Added gray background text to authors field to assist newcomers

CHANGELOG.md

@@ -61,6 +61,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 - Change "Recent files" to "Recent databases" to keep the file menu consistent
 - Customized importer files need to be slightly changed since the class `ImportFormat` was renamed to `Importer`
 - [koppor#5](https://github.com/koppor/jabref/issues/5) When entries are found while dropping a pdf with xmp meta data the found entries will be displayed in the import dialog
+- [koppor#61](https://github.com/koppor/jabref/issues/61) Display gray background text in "Author" and "Editor" field to assist newcomers
 
 ### Fixed
 - Fixed [#2089](https://github.com/JabRef/jabref/issues/2089): Fixed faulty cite key generation

src/main/java/net/sf/jabref/gui/entryeditor/EntryEditorTab.java

@@ -35,7 +35,9 @@
 import net.sf.jabref.gui.keyboard.KeyBinding;
 import net.sf.jabref.gui.util.GUIUtil;
 import net.sf.jabref.logic.autocompleter.AutoCompleter;
+import net.sf.jabref.logic.l10n.Localization;
 import net.sf.jabref.model.entry.BibEntry;
+import net.sf.jabref.model.entry.FieldName;
 import net.sf.jabref.model.entry.FieldProperty;
 import net.sf.jabref.model.entry.InternalBibtexFields;
 
@@ -151,7 +153,12 @@ private void setupPanel(JabRefFrame frame, BasePanel bPanel, boolean addKeyField
                         false);
                 defaultHeight = 0;
             } else {
-                fieldEditor = new TextArea(field, null);
+                String prompt = "";
+                if (field.equals(FieldName.AUTHOR) || field.equals(FieldName.EDITOR)) {
+                    prompt = String.format("%1$s and %1$s and others", Localization.lang("Firstname Lastname"));
+                }
+
+                fieldEditor = new TextArea(field, null, prompt);
                 bPanel.frame().getGlobalSearchBar().getSearchQueryHighlightObservable().addSearchListener((TextArea) fieldEditor);
                 defaultHeight = fieldEditor.getPane().getPreferredSize().height;
             }

src/main/java/net/sf/jabref/gui/fieldeditors/JTextAreaWithHighlighting.java

@@ -6,7 +6,6 @@
 import java.util.regex.Pattern;
 
 import javax.swing.AbstractAction;
-import javax.swing.JTextArea;
 import javax.swing.KeyStroke;
 import javax.swing.text.BadLocationException;
 import javax.swing.text.DefaultHighlighter;
@@ -20,13 +19,14 @@
 import net.sf.jabref.Globals;
 import net.sf.jabref.gui.actions.Actions;
 import net.sf.jabref.gui.actions.PasteAction;
+import net.sf.jabref.gui.util.component.JTextAreaWithPlaceholder;
 import net.sf.jabref.logic.search.SearchQueryHighlightListener;
 import net.sf.jabref.preferences.JabRefPreferences;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
-public class JTextAreaWithHighlighting extends JTextArea implements SearchQueryHighlightListener {
+public class JTextAreaWithHighlighting extends JTextAreaWithPlaceholder implements SearchQueryHighlightListener {
 
     private static final Log LOGGER = LogFactory.getLog(JTextAreaWithHighlighting.class);
 
@@ -35,13 +35,22 @@ public class JTextAreaWithHighlighting extends JTextArea implements SearchQueryH
     private UndoManager undo;
 
     public JTextAreaWithHighlighting() {
-        super();
-        setupUndoRedo();
-        setupPasteListener();
+        this("");
+    }
+
+    public JTextAreaWithHighlighting(String text) {
+        this(text, "");
     }
 
-    JTextAreaWithHighlighting(String text) {
-        super(text);
+    /**
+     * Creates a text area with the ability to highlight parts of the content.
+     * It also defines a placeholder which will be displayed the content is empty.
+     *
+     * @param text
+     * @param placeholder
+     */
+    public JTextAreaWithHighlighting(String text, String placeholder) {
+        super(text, placeholder);
         setupUndoRedo();
         setupPasteListener();
     }

src/main/java/net/sf/jabref/gui/fieldeditors/TextArea.java

@@ -36,7 +36,11 @@ public class TextArea extends JTextAreaWithHighlighting implements FieldEditor {
 
 
     public TextArea(String fieldName, String content) {
-        super(content);
+        this(fieldName, content, "");
+    }
+
+    public TextArea(String fieldName, String content, String title) {
+        super(content, title);
 
