Merge branch 'subtree'
[fanfix.git] / src / jexer / TEditorWidget.java
index dcd2feaa74da296ff5b009cf9c00ec7a7babba1e..bea25eda3e74c9c0e2c60c012dfd4e976d1198e4 100644 (file)
 package jexer;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 
 import jexer.bits.CellAttributes;
+import jexer.bits.StringUtils;
 import jexer.event.TCommandEvent;
 import jexer.event.TKeypressEvent;
 import jexer.event.TMouseEvent;
@@ -63,10 +66,10 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
     /**
      * The document being edited.
      */
-    private Document document;
+    protected Document document;
 
     /**
-     * The default color for the TEditor class.
+     * The default color for the editable text.
      */
     private CellAttributes defaultColor = null;
 
@@ -80,11 +83,6 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
      */
     private int leftColumn = 0;
 
-    /**
-     * If true, selection is a rectangle.
-     */
-    private boolean selectionRectangle = false;
-
     /**
      * If true, the mouse is dragging a selection.
      */
@@ -110,6 +108,42 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
      */
     private int selectionLine1;
 
+    /**
+     * The list of undo/redo states.
+     */
+    private List<SavedState> undoList = new ArrayList<SavedState>();
+
+    /**
+     * The position in undoList for undo/redo.
+     */
+    private int undoListI = 0;
+
+    /**
+     * The maximum size of the undo list.
+     */
+    private int undoLevel = 50;
+
+    /**
+     * The saved state for an undo/redo operation.
+     */
+    private class SavedState {
+        /**
+         * The Document state.
+         */
+        public Document document;
+
+        /**
+         * The topmost line number in the visible area.  0-based.
+         */
+        public int topLine = 0;
+
+        /**
+         * The leftmost column number in the visible area.  0-based.
+         */
+        public int leftColumn = 0;
+
+    }
+
     // ------------------------------------------------------------------------
     // Constructors -----------------------------------------------------------
     // ------------------------------------------------------------------------
@@ -168,21 +202,22 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
 
         if (mouse.isMouse1()) {
             // Selection.
-            if (inSelection) {
-                selectionColumn1 = leftColumn + mouse.getX();
-                selectionLine1 = topLine + mouse.getY();
-            } else if (mouse.isShift() || mouse.isCtrl()) {
-                inSelection = true;
-                selectionColumn0 = leftColumn + mouse.getX();
+            int newLine = topLine + mouse.getY();
+            int newX = leftColumn + mouse.getX();
+
+            inSelection = true;
+            if (newLine > document.getLineCount() - 1) {
+                selectionLine0 = document.getLineCount() - 1;
+            } else {
                 selectionLine0 = topLine + mouse.getY();
-                selectionColumn1 = selectionColumn0;
-                selectionLine1 = selectionLine0;
-                selectionRectangle = mouse.isAlt() | mouse.isCtrl();
             }
+            selectionColumn0 = leftColumn + mouse.getX();
+            selectionColumn0 = Math.max(0, Math.min(selectionColumn0,
+                    document.getLine(selectionLine0).getDisplayLength() - 1));
+            selectionColumn1 = selectionColumn0;
+            selectionLine1 = selectionLine0;
 
             // 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);
@@ -196,7 +231,6 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
                 if (inSelection) {
                     selectionColumn1 = document.getCursor();
                     selectionLine1 = document.getLineNumber();
-                    selectionRectangle = mouse.isCtrl();
                 }
                 return;
             }
@@ -213,7 +247,6 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
             if (inSelection) {
                 selectionColumn1 = document.getCursor();
                 selectionLine1 = document.getLineNumber();
-                selectionRectangle = mouse.isCtrl();
             }
             return;
         } else {
@@ -233,22 +266,25 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
     public void onMouseMotion(final TMouseEvent mouse) {
 
