Lightpen on

2026-08-24 16:45:55 +00:00 · 2026-08-24 16:35:24 +00:00
7 changed files with 197 additions and 48 deletions
@@ -1,4 +1,7 @@
 j3270.log.*
+*.txt
+*.py
+*.pcap
 build/*
 *.log
 .DS_Store
@@ -120,7 +120,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate

        // Actions menu
        JMenu actionsMenu = createMenu("Actions");
-        actionsMenu.add(createMenuItem("Clear", KeyEvent.VK_L, () -> {
+        actionsMenu.add(createMenuItem("Clear", KeyEvent.VK_K, () -> {
            if (client != null)
                client.sendClear();
            terminalPanel.repaint();
@@ -131,6 +131,10 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
            terminalPanel.repaint();
        }));
        actionsMenu.addSeparator();
+        actionsMenu.add(createMenuItem("Toggle Light Pen (Alt+L)", KeyEvent.VK_L, () -> {
+            terminalPanel.toggleLightPen();
+        }, true));
+        actionsMenu.addSeparator();
        actionsMenu.add(createMenuItem("File Transfer...", KeyEvent.VK_T, this::showFileTransferDialog));
        menuBar.add(actionsMenu);

@@ -149,18 +153,22 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
        return menu;
    }

-    private JMenuItem createMenuItem(String text, int acceleratorKey, Runnable action) {
-        JMenuItem item = new JMenuItem(text);
+    private JMenuItem createMenuItem(String name, int mnemonic, Runnable action, boolean useAlt) {
+        JMenuItem item = new JMenuItem(name);
        item.setBackground(new Color(40, 40, 40));
        item.setForeground(new Color(200, 200, 200));
-        if (acceleratorKey > 0) {
-            item.setAccelerator(KeyStroke.getKeyStroke(acceleratorKey,
-                    Toolkit.getDefaultToolkit().getMenuShortcutKeyMaskEx()));
+        if (mnemonic > 0) {
+            int modifier = useAlt ? KeyEvent.ALT_DOWN_MASK : Toolkit.getDefaultToolkit().getMenuShortcutKeyMaskEx();
+            item.setAccelerator(KeyStroke.getKeyStroke(mnemonic, modifier));
        }
        item.addActionListener(e -> action.run());
        return item;
    }

+    private JMenuItem createMenuItem(String name, int mnemonic, Runnable action) {
+        return createMenuItem(name, mnemonic, action, false);
+    }
+
    private void showFileTransferDialog() {
        if (client == null) {
            JOptionPane.showMessageDialog(this, "Connect to a host before using File Transfer.",
@@ -278,7 +286,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
        client.addScreenUpdateListener(this);

        terminalPanel.setClient(client);
-        statusBar.setClient(client);
+        statusBar.setClient(client, terminalPanel);

        String tlsIndicator = config.isUseTls() ? (config.isTlsVerifyCert() ? " [TLS]" : " [TLS/Unverified]") : "";
        setTitle("j3270 — " + config.getHost() + ":" + config.getPort() + tlsIndicator);
@@ -312,7 +320,7 @@ public class J3270App extends JFrame implements ConnectionListener, ScreenUpdate
            client.disconnect();
            client = null;
            terminalPanel.setClient(null);
-            statusBar.setClient(null);
+            statusBar.setClient(null, terminalPanel);
            terminalPanel.repaint();
            setTitle("j3270 — Java TN3270 Terminal Emulator");
        }
@@ -22,6 +22,7 @@ public class StatusBar extends JPanel {
    private final JLabel modelInfo;

    private Telnet3270Client client;
+    private TerminalPanel terminalPanel;

    // OIA colors
    private static final Color OIA_BG = new Color(20, 20, 20);
@@ -44,6 +45,19 @@ public class StatusBar extends JPanel {
        modelInfo = createLabel("", oiaFont, OIA_DIM);
        cursorPosition = createLabel("001/001", oiaFont, OIA_FG);

