bug 415476: SWING: SwingScoutClipboardService.setContents(..)-copied

content cannot be pasted within scout application 
https://bugs.eclipse.org/bugs/show_bug.cgi?id=415476

Reset InputStream if it is read again and added JUnit test

Change-Id: Id3fc7b55b67a71c652ecd6d289c1731f42d5b8be
Signed-off-by: Matthias Nick <Matthias.Nick@bsiag.com>
Reviewed-on: https://git.eclipse.org/r/16535
Tested-by: Hudson CI
Reviewed-by: Matthias Villiger <mvi@bsiag.com>
IP-Clean: Matthias Villiger <mvi@bsiag.com>

2 files changed, 151 insertions, 1 deletions

diff --git a/org.eclipse.scout.rt.ui.swing.test/src/org/eclipse/scout/rt/ui/swing/dnd/clipboard/SwingScoutClipboardTest.java b/org.eclipse.scout.rt.ui.swing.test/src/org/eclipse/scout/rt/ui/swing/dnd/clipboard/SwingScoutClipboardTest.java
new file mode 100644
index 0000000000..a2ae386892
--- /dev/null
+++ b/org.eclipse.scout.rt.ui.swing.test/src/org/eclipse/scout/rt/ui/swing/dnd/clipboard/SwingScoutClipboardTest.java
@@ -0,0 +1,125 @@
+/*******************************************************************************
+ * Copyright (c) 2013 BSI Business Systems Integration AG.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     BSI Business Systems Integration AG - initial API and implementation
+ ******************************************************************************/
+package org.eclipse.scout.rt.ui.swing.dnd.clipboard;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.awt.Toolkit;
+import java.awt.datatransfer.DataFlavor;
+import java.awt.datatransfer.Transferable;
+import java.io.BufferedReader;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+
+import javax.swing.JTextField;
+
+import org.eclipse.scout.commons.StringUtility;
+import org.eclipse.scout.commons.dnd.TextTransferObject;
+import org.eclipse.scout.rt.ui.swing.services.common.clipboard.SwingScoutClipboardService;
+import org.junit.Test;
+
+/**
+ * This JUnit test tests the clipboard functionality for Swing
+ * 
+ * @since 3.10.0-M2
+ */
+public class SwingScoutClipboardTest {
+
+  private static final String clipboardText = "some Text";
+
+  @Test
+  public void testBestTextFlavor() throws Exception {
+    setTextToClipboard();
+
+    Transferable transferable = Toolkit.getDefaultToolkit().getSystemClipboard().getContents(null);
+    DataFlavor[] flavors = transferable.getTransferDataFlavors();
+    assertTrue(flavors.length > 0);
+    DataFlavor bestTextFlavor = new DataFlavor().selectBestTextFlavor(flavors);
+    Object content = transferable.getTransferData(bestTextFlavor);
+    if (content instanceof String) {
+      assertEquals(clipboardText, content);
+    }
+  }
+
+  @Test
+  public void testMultiplePastes() throws Exception {
+    setTextToClipboard();
+
+    Transferable transferable = Toolkit.getDefaultToolkit().getSystemClipboard().getContents(null);
+    DataFlavor[] flavors = transferable.getTransferDataFlavors();
+    assertTrue(flavors.length > 0);
+
+    //simulates paste attempt 1
+    for (DataFlavor flavor : flavors) {
+      Object content = transferable.getTransferData(flavor);
+      if (content instanceof String) {
+        assertEquals(clipboardText, content);
+      }
+      else if (content instanceof InputStream) {
+        assertEquals(clipboardText, getStringOfInputStream((InputStream) content, flavor.getParameter("charset")));
+      }
+    }
+
+    //simulates paste attempt 2
+    for (DataFlavor flavor : flavors) {
+      Object content = transferable.getTransferData(flavor);
+      if (content instanceof String) {
+        assertEquals(clipboardText, content);
+      }
+      else if (content instanceof InputStream) {
+        assertEquals(clipboardText, getStringOfInputStream((InputStream) content, flavor.getParameter("charset")));
+      }
+    }
+  }
+
+  @Test
+  public void testPasteWithTextField() throws Exception {
+    setTextToClipboard();
+
+    JTextField textfield = new JTextField();
+    textfield.paste();
+
+    assertEquals(clipboardText, textfield.getText());
+
+    textfield.paste();
+    textfield.paste();
+    textfield.paste();
+
+    assertEquals(clipboardText + clipboardText + clipboardText + clipboardText, textfield.getText());
+  }
+
+  private void setTextToClipboard() throws Exception {
+    SwingScoutClipboardService service = new SwingScoutClipboardService();
+    TextTransferObject textTransferObject = new TextTransferObject(clipboardText);
+    service.setContents(textTransferObject);
+    Thread.sleep(500); //Wait half a second to make sure the content is in the clipboard
+  }
+
+  private String getStringOfInputStream(InputStream is, String encoding) throws Exception {
+    BufferedReader br = null;
+    Reader reader = null;
+    StringBuilder sb = new StringBuilder();
+    if (StringUtility.hasText(encoding)) {
+      reader = new InputStreamReader(is, encoding);
+    }
+    else {
+      reader = new InputStreamReader(is);
+    }
+    String line;
+    br = new BufferedReader(reader);
+    while ((line = br.readLine()) != null) {
+      sb.append(line);
+    }
+    return sb.toString();
+  }
+}
diff --git a/org.eclipse.scout.rt.ui.swing/src/org/eclipse/scout/rt/ui/swing/dnd/TextTransferable.java b/org.eclipse.scout.rt.ui.swing/src/org/eclipse/scout/rt/ui/swing/dnd/TextTransferable.java
index 238bf198c5..ef0c84abea 100644
--- a/org.eclipse.scout.rt.ui.swing/src/org/eclipse/scout/rt/ui/swing/dnd/TextTransferable.java
+++ b/org.eclipse.scout.rt.ui.swing/src/org/eclipse/scout/rt/ui/swing/dnd/TextTransferable.java
@@ -66,7 +66,32 @@ public class TextTransferable implements Transferable {
     if (!isDataFlavorSupported(flavor)) {
       throw new UnsupportedFlavorException(flavor);
     }
-    return m_flavorMap.get(flavor);
+    Object result = m_flavorMap.get(flavor);
+    if (result instanceof InputStream) {
+      resetInputStreamToStartFromBeginning((InputStream) result);
+    }
+    return result;
+  }
+
+  /**
+   * This method resets the InputStream by setting its 'pos' attribute to 0.
+   * When the paste command is called e.g. on a textfield and a InputStream is returned,
+   * the InputStream's content is pasted to the textfield. If paste is called
+   * again, the same InputStream is returned, however the 'pos' attribute is now at the
+   * end of the content. The paste command doesn't seem to work anymore. Thus we
+   * have to reset the start position of the InputStream to 0.
+   * 
+   * @since 3.10.0-M2
+   */
+  private void resetInputStreamToStartFromBeginning(InputStream is) {
+    if (is != null) {
+      try {
+        is.reset();
+      }
+      catch (IOException e) {
+        LOG.error("failed to reset the InputStream", e);
+      }
+    }
   }
 
   private InputStream toInputStream(String value, String encoding) {