Doc: Clean up and modernize SQL example: Books

* Replace Qt4-style connects.
* Reformat code to adhere to 80 column width.
* Touch comments to make location and style consistent.
* Rename a label in the UI form.

Task-number: QTBUG-68652
Change-Id: Icc592f7b5a013d1806bc36c45057b35472b6efbb
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

3 files changed, 126 insertions, 93 deletions

diff --git a/examples/sql/books/bookdelegate.cpp b/examples/sql/books/bookdelegate.cpp
index 6a42fd2db7..4115f80cf3 100644
--- a/examples/sql/books/bookdelegate.cpp
+++ b/examples/sql/books/bookdelegate.cpp
@@ -62,15 +62,21 @@ void BookDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
 {
     if (index.column() != 5) {
         QStyleOptionViewItem opt = option;
-        opt.rect.adjust(0, 0, -1, -1); // since we draw the grid ourselves
+        // Since we draw the grid ourselves:
+        opt.rect.adjust(0, 0, -1, -1);
         QSqlRelationalDelegate::paint(painter, opt, index);
     } else {
         const QAbstractItemModel *model = index.model();
         QPalette::ColorGroup cg = (option.state & QStyle::State_Enabled) ?
-            (option.state & QStyle::State_Active) ? QPalette::Normal : QPalette::Inactive : QPalette::Disabled;
+            (option.state & QStyle::State_Active) ?
+                        QPalette::Normal :
+                        QPalette::Inactive :
+                        QPalette::Disabled;
 
         if (option.state & QStyle::State_Selected)
-            painter->fillRect(option.rect, option.palette.color(cg, QPalette::Highlight));
+            painter->fillRect(
+                        option.rect,
+                        option.palette.color(cg, QPalette::Highlight));
 
         int rating = model->data(index, Qt::DisplayRole).toInt();
         int width = star.width();
@@ -81,7 +87,8 @@ void BookDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
             painter->drawPixmap(x, y, star);
             x += width;
         }
-        drawFocus(painter, option, option.rect.adjusted(0, 0, -1, -1)); // since we draw the grid ourselves
+        // Since we draw the grid ourselves:
+        drawFocus(painter, option, option.rect.adjusted(0, 0, -1, -1));
     }
 
     QPen pen = painter->pen();
@@ -96,8 +103,8 @@ QSize BookDelegate::sizeHint(const QStyleOptionViewItem &option,
 {
     if (index.column() == 5)
         return QSize(5 * star.width(), star.height()) + QSize(1, 1);
-
-    return QSqlRelationalDelegate::sizeHint(option, index) + QSize(1, 1); // since we draw the grid ourselves
+    // Since we draw the grid ourselves:
+    return QSqlRelationalDelegate::sizeHint(option, index) + QSize(1, 1);
 }
 
 bool BookDelegate::editorEvent(QEvent *event, QAbstractItemModel *model,
@@ -112,19 +119,21 @@ bool BookDelegate::editorEvent(QEvent *event, QAbstractItemModel *model,
         int stars = qBound(0, int(0.7 + qreal(mouseEvent->pos().x()
             - option.rect.x()) / star.width()), 5);
         model->setData(index, QVariant(stars));
-        return false; //so that the selection can change
+        // So that the selection can change:
+        return false;
     }
 
     return true;
 }
 
-QWidget *BookDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option,
+QWidget *BookDelegate::createEditor(QWidget *parent,
+                                    const QStyleOptionViewItem &option,
                                     const QModelIndex &index) const
 {
     if (index.column() != 4)
         return QSqlRelationalDelegate::createEditor(parent, option, index);
 
-    // for editing the year, return a spinbox with a range from -1000 to 2100.
+    // For editing the year, return a spinbox with a range from -1000 to 2100.
     QSpinBox *sb = new QSpinBox(parent);
     sb->setFrame(false);
     sb->setMaximum(2100);
@@ -132,4 +141,3 @@ QWidget *BookDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem
 
     return sb;
 }
-
diff --git a/examples/sql/books/bookwindow.cpp b/examples/sql/books/bookwindow.cpp
index 1428bc04b5..d85b438956 100644
--- a/examples/sql/books/bookwindow.cpp
+++ b/examples/sql/books/bookwindow.cpp
@@ -59,53 +59,61 @@ BookWindow::BookWindow()
     ui.setupUi(this);
 
     if (!QSqlDatabase::drivers().contains("QSQLITE"))
-        QMessageBox::critical(this, "Unable to load database", "This demo needs the SQLITE driver");
+        QMessageBox::critical(
+                    this,
+                    "Unable to load database",
+                    "This demo needs the SQLITE driver"
+                    );
 
-    // initialize the database
+    // Initialize the database:
     QSqlError err = initDb();
     if (err.type() != QSqlError::NoError) {
         showError(err);
         return;
     }
 
-    // Create the data model
+    // Create the data model:
     model = new QSqlRelationalTableModel(ui.bookTable);
     model->setEditStrategy(QSqlTableModel::OnManualSubmit);
     model->setTable("books");
 
