fix mouse selection
[fanfix.git] / src / jexer / TEditorWidget.java
index 690c5731f280a936cd1ce6f5ac3bbcf0c4d4f4ac..a329dfa347b770dcb279140a1c5ef170f72aab64 100644 (file)
@@ -3,7 +3,7 @@
  *
  * The MIT License (MIT)
  *
- * Copyright (C) 2017 Kevin Lamonte
+ * Copyright (C) 2019 Kevin Lamonte
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -31,19 +31,35 @@ package jexer;
 import java.io.IOException;
 
 import jexer.bits.CellAttributes;
+import jexer.bits.StringUtils;
+import jexer.event.TCommandEvent;
 import jexer.event.TKeypressEvent;
 import jexer.event.TMouseEvent;
 import jexer.event.TResizeEvent;
 import jexer.teditor.Document;
 import jexer.teditor.Line;
 import jexer.teditor.Word;
+import static jexer.TCommand.*;
 import static jexer.TKeypress.*;
 
 /**
  * TEditorWidget displays an editable text document.  It is unaware of
  * scrolling behavior, but can respond to mouse and keyboard events.
  */
-public final class TEditorWidget extends TWidget {
+public class TEditorWidget extends TWidget implements EditMenuUser {
+
+    // ------------------------------------------------------------------------
+    // Constants --------------------------------------------------------------
+    // ------------------------------------------------------------------------
+
+    /**
+     * The number of lines to scroll on mouse wheel up/down.
+     */
+    private static final int wheelScrollSize = 3;
+
+    // ------------------------------------------------------------------------
+    // Variables --------------------------------------------------------------
+    // ------------------------------------------------------------------------
 
     /**
      * The document being edited.
@@ -65,6 +81,35 @@ public final class TEditorWidget extends TWidget {
      */
     private int leftColumn = 0;
 
+    /**
+     * If true, the mouse is dragging a selection.
+     */
+    private boolean inSelection = false;
+
+    /**
+     * Selection starting column.
+     */
+    private int selectionColumn0;
+
+    /**
+     * Selection starting line.
+     */
+    private int selectionLine0;
+
+    /**
+     * Selection ending column.
+     */
+    private int selectionColumn1;
+
+    /**
+     * Selection ending line.
+     */
+    private int selectionLine1;
+
+    // ------------------------------------------------------------------------
+    // Constructors -----------------------------------------------------------
+    // ------------------------------------------------------------------------
+
     /**
      * Public constructor.
      *
@@ -87,32 +132,9 @@ public final class TEditorWidget extends TWidget {
         document = new Document(text, defaultColor);
     }
 
-    /**
-     * Draw the text box.
-     */
-    @Override
-    public void draw() {
-        for (int i = 0; i < getHeight(); i++) {
-            // Background line
-            getScreen().hLineXY(0, i, getWidth(), ' ', defaultColor);
-
-            // Now draw document's line
-            if (topLine + i < document.getLineCount()) {
-                Line line = document.getLine(topLine + i);
-                int x = 0;
-                for (Word word: line.getWords()) {
-                    // For now, we are cheating: draw outside the left region
-                    // if needed and let screen do the clipping.
-                    getScreen().putStringXY(x - leftColumn, i, word.getText(),
-                        word.getColor());
-                    x += word.getDisplayLength();
-                    if (x - leftColumn > getWidth()) {
-                        break;
-                    }
-                }
-            }
-        }
-    }
+    // ------------------------------------------------------------------------
+    // Event handlers ---------------------------------------------------------
+    // ------------------------------------------------------------------------
 