+        JButton lpButton = new JButton("LightPen: OFF");
+        lpButton.setFont(oiaFont);
+        lpButton.setForeground(OIA_FG);
+        lpButton.setBackground(OIA_BG);
+        lpButton.setBorder(BorderFactory.createEmptyBorder(0, 5, 0, 5));
+        lpButton.setFocusable(false);
+        lpButton.addActionListener(e -> {
+            if (terminalPanel != null) {
+                terminalPanel.toggleLightPen();
+                lpButton.setText("LightPen: " + (terminalPanel.isLightPenMode() ? "ON" : "OFF"));
+            }
+        });
+
        add(Box.createHorizontalStrut(6));
        add(connectionStatus);
        add(Box.createHorizontalStrut(10));
@@ -52,6 +66,8 @@ public class StatusBar extends JPanel {
        add(luName);
        add(Box.createHorizontalStrut(12));
        add(lockStatus);
+        add(Box.createHorizontalStrut(12));
+        add(lpButton);
        add(Box.createHorizontalGlue());
        add(modelInfo);
        add(Box.createHorizontalStrut(12));
@@ -66,8 +82,9 @@ public class StatusBar extends JPanel {
        return label;
    }

-    public void setClient(Telnet3270Client client) {
+    public void setClient(Telnet3270Client client, TerminalPanel terminalPanel) {
        this.client = client;
+        this.terminalPanel = terminalPanel;
    }

    public void updateStatus() {
@@ -62,6 +62,9 @@ public class TerminalPanel extends JPanel {
    private static final Color SELECTION_COLOR = new Color(75, 110, 175, 100);

    // ========== Resize guard ==========
+    private boolean lightPenMode = false;
+    private long lastGraphicsUpdateCount = -1;
+    private java.awt.image.BufferedImage cachedGraphicsImage = null;
    private boolean resizeGuard = false;

    /**
@@ -70,7 +73,7 @@ public class TerminalPanel extends JPanel {
     */
    private int getRenderOffsetX() {
        int termCols = 80;
-        if (client != null) termCols = client.getScreenBuffer().getCols();
+        if (client != null) termCols = client.getScreenBuffer().getDisplayCols();
        int gridW = termCols * cellWidth;
        int extra = getWidth() - gridW;
        return Math.max(padding, extra / 2);
@@ -78,10 +81,11 @@ public class TerminalPanel extends JPanel {

    /**
     * Compute the vertical render offset to center the grid within the panel.
+     * Must use getDisplayRows() to match paintComponent's iteration.
     */
    private int getRenderOffsetY() {
        int termRows = 24;
-        if (client != null) termRows = client.getScreenBuffer().getRows();
+        if (client != null) termRows = client.getScreenBuffer().getDisplayRows();
        int gridH = termRows * cellHeight;
        int extra = getHeight() - gridH;
        return Math.max(padding, extra / 2);
@@ -148,10 +152,12 @@ public class TerminalPanel extends JPanel {
                    ScreenBuffer sb = client.getScreenBuffer();
                    int ox = getRenderOffsetX();
                    int oy = getRenderOffsetY();
+                    int displayCols = sb.getDisplayCols();
+                    int displayRows = sb.getDisplayRows();
                    int col = (e.getX() - ox) / cellWidth;
                    int row = (e.getY() - oy) / cellHeight;
-                    col = Math.max(0, Math.min(col, sb.getCols() - 1));
-                    row = Math.max(0, Math.min(row, sb.getRows() - 1));
+                    col = Math.max(0, Math.min(col, displayCols - 1));
+                    row = Math.max(0, Math.min(row, displayRows - 1));

                    // Start selection
                    selectionStartRow = row;
@@ -171,8 +177,8 @@ public class TerminalPanel extends JPanel {
                    int oy = getRenderOffsetY();
                    int col = (e.getX() - ox) / cellWidth;
                    int row = (e.getY() - oy) / cellHeight;
-                    col = Math.max(0, Math.min(col, sb.getCols() - 1));
-                    row = Math.max(0, Math.min(row, sb.getRows() - 1));
+                    col = Math.max(0, Math.min(col, sb.getDisplayCols() - 1));
+                    row = Math.max(0, Math.min(row, sb.getDisplayRows() - 1));

