Added auto Plan Preview tab and EXCEPT_PLAN mode for inline diff preview

CHANGELOG.md

@@ -1,3 +1,4 @@
+- Added automatic Markdown Preview tab when Claude writes a plan file (configurable in Settings → General)
 - Added `show_markdown` MCP tool: displays markdown text in a NetBeans Markdown Preview tab
 - Added `show_markdown_file` MCP tool: opens a live-updating Markdown Preview tab for a .md file on disk
 

docs/user-manual.md

@@ -317,12 +317,30 @@ Press Escape to click Cancel.
 
 ### Markdown preview
 
-For `.md` files, a rendered markdown preview is shown alongside the raw diff. Toggle it via **right-click on the diff → Preview Markdown** (checkbox). The default state is configured in **Tools → Options → Claude Code → General → Show markdown preview for .md files in diff**. Toggling in the context menu does not change the global setting.
+For `.md` files, a rendered markdown preview is shown alongside the raw diff. Toggle it via **right-click on the diff → Preview Markdown** (checkbox). The default state is configured in **Tools → Options → Claude Code → General → Markdown preview in diff**, which offers three options:
+
+| Option | Behaviour |
+|--------|-----------|
+| **Always** | Always show the inline preview for `.md` files in the diff panel (default) |
+| **Never** | Never show the inline preview |
+| **Except when Plan Preview tab is open** | Show the inline preview, but suppress it when a dedicated live Plan Preview tab is already visible for a file in the `plans/` directory |
+
+Toggling in the context menu does not change the global setting.
 
 **Pin Preview** — opens the rendered markdown (proposed content) in a separate IDE tab that remains open after the diff is closed.
 
 Both features are especially useful in Claude's plan mode: they let you read the formatted plan before deciding whether to accept it.
 
+### Auto Plan Preview
+
+When Claude writes a plan file to a `plans/` directory (e.g. `~/.claude/plans/my-plan.md`), the plugin can automatically open a live **Markdown Preview** tab the moment you click **Accept** in the diff panel.
+
+- The preview opens immediately when you click **Accept**; the file content appears within a second or two as Claude finishes writing it.
+- If you click **Accept** again for the same plan file (e.g. after an update), the existing preview tab refreshes in-place instead of opening a new tab.
+- The feature works with any `CLAUDE_CONFIG_DIR` location — it detects the `plans/` directory by name, so named profiles with custom config directories are supported automatically.
+
+**Enable / disable:** **Tools → Options → Claude Code → General → Automatically open Plan Preview tab when Claude writes a plan**.
+
 If the file being edited is outside the current project directory, a warning ⚠ is shown in the diff panel.
 
 ---
@@ -343,7 +361,8 @@ Open **Tools → Options → Claude Code** in NetBeans.
 | Insert newline key | Enter | Key combination that inserts a newline in the input area. The send and newline keys are configured independently but cannot be set to the same value. |
 | Open file diff in a separate tab | Off | Opens the diff panel in a new IDE tab instead of embedding it in the session tab. |
 | File diff tab dock position | Editor area | Where the File Diff tab is docked when opened as a separate tab. Enabled only when "Open file diff in a separate tab" is checked. |
-| Show markdown preview for .md files in diff | On | Shows a rendered markdown preview alongside the raw diff for `.md` files. |
+| Markdown preview in diff | Always | Controls when the inline markdown preview is shown for `.md` files in the diff panel. **Always** — always show it. **Never** — never show it. **Except when Plan Preview tab is open** — show it, but suppress it when the diffed file is a plan file and Auto Plan Preview is on (or its tab is already open). |
+| Automatically open Plan Preview tab when Claude writes a plan | On | When enabled, a live Markdown Preview tab opens automatically as soon as the user clicks Allow in a diff panel for a file in a `plans/` directory. |
 | Markdown preview dock position | Right side | Where the Markdown Preview tab is docked when first opened. Choices: Editor area, Right side, Left side top, Left side bottom, Bottom dock. |
 | Choice menu focus | Grab focus | Controls whether the choice menu panel grabs keyboard focus when it appears. Choices: Grab focus, Show without grabbing focus, Hide menu. |
 | Terminal font | Auto | Font used in the embedded terminal. Click **Choose…** to open the font picker. The label shows the resolved font name (e.g. `Adwaita Mono, 14 (Auto)` when auto-detection is active, or `Monospaced, 14` when set explicitly). |
@@ -657,6 +676,8 @@ The plugin exposes a set of IDE tools to Claude via an MCP (Model Context Protoc
 | `openDiff` | Shows a git diff for a file in the diff viewer |
 | `closeAllDiffTabs` | Closes all open diff viewer tabs |
 | `permission_prompt` | Shows proposed file changes in the diff panel and waits for your approval |
+| `show_markdown` | Renders markdown text directly in a Markdown Preview tab; accepts the markdown content plus optional title and file path |
+| `show_markdown_file` | Opens a live-updating Markdown Preview tab for an existing `.md` file on disk; the tab automatically refreshes when the file changes |
 