     /**
      * Handle mouse press events.
@@ -122,21 +144,32 @@ public final class TEditorWidget extends TWidget {
     @Override
     public void onMouseDown(final TMouseEvent mouse) {
         if (mouse.isMouseWheelUp()) {
-            if (topLine > 0) {
-                topLine--;
-                alignDocument(false);
+            for (int i = 0; i < wheelScrollSize; i++) {
+                if (topLine > 0) {
+                    topLine--;
+                    alignDocument(false);
+                }
             }
             return;
         }
         if (mouse.isMouseWheelDown()) {
-            if (topLine < document.getLineCount() - 1) {
-                topLine++;
-                alignDocument(true);
+            for (int i = 0; i < wheelScrollSize; i++) {
+                if (topLine < document.getLineCount() - 1) {
+                    topLine++;
+                    alignDocument(true);
+                }
             }
             return;
         }
 
         if (mouse.isMouse1()) {
+            // Selection.
+            inSelection = true;
+            selectionColumn0 = leftColumn + mouse.getX();
+            selectionLine0 = topLine + mouse.getY();
+            selectionColumn1 = selectionColumn0;
+            selectionLine1 = selectionLine0;
+
             // Set the row and column
             int newLine = topLine + mouse.getY();
             int newX = leftColumn + mouse.getX();
@@ -150,19 +183,29 @@ public final class TEditorWidget extends TWidget {
                     setCursorY(mouse.getY());
                 }
                 alignCursor();
+                if (inSelection) {
+                    selectionColumn1 = document.getCursor();
+                    selectionLine1 = document.getLineNumber();
+                }
                 return;
             }
 
             document.setLineNumber(newLine);
             setCursorY(mouse.getY());
-            if (newX > document.getCurrentLine().getDisplayLength()) {
+            if (newX >= document.getCurrentLine().getDisplayLength()) {
                 document.end();
                 alignCursor();
             } else {
                 document.setCursor(newX);
                 setCursorX(mouse.getX());
             }
+            if (inSelection) {
+                selectionColumn1 = document.getCursor();
+                selectionLine1 = document.getLineNumber();
+            }
             return;
+        } else {
+            inSelection = false;
         }
 
         // Pass to children
@@ -170,94 +213,64 @@ public final class TEditorWidget extends TWidget {
     }
 
     /**
-     * Align visible area with document current line.
+     * Handle mouse motion events.
      *
-     * @param topLineIsTop if true, make the top visible line the document
-     * current line if it was off-screen.  If false, make the bottom visible
-     * line the document current line.
+     * @param mouse mouse motion event
      */
-    private void alignTopLine(final boolean topLineIsTop) {
-        int line = document.getLineNumber();
+    @Override
+    public void onMouseMotion(final TMouseEvent mouse) {
 
-        if ((line < topLine) || (line > topLine + getHeight() - 1)) {
-            // Need to move topLine to bring document back into view.
-            if (topLineIsTop) {
-                topLine = line - (getHeight() - 1);
-                if (topLine < 0) {
-                    topLine = 0;
-                }
-                assert (topLine >= 0);
+        if (mouse.isMouse1()) {
+            // Selection.
+            if (inSelection) {
+                selectionColumn1 = leftColumn + mouse.getX();
+                selectionLine1 = topLine + mouse.getY();
             } else {
-                topLine = line;
-                assert (topLine >= 0);
+                inSelection = true;
+                selectionColumn0 = leftColumn + mouse.getX();
+                selectionLine0 = topLine + mouse.getY();
+                selectionColumn1 = selectionColumn0;
+                selectionLine1 = selectionLine0;
             }
-        }
 
-        /*
-        System.err.println("line " + line + " topLine " + topLine);
-        */
-
-        // Document is in view, let's set cursorY
-        assert (line >= topLine);
-        setCursorY(line - topLine);
-        alignCursor();
-    }
-
-    /**
-     * Align document current line with visible area.
-     *
-     * @param topLineIsTop if true, make the top visible line the document
-     * current line if it was off-screen.  If false, make the bottom visible
-     * line the document current line.
-     */
-    private void alignDocument(final boolean topLineIsTop) {
-        int line = document.getLineNumber();
-        int cursor = document.getCursor();
+            // Set the row and column
+            int newLine = topLine + mouse.getY();
+            int newX = leftColumn + mouse.getX();
+            if (newLine > document.getLineCount() - 1) {
+                // Go to the end
+                document.setLineNumber(document.getLineCount() - 1);
+                document.end();
+                if (newLine > document.getLineCount() - 1) {
+                    setCursorY(document.getLineCount() - 1 - topLine);
+                } else {
+                    setCursorY(mouse.getY());
+                }
+                alignCursor();
+                if (inSelection) {
+                    selectionColumn1 = document.getCursor();
+                    selectionLine1 = document.getLineNumber();
+                }
+                return;
+            }
 