                    selectionEndRow = row;
                    selectionEndCol = col;
@@ -204,9 +210,16 @@ public class TerminalPanel extends JPanel {
                    if (selectionStartRow == selectionEndRow && selectionStartCol == selectionEndCol) {
                        if (client != null && client.getConnectionState().isFullSession()) {
                            ScreenBuffer sb = client.getScreenBuffer();
-                            int newAddr = selectionStartRow * sb.getCols() + selectionStartCol;
+                            int displayCols = sb.getDisplayCols();
+                            int newAddr = selectionStartRow * displayCols + selectionStartCol;
                            sb.setCursorAddress(newAddr);
                            clearSelection();
+                            if (lightPenMode) {
+                                if (client.getInputProcessor().lightPenSelect(newAddr)) {
+                                    refreshScreen();
+                                    return;
+                                }
+                            }
                            
                            if (client.getGocaDecoder() != null && client.getGraphicsPlane() != null) {
                                int ox = getRenderOffsetX();
@@ -435,8 +448,8 @@ public class TerminalPanel extends JPanel {
        int termRows = 24;
        if (client != null) {
            ScreenBuffer sb = client.getScreenBuffer();
-            termCols = sb.getCols();
-            termRows = sb.getRows();
+            termCols = sb.getDisplayCols();
+            termRows = sb.getDisplayRows();
        }

        // Use minimal padding for the fit calculation
@@ -558,6 +571,7 @@ public class TerminalPanel extends JPanel {
        int shortcutMask = Toolkit.getDefaultToolkit().getMenuShortcutKeyMaskEx();
        im.put(KeyStroke.getKeyStroke(KeyEvent.VK_C, shortcutMask), "j3270-COPY");
        im.put(KeyStroke.getKeyStroke(KeyEvent.VK_V, shortcutMask), "j3270-PASTE");
+        im.put(KeyStroke.getKeyStroke(KeyEvent.VK_L, java.awt.event.InputEvent.ALT_DOWN_MASK), "j3270-LIGHTPEN");

        // Create actions for all bound keys
        am.put("j3270-ENTER", createAction(this::handleEnter));
@@ -586,6 +600,7 @@ public class TerminalPanel extends JPanel {
        // Copy/Paste actions
        am.put("j3270-COPY", createAction(this::copySelection));
        am.put("j3270-PASTE", createAction(this::pasteClipboard));
+        am.put("j3270-LIGHTPEN", createAction(this::toggleLightPen));

        for (int i = 1; i <= 24; i++) {
            final int pf = i;
@@ -858,8 +873,8 @@ public class TerminalPanel extends JPanel {
            // Use the CURRENT screen dimensions (not max) to eliminate extra space.
            // When the host switches to alternate screen, onScreenSizeChanged fires
            // and the frame re-packs.
-            int displayCols = sb.getCols();
-            int displayRows = sb.getRows();
+            int displayCols = sb.getDisplayCols();
+            int displayRows = sb.getDisplayRows();
            return new Dimension(displayCols * cellWidth + padding * 2,
                    displayRows * cellHeight + padding * 2);
        }
@@ -900,9 +915,13 @@ public class TerminalPanel extends JPanel {
            int gHeight = client.getGraphicsPlane().getCanvasHeight();
            int[] rgb = client.getGraphicsPlane().getRgbBuffer();
            if (rgb != null && gWidth > 0 && gHeight > 0) {
-                java.awt.image.BufferedImage img = new java.awt.image.BufferedImage(gWidth, gHeight, java.awt.image.BufferedImage.TYPE_INT_ARGB);
-                img.setRGB(0, 0, gWidth, gHeight, rgb, 0, gWidth);
-                g2.drawImage(img, ox, oy, gridW, gridH, null);
+                long currentUpdateCount = client.getGraphicsPlane().getUpdateCount();
+                if (cachedGraphicsImage == null || currentUpdateCount != lastGraphicsUpdateCount || cachedGraphicsImage.getWidth() != gWidth || cachedGraphicsImage.getHeight() != gHeight) {
+                    cachedGraphicsImage = new java.awt.image.BufferedImage(gWidth, gHeight, java.awt.image.BufferedImage.TYPE_INT_ARGB);
+                    cachedGraphicsImage.setRGB(0, 0, gWidth, gHeight, rgb, 0, gWidth);
+                    lastGraphicsUpdateCount = currentUpdateCount;
+                }
+                g2.drawImage(cachedGraphicsImage, ox, oy, gridW, gridH, null);
            }
        }