 ### Prompts that work well with IDE tools
 

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>io.github.nbclaudecodegui</groupId>
     <artifactId>netbeans-claude-code-gui</artifactId>
-    <version>0.23.1-SNAPSHOT</version>
+    <version>0.23.6-SNAPSHOT</version>
     <packaging>nbm</packaging>
     <name>Netbeans Plugin Claude Code GUI</name>
     <description>NetBeans plugin that provides a GUI for Claude Code CLI — run claude code sessions directly inside the IDE.</description>

src/main/java/io/github/nbclaudecodegui/mcp/NetBeansMCPHandler.java

@@ -50,7 +50,9 @@
 import javax.swing.SwingUtilities;
 import org.openide.windows.WindowManager;
 import io.github.nbclaudecodegui.ui.ClaudeSessionTab;
+import io.github.nbclaudecodegui.settings.ClaudeCodePreferences;
 import io.github.nbclaudecodegui.ui.FileDiffOpener;
+import io.github.nbclaudecodegui.ui.MarkdownPreviewTab;
 import io.github.nbclaudecodegui.mcp.tools.DiffTabTracker;
 import io.github.nbclaudecodegui.mcp.tools.GetDiagnostics;
 import io.github.nbclaudecodegui.mcp.tools.GetOpenEditors;
@@ -548,7 +550,10 @@ public CompletableFuture<String> handlePreToolUse(String hookJson) {
             CompletableFuture<String> future = DiffTabTracker.registerHookFuture(tabName);
 
             FileDiffOpener.open(filePath, before, after, tabName, cwd,
-            () -> DiffTabTracker.resolveHook(tabName, hookAllowJson()),
+            () -> {
+                DiffTabTracker.resolveHook(tabName, hookAllowJson());
+                openPlanPreviewIfNeeded(toolInput, filePath);
+            },
             reason -> DiffTabTracker.resolveHook(tabName, hookDenyJson(reason)),
             () -> {
                 DiffTabTracker.resolveHook(tabName, hookDenyJson(""));
@@ -565,6 +570,35 @@ public CompletableFuture<String> handlePreToolUse(String hookJson) {
         }
     }
 
