItem(tree, SWT.NONE);
	item.setText(0, "item "+i+" a");
	item.setText(3, "item "+i+" d");
	}
	/*
	* NOTE: MeasureItem, PaintItem and EraseItem are called repeatedly.
	* Therefore, it is critical for performance that these methods be
	* as efficient as possible.
	*/
	final String string = "text that spans two columns";
	GC gc = new GC(tree);
	final Point extent = gc.stringExtent(string);
	gc.dispose();
	final Color red = display.getSystemColor(SWT.COLOR_RED);
	Listener paintListener = event -> {
	switch(event.type) {
	case SWT.MeasureItem: {
	if (event.index == 1 \|\| event.index == 2) {
	event.width = extent.x/2;
	event.height = Math.max(event.height, extent.y + 2);
	}
	break;
	}
	case SWT.PaintItem: {
	if (event.index == 1 \|\| event.index == 2) {
	int offset = 0;
	if (event.index == 2) {
	TreeColumn column1 = tree.getColumn(1);
	offset = column1.getWidth();
	}
	event.gc.setForeground(red);
	int y = event.y + (event.height - extent.y)/2;
	event.gc.drawString(string, event.x - offset, y, true);
	}
	break;
	}
	}
	};
	tree.addListener(SWT.MeasureItem, paintListener);
	tree.addListener(SWT.PaintItem, paintListener);
	for (int i = 0; i < columnCount; i++) {
	tree.getColumn(i).pack();
	}
	shell.setSize(SWIDTH, SHEIGHT);
	shell.open();
	mainLoop(shell);
	}

	@Test
	public void bug73812_treeColumn_getWidth_0 () {
	Shell shell = mkShell("Verify that all columns are of same width. (100).");
	shell.setSize(SWIDTH, SHEIGHT);
	shell.setLayout(new FillLayout());

	final Tree tt = new Tree(shell, SWT.FULL_SELECTION \| SWT.MULTI \| SWT.VIRTUAL);
	tt.setLinesVisible(true);
	tt.setHeaderVisible(true);

	for (int i = 0; i < 10; i++) {
	TreeColumn tc = new TreeColumn(tt, SWT.NONE);
	tc.setWidth(100);
	System.out.println(tc.getWidth());
	tc.setWidth(tc.getWidth());
	tc.setText("Column " + i);
	}

	for (int i = 0; i < 100; i++) {
	new TreeItem(tt, SWT.NONE);
	}

	shell.open();
	mainLoop(shell);
	}

	/**
	* Last column should be big enough so that text inside it can be read.
	* Notion that getWidth() when called after setWidth() returns a different size.
	*/
	@Test
	public void bug51079_setWidth_getWidth() {
	Shell shell = mkShell("column SetGet Width : Make shell smaller and bigger. If you don't see COL_SIZE_ERROR in console, all is well.");
	shell.setSize(SWIDTH, SHEIGHT);
	shell.setLayout(new FillLayout());
	StringBuilder sbBuffer = new StringBuilder();

	final Composite comp = new Composite(shell, SWT.NONE);
	final Tree tree = new Tree(comp, SWT.BORDER \| SWT.V_SCROLL \| SWT.H_SCROLL \| SWT.SINGLE \| SWT.FULL_SELECTION);
	tree.setHeaderVisible(true);
	tree.setLinesVisible(true);
	final TreeColumn column1 = new TreeColumn(tree, SWT.NONE);
	column1.setText("Column 1");
	column1.setResizable(false);
	final TreeColumn column2 = new TreeColumn(tree, SWT.NONE);
	column2.setText("Column 2");
	column2.setResizable(false);
	for (int i = 0; i < 60; i++) {
	TreeItem item = new TreeItem(tree, SWT.NONE);
	sbBuffer.append("M");
	item.setText(new String[] { "item 0 " + sbBuffer.toString() + " " + i, "item 1 " + i });
	}

	Consumer<Integer> setColumnWidths = (width) -> {
	int c1w = (int)(width * 0.9);
	column1.setWidth(c1w);
	int c1wPost = column1.getWidth();
	if (c1w != c1wPost)
	System.err.println("COL_SIZE_ERROR 1 Expected:" + c1w + " actual:" + c1wPost);

	int c2w = width - column1.getWidth();
	column2.setWidth(c2w);
	int c2wPost = column2.getWidth();
	if (c2w != c2wPost)
	System.err.println("COL_SIZE_ERROR 2 Expected:" + c2w + " actual:" + column2.getWidth());
	};

	comp.addControlListener(new ControlAdapter()
	{
	@Override
	public void controlResized(ControlEvent e)
	{
	Rectangle area = tree.getParent().getClientArea();
	Point preferredSize = tree.computeSize(SWT.DEFAULT, SWT.DEFAULT);
	int width = area.width - 2 * tree.getBorderWidth();
	if (preferredSize.y > area.height)
	{
	// Subtract the scrollbar width from the total column width
	// if a vertical scrollbar will be required
	Point vBarSize = tree.getVerticalBar().getSize();
	width -= vBarSize.x;
	}
	Point oldSize = tree.getSize();
	if (oldSize.x > area.width)
	{
	// tree is getting smaller so make the columns
	// smaller first and then resize the tree to
	// match the client area width
	setColumnWidths.accept(width);
	tree.setSize(area.width, area.height);
	}
	else
	{
	// tree is getting bigger so make the tree
	// bigger first and then make the columns wider
	// to match the client area width
	tree.setSize(area.width, area.height);
	setColumnWidths.accept(width);
	}
	}
	});
	shell.open();
	mainLoop(shell);
	}

	@Test
	public void basicTree_Snippet35() {
	// original was table, modified for tree.
	Shell shell = mkShell("TREE: Basic Tree with a few items, no column, no headers");
	shell.setLayout(new FillLayout());
	Tree tree = new Tree (shell, SWT.BORDER \| SWT.V_SCROLL \| SWT.H_SCROLL);
	for (int i=0; i<12; i++) {
	TreeItem item = new TreeItem (tree, 0);
	item.setText ("Item " + i);
	}
	shell.setSize (SWIDTH, SHEIGHT);
	shell.open ();
	mainLoop(shell);
	}
	}