@@ -1039,8 +1058,14 @@ public class TerminalPanel extends JPanel {
        if (client.getGocaDecoder() != null && client.getGocaDecoder().isGraphicsCursorActive() && client.getGraphicsPlane() != null) {
            int gocaX = client.getGocaDecoder().getGraphicCursorX();
            int gocaY = client.getGocaDecoder().getGraphicCursorY();
-            int px = ox + client.getGraphicsPlane().mapX(gocaX);
-            int py = oy + client.getGraphicsPlane().mapY(gocaY);
+            int canvasPx = client.getGraphicsPlane().mapX(gocaX);
+            int canvasPy = client.getGraphicsPlane().mapY(gocaY);
+            int gridW = cols * cellWidth;
+            int gridH = rows * cellHeight;
+            int gWidth = client.getGraphicsPlane().getCanvasWidth();
+            int gHeight = client.getGraphicsPlane().getCanvasHeight();
+            int px = ox + (gWidth > 0 ? (int)Math.round((double)canvasPx * gridW / gWidth) : canvasPx);
+            int py = oy + (gHeight > 0 ? (int)Math.round((double)canvasPy * gridH / gHeight) : canvasPy);

            g2.setColor(Color.WHITE);
            g2.setXORMode(Color.BLACK);
@@ -1063,6 +1088,13 @@ public class TerminalPanel extends JPanel {
            g2.fillRect(cx, cy, cellWidth, cellHeight);
            g2.setPaintMode();
        }
+
+        // Draw Light Pen mode indicator
+        if (lightPenMode) {
+            g2.setFont(new Font(Font.MONOSPACED, Font.BOLD, 12));
+            g2.setColor(new Color(50, 255, 50));
+            g2.drawString("LP", ox + 2, oy + rows * cellHeight + 14);
+        }
    }

    private Color getColorForAttribute(ExtendedAttribute ea, ExtendedAttribute currentFieldEa, byte currentFA) {
@@ -1103,4 +1135,13 @@ public class TerminalPanel extends JPanel {
        if (blinkTimer != null)
            blinkTimer.stop();
    }
+    public void toggleLightPen() {
+        this.lightPenMode = !this.lightPenMode;
+        System.out.println("Light Pen mode: " + (this.lightPenMode ? "ON" : "OFF"));
+        repaint();
+    }
+    
+    public boolean isLightPenMode() {
+        return this.lightPenMode;
+    }
 }
@@ -829,39 +829,51 @@ public class GocaDecoder {

    private void processArc(byte[] data, int off, int len, boolean fromCurPos, boolean isFull) {
        int pos = off;
-        int startX = curX;
-        int startY = curY;
+        int centerX = curX;
+        int centerY = curY;

        if (!fromCurPos && pos + 4 <= off + len) {
-            startX = readCoord(data, pos);
-            startY = readCoord(data, pos + 2);
+            centerX = readCoord(data, pos);
+            centerY = readCoord(data, pos + 2);
            pos += 4;
        }

-        double multiplier = 1.0;
-        if (pos + 2 <= off + len) {
-            multiplier = (data[pos] & 0xFF) + ((data[pos + 1] & 0xFF) / 255.0);
-            if (multiplier == 0.0) multiplier = 1.0;
+        double sweepFraction = 1.0;
+        if (!isFull && pos + 2 <= off + len) {
+            byte intPart = data[pos];
+            double fracPart = (data[pos + 1] & 0xFF) / 256.0;
+            sweepFraction = intPart + (intPart >= 0 ? fracPart : -fracPart);
        }

-        int dxP = Math.abs(arcParamP - arcParamR);
-        int dyQ = Math.abs(arcParamQ - arcParamS);
-        if (dxP == 0) dxP = 10;
-        if (dyQ == 0) dyQ = 10;
+        int pxCenter = plane.mapX(centerX);
+        int pyCenter = plane.mapY(centerY);
+        int pxCur = plane.mapX(curX);
+        int pyCur = plane.mapY(curY);