-    // Remember the indexes of the columns
+    // Remember the indexes of the columns:
     authorIdx = model->fieldIndex("author");
     genreIdx = model->fieldIndex("genre");
 
-    // Set the relations to the other database tables
+    // Set the relations to the other database tables:
     model->setRelation(authorIdx, QSqlRelation("authors", "id", "name"));
     model->setRelation(genreIdx, QSqlRelation("genres", "id", "name"));
 
-    // Set the localized header captions
+    // Set the localized header captions:
     model->setHeaderData(authorIdx, Qt::Horizontal, tr("Author Name"));
     model->setHeaderData(genreIdx, Qt::Horizontal, tr("Genre"));
-    model->setHeaderData(model->fieldIndex("title"), Qt::Horizontal, tr("Title"));
+    model->setHeaderData(model->fieldIndex("title"),
+                         Qt::Horizontal, tr("Title"));
     model->setHeaderData(model->fieldIndex("year"), Qt::Horizontal, tr("Year"));
-    model->setHeaderData(model->fieldIndex("rating"), Qt::Horizontal, tr("Rating"));
+    model->setHeaderData(model->fieldIndex("rating"),
+                         Qt::Horizontal, tr("Rating"));
 
-    // Populate the model
+    // Populate the model:
     if (!model->select()) {
         showError(model->lastError());
         return;
     }
 
-    // Set the model and hide the ID column
+    // Set the model and hide the ID column:
     ui.bookTable->setModel(model);
     ui.bookTable->setItemDelegate(new BookDelegate(ui.bookTable));
     ui.bookTable->setColumnHidden(model->fieldIndex("id"), true);
     ui.bookTable->setSelectionMode(QAbstractItemView::SingleSelection);
 
-    // Initialize the Author combo box
+    // Initialize the Author combo box:
     ui.authorEdit->setModel(model->relationModel(authorIdx));
-    ui.authorEdit->setModelColumn(model->relationModel(authorIdx)->fieldIndex("name"));
+    ui.authorEdit->setModelColumn(
+                model->relationModel(authorIdx)->fieldIndex("name"));
 
     ui.genreEdit->setModel(model->relationModel(genreIdx));
-    ui.genreEdit->setModelColumn(model->relationModel(genreIdx)->fieldIndex("name"));
+    ui.genreEdit->setModelColumn(
+                model->relationModel(genreIdx)->fieldIndex("name"));
 
     QDataWidgetMapper *mapper = new QDataWidgetMapper(this);
     mapper->setModel(model);
@@ -116,8 +124,11 @@ BookWindow::BookWindow()
     mapper->addMapping(ui.genreEdit, genreIdx);
     mapper->addMapping(ui.ratingEdit, model->fieldIndex("rating"));
 
-    connect(ui.bookTable->selectionModel(), SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
-            mapper, SLOT(setCurrentModelIndex(QModelIndex)));
+    connect(ui.bookTable->selectionModel(),
+            &QItemSelectionModel::currentRowChanged,
+            mapper,
+            &QDataWidgetMapper::setCurrentModelIndex
+            );
 