-        if ((line < topLine) || (line > topLine + getHeight() - 1)) {
-            // Need to move document to ensure it fits view.
-            if (topLineIsTop) {
-                document.setLineNumber(topLine);
+            document.setLineNumber(newLine);
+            setCursorY(mouse.getY());
+            if (newX >= document.getCurrentLine().getDisplayLength()) {
+                document.end();
+                alignCursor();
             } else {
-                document.setLineNumber(topLine + (getHeight() - 1));
+                document.setCursor(newX);
+                setCursorX(mouse.getX());
             }
-            if (cursor < document.getCurrentLine().getDisplayLength()) {
-                document.setCursor(cursor);
+            if (inSelection) {
+                selectionColumn1 = document.getCursor();
+                selectionLine1 = document.getLineNumber();
             }
+            return;
         }
 
-        /*
-        System.err.println("getLineNumber() " + document.getLineNumber() +
-            " topLine " + topLine);
-        */
-
-        // Document is in view, let's set cursorY
-        setCursorY(document.getLineNumber() - topLine);
-        alignCursor();
-    }
-
-    /**
-     * Align visible cursor with document cursor.
-     */
-    private void alignCursor() {
-        int width = getWidth();
-
-        int desiredX = document.getCursor() - leftColumn;
-        if (desiredX < 0) {
-            // We need to push the screen to the left.
-            leftColumn = document.getCursor();
-        } else if (desiredX > width - 1) {
-            // We need to push the screen to the right.
-            leftColumn = document.getCursor() - (width - 1);
-        }
-
-        /*
-        System.err.println("document cursor " + document.getCursor() +
-            " leftColumn " + leftColumn);
-        */
-
-
-        setCursorX(document.getCursor() - leftColumn);
+        // Pass to children
+        super.onMouseDown(mouse);
     }
 
