From 5855c0ea7fa415e45c11c13d7d665796a65babdf Mon Sep 17 00:00:00 2001
From: Radek Davidek <rdavidek@trask.cz>
Date: Tue, 10 Feb 2026 18:36:03 +0100
Subject: [PATCH] max lines

---
 .../java/cz/kamma/kfmanager/config/AppConfig.java  |  8 ++++++++
 .../kamma/kfmanager/ui/FileComparisonDialog.java   |  3 ++-
 .../java/cz/kamma/kfmanager/ui/SettingsDialog.java | 14 ++++++++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/main/java/cz/kamma/kfmanager/config/AppConfig.java b/src/main/java/cz/kamma/kfmanager/config/AppConfig.java
index 768c84f..e410fab 100644
--- a/src/main/java/cz/kamma/kfmanager/config/AppConfig.java
+++ b/src/main/java/cz/kamma/kfmanager/config/AppConfig.java
@@ -1010,4 +1010,12 @@ public class AppConfig {
     public void setDividerPosition(double position) {
         properties.setProperty("mainPanel.dividerPosition", String.valueOf(position));
     }
+
+    public int getMaxCompareLines() {
+        return Integer.parseInt(properties.getProperty("compare.maxLines", "10000"));
+    }
+
+    public void setMaxCompareLines(int lines) {
+        properties.setProperty("compare.maxLines", String.valueOf(lines));
+    }
 }
diff --git a/src/main/java/cz/kamma/kfmanager/ui/FileComparisonDialog.java b/src/main/java/cz/kamma/kfmanager/ui/FileComparisonDialog.java
index 14b88e2..9506868 100644
--- a/src/main/java/cz/kamma/kfmanager/ui/FileComparisonDialog.java
+++ b/src/main/java/cz/kamma/kfmanager/ui/FileComparisonDialog.java
@@ -305,7 +305,8 @@ public class FileComparisonDialog extends JFrame {
         if (lines1.isEmpty() || lines2.isEmpty()) return;
 
         // Skip alignment for very large files to avoid O(N^2) memory/time issues
-        if (lines1.size() > 2000 || lines2.size() > 2000) return;
+        int maxLines = config.getMaxCompareLines();
+        if (lines1.size() > maxLines || lines2.size() > maxLines) return;
 
         int n = lines1.size();
         int m = lines2.size();
diff --git a/src/main/java/cz/kamma/kfmanager/ui/SettingsDialog.java b/src/main/java/cz/kamma/kfmanager/ui/SettingsDialog.java
index 1e85d71..993e6f4 100644
--- a/src/main/java/cz/kamma/kfmanager/ui/SettingsDialog.java
+++ b/src/main/java/cz/kamma/kfmanager/ui/SettingsDialog.java
@@ -76,6 +76,7 @@ public class SettingsDialog extends JDialog {
     private final String originalExternalEditorPath;
     private final int originalToolbarButtonSize;
     private final int originalToolbarIconSize;
+    private final int originalMaxCompareLines;
     private final java.util.List<cz.kamma.kfmanager.config.AppConfig.OpenWithEntry> originalOpenWithEntries;
 
     // Appearance controls
@@ -110,6 +111,7 @@ public class SettingsDialog extends JDialog {
         this.originalExternalEditorPath = config.getExternalEditorPath();
         this.originalToolbarButtonSize = config.getToolbarButtonSize();
         this.originalToolbarIconSize = config.getToolbarIconSize();
+        this.originalMaxCompareLines = config.getMaxCompareLines();
         this.originalOpenWithEntries = new java.util.ArrayList<>(config.getOpenWithEntries());
 
         setDefaultCloseOperation(DISPOSE_ON_CLOSE);
@@ -264,6 +266,8 @@ public class SettingsDialog extends JDialog {
                 try {
                     JSpinner ari = (JSpinner) behaviorHolder.getClientProperty("autoRefreshInterval");
                     if (ari != null) config.setAutoRefreshInterval((Integer) ari.getValue());
+                    JSpinner mcl = (JSpinner) behaviorHolder.getClientProperty("maxCompareLines");
+                    if (mcl != null) config.setMaxCompareLines((Integer) mcl.getValue());
                 } catch (Exception ignore) {}
             }
 
@@ -288,6 +292,7 @@ public class SettingsDialog extends JDialog {
             config.setExternalEditorPath(originalExternalEditorPath);
             config.setToolbarButtonSize(originalToolbarButtonSize);
             config.setToolbarIconSize(originalToolbarIconSize);
+            config.setMaxCompareLines(originalMaxCompareLines);
             config.setOpenWithEntries(originalOpenWithEntries);
             
             // Notify UI to revert changes
@@ -624,8 +629,17 @@ public class SettingsDialog extends JDialog {
         gbc.gridx = 1; gbc.gridy = row++; gbc.weightx = 1.0;
         grid.add(refreshInt, gbc);
 
+        // Max lines for file comparison
+        gbc.gridx = 0; gbc.gridy = row; gbc.weightx = 0.0;
+        grid.add(new JLabel("Max lines for smart comparison:"), gbc);
+
+        JSpinner maxLines = new JSpinner(new SpinnerNumberModel(config.getMaxCompareLines(), 100, 100000, 100));
+        gbc.gridx = 1; gbc.gridy = row++; gbc.weightx = 1.0;
+        grid.add(maxLines, gbc);
+
         p.add(grid, BorderLayout.NORTH);
         p.putClientProperty("autoRefreshInterval", refreshInt);
+        p.putClientProperty("maxCompareLines", maxLines);
         panels.put("Behavior", p);
         return p;
     }