 
         updateFont();

src/main/java/net/sf/jabref/gui/fieldeditors/TextField.java

@@ -7,7 +7,6 @@
 import javax.swing.AbstractAction;
 import javax.swing.JComponent;
 import javax.swing.JLabel;
-import javax.swing.JTextField;
 import javax.swing.SwingUtilities;
 import javax.swing.text.Document;
 import javax.swing.undo.CannotRedoException;
@@ -20,6 +19,7 @@
 import net.sf.jabref.gui.actions.PasteAction;
 import net.sf.jabref.gui.autocompleter.AutoCompleteListener;
 import net.sf.jabref.gui.fieldeditors.contextmenu.FieldTextMenu;
+import net.sf.jabref.gui.util.component.JTextFieldWithPlaceholder;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -28,7 +28,7 @@
  * An implementation of the FieldEditor backed by a JTextField. Used for single-line input, only BibTex key at the
  * moment?!
  */
-public class TextField extends JTextField implements FieldEditor {
+public class TextField extends JTextFieldWithPlaceholder implements FieldEditor {
 
     private static final Log LOGGER = LogFactory.getLog(TextField.class);
 
@@ -39,7 +39,11 @@ public class TextField extends JTextField implements FieldEditor {
 
 
     public TextField(String fieldName, String content, boolean changeColorOnFocus) {
-        super(content);
+        this(fieldName, content, changeColorOnFocus, "");
+    }
+
+    public TextField(String fieldName, String content, boolean changeColorOnFocus, String title) {
+        super(content, title);
 
         setupPasteListener();
         setupUndoRedo();

src/main/java/net/sf/jabref/gui/search/GlobalSearchBar.java

@@ -29,7 +29,7 @@
 import net.sf.jabref.gui.keyboard.KeyBinding;
 import net.sf.jabref.gui.maintable.MainTable;
 import net.sf.jabref.gui.maintable.MainTableDataModel;
-import net.sf.jabref.gui.util.component.JTextFieldWithUnfocusedText;
+import net.sf.jabref.gui.util.component.JTextFieldWithPlaceholder;
 import net.sf.jabref.logic.autocompleter.AutoCompleter;
 import net.sf.jabref.logic.help.HelpFile;
 import net.sf.jabref.logic.l10n.Localization;
@@ -49,7 +49,7 @@ public class GlobalSearchBar extends JPanel {
     private final JabRefFrame frame;
 
     private final JLabel searchIcon = new JLabel(IconTheme.JabRefIcon.SEARCH.getSmallIcon());
-    private final JTextFieldWithUnfocusedText searchField = new JTextFieldWithUnfocusedText(Localization.lang("Search") + "...");
+    private final JTextFieldWithPlaceholder searchField = new JTextFieldWithPlaceholder(Localization.lang("Search") + "...");
     private JButton openCurrentResultsInDialog = new JButton(IconTheme.JabRefIcon.OPEN_IN_NEW_WINDOW.getSmallIcon());
 
     private final JToggleButton caseSensitive;