     /**
@@ -267,25 +280,77 @@ public final class TEditorWidget extends TWidget {
      */
     @Override
     public void onKeypress(final TKeypressEvent keypress) {
-        if (keypress.equals(kbLeft)) {
+        if (keypress.getKey().isShift()) {
+            // Selection.
+            if (!inSelection) {
+                inSelection = true;
+                selectionColumn0 = document.getCursor();
+                selectionLine0 = document.getLineNumber();
+                selectionColumn1 = selectionColumn0;
+                selectionLine1 = selectionLine0;
+            }
+        } else {
+            if (keypress.equals(kbLeft)
+                || keypress.equals(kbRight)
+                || keypress.equals(kbUp)
+                || keypress.equals(kbDown)
+                || keypress.equals(kbPgDn)
+                || keypress.equals(kbPgUp)
+                || keypress.equals(kbHome)
+                || keypress.equals(kbEnd)
+            ) {
+                // Non-shifted navigation keys disable selection.
+                inSelection = false;
+            }
+        }
+
+        if (keypress.equals(kbLeft)
+            || keypress.equals(kbShiftLeft)
+        ) {
             document.left();
             alignTopLine(false);
-        } else if (keypress.equals(kbRight)) {
+        } else if (keypress.equals(kbRight)
+            || keypress.equals(kbShiftRight)
+        ) {
             document.right();
             alignTopLine(true);
-        } else if (keypress.equals(kbUp)) {
+        } else if (keypress.equals(kbAltLeft)
+            || keypress.equals(kbCtrlLeft)
+            || keypress.equals(kbAltShiftLeft)
+            || keypress.equals(kbCtrlShiftLeft)
+        ) {
+            document.backwardsWord();
+            alignTopLine(false);
+        } else if (keypress.equals(kbAltRight)
+            || keypress.equals(kbCtrlRight)
+            || keypress.equals(kbAltShiftRight)
+            || keypress.equals(kbCtrlShiftRight)
+        ) {
+            document.forwardsWord();
+            alignTopLine(true);
+        } else if (keypress.equals(kbUp)
+            || keypress.equals(kbShiftUp)
+        ) {
             document.up();
             alignTopLine(false);
-        } else if (keypress.equals(kbDown)) {
+        } else if (keypress.equals(kbDown)
+            || keypress.equals(kbShiftDown)
+        ) {
             document.down();
             alignTopLine(true);
-        } else if (keypress.equals(kbPgUp)) {
+        } else if (keypress.equals(kbPgUp)
+            || keypress.equals(kbShiftPgUp)
+        ) {
             document.up(getHeight() - 1);
             alignTopLine(false);
-        } else if (keypress.equals(kbPgDn)) {
+        } else if (keypress.equals(kbPgDn)
+            || keypress.equals(kbShiftPgDn)
+        ) {
             document.down(getHeight() - 1);
             alignTopLine(true);
-        } else if (keypress.equals(kbHome)) {
+        } else if (keypress.equals(kbHome)
+            || keypress.equals(kbShiftHome)
+        ) {
             if (document.home()) {
                 leftColumn = 0;
                 if (leftColumn < 0) {
@@ -293,37 +358,54 @@ public final class TEditorWidget extends TWidget {
                 }
                 setCursorX(0);
             }
-        } else if (keypress.equals(kbEnd)) {
+        } else if (keypress.equals(kbEnd)
+            || keypress.equals(kbShiftEnd)
+        ) {
             if (document.end()) {
                 alignCursor();
             }
-        } else if (keypress.equals(kbCtrlHome)) {
+        } else if (keypress.equals(kbCtrlHome)
+            || keypress.equals(kbCtrlShiftHome)
+        ) {
             document.setLineNumber(0);
             document.home();
             topLine = 0;
             leftColumn = 0;
             setCursorX(0);
             setCursorY(0);
-        } else if (keypress.equals(kbCtrlEnd)) {
+        } else if (keypress.equals(kbCtrlEnd)
+            || keypress.equals(kbCtrlShiftEnd)
+        ) {
             document.setLineNumber(document.getLineCount() - 1);
             document.end();
             alignTopLine(false);
         } else if (keypress.equals(kbIns)) {
             document.setOverwrite(!document.getOverwrite());
         } else if (keypress.equals(kbDel)) {
-            document.del();
+            if (inSelection) {
+                deleteSelection();
+            } else {
+                document.del();
+            }
             alignCursor();
-        } else if (keypress.equals(kbBackspace)) {
-            document.backspace();
+        } else if (keypress.equals(kbBackspace)
+            || keypress.equals(kbBackspaceDel)
+        ) {
+            if (inSelection) {
+                deleteSelection();
+            } else {
+                document.backspace();
+            }
             alignTopLine(false);
         } else if (keypress.equals(kbTab)) {
-            // TODO: tab character.  For now just add spaces until we hit
-            // modulo 8.
+            deleteSelection();
+            // Add spaces until we hit modulo 8.
             for (int i = document.getCursor(); (i + 1) % 8 != 0; i++) {
                 document.addChar(' ');
             }
             alignCursor();
         } else if (keypress.equals(kbEnter)) {
+            deleteSelection();
             document.enter();
             alignTopLine(true);
         } else if (!keypress.getKey().isFnKey()
@@ -331,12 +413,18 @@ public final class TEditorWidget extends TWidget {
             && !keypress.getKey().isCtrl()
         ) {
             // Plain old keystroke, process it
+            deleteSelection();
             document.addChar(keypress.getKey().getChar());
             alignCursor();
         } else {
             // Pass other keys (tab etc.) on to TWidget
             super.onKeypress(keypress);
         }
+
+        if (inSelection) {
+            selectionColumn1 = document.getCursor();
+            selectionLine1 = document.getLineNumber();
+        }
     }
 
     /**
@@ -367,6 +455,224 @@ public final class TEditorWidget extends TWidget {
         }
     }
 
