Made CodeDocument:: replaceAllContent apply a diff of only the changed regions.

extras/Introjucer/Source/Code Editor/jucer_SourceCodeEditor.cpp

@@ -38,6 +38,7 @@ CodeDocument& SourceCodeDocument::getCodeDocument()
     {
         codeDoc = new CodeDocument();
         reloadInternal();
+        codeDoc->clearUndoHistory();
     }
 
     return *codeDoc;
@@ -61,11 +62,8 @@ void SourceCodeDocument::reloadInternal()
 {
     jassert (codeDoc != nullptr);
     modDetector.updateHash();
-
-    ScopedPointer <InputStream> in (modDetector.getFile().createInputStream());
-
-    if (in != nullptr)
-        codeDoc->loadFromStream (*in);
+    codeDoc->replaceAllContent (modDetector.getFile().loadFileAsString());
+    codeDoc->setSavePoint();
 }
 
 bool SourceCodeDocument::save()

modules/juce_gui_extra/code_editor/juce_CodeDocument.cpp

@@ -569,8 +569,17 @@ void CodeDocument::insertText (int insertIndex, const String& text)
 
 void CodeDocument::replaceAllContent (const String& newContent)
 {
-    remove (0, getNumCharacters(), true);
-    insert (newContent, 0, true);
+    TextDiff diff (getAllContent(), newContent);
+
+    for (int i = 0; i < diff.changes.size(); ++i)
+    {
+        const TextDiff::Change& c = diff.changes.getReference(i);
+
+        if (c.isDeletion())
+            remove (c.start, c.start + c.length, true);
+        else
+            insert (c.insertedText, c.start, true);
+    }
 }
 
 bool CodeDocument::loadFromStream (InputStream& stream)