     ui.bookTable->setCurrentIndex(model->index(0, 0));
 }
@@ -127,4 +138,3 @@ void BookWindow::showError(const QSqlError &err)
     QMessageBox::critical(this, "Unable to initialize Database",
                 "Error initializing database: " + err.text());
 }
-
diff --git a/examples/sql/books/bookwindow.ui b/examples/sql/books/bookwindow.ui
index 659d324564..c81a86cb2c 100644
--- a/examples/sql/books/bookwindow.ui
+++ b/examples/sql/books/bookwindow.ui
@@ -1,10 +1,8 @@
-<ui version="4.0" >
- <author></author>
- <comment></comment>
- <exportmacro></exportmacro>
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
  <class>BookWindow</class>
- <widget class="QMainWindow" name="BookWindow" >
- <property name="geometry" >
+ <widget class="QMainWindow" name="BookWindow">
+  <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
@@ -12,117 +10,135 @@
     <height>420</height>
    </rect>
   </property>
-  <property name="windowTitle" >
+  <property name="windowTitle">
    <string>Books</string>
   </property>
-  <widget class="QWidget" name="centralWidget" >
-   <layout class="QVBoxLayout" >
-    <property name="margin" >
+  <widget class="QWidget" name="centralWidget">
+   <layout class="QVBoxLayout">
+    <property name="spacing">
+     <number>6</number>
+    </property>
+    <property name="leftMargin">
      <number>9</number>
     </property>
-    <property name="spacing" >
-     <number>6</number>
+    <property name="topMargin">
+     <number>9</number>
+    </property>
+    <property name="rightMargin">
+     <number>9</number>
+    </property>
+    <property name="bottomMargin">
+     <number>9</number>
     </property>
     <item>
-     <widget class="QGroupBox" name="groupBox" >
-      <property name="title" >
+     <widget class="QGroupBox" name="groupBox">
+      <property name="title">
        <string>Books</string>
       </property>
-      <layout class="QVBoxLayout" >
-       <property name="margin" >
+      <layout class="QVBoxLayout">
+       <property name="spacing">
+        <number>6</number>
+       </property>
+       <property name="leftMargin">
         <number>9</number>
        </property>
-       <property name="spacing" >
-        <number>6</number>
+       <property name="topMargin">
+        <number>9</number>
+       </property>
+       <property name="rightMargin">
+        <number>9</number>
+       </property>
+       <property name="bottomMargin">
+        <number>9</number>
        </property>
        <item>
-        <widget class="QTableView" name="bookTable" >
-         <property name="selectionBehavior" >
+        <widget class="QTableView" name="bookTable">
+         <property name="selectionBehavior">
           <enum>QAbstractItemView::SelectRows</enum>
          </property>
         </widget>
        </item>
        <item>
-        <widget class="QGroupBox" name="groupBox_2" >
-         <property name="title" >
+        <widget class="QGroupBox" name="groupBox_2">
+         <property name="title">
           <string>Details</string>
          </property>
-         <layout class="QFormLayout" >
-	   <item row="0" column="0" >
-           <widget class="QLabel" name="label_5" >
-            <property name="text" >
-             <string>&lt;b>Title:&lt;/b></string>
+         <layout class="QFormLayout">
+          <item row="0" column="0">
+           <widget class="QLabel" name="label_5">
+            <property name="text">
+             <string>&lt;b&gt;Title:&lt;/b&gt;</string>
             </property>
            </widget>
           </item>
-          <item row="0" column="1" >
-           <widget class="QLineEdit" name="titleEdit" >
-            <property name="enabled" >
+          <item row="0" column="1">
+           <widget class="QLineEdit" name="titleEdit">
+            <property name="enabled">
              <bool>true</bool>
             </property>
            </widget>
           </item>
-          <item row="1" column="0" >
-           <widget class="QLabel" name="label_2_2_2_2" >
-            <property name="text" >
-             <string>&lt;b>Author: &lt;/b></string>
+          <item row="1" column="0">
+           <widget class="QLabel" name="label_2">
+            <property name="text">
+             <string>&lt;b&gt;Author: &lt;/b&gt;</string>
             </property>
            </widget>
-	    </item>
-	     <item row="1" column="1" >
-           <widget class="QComboBox" name="authorEdit" >
-            <property name="enabled" >
+          </item>
+          <item row="1" column="1">
+           <widget class="QComboBox" name="authorEdit">
+            <property name="enabled">
              <bool>true</bool>
             </property>
            </widget>
-          </item>	   
-	  <item row="2" column="0" >
-           <widget class="QLabel" name="label_3" >
-            <property name="text" >
-             <string>&lt;b>Genre:&lt;/b></string>
+          </item>
+          <item row="2" column="0">
+           <widget class="QLabel" name="label_3">
+            <property name="text">
+             <string>&lt;b&gt;Genre:&lt;/b&gt;</string>
             </property>
            </widget>
           </item>
-          <item row="2" column="1" >
-           <widget class="QComboBox" name="genreEdit" >
-            <property name="enabled" >
+          <item row="2" column="1">
+           <widget class="QComboBox" name="genreEdit">
+            <property name="enabled">
              <bool>true</bool>
             </property>
            </widget>
           </item>
-          <item row="3" column="0" >
-           <widget class="QLabel" name="label_4" >
-            <property name="text" >
-             <string>&lt;b>Year:&lt;/b></string>
+          <item row="3" column="0">
+           <widget class="QLabel" name="label_4">
+            <property name="text">
+             <string>&lt;b&gt;Year:&lt;/b&gt;</string>
             </property>
            </widget>
-          </item>       
-          <item row="3" column="1" >
-           <widget class="QSpinBox" name="yearEdit" >
-            <property name="enabled" >
+          </item>
+          <item row="3" column="1">
+           <widget class="QSpinBox" name="yearEdit">
+            <property name="enabled">
              <bool>true</bool>
             </property>
-            <property name="prefix" >
+            <property name="prefix">
              <string/>
             </property>
-            <property name="maximum" >
-             <number>2100</number>
-            </property>
-            <property name="minimum" >
+            <property name="minimum">
              <number>-1000</number>
             </property>
+            <property name="maximum">
+             <number>2100</number>
+            </property>
            </widget>
           </item>
-          <item row="4" column="0" >
-           <widget class="QLabel" name="label" >
-            <property name="text" >
-             <string>&lt;b>Rating:&lt;/b></string>
+          <item row="4" column="0">
+           <widget class="QLabel" name="label">
+            <property name="text">
+             <string>&lt;b&gt;Rating:&lt;/b&gt;</string>
             </property>
            </widget>
           </item>
-          <item row="4" column="1" >
-           <widget class="QSpinBox" name="ratingEdit" >
-            <property name="maximum" >
+          <item row="4" column="1">
+           <widget class="QSpinBox" name="ratingEdit">
+            <property name="maximum">
              <number>5</number>
             </property>
            </widget>
@@ -136,7 +152,6 @@
    </layout>
   </widget>
  </widget>
- <pixmapfunction></pixmapfunction>
  <tabstops>
   <tabstop>bookTable</tabstop>
   <tabstop>titleEdit</tabstop>