+    /**
+     * Handle posted command events.
+     *
+     * @param command command event
+     */
+    @Override
+    public void onCommand(final TCommandEvent command) {
+        if (command.equals(cmCut)) {
+            // Copy text to clipboard, and then remove it.
+            copySelection();
+            deleteSelection();
+            return;
+        }
+
+        if (command.equals(cmCopy)) {
+            // Copy text to clipboard.
+            copySelection();
+            return;
+        }
+
+        if (command.equals(cmPaste)) {
+            // Delete selected text, then paste text from clipboard.
+            deleteSelection();
+
+            String text = getClipboard().pasteText();
+            if (text != null) {
+                for (int i = 0; i < text.length(); ) {
+                    int ch = text.codePointAt(i);
+                    onKeypress(new TKeypressEvent(false, 0, ch, false, false,
+                            false));
+                    i += Character.charCount(ch);
+                }
+            }
+            return;
+        }
+
+        if (command.equals(cmClear)) {
+            // Remove text.
+            deleteSelection();
+            return;
+        }
+
+    }
+
+    // ------------------------------------------------------------------------
+    // TWidget ----------------------------------------------------------------
+    // ------------------------------------------------------------------------
+
+    /**
+     * Draw the text box.
+     */
+    @Override
+    public void draw() {
+        CellAttributes selectedColor = getTheme().getColor("teditor.selected");
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
+
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 <= selectionLine0))
+            || ((selectionColumn1 <= selectionColumn0)
+                && (selectionLine1 < selectionLine0))
+        ) {
+            // The user selected from bottom-right to top-left.  Reverse the
+            // coordinates for the inverted section.
+            startCol = selectionColumn1;
+            startRow = selectionLine1;
+            endCol = selectionColumn0;
+            endRow = selectionLine0;
+        }
+
+        for (int i = 0; i < getHeight(); i++) {
+            // Background line
+            getScreen().hLineXY(0, i, getWidth(), ' ', defaultColor);
+
+            // Now draw document's line
+            if (topLine + i < document.getLineCount()) {
+                Line line = document.getLine(topLine + i);
+                int x = 0;
+                for (Word word: line.getWords()) {
+                    // For now, we are cheating: draw outside the left region
+                    // if needed and let screen do the clipping.
+                    getScreen().putStringXY(x - leftColumn, i, word.getText(),
+                        word.getColor());
+                    x += word.getDisplayLength();
+                    if (x - leftColumn > getWidth()) {
+                        break;
+                    }
+                }
+
+                // Highlight selected region
+                if (inSelection) {
+                    if (startRow == endRow) {
+                        if (topLine + i == startRow) {
+                            for (x = startCol; x <= endCol; x++) {
+                                putAttrXY(x - leftColumn, i, selectedColor);
+                            }
+                        }
+                    } else {
+                        if (topLine + i == startRow) {
+                            for (x = startCol; x < line.getDisplayLength(); x++) {
+                                putAttrXY(x - leftColumn, i, selectedColor);
+                            }
+                        } else if (topLine + i == endRow) {
+                            for (x = 0; x <= endCol; x++) {
+                                putAttrXY(x - leftColumn, i, selectedColor);
+                            }
+                        } else if ((topLine + i >= startRow)
+                            && (topLine + i <= endRow)
+                        ) {
+                            for (x = 0; x < getWidth(); x++) {
+                                putAttrXY(x, i, selectedColor);
+                            }
+                        }
+                    }
+                }
+
+            }
+        }
+    }
+
+    // ------------------------------------------------------------------------
+    // TEditorWidget ----------------------------------------------------------
+    // ------------------------------------------------------------------------
+
+    /**
+     * Align visible area with document current line.
+     *
+     * @param topLineIsTop if true, make the top visible line the document
+     * current line if it was off-screen.  If false, make the bottom visible
+     * line the document current line.
+     */
+    private void alignTopLine(final boolean topLineIsTop) {
+        int line = document.getLineNumber();
+
+        if ((line < topLine) || (line > topLine + getHeight() - 1)) {
+            // Need to move topLine to bring document back into view.
+            if (topLineIsTop) {
+                topLine = line - (getHeight() - 1);
+                if (topLine < 0) {
+                    topLine = 0;
+                }
+                assert (topLine >= 0);
+            } else {
+                topLine = line;
+                assert (topLine >= 0);
+            }
+        }
+
+        /*
+        System.err.println("line " + line + " topLine " + topLine);
+        */
+
+        // Document is in view, let's set cursorY
+        assert (line >= topLine);
+        setCursorY(line - topLine);
+        alignCursor();
+    }
+
+    /**
+     * Align document current line with visible area.
+     *
+     * @param topLineIsTop if true, make the top visible line the document
+     * current line if it was off-screen.  If false, make the bottom visible
+     * line the document current line.
+     */
+    private void alignDocument(final boolean topLineIsTop) {
+        int line = document.getLineNumber();
+        int cursor = document.getCursor();
+
+        if ((line < topLine) || (line > topLine + getHeight() - 1)) {
+            // Need to move document to ensure it fits view.
+            if (topLineIsTop) {
+                document.setLineNumber(topLine);
+            } else {
+                document.setLineNumber(topLine + (getHeight() - 1));
+            }
+            if (cursor < document.getCurrentLine().getDisplayLength()) {
+                document.setCursor(cursor);
+            }
+        }
+
+        /*
+        System.err.println("getLineNumber() " + document.getLineNumber() +
+            " topLine " + topLine);
+        */
+
+        // Document is in view, let's set cursorY
+        setCursorY(document.getLineNumber() - topLine);
+        alignCursor();
+    }
+
+    /**
+     * Align visible cursor with document cursor.
+     */
+    private void alignCursor() {
+        int width = getWidth();
+
+        int desiredX = document.getCursor() - leftColumn;
+        if (desiredX < 0) {
+            // We need to push the screen to the left.
+            leftColumn = document.getCursor();
+        } else if (desiredX > width - 1) {
+            // We need to push the screen to the right.
+            leftColumn = document.getCursor() - (width - 1);
+        }
+
+        /*
+        System.err.println("document cursor " + document.getCursor() +
+            " leftColumn " + leftColumn);
+        */
+
+
+        setCursorX(document.getCursor() - leftColumn);
+    }
+
     /**
      * Get the number of lines in the underlying Document.
      *
@@ -376,6 +682,28 @@ public final class TEditorWidget extends TWidget {
         return document.getLineCount();
     }
 