         if (mouse.isMouse1()) {
+            // Set the row and column
+            int newLine = topLine + mouse.getY();
+            int newX = leftColumn + mouse.getX();
+            if ((newLine < 0) || (newX < 0)) {
+                return;
+            }
+
             // Selection.
             if (inSelection) {
-                selectionColumn1 = leftColumn + mouse.getX();
-                selectionLine1 = topLine + mouse.getY();
-            } else if (mouse.isShift() || mouse.isCtrl()) {
+                selectionColumn1 = newX;
+                selectionLine1 = newLine;
+            } else {
                 inSelection = true;
-                selectionColumn0 = leftColumn + mouse.getX();
-                selectionLine0 = topLine + mouse.getY();
+                selectionColumn0 = newX;
+                selectionLine0 = newLine;
                 selectionColumn1 = selectionColumn0;
                 selectionLine1 = selectionLine0;
-                selectionRectangle = mouse.isAlt() | mouse.isCtrl();
             }
 
-            // 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);
@@ -262,11 +298,9 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
                 if (inSelection) {
                     selectionColumn1 = document.getCursor();
                     selectionLine1 = document.getLineNumber();
-                    selectionRectangle = mouse.isCtrl();
                 }
                 return;
             }
-
             document.setLineNumber(newLine);
             setCursorY(mouse.getY());
             if (newX >= document.getCurrentLine().getDisplayLength()) {
@@ -279,30 +313,14 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
             if (inSelection) {
                 selectionColumn1 = document.getCursor();
                 selectionLine1 = document.getLineNumber();
-                selectionRectangle = mouse.isCtrl();
             }
             return;
-        } else {
-            inSelection = false;
         }
 
         // Pass to children
         super.onMouseDown(mouse);
     }
 
-    /**
-     * Handle mouse release events.
-     *
-     * @param mouse mouse button release event
-     */
-    @Override
-    public void onMouseUp(final TMouseEvent mouse) {
-        inSelection = false;
-
-        // Pass to children
-        super.onMouseDown(mouse);
-    }
-
     /**
      * Handle keystrokes.
      *
@@ -310,18 +328,44 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
      */
     @Override
     public void onKeypress(final TKeypressEvent keypress) {
-        if (keypress.getKey().isShift() || keypress.getKey().isCtrl()) {
-            // Selection.
-            if (!inSelection) {
-                inSelection = true;
-                selectionColumn0 = document.getCursor();
-                selectionLine0 = document.getLineNumber();
-                selectionColumn1 = selectionColumn0;
-                selectionLine1 = selectionLine0;
-                selectionRectangle = keypress.getKey().isCtrl();
+        if (keypress.getKey().isShift()) {
+            if (keypress.equals(kbShiftLeft)
+                || keypress.equals(kbShiftRight)
+                || keypress.equals(kbShiftUp)
+                || keypress.equals(kbShiftDown)
+                || keypress.equals(kbShiftPgDn)
+                || keypress.equals(kbShiftPgUp)
+                || keypress.equals(kbShiftHome)
+                || keypress.equals(kbShiftEnd)
+            ) {
+                // Shifted navigation keys enable selection
+                if (!inSelection) {
+                    inSelection = true;
+                    selectionColumn0 = document.getCursor();
+                    selectionLine0 = document.getLineNumber();
+                    selectionColumn1 = selectionColumn0;
+                    selectionLine1 = selectionLine0;
+                }
             }
         } else {
-            inSelection = false;
+            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 ((selectionColumn0 == selectionColumn1)
+                && (selectionLine0 == selectionLine1)
+            ) {
+                // The user clicked a spot and started typing.
+                inSelection = false;
+            }
         }
 