+    /**
+     * Opens a live Markdown Preview tab for the written file when it is a plan
+     * file ({@code <configDir>/plans/*.md}) and the {@code autoPlanPreview}
+     * setting is enabled.  Called after the user approves a Write hook.
+     *
+     * <p>The plans directory is identified by the parent directory being named
+     * {@code "plans"}, making it robust against different {@code CLAUDE_CONFIG_DIR}
+     * values (default {@code ~/.claude}, isolated profiles, etc.)
+     *
+     * <p>The tab is opened before Claude writes the file; {@link MarkdownPreviewTab#openLive}
+     * schedules a deferred {@code forceReload()} that wires the {@link org.openide.filesystems.FileChangeListener}
+     * once the file appears on disk.
+     */
+    private void openPlanPreviewIfNeeded(JsonNode toolInput, String filePath) {
+        if (!ClaudeCodePreferences.isAutoPlanPreview()) return;
+        if (filePath == null || filePath.isEmpty() || !filePath.endsWith(".md")) return;
+        java.nio.file.Path p = java.nio.file.Path.of(filePath);
+        if (p.getParent() == null
+                || !"plans".equals(p.getParent().getFileName().toString())) return;
+        File file = new File(filePath);
+        FileObject fo = FileUtil.toFileObject(FileUtil.normalizeFile(file));
+        String currentContent = "";
+        if (fo != null) {
+            try { currentContent = fo.asText(); } catch (java.io.IOException ignored) {}
+        }
+        final String initialContent = currentContent;
+        SwingUtilities.invokeLater(() -> MarkdownPreviewTab.openLive(filePath, initialContent, fo));
+    }
+
     private static boolean isFileEditTool(String toolName) {
         return "Edit".equals(toolName) || "Write".equals(toolName) || "MultiEdit".equals(toolName);
     }

src/main/java/io/github/nbclaudecodegui/settings/ClaudeCodeOptionsPanel.java

@@ -2,6 +2,9 @@
 
 import io.github.nbclaudecodegui.model.FavoriteEntry;
 import io.github.nbclaudecodegui.model.PromptFavoritesStore;
+import javax.swing.DefaultListCellRenderer;
+import javax.swing.JComboBox;
+import javax.swing.JList;
 import io.github.nbclaudecodegui.ui.FavoritesPanel;
 import java.awt.BorderLayout;
 import java.awt.GridBagConstraints;
@@ -72,8 +75,12 @@ public final class ClaudeCodeOptionsPanel extends JPanel {
     private javax.swing.JCheckBox debugCheckBox;
     /** Checkbox to open diff in a separate tab. */
     private javax.swing.JCheckBox diffInSessionCheck;
-    /** Checkbox to show markdown preview for .md files in diff. */
-    private javax.swing.JCheckBox mdPreviewInDiffCheck;
+    /** Label for the markdown preview in diff combobox. */
+    private JLabel mdPreviewInDiffLabel;
+    /** Combobox for the markdown preview in diff mode. */
+    private JComboBox<MdPreviewInDiffMode> mdPreviewInDiffCombo;
+    /** Checkbox to automatically open Plan Preview when Claude writes a plan file. */
+    private javax.swing.JCheckBox autoPlanPreviewCheck;
     /** Checkbox for context-menu session mode (checked = New, unchecked = Continue last). */
     private javax.swing.JCheckBox startNewSessionCheck;
     /** Spinner for the maximum number of sessions shown in the session list. */
@@ -219,13 +226,36 @@ private JPanel buildGeneralPanel() {
         row++;
 
         // --- md preview in diff ---
-        mdPreviewInDiffCheck = new javax.swing.JCheckBox("Show markdown preview for .md files in diff");
-        GridBagConstraints mdGbc = new GridBagConstraints();
-        mdGbc.gridx = 0; mdGbc.gridy = row;
-        mdGbc.gridwidth = 3;
-        mdGbc.anchor = GridBagConstraints.WEST;
-        mdGbc.insets = new Insets(4, 8, 4, 8);
-        form.add(mdPreviewInDiffCheck, mdGbc);
+        mdPreviewInDiffLabel = new JLabel("Markdown preview in diff:");
+        form.add(mdPreviewInDiffLabel, gbc(0, row, false));
+        mdPreviewInDiffCombo = new JComboBox<>(MdPreviewInDiffMode.values());
+        mdPreviewInDiffCombo.setRenderer(new DefaultListCellRenderer() {
+            @Override
+            public java.awt.Component getListCellRendererComponent(
+                    JList<?> list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
+                super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
+                if (value instanceof MdPreviewInDiffMode mode) {
+                    setText(switch (mode) {
+                        case ALWAYS      -> "Always";
+                        case NEVER       -> "Never";
+                        case EXCEPT_PLAN -> "Except when Plan Preview tab is open";
+                    });
+                }
+                return this;
+            }
+        });
+        form.add(mdPreviewInDiffCombo, gbc(1, row, false));
+        row++;
+
+        // --- auto plan preview ---
+        autoPlanPreviewCheck = new javax.swing.JCheckBox(
+                "Automatically open Plan Preview tab when Claude writes a plan");
+        GridBagConstraints appGbc = new GridBagConstraints();
+        appGbc.gridx = 0; appGbc.gridy = row;
+        appGbc.gridwidth = 3;
+        appGbc.anchor = GridBagConstraints.WEST;
+        appGbc.insets = new Insets(4, 8, 4, 8);
+        form.add(autoPlanPreviewCheck, appGbc);
         row++;
 