src/main/java/net/sf/jabref/gui/util/component/JTextAreaWithPlaceholder.java

@@ -0,0 +1,90 @@
+package net.sf.jabref.gui.util.component;
+
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+import java.awt.event.KeyEvent;
+import java.awt.event.KeyListener;
+
+import javax.swing.JTextArea;
+import javax.swing.UIManager;
+
+/**
+ * A text area which displays a predefined text the same way as {@link JTextFieldWithPlaceholder} does.
+ */
+public class JTextAreaWithPlaceholder extends JTextArea implements KeyListener {
+
+    private final String textWhenNotFocused;
+
+    public JTextAreaWithPlaceholder() {
+        this("");
+    }
+
+    /**
+     * Additionally to {@link JTextAreaWithPlaceholder#JTextAreaWithPlaceholder(String)}
+     * this also sets the initial text of the text field component.
+     *
+     * @param content as the text of the textfield
+     * @param placeholder as the placeholder of the textfield
+     */
+    public JTextAreaWithPlaceholder(String content, String placeholder) {
+        this(placeholder);
+        setText(content);
+    }
+
+    /**
+     * This will create a {@link JTextArea} with a placeholder text. The placeholder
+     * will always be displayed if the text of the {@link JTextArea} is empty.
+     *
+     * @param placeholder as the placeholder of the textarea
+     */
+    public JTextAreaWithPlaceholder(String placeholder) {
+        super();
+        this.setEditable(true);
+        this.setText("");
+        this.textWhenNotFocused = placeholder;
+    }
+
+    @Override
+    protected void paintComponent(Graphics graphics) {
+        super.paintComponent(graphics);
+
+        if (this.getText().isEmpty()) {
+            Font prev = graphics.getFont();
+            Color prevColor = graphics.getColor();
+            graphics.setColor(UIManager.getColor("textInactiveText"));
+            int textHeight = graphics.getFontMetrics().getHeight();
+            int x = this.getInsets().left;
+            Graphics2D g2d = (Graphics2D) graphics;
+            RenderingHints hints = g2d.getRenderingHints();
+            g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
+            g2d.drawString(textWhenNotFocused, x, textHeight + this.getInsets().top);
+            g2d.setRenderingHints(hints);
+            graphics.setFont(prev);
+            graphics.setColor(prevColor);
+        }
+    }
+
+    @Override
+    public void keyTyped(KeyEvent e) {
+        if (this.getText().isEmpty()) {
+            this.repaint();
+        }
+    }
+
+    @Override
+    public void keyPressed(KeyEvent e) {
+        if (this.getText().isEmpty()) {
+            this.repaint();
+        }
+    }
+
+    @Override
+    public void keyReleased(KeyEvent e) {
+        if (this.getText().isEmpty()) {
+            this.repaint();
+        }
+    }
+}

src/main/java/net/sf/jabref/gui/util/component/JTextFieldWithPlaceholder.java

@@ -0,0 +1,91 @@
+package net.sf.jabref.gui.util.component;
+
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+import java.awt.event.KeyEvent;
+import java.awt.event.KeyListener;
+
+import javax.swing.JTextField;
+import javax.swing.UIManager;
+
+/**
+ * A text field which displays a predefined text (e.g. "Search") if the text field is empty.
+ * This is similar to a html5 input element with a defined placeholder attribute.
+ * Implementation based on https://gmigdos.wordpress.com/2010/03/30/java-a-custom-jtextfield-for-searching/
+ */
+public class JTextFieldWithPlaceholder extends JTextField implements KeyListener {
+
+    private final String textWhenNotFocused;
+
+    /**
+     * Additionally to {@link JTextFieldWithPlaceholder#JTextFieldWithPlaceholder(String)}
+     * this also sets the initial text of the text field component.
+     *
+     * @param content as the text of the textfield
+     * @param placeholder as the placeholder of the textfield
+     */
+    public JTextFieldWithPlaceholder(String content, String placeholder) {
+        this(placeholder);
+        setText(content);
+    }
+
+    /**
+     * This will create a {@link JTextField} with a placeholder text. The placeholder
+     * will always be displayed if the text of the {@link JTextField} is empty.
+     *
+     * @param placeholder as the placeholder of the textfield
+     */
+    public JTextFieldWithPlaceholder(String placeholder) {
+        super();
+        this.setEditable(true);
+        this.setText("");
+        this.textWhenNotFocused = placeholder;
+    }
+
+    @Override
+    protected void paintComponent(Graphics graphics) {
+        super.paintComponent(graphics);
+
+        if (this.getText().isEmpty()) {
+            int height = this.getHeight();
+            Font prev = graphics.getFont();
+            Color prevColor = graphics.getColor();
+            graphics.setColor(UIManager.getColor("textInactiveText"));
+            int textHeight = graphics.getFontMetrics().getHeight();
+            int textBottom = (((height - textHeight) / 2) + textHeight) - 4;
+            int x = this.getInsets().left;
+            Graphics2D g2d = (Graphics2D) graphics;
+            RenderingHints hints = g2d.getRenderingHints();
+            g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
+            g2d.drawString(textWhenNotFocused, x, textBottom);
+            g2d.setRenderingHints(hints);
+            graphics.setFont(prev);
+            graphics.setColor(prevColor);
+        }
+    }
+
+    @Override
+    public void keyTyped(KeyEvent e) {
+        if (this.getText().isEmpty()) {
+            this.repaint();
+        }
+    }
+
+    @Override
+    public void keyPressed(KeyEvent e) {
+        if (this.getText().isEmpty()) {
+            this.repaint();
+        }
+    }
+
+    @Override
+    public void keyReleased(KeyEvent e) {
+        if (this.getText().isEmpty()) {
+            this.repaint();
+        }
+    }
+
+}