         if (keypress.equals(kbLeft)
@@ -336,11 +380,15 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
             alignTopLine(true);
         } 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);
@@ -354,13 +402,19 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
         ) {
             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) {
@@ -368,38 +422,62 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
                 }
                 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());
+            document.setOverwrite(!document.isOverwrite());
         } else if (keypress.equals(kbDel)) {
-            document.del();
-            alignCursor();
+            if (inSelection) {
+                deleteSelection();
+                alignCursor();
+            } else {
+                saveUndo();
+                document.del();
+                alignCursor();
+            }
         } else if (keypress.equals(kbBackspace)
             || keypress.equals(kbBackspaceDel)
         ) {
-            document.backspace();
-            alignTopLine(false);
-        } else if (keypress.equals(kbTab)) {
-            // Add spaces until we hit modulo 8.
-            for (int i = document.getCursor(); (i + 1) % 8 != 0; i++) {
-                document.addChar(' ');
+            if (inSelection) {
+                deleteSelection();
+                alignTopLine(false);
+            } else {
+                saveUndo();
+                document.backspace();
+                alignTopLine(false);
             }
+        } else if (keypress.equals(kbTab)) {
+            deleteSelection();
+            saveUndo();
+            document.tab();
+            alignCursor();
+        } else if (keypress.equals(kbShiftTab)) {
+            deleteSelection();
+            saveUndo();
+            document.backTab();
             alignCursor();
         } else if (keypress.equals(kbEnter)) {
+            deleteSelection();
+            saveUndo();
             document.enter();
             alignTopLine(true);
         } else if (!keypress.getKey().isFnKey()
@@ -407,6 +485,8 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
             && !keypress.getKey().isCtrl()
         ) {
             // Plain old keystroke, process it
+            deleteSelection();
+            saveUndo();
             document.addChar(keypress.getKey().getChar());
             alignCursor();
         } else {
@@ -417,7 +497,6 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
         if (inSelection) {
             selectionColumn1 = document.getCursor();
             selectionLine1 = document.getLineNumber();
-            selectionRectangle = keypress.getKey().isCtrl();
         }
     }
 
@@ -458,18 +537,14 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
     public void onCommand(final TCommandEvent command) {
         if (command.equals(cmCut)) {
             // Copy text to clipboard, and then remove it.
-
-            // TODO
-
+            copySelection();
             deleteSelection();
             return;
         }
 
         if (command.equals(cmCopy)) {
             // Copy text to clipboard.
-
-            // TODO
-
+            copySelection();
             return;
         }
 
@@ -481,8 +556,21 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
             if (text != null) {
                 for (int i = 0; i < text.length(); ) {
                     int ch = text.codePointAt(i);
-                    onKeypress(new TKeypressEvent(false, 0, ch, false, false,
-                            false));
+                    switch (ch) {
+                    case '\n':
+                        onKeypress(new TKeypressEvent(kbEnter));
+                        break;
+                    case '\t':
+                        onKeypress(new TKeypressEvent(kbTab));
+                        break;
+                    default:
+                        if ((ch >= 0x20) && (ch != 0x7F)) {
+                            onKeypress(new TKeypressEvent(false, 0, ch,
+                                    false, false, false));
+                        }
+                        break;
+                    }
+
                     i += Character.charCount(ch);
                 }
             }
@@ -506,6 +594,30 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
      */
     @Override
     public void draw() {
+        CellAttributes selectedColor = getTheme().getColor("teditor.selected");
+
+        boolean drawSelection = true;
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
+
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 == selectionLine0))
+            || (selectionLine1 < selectionLine0)
+        ) {
+            // The user selected from bottom-to-top and/or right-to-left.
+            // Reverse the coordinates for the inverted section.
+            startCol = selectionColumn1;
+            startRow = selectionLine1;
+            endCol = selectionColumn0;
+            endRow = selectionLine0;
+        }
+        if ((startCol == endCol) && (startRow == endRow)) {
+            drawSelection = false;
+        }
+
         for (int i = 0; i < getHeight(); i++) {
             // Background line
             getScreen().hLineXY(0, i, getWidth(), ' ', defaultColor);
@@ -524,9 +636,35 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
                         break;
                     }
                 }
-            }
 
-            // TODO: highlight selected region
+                // Highlight selected region
+                if (inSelection && drawSelection) {
+                    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);
+                            }
+                        }
+                    }
+                }
+
+            }
         }
     }
 
@@ -534,6 +672,15 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
     // TEditorWidget ----------------------------------------------------------
     // ------------------------------------------------------------------------
 
