Fixed: [ Issue 70 ] Validation doesn't start until editing
https://code.google.com/p/protobuf-dt/issues/detail?id=70

Working on preference page for validation options.
diff --git a/com.google.eclipse.protobuf.ui/OSGI-INF/l10n/bundle.properties b/com.google.eclipse.protobuf.ui/OSGI-INF/l10n/bundle.properties
index dbc0008..c481882 100644
--- a/com.google.eclipse.protobuf.ui/OSGI-INF/l10n/bundle.properties
+++ b/com.google.eclipse.protobuf.ui/OSGI-INF/l10n/bundle.properties
@@ -6,7 +6,7 @@
 page.name.0 = Syntax Coloring
 page.name.1 = Templates
 page.name.2 = Compiler
-page.name.3 = Paths
+page.name.3 = Import Paths
 keyword.label = Protocol Buffer
 command.description = Trigger expensive validation
 command.name = Validate
diff --git a/com.google.eclipse.protobuf.ui/plugin.xml b/com.google.eclipse.protobuf.ui/plugin.xml
index da63f1b..7f6628a 100644
--- a/com.google.eclipse.protobuf.ui/plugin.xml
+++ b/com.google.eclipse.protobuf.ui/plugin.xml
@@ -48,7 +48,7 @@
   </extension>
   <extension point="org.eclipse.ui.preferencePages">
     <page
-      class="com.google.eclipse.protobuf.ui.ProtobufExecutableExtensionFactory:com.google.eclipse.protobuf.ui.preferences.RootPreferencePage"
+      class="com.google.eclipse.protobuf.ui.ProtobufExecutableExtensionFactory:com.google.eclipse.protobuf.ui.preferences.general.GeneralSettingsPreferencePage"
       id="com.google.eclipse.protobuf.Protobuf" name="%page.name">
       <keywordReference id="com.google.eclipse.protobuf.ui.keyword_Protobuf" />
     </page>
@@ -161,7 +161,7 @@
   </extension>
   <extension point="org.eclipse.ui.propertyPages">
     <page
-      class="com.google.eclipse.protobuf.ui.ProtobufExecutableExtensionFactory:com.google.eclipse.protobuf.ui.preferences.RootPreferencePage"
+      class="com.google.eclipse.protobuf.ui.ProtobufExecutableExtensionFactory:com.google.eclipse.protobuf.ui.preferences.general.GeneralSettingsPreferencePage"
       id="com.google.eclipse.protobuf.Protobuf"
       name="%page.name" selectionFilter="single">
     </page>
diff --git a/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/preferences/RootPreferencePage.java b/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/preferences/RootPreferencePage.java
deleted file mode 100644
index af1538a..0000000
--- a/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/preferences/RootPreferencePage.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright (c) 2011 Google Inc.
- *
- * All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse
- * Public License v1.0 which accompanies this distribution, and is available at
- *
- * http://www.eclipse.org/legal/epl-v10.html
- */
-package com.google.eclipse.protobuf.ui.preferences;
-
-import org.eclipse.jface.preference.IPreferenceStore;
-import org.eclipse.swt.SWT;
-import org.eclipse.swt.widgets.*;
-
-/**
- * @author alruiz@google.com (Alex Ruiz)
- */
-public class RootPreferencePage extends PreferenceAndPropertyPage {
-
-  private static final String PREFERENCE_PAGE_ID = RootPreferencePage.class.getName();
-  
-  /** {@inheritDoc} */
-  @Override protected Control createContents(Composite parent) {
-    // generated by WindowBuilder
-    Composite contents = super.contentsComposite(parent);
-    Label label = new Label(contents, SWT.NONE);
-    label.setText("General Settings.");
-    return contents;
-  }
-
-  /** {@inheritDoc} */
-  @Override protected void onProjectSettingsActivation(boolean active) {}
-
-  /** {@inheritDoc} */
-  @Override protected String preferencePageId() {
-    return PREFERENCE_PAGE_ID;
-  }
-
-  /** {@inheritDoc} */
-  @Override protected void savePreferences(IPreferenceStore store) {}
-
-  /** {@inheritDoc} */
-  @Override protected void performDefaults(IPreferenceStore store) {}
-}
diff --git a/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/preferences/general/GeneralSettingsPreferencePage.java b/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/preferences/general/GeneralSettingsPreferencePage.java
new file mode 100644
index 0000000..e95946e
--- /dev/null
+++ b/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/preferences/general/GeneralSettingsPreferencePage.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2011 Google Inc.
+ *
+ * All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse
+ * Public License v1.0 which accompanies this distribution, and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+package com.google.eclipse.protobuf.ui.preferences.general;
+
+import com.google.eclipse.protobuf.ui.preferences.PreferenceAndPropertyPage;
+
+import org.eclipse.jface.preference.IPreferenceStore;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.widgets.*;
+import org.eclipse.swt.layout.GridData;
+import org.eclipse.swt.layout.GridLayout;
+
+/**
+ * @author alruiz@google.com (Alex Ruiz)
+ */
+public class GeneralSettingsPreferencePage extends PreferenceAndPropertyPage {
+  public GeneralSettingsPreferencePage() {
+  }
+
+  private static final String PREFERENCE_PAGE_ID = GeneralSettingsPreferencePage.class.getName();
+  
+  /** {@inheritDoc} */
+  @Override protected Control createContents(Composite parent) {
+    // generated by WindowBuilder
+    Composite contents = super.contentsComposite(parent);
+    GridLayout gridLayout = (GridLayout) contents.getLayout();
+    gridLayout.numColumns = 2;
+   
+    Group grpValidation = new Group(contents, SWT.NONE);
+    grpValidation.setLayout(new GridLayout(1, false));
+    grpValidation.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false, 2, 1));
+    grpValidation.setText("Content Validation");
+    
+    Button btnValidateOnActivation = new Button(grpValidation, SWT.CHECK);
+    btnValidateOnActivation.setText("Validate files when activated");
+    return contents;
+  }
+
+  /** {@inheritDoc} */
+  @Override protected void onProjectSettingsActivation(boolean active) {}
+
+  /** {@inheritDoc} */
+  @Override protected String preferencePageId() {
+    return PREFERENCE_PAGE_ID;
+  }
+
+  /** {@inheritDoc} */
+  @Override protected void savePreferences(IPreferenceStore store) {}
+
+  /** {@inheritDoc} */
+  @Override protected void performDefaults(IPreferenceStore store) {}
+}