Help: Save home page in Qt Creator settings instead of help collection

And do not save the default page anywhere at all.
This simplifies the logic, and makes the setting independent of help
engine initialization.

Change-Id: I264903229e274a0bf25c18b33734d36432aa525f
Task-number: QTCREATORBUG-13198
Reviewed-by: Robert Loehning <robert.loehning@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/help/generalsettingspage.cpp

@@ -91,12 +91,7 @@ QWidget *GeneralSettingsPage::widget()
         updateFontStyle();
         updateFontFamily();
 
-        m_homePage = HelpManager::customValue(QLatin1String("HomePage"), QString())
-                .toString();
-        if (m_homePage.isEmpty()) {
-            m_homePage = HelpManager::customValue(QLatin1String("DefaultHomePage"),
-                                                  Help::Constants::AboutBlank).toString();
-        }
+        m_homePage = LocalHelpManager::homePage();
         m_ui->homePageLineEdit->setText(m_homePage);
 
         m_startOption = HelpManager::customValue(QLatin1String("StartOption"),
@@ -168,7 +163,7 @@ void GeneralSettingsPage::apply()
     m_ui->homePageLineEdit->setText(homePage);
     if (m_homePage != homePage) {
         m_homePage = homePage;
-        HelpManager::setCustomValue(QLatin1String("HomePage"), homePage);
+        LocalHelpManager::setHomePage(homePage);
     }
 
     const int startOption = m_ui->helpStartComboBox->currentIndex();
@@ -210,8 +205,7 @@ void GeneralSettingsPage::setBlankPage()
 
 void GeneralSettingsPage::setDefaultPage()
 {
-    m_ui->homePageLineEdit->setText(
-        HelpManager::customValue(QLatin1String("DefaultHomePage"), QString()).toString());
+    m_ui->homePageLineEdit->setText(LocalHelpManager::defaultHomePage());
 }
 
 void GeneralSettingsPage::importBookmarks()

src/plugins/help/helpviewer.cpp

@@ -144,16 +144,7 @@ bool HelpViewer::launchWithExternalApp(const QUrl &url)
 
 void HelpViewer::home()
 {
-    const QHelpEngineCore &engine = LocalHelpManager::helpEngine();
-    QString homepage = engine.customValue(QLatin1String("HomePage"),
-        QLatin1String("")).toString();
-
-    if (homepage.isEmpty()) {
-        homepage = engine.customValue(QLatin1String("DefaultHomePage"),
-            Help::Constants::AboutBlank).toString();
-    }
-
-    setSource(homepage);
+    setSource(LocalHelpManager::homePage());
 }
 
 void HelpViewer::slotLoadStarted()

src/plugins/help/localhelpmanager.cpp

@@ -35,6 +35,7 @@
 #include "helpviewer.h"
 
 #include <app/app_version.h>
+#include <coreplugin/icore.h>
 #include <coreplugin/helpmanager.h>
 #include <utils/qtcassert.h>
 
@@ -56,6 +57,8 @@ QStandardItemModel *LocalHelpManager::m_filterModel = 0;
 QString LocalHelpManager::m_currentFilter = QString();
 int LocalHelpManager::m_currentFilterIndex = -1;
 
+static char kHelpHomePageKey[] = "Help/HomePage";
+
 LocalHelpManager::LocalHelpManager(QObject *parent)
     : QObject(parent)
     , m_guiNeedsSetup(true)
@@ -83,6 +86,25 @@ LocalHelpManager *LocalHelpManager::instance()
     return m_instance;
 }
 
+QString LocalHelpManager::defaultHomePage()
+{
+    static const QString url = QString::fromLatin1("qthelp://org.qt-project.qtcreator."
+        "%1%2%3/doc/index.html").arg(IDE_VERSION_MAJOR).arg(IDE_VERSION_MINOR)
+        .arg(IDE_VERSION_RELEASE);
+    return url;
+}
+
+QString LocalHelpManager::homePage()
+{
+    return Core::ICore::settings()->value(QLatin1String(kHelpHomePageKey),
+                                          defaultHomePage()).toString();
+}
+
+void LocalHelpManager::setHomePage(const QString &page)
+{
+    Core::ICore::settings()->setValue(QLatin1String(kHelpHomePageKey), page);
+}
+
 void LocalHelpManager::setupGuiHelpEngine()
 {
     if (m_needsCollectionFile) {
@@ -120,10 +142,6 @@ BookmarkManager& LocalHelpManager::bookmarkManager()
         if (!m_bookmarkManager) {
             m_bookmarkManager = new BookmarkManager;
             m_bookmarkManager->setupBookmarkModels();
-            const QString &url = QString::fromLatin1("qthelp://org.qt-project.qtcreator."
-                "%1%2%3/doc/index.html").arg(IDE_VERSION_MAJOR).arg(IDE_VERSION_MINOR)
-                .arg(IDE_VERSION_RELEASE);
-            helpEngine().setCustomValue(QLatin1String("DefaultHomePage"), url);
         }
     }
     return *m_bookmarkManager;

src/plugins/help/localhelpmanager.h

@@ -60,6 +60,10 @@ public:
 
     static LocalHelpManager *instance();
 
+    static QString defaultHomePage();
+    static QString homePage();
+    static void setHomePage(const QString &page);
+
     void setupGuiHelpEngine();
     void setEngineNeedsUpdate();
 

src/plugins/help/openpagesmanager.cpp

@@ -129,14 +129,12 @@ void OpenPagesManager::setupInitialPages()
     const QHelpEngineCore &engine = LocalHelpManager::helpEngine();
     const int option = engine.customValue(QLatin1String("StartOption"),
         Help::Constants::ShowLastPages).toInt();
-    QString homePage = engine.customValue(QLatin1String("DefaultHomePage"),
-        Help::Constants::AboutBlank).toString();
+    QString homePage = LocalHelpManager::homePage();
 
     int initialPage = 0;
     switch (option) {
         case Help::Constants::ShowHomePage: {
-            m_model->addPage(engine.customValue(QLatin1String("HomePage"),
-                homePage).toString());
+            m_model->addPage(homePage);
         }   break;
 
         case Help::Constants::ShowBlankPage: {