+    /**
+     * Get the current visible top row number.  1-based.
+     *
+     * @return the visible top row number.  Row 1 is the first row.
+     */
+    public int getVisibleRowNumber() {
+        return topLine + 1;
+    }
+
+    /**
+     * Set the current visible row number.  1-based.
+     *
+     * @param row the new visible row number.  Row 1 is the first row.
+     */
+    public void setVisibleRowNumber(final int row) {
+        assert (row > 0);
+        if ((row > 0) && (row < document.getLineCount())) {
+            topLine = row - 1;
+            alignDocument(true);
+        }
+    }
+
     /**
      * Get the current editing row number.  1-based.
      *
@@ -398,6 +726,29 @@ public final class TEditorWidget extends TWidget {
         }
     }
 
+    /**
+     * Set the current visible column number.  1-based.
+     *
+     * @return the visible column number.  Column 1 is the first column.
+     */
+    public int getVisibleColumnNumber() {
+        return leftColumn + 1;
+    }
+
+    /**
+     * Set the current visible column number.  1-based.
+     *
+     * @param column the new visible column number.  Column 1 is the first
+     * column.
+     */
+    public void setVisibleColumnNumber(final int column) {
+        assert (column > 0);
+        if ((column > 0) && (column < document.getLineLengthMax())) {
+            leftColumn = column - 1;
+            alignDocument(true);
+        }
+    }
+
     /**
      * Get the current editing column number.  1-based.
      *
@@ -457,4 +808,167 @@ public final class TEditorWidget extends TWidget {
         document.saveToFilename(filename);
     }
 