         // --- markdown preview dock mode ---
@@ -444,7 +474,8 @@ void load() {
         debugCheckBox.setSelected(ClaudeCodePreferences.isDebugMode());
         diffInSessionCheck.setSelected(
                 ClaudeCodePreferences.isOpenDiffInSeparateTab());
-        mdPreviewInDiffCheck.setSelected(ClaudeCodePreferences.isMdPreviewInDiff());
+        mdPreviewInDiffCombo.setSelectedItem(ClaudeCodePreferences.getMdPreviewInDiffMode());
+        autoPlanPreviewCheck.setSelected(ClaudeCodePreferences.isAutoPlanPreview());
         startNewSessionCheck.setSelected(
                 ClaudeCodePreferences.getContextMenuSessionMode()
                         == io.github.nbclaudecodegui.model.SessionMode.NEW);
@@ -489,7 +520,9 @@ void store() {
         ClaudeCodePreferences.setHistoryTtlDays((Integer) historyTtlDaysSpinner.getValue());
         ClaudeCodePreferences.setDebugMode(debugCheckBox.isSelected());
         ClaudeCodePreferences.setOpenDiffInSeparateTab(diffInSessionCheck.isSelected());
-        ClaudeCodePreferences.setMdPreviewInDiff(mdPreviewInDiffCheck.isSelected());
+        MdPreviewInDiffMode selMode = (MdPreviewInDiffMode) mdPreviewInDiffCombo.getSelectedItem();
+        if (selMode != null) ClaudeCodePreferences.setMdPreviewInDiffMode(selMode);
+        ClaudeCodePreferences.setAutoPlanPreview(autoPlanPreviewCheck.isSelected());
         ClaudeCodePreferences.setContextMenuSessionMode(
                 startNewSessionCheck.isSelected()
                         ? io.github.nbclaudecodegui.model.SessionMode.NEW

src/main/java/io/github/nbclaudecodegui/settings/ClaudeCodePreferences.java

@@ -380,31 +380,78 @@ public static void setOpenDiffInSeparateTab(boolean v) {
     }
 
     // -------------------------------------------------------------------------
-    // mdPreviewInDiff
+    // mdPreviewInDiffMode
     // -------------------------------------------------------------------------
 
-    /** Preference key: show markdown preview for .md files in diff. */
-    public static final String KEY_MD_PREVIEW_IN_DIFF = "mdPreviewInDiff";
-    /** Default: markdown preview enabled. */
-    public static final boolean DEFAULT_MD_PREVIEW_IN_DIFF = true;
+    /** Preference key: when to show markdown preview for .md files in diff. */
+    public static final String KEY_MD_PREVIEW_IN_DIFF_MODE = "mdPreviewInDiffMode";
+    /** Default: always show the inline preview. */
+    public static final MdPreviewInDiffMode DEFAULT_MD_PREVIEW_IN_DIFF_MODE =
+            MdPreviewInDiffMode.ALWAYS;
 