+    /**
+     * Set the undo level.
+     *
+     * @param undoLevel the maximum number of undo operations
+     */
+    public void setUndoLevel(final int undoLevel) {
+        this.undoLevel = undoLevel;
+    }
+
     /**
      * Align visible area with document current line.
      *
@@ -741,6 +888,17 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
         return document.getLineLengthMax() + 1;
     }
 
+    /**
+     * Get the current editing row plain text.  1-based.
+     *
+     * @param row the editing row number.  Row 1 is the first row.
+     * @return the plain text of the row
+     */
+    public String getEditingRawLine(final int row) {
+        Line line  = document.getLine(row - 1);
+        return line.getRawString();
+    }
+
     /**
      * Get the dirty value.
      *
@@ -750,6 +908,22 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
         return document.isDirty();
     }
 
+    /**
+     * Unset the dirty flag.
+     */
+    public void setNotDirty() {
+        document.setNotDirty();
+    }
+
+    /**
+     * Get the overwrite value.
+     *
+     * @return true if new text will overwrite old text
+     */
+    public boolean isOverwrite() {
+        return document.isOverwrite();
+    }
+
     /**
      * Save contents to file.
      *
@@ -764,11 +938,396 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
      * Delete text within the selection bounds.
      */
     private void deleteSelection() {
-        if (inSelection == false) {
+        if (!inSelection) {
+            return;
+        }
+
+        saveUndo();
+
+        inSelection = false;
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
+
+        /*
+        System.err.println("INITIAL: " + startRow + " " + startCol + " " +
+            endRow + " " + endCol + " " +
+            document.getLineNumber() + " " + document.getCursor());
+         */
+
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 == selectionLine0))
+            || (selectionLine1 < selectionLine0)
+        ) {
+            // The user selected from bottom-to-top and/or right-to-left.
+            // Reverse the coordinates for the inverted section.
+            startCol = selectionColumn1;
+            startRow = selectionLine1;
+            endCol = selectionColumn0;
+            endRow = selectionLine0;
+
+            if (endRow >= document.getLineCount()) {
+                // The selection started beyond EOF, trim it to EOF.
+                endRow = document.getLineCount() - 1;
+                endCol = document.getLine(endRow).getDisplayLength();
+            } else if (endRow == document.getLineCount() - 1) {
+                // The selection started beyond EOF, trim it to EOF.
+                if (endCol >= document.getLine(endRow).getDisplayLength()) {
+                    endCol = document.getLine(endRow).getDisplayLength() - 1;
+                }
+            }
+        }
+        /*
+        System.err.println("FLIP: " + startRow + " " + startCol + " " +
+            endRow + " " + endCol + " " +
+            document.getLineNumber() + " " + document.getCursor());
+        System.err.println(" --END: " + endRow + " " + document.getLineCount() +
+            " " + document.getLine(endRow).getDisplayLength());
+         */
+
+        assert (endRow < document.getLineCount());
+        if (endCol >= document.getLine(endRow).getDisplayLength()) {
+            endCol = document.getLine(endRow).getDisplayLength() - 1;
+        }
+        if (endCol < 0) {
+            endCol = 0;
+        }
+        if (startCol >= document.getLine(startRow).getDisplayLength()) {
+            startCol = document.getLine(startRow).getDisplayLength() - 1;
+        }
+        if (startCol < 0) {
+            startCol = 0;
+        }
+
+        // Place the cursor on the selection end, and "press backspace" until
+        // the cursor matches the selection start.
+        /*
+        System.err.println("BEFORE: " + startRow + " " + startCol + " " +
+            endRow + " " + endCol + " " +
+            document.getLineNumber() + " " + document.getCursor());
+         */
+        document.setLineNumber(endRow);
+        document.setCursor(endCol + 1);
+        while (!((document.getLineNumber() == startRow)
+                && (document.getCursor() == startCol))
+        ) {
+            /*
+            System.err.println("DURING: " + startRow + " " + startCol + " " +
+                endRow + " " + endCol + " " +
+                document.getLineNumber() + " " + document.getCursor());
+             */
+
+            document.backspace();
+        }
+        alignTopLine(true);
+    }
+
+    /**
+     * Copy text within the selection bounds to clipboard.
+     */
+    private void copySelection() {
+        if (!inSelection) {
             return;
         }
+        getClipboard().copyText(getSelection());
+    }
+
+    /**
+     * Set the selection.
+     *
+     * @param startRow the starting row number.  0-based: row 0 is the first
+     * row.
+     * @param startColumn the starting column number.  0-based: column 0 is
+     * the first column.
+     * @param endRow the ending row number.  0-based: row 0 is the first row.
+     * @param endColumn the ending column number.  0-based: column 0 is the
+     * first column.
+     */
+    public void setSelection(final int startRow, final int startColumn,
+        final int endRow, final int endColumn) {
+
+        inSelection = true;
+        selectionLine0 = startRow;
+        selectionColumn0 = startColumn;
+        selectionLine1 = endRow;
+        selectionColumn1 = endColumn;
+    }
+
+    /**
+     * Copy text within the selection bounds to a string.
+     *
+     * @return the selection as a string, or null if there is no selection
+     */
+    public String getSelection() {
+        if (!inSelection) {
+            return null;
+        }
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
+
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 == selectionLine0))
+            || (selectionLine1 < selectionLine0)
+        ) {
+            // The user selected from bottom-to-top and/or right-to-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);
+            }
+        }
+        return sb.toString();
+    }
+
+    /**
+     * Get the selection starting row number.
+     *
+     * @return the starting row number, or -1 if there is no selection.
+     * 0-based: row 0 is the first row.
+     */
+    public int getSelectionStartRow() {
+        if (!inSelection) {
+            return -1;
+        }
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
+
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 == selectionLine0))
+            || (selectionLine1 < selectionLine0)
+        ) {
+            // The user selected from bottom-to-top and/or right-to-left.
+            // Reverse the coordinates for the inverted section.
+            startCol = selectionColumn1;
+            startRow = selectionLine1;
+            endCol = selectionColumn0;
+            endRow = selectionLine0;
+        }
+        return startRow;
+    }
+
+    /**
+     * Get the selection starting column number.
+     *
+     * @return the starting column number, or -1 if there is no selection.
+     * 0-based: column 0 is the first column.
+     */
+    public int getSelectionStartColumn() {
+        if (!inSelection) {
+            return -1;
+        }
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
+
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 == selectionLine0))
+            || (selectionLine1 < selectionLine0)
+        ) {
+            // The user selected from bottom-to-top and/or right-to-left.
+            // Reverse the coordinates for the inverted section.
+            startCol = selectionColumn1;
+            startRow = selectionLine1;
+            endCol = selectionColumn0;
+            endRow = selectionLine0;
+        }
+        return startCol;
+    }
+
+    /**
+     * Get the selection ending row number.
+     *
+     * @return the ending row number, or -1 if there is no selection.
+     * 0-based: row 0 is the first row.
+     */
+    public int getSelectionEndRow() {
+        if (!inSelection) {
+            return -1;
+        }
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
 