+    /**
+     * Delete text within the selection bounds.
+     */
+    private void deleteSelection() {
+        if (inSelection == false) {
+            return;
+        }
+        inSelection = false;
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
+
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 <= selectionLine0))
+            || ((selectionColumn1 <= selectionColumn0)
+                && (selectionLine1 < selectionLine0))
+        ) {
+            // The user selected from bottom-right to top-left.  Reverse the
+            // coordinates for the inverted section.
+            startCol = selectionColumn1;
+            startRow = selectionLine1;
+            endCol = selectionColumn0;
+            endRow = selectionLine0;
+        }
+
+        // Place the cursor on the selection end, and "press backspace" until
+        // the cursor matches the selection start.
+        document.setLineNumber(endRow);
+        document.setCursor(endCol + 1);
+        while (!((document.getLineNumber() == startRow)
+                && (document.getCursor() == startCol))
+        ) {
+            document.backspace();
+        }
+        alignTopLine(true);
+    }
+
+    /**
+     * Copy text within the selection bounds to clipboard.
+     */
+    private void copySelection() {
+        if (inSelection == false) {
+            return;
+        }
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
+
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 <= selectionLine0))
+            || ((selectionColumn1 <= selectionColumn0)
+                && (selectionLine1 < selectionLine0))
+        ) {
+            // The user selected from bottom-right to top-left.  Reverse the
+            // coordinates for the inverted section.
+            startCol = selectionColumn1;
+            startRow = selectionLine1;
+            endCol = selectionColumn0;
+            endRow = selectionLine0;
+        }
+
+        StringBuilder sb = new StringBuilder();
+
+        if (endRow > startRow) {
+            // First line
+            String line = document.getLine(startRow).getRawString();
+            int x = 0;
+            for (int i = 0; i < line.length(); ) {
+                int ch = line.codePointAt(i);
+
+                if (x >= startCol) {
+                    sb.append(Character.toChars(ch));
+                }
+                x += StringUtils.width(ch);
+                i += Character.charCount(ch);
+            }
+            sb.append("\n");
+
+            // Middle lines
+            for (int y = startRow + 1; y < endRow; y++) {
+                sb.append(document.getLine(y).getRawString());
+                sb.append("\n");
+            }
+
+            // Final line
+            line = document.getLine(endRow).getRawString();
+            x = 0;
+            for (int i = 0; i < line.length(); ) {
+                int ch = line.codePointAt(i);
+
+                if (x > endCol) {
+                    break;
+                }
+
+                sb.append(Character.toChars(ch));
+                x += StringUtils.width(ch);
+                i += Character.charCount(ch);
+            }
+        } else {
+            assert (startRow == endRow);
+
+            // Only one line
+            String line = document.getLine(startRow).getRawString();
+            int x = 0;
+            for (int i = 0; i < line.length(); ) {
+                int ch = line.codePointAt(i);
+
+                if ((x >= startCol) && (x <= endCol)) {
+                    sb.append(Character.toChars(ch));
+                }
+
+                x += StringUtils.width(ch);
+                i += Character.charCount(ch);
+            }
+        }
+
+        getClipboard().copyText(sb.toString());
+    }
+
+    // ------------------------------------------------------------------------
+    // EditMenuUser -----------------------------------------------------------
+    // ------------------------------------------------------------------------
+
+    /**
+     * Check if the cut menu item should be enabled.
+     *
+     * @return true if the cut menu item should be enabled
+     */
+    public boolean isEditMenuCut() {
+        return true;
+    }
+
+    /**
+     * Check if the copy menu item should be enabled.
+     *
+     * @return true if the copy menu item should be enabled
+     */
+    public boolean isEditMenuCopy() {
+        return true;
+    }
+
+    /**
+     * Check if the paste menu item should be enabled.
+     *
+     * @return true if the paste menu item should be enabled
+     */
+    public boolean isEditMenuPaste() {
+        return true;
+    }
+
+    /**
+     * Check if the clear menu item should be enabled.
+     *
+     * @return true if the clear menu item should be enabled
+     */
+    public boolean isEditMenuClear() {
+        return true;
+    }
+
 }