-        int rxVirtual = (int) (dxP * multiplier);
-        int ryVirtual = (int) (dyQ * multiplier);
+        double radius = Math.sqrt(Math.pow(pxCur - pxCenter, 2) + Math.pow(pyCur - pyCenter, 2));
+        int rx = (int) Math.round(radius);
+        int ry = rx;
+        if (rx <= 0) {
+            rx = 10;
+            ry = 10;
+        }

-        int rx = Math.abs(plane.mapX(rxVirtual) - plane.mapX(0));
-        int ry = Math.abs(plane.mapY(ryVirtual) - plane.mapY(0));
-        if (rx <= 0) rx = 10;
-        if (ry <= 0) ry = 10;
+        double startAngleRad = Math.atan2(pyCenter - pyCur, pxCur - pxCenter);
+        double startAngleDeg = Math.toDegrees(startAngleRad);
+        if (startAngleDeg < 0) startAngleDeg += 360.0;
        
-        plane.drawArc(plane.mapX(startX), plane.mapY(startY), rx, ry, 0.0, 360.0,
+        double sweepAngleDeg = isFull ? 360.0 : (sweepFraction * 360.0);
+
+        plane.drawArc(pxCenter, pyCenter, rx, ry, startAngleDeg, sweepAngleDeg,
                      curColor, lineType, lineWidth, isFull);

-        curX = startX;
-        curY = startY;
+        // Arc ends at the end of the sweep
+        double endAngleRad = Math.toRadians(startAngleDeg + sweepAngleDeg);
+        int pxEnd = (int) Math.round(pxCenter + rx * Math.cos(endAngleRad));
+        int pyEnd = (int) Math.round(pyCenter - ry * Math.sin(endAngleRad));
+        
+        curX = plane.unmapX(pxEnd);
+        curY = plane.unmapY(pyEnd);
    }

    private void processFillet(byte[] data, int off, int len, boolean fromCurPos) {
@@ -932,8 +944,9 @@ public class GocaDecoder {
        int textLen = end - pos;
        if (textLen <= 0) return;

-        int cw = charWidth > 0 ? (int) Math.round((double) charWidth * plane.getCanvasWidth() / (plane.getScreenCols() * 9.0)) : 12;
-        int ch = charHeight > 0 ? (int) Math.round((double) charHeight * plane.getCanvasHeight() / (plane.getScreenRows() * 16.0)) : 20;
+        // IBM 3279 vector graphics base cell is 9x12
+        int cw = charWidth > 0 ? (int) Math.round((double) charWidth * plane.getCanvasWidth() / (plane.getScreenCols() * 9.0)) : 10;
+        int ch = charHeight > 0 ? (int) Math.round((double) charHeight * plane.getCanvasHeight() / (plane.getScreenRows() * 12.0)) : 14;

        if (charSet != 0 && programSymbolManager != null) {
            for (int i = 0; i < textLen; i++) {
@@ -40,6 +40,7 @@ public class GraphicsPlane {
    private int canvasHeight = 600;
    private int[] rgbBuffer;
    private boolean hasContent = false;
+    private long updateCount = 0;

    private int screenCols = 80;
    private int screenRows = 24;
@@ -79,6 +80,11 @@ public class GraphicsPlane {
            Arrays.fill(rgbBuffer, 0);
        }
        hasContent = false;
+        updateCount++;
+    }
+
+    public synchronized long getUpdateCount() {
+        return updateCount;
    }

    public synchronized boolean hasContent() {
@@ -162,6 +168,7 @@ public class GraphicsPlane {
        if (x >= 0 && x < canvasWidth && y >= 0 && y < canvasHeight) {
            rgbBuffer[y * canvasWidth + x] = colorArgb;
            hasContent = true;
+        updateCount++;
        }
    }

@@ -203,6 +210,7 @@ public class GraphicsPlane {
            }
        }
        hasContent = true;
+        updateCount++;
    }

    private boolean shouldPlotLinePixel(int step, int lineType) {
@@ -266,6 +274,7 @@ public class GraphicsPlane {
            prevY = nextY;
        }
        hasContent = true;
+        updateCount++;
    }