-        // TODO
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 == selectionLine0))
+            || (selectionLine1 < selectionLine0)
+        ) {
+            // The user selected from bottom-to-top and/or right-to-left.
+            // Reverse the coordinates for the inverted section.
+            startCol = selectionColumn1;
+            startRow = selectionLine1;
+            endCol = selectionColumn0;
+            endRow = selectionLine0;
+        }
+        return endRow;
+    }
+
+    /**
+     * Get the selection ending column number.
+     *
+     * @return the ending column number, or -1 if there is no selection.
+     * 0-based: column 0 is the first column.
+     */
+    public int getSelectionEndColumn() {
+        if (!inSelection) {
+            return -1;
+        }
+
+        int startCol = selectionColumn0;
+        int startRow = selectionLine0;
+        int endCol = selectionColumn1;
+        int endRow = selectionLine1;
+
+        if (((selectionColumn1 < selectionColumn0)
+                && (selectionLine1 == selectionLine0))
+            || (selectionLine1 < selectionLine0)
+        ) {
+            // The user selected from bottom-to-top and/or right-to-left.
+            // Reverse the coordinates for the inverted section.
+            startCol = selectionColumn1;
+            startRow = selectionLine1;
+            endCol = selectionColumn0;
+            endRow = selectionLine0;
+        }
+        return endCol;
+    }
+
+    /**
+     * Unset the selection.
+     */
+    public void unsetSelection() {
+        inSelection = false;
+    }
+
+    /**
+     * Replace whatever is being selected with new text.  If not in
+     * selection, nothing is replaced.
+     *
+     * @param text the new replacement text
+     */
+    public void replaceSelection(final String text) {
+        if (!inSelection) {
+            return;
+        }
+
+        // Delete selected text, then paste text from clipboard.
+        deleteSelection();
+
+        for (int i = 0; i < text.length(); ) {
+            int ch = text.codePointAt(i);
+            switch (ch) {
+            case '\n':
+                onKeypress(new TKeypressEvent(kbEnter));
+                break;
+            case '\t':
+                onKeypress(new TKeypressEvent(kbTab));
+                break;
+            default:
+                if ((ch >= 0x20) && (ch != 0x7F)) {
+                    onKeypress(new TKeypressEvent(false, 0, ch,
+                            false, false, false));
+                }
+                break;
+            }
+            i += Character.charCount(ch);
+        }
+    }
+
+    /**
+     * Check if selection is available.
+     *
+     * @return true if a selection has been made
+     */
+    public boolean hasSelection() {
+        return inSelection;
+    }
+
+    /**
+     * Get the entire contents of the editor as one string.
+     *
+     * @return the editor contents
+     */
+    public String getText() {
+        return document.getText();
+    }
+
+    /**
+     * Set the entire contents of the editor from one string.
+     *
+     * @param text the new contents
+     */
+    public void setText(final String text) {
+        document = new Document(text, defaultColor);
+        unsetSelection();
+        topLine = 0;
+        leftColumn = 0;
     }
 