     /**
-     * Returns whether the markdown preview is shown for .md files in diffs.
+     * Returns the current mode for showing the inline Markdown preview in the diff panel.
      *
-     * @return {@code true} if the preview is enabled
+     * @return the {@link MdPreviewInDiffMode}, never {@code null}
      */
+    public static MdPreviewInDiffMode getMdPreviewInDiffMode() {
+        String raw = NbPreferences.forModule(ClaudeCodePreferences.class)
+                .get(KEY_MD_PREVIEW_IN_DIFF_MODE, DEFAULT_MD_PREVIEW_IN_DIFF_MODE.name());
+        try {
+            return MdPreviewInDiffMode.valueOf(raw);
+        } catch (IllegalArgumentException e) {
+            return DEFAULT_MD_PREVIEW_IN_DIFF_MODE;
+        }
+    }
+
+    /**
+     * Persists the markdown-preview-in-diff mode setting.
+     *
+     * @param v the mode to store, must not be {@code null}
+     */
+    public static void setMdPreviewInDiffMode(MdPreviewInDiffMode v) {
+        NbPreferences.forModule(ClaudeCodePreferences.class)
+                .put(KEY_MD_PREVIEW_IN_DIFF_MODE, v.name());
+    }
+
+    /**
+     * Returns {@code true} if the inline Markdown preview is enabled in any form.
+     *
+     * @deprecated Use {@link #getMdPreviewInDiffMode()} for full control.
+     */
+    @Deprecated
     public static boolean isMdPreviewInDiff() {
+        return getMdPreviewInDiffMode() != MdPreviewInDiffMode.NEVER;
+    }
+
+    // -------------------------------------------------------------------------
+    // autoPlanPreview
+    // -------------------------------------------------------------------------
+
+    /** Preference key: automatically open Markdown Preview when Claude writes a plan file. */
+    public static final String KEY_AUTO_PLAN_PREVIEW = "autoPlanPreview";
+    /** Default: auto plan preview enabled. */
+    public static final boolean DEFAULT_AUTO_PLAN_PREVIEW = true;
+
+    /**
+     * Returns {@code true} if the plugin should automatically open a live Markdown
+     * Preview tab when Claude writes a plan file to any {@code plans/} directory.
+     *
+     * @return {@code true} if auto plan preview is enabled
+     */
+    public static boolean isAutoPlanPreview() {
         return NbPreferences.forModule(ClaudeCodePreferences.class)
-                .getBoolean(KEY_MD_PREVIEW_IN_DIFF, DEFAULT_MD_PREVIEW_IN_DIFF);
+                .getBoolean(KEY_AUTO_PLAN_PREVIEW, DEFAULT_AUTO_PLAN_PREVIEW);
     }
 
     /**
-     * Persists the markdown-preview-in-diff setting.
+     * Persists the auto-plan-preview setting.
      *
-     * @param v {@code true} to enable the preview
+     * @param v {@code true} to enable automatic plan preview
      */
-    public static void setMdPreviewInDiff(boolean v) {
-        NbPreferences.forModule(ClaudeCodePreferences.class).putBoolean(KEY_MD_PREVIEW_IN_DIFF, v);
+    public static void setAutoPlanPreview(boolean v) {
+        NbPreferences.forModule(ClaudeCodePreferences.class)
+                .putBoolean(KEY_AUTO_PLAN_PREVIEW, v);
     }
 
     // -------------------------------------------------------------------------

src/main/java/io/github/nbclaudecodegui/settings/MdPreviewInDiffMode.java

@@ -0,0 +1,17 @@
+package io.github.nbclaudecodegui.settings;
+
+/**
+ * Controls when the inline Markdown preview is shown inside the file diff panel.
+ */
+public enum MdPreviewInDiffMode {
+    /** Always show the inline preview for .md files in the diff panel. */
+    ALWAYS,
+    /** Never show the inline preview. */
+    NEVER,
+    /**
+     * Show the inline preview, except when a live Plan Preview tab is already
+     * open for a file in the {@code plans/} directory — in that case the
+     * dedicated preview tab makes the inline one redundant.
+     */
+    EXCEPT_PLAN
+}