    /**
@@ -304,6 +313,7 @@ public class GraphicsPlane {
            }
        }
        hasContent = true;
+        updateCount++;
    }

    /**
@@ -380,6 +390,7 @@ public class GraphicsPlane {
            }
        }
        hasContent = true;
+        updateCount++;
    }

    /**
@@ -445,6 +456,7 @@ public class GraphicsPlane {
                break;
        }
        hasContent = true;
+        updateCount++;
    }

    private static final int[] VSS_OFFSETS = new int[256];
@@ -493,6 +505,7 @@ public class GraphicsPlane {
            }
        }
        hasContent = true;
+        updateCount++;
    }

    private void drawVssChar(int x, int y, char c, int color, int cw, int ch) {
@@ -558,5 +571,6 @@ public class GraphicsPlane {
            }
        }
        hasContent = true;
+        updateCount++;
    }
 }
@@ -352,6 +352,59 @@ public class InputProcessor {

    // ========== Cursor movement ==========

+    /**
+     * Simulate a Text Light Pen selection.
+     */
+    public boolean lightPenSelect(int address) {
+        if (screen == null || !screen.isFormatted()) {
+            return false;
+        }
+        int size = screen.getRows() * screen.getCols();
+        int faPos = screen.findFieldAttribute(address);
+        if (faPos < 0) {
+            return false;
+        }
+
+        ExtendedAttribute faCell = screen.getCell(faPos);
+        int fa = faCell.fa & 0xFF;
+        if (!org.lib3270j.protocol.DS3270Constants.faIsSelectable(fa)) {
+            return false;
+        }
+
+        int designatorPos = (faPos + 1) % size;
+        ExtendedAttribute desCell = screen.getCell(designatorPos);
+        int ebcdic = desCell.ec & 0xFF;
+        char ascii = (char) desCell.ucs4;
+
+        screen.setCursorAddress(designatorPos);
+
+        if (ebcdic == 0x00 || ebcdic == 0x40 || ascii == ' ' || ascii == 0 || (ebcdic != 0x50 && ascii != '&' && ebcdic != 0x6F && ascii != '?' && ebcdic != 0x6E && ascii != '>')) {
+            faCell.fa |= org.lib3270j.protocol.DS3270Constants.FA_MODIFY;
+            sendAid(org.lib3270j.protocol.DS3270Constants.AID_SELECT);
+            return true;
+        } else if (ebcdic == 0x50 || ascii == '&') {
+            faCell.fa |= org.lib3270j.protocol.DS3270Constants.FA_MODIFY;
+            sendAid(org.lib3270j.protocol.DS3270Constants.AID_ENTER);
+            return true;
+        } else if (ebcdic == 0x6F || ascii == '?') {
+            desCell.ec = (byte) 0x6E;
+            desCell.ucs4 = '>';
+            faCell.fa |= org.lib3270j.protocol.DS3270Constants.FA_MODIFY;
+            screen.updateDisplaySnapshot();
+            return true;
+        } else if (ebcdic == 0x6E || ascii == '>') {
+            desCell.ec = (byte) 0x6F;
+            desCell.ucs4 = '?';
+            faCell.fa &= ~org.lib3270j.protocol.DS3270Constants.FA_MODIFY;
+            screen.updateDisplaySnapshot();
+            return true;
+        } else {
+            faCell.fa |= org.lib3270j.protocol.DS3270Constants.FA_MODIFY;
+            sendAid(org.lib3270j.protocol.DS3270Constants.AID_SELECT);
+            return true;
+        }
+    }
+
    public void cursorUp() {
        int addr = screen.getCursorAddress();
        addr -= screen.getCols();
Author	SHA1	Message	Date
rudi	e28b7dc30a	Lightpen on Build and Test j3270 / Build JAR & Run Tests (push) Successful in 37s Details	2026-08-24 16:45:55 +00:00
rudi	d9df1052a1	Lightpen on	2026-08-24 16:35:24 +00:00