     // ------------------------------------------------------------------------
@@ -811,4 +1370,72 @@ public class TEditorWidget extends TWidget implements EditMenuUser {
         return true;
     }
 
+    /**
+     * Save undo state.
+     */
+    private void saveUndo() {
+        SavedState state = new SavedState();
+        state.document = document.dup();
+        state.topLine = topLine;
+        state.leftColumn = leftColumn;
+        if (undoLevel > 0) {
+            while (undoList.size() > undoLevel) {
+                undoList.remove(0);
+            }
+        }
+        undoList.add(state);
+        undoListI = undoList.size() - 1;
+    }
+
+    /**
+     * Undo an edit.
+     */
+    public void undo() {
+        inSelection = false;
+        if ((undoListI >= 0) && (undoListI < undoList.size())) {
+            SavedState state = undoList.get(undoListI);
+            document = state.document.dup();
+            topLine = state.topLine;
+            leftColumn = state.leftColumn;
+            undoListI--;
+            setCursorY(document.getLineNumber() - topLine);
+            alignCursor();
+        }
+    }
+
+    /**
+     * Redo an edit.
+     */
+    public void redo() {
+        inSelection = false;
+        if ((undoListI >= 0) && (undoListI < undoList.size())) {
+            SavedState state = undoList.get(undoListI);
+            document = state.document.dup();
+            topLine = state.topLine;
+            leftColumn = state.leftColumn;
+            undoListI++;
+            setCursorY(document.getLineNumber() - topLine);
+            alignCursor();
+        }
+    }
+
+    /**
+     * Trim trailing whitespace from lines and trailing empty
+     * lines from the document.
+     */
+    public void cleanWhitespace() {
+        document.cleanWhitespace();
+        setCursorY(document.getLineNumber() - topLine);
+        alignCursor();
+    }
+
+    /**
+     * Set keyword highlighting.
+     *
+     * @param enabled if true, enable keyword highlighting
+     */
+    public void setHighlighting(final boolean enabled) {
+        document.setHighlighting(enabled);
+    }
+
 }