LayoutBuilder: Introduce markers for space and stretch

... and groupbox titles.

Change-Id: Ie57d7857230692f599de8d362c570b9163626dee
Reviewed-by: David Schulz <david.schulz@qt.io>

src/libs/utils/layoutbuilder.cpp

@@ -348,15 +348,15 @@ LayoutBuilder &LayoutBuilder::addItem(const LayoutItem &item)
                 m_gridLayout->addWidget(widget, m_currentGridRow, m_currentGridColumn, 1, item.span, align);
             }
             m_currentGridColumn += item.span;
-            if (item.linebreak)
+            if (item.specialType == SpecialType::Break)
                 finishRow();
         } else if (m_boxLayout) {
             if (auto widget = item.widget) {
                 m_boxLayout->addWidget(widget);
-            } else if (item.stretch != 0) {
-                m_boxLayout->addStretch(item.stretch);
-            } else if (item.space != 0) {
-                m_boxLayout->addSpacing(item.space);
+            } else if (item.specialType == SpecialType::Stretch) {
+                m_boxLayout->addStretch(item.specialValue.toInt());
+            } else if (item.specialType == SpecialType::Space) {
+                m_boxLayout->addSpacing(item.specialValue.toInt());
             }
         } else {
             m_pendingFormItems.append(item);
@@ -383,14 +383,33 @@ void LayoutBuilder::attachTo(QWidget *w, bool stretchAtBottom)
         builder.addItem(Stretch());
 }
 
-namespace Layouting {
-
-Group::Group(std::initializer_list<LayoutItem> items)
-    : LayoutBuilder(new QGroupBox, VBoxWithMargins)
+LayoutBuilder::Break::Break()
 {
-    addItems(items);
+    specialType = LayoutBuilder::SpecialType::Break;
 }
 
+LayoutBuilder::Stretch::Stretch(int stretch)
+{
+    specialType = LayoutBuilder::SpecialType::Stretch;
+    specialValue = stretch;
+}
+
+LayoutBuilder::Space::Space(int space)
+{
+    specialType = LayoutBuilder::SpecialType::Space;
+    specialValue = space;
+}
+
+LayoutBuilder::Title::Title(const QString &title)
+{
+    specialType = LayoutBuilder::SpecialType::Title;
+    specialValue = title;
+}
+
+// FIXME: Decide on which style to use:
+//    Group { Title(...), child1, child2, ...};   or
+//    Group { child1, child2, ... }.withTitle(...);
+
 Layouting::Group &Layouting::Group::withTitle(const QString &title)
 {
     if (auto box = qobject_cast<QGroupBox *>(parentWidget()))
@@ -398,6 +417,22 @@ Layouting::Group &Layouting::Group::withTitle(const QString &title)
     return *this;
 }
 
+namespace Layouting {
+
+Group::Group(std::initializer_list<LayoutItem> items)
+    : LayoutBuilder(new QGroupBox, VBoxWithMargins)
+{
+    for (const LayoutItem &item : items) {
+        if (item.specialType == LayoutBuilder::SpecialType::Title) {
+            auto box = qobject_cast<QGroupBox *>(parentWidget());
+            QTC_ASSERT(box, continue);
+            box->setTitle(item.specialValue.toString());
+        } else {
+            addItem(item);
+        }
+    }
+}
+
 Box::Box(LayoutType type, const LayoutItems &items)
     : LayoutBuilder(type, items)
 {}

src/libs/utils/layoutbuilder.h

@@ -29,6 +29,7 @@
 
 #include <QList>
 #include <QString>
+#include <QVariant>
 
 QT_BEGIN_NAMESPACE
 class QBoxLayout;
@@ -58,6 +59,16 @@ public:
     };
     enum Alignment { DefaultAlignment, AlignAsFormLabel };
 
+    enum class SpecialType {
+        NotSpecial,
+        Align,
+        Space,
+        Span,
+        Stretch,
+        Break,
+        Title
+    };
+
     class QTCREATOR_UTILS_EXPORT LayoutItem
     {
     public:
@@ -72,34 +83,15 @@ public:
         QLayout *layout = nullptr;
         QWidget *widget = nullptr;
         BaseAspect *aspect = nullptr;
-        QString text;
+        QString text; // FIXME: Use specialValue for that
         int span = 1;
         Alignment align;
-        int space = 0;
-        int stretch = 0;
-        bool linebreak = false;
+        SpecialType specialType = SpecialType::NotSpecial;
+        QVariant specialValue;
     };
 
     using LayoutItems = QList<LayoutItem>;
 
-    class QTCREATOR_UTILS_EXPORT Space : public LayoutItem
-    {
-    public:
-        explicit Space(int space_) { space = space_; }
-    };
-
-    class QTCREATOR_UTILS_EXPORT Stretch : public LayoutItem
-    {
-    public:
-        explicit Stretch(int stretch_ = 1) { stretch = stretch_; }
-    };
-
-    class QTCREATOR_UTILS_EXPORT Break : public LayoutItem
-    {
-    public:
-        Break() { linebreak = true; }
-    };
-
     explicit LayoutBuilder(QWidget *parent, LayoutType layoutType = Form);
     explicit LayoutBuilder(QLayout *layout); // Adds to existing layout.
     explicit LayoutBuilder(LayoutType layoutType, const LayoutItems &items = {});
@@ -123,6 +115,30 @@ public:
 
     void attachTo(QWidget *w, bool stretchAtBottom = true);
 
+    class QTCREATOR_UTILS_EXPORT Space : public LayoutItem
+    {
+    public:
+        explicit Space(int space);
+    };
+
+    class QTCREATOR_UTILS_EXPORT Stretch : public LayoutItem
+    {
+    public:
+        explicit Stretch(int stretch = 1);
+    };
+
+    class QTCREATOR_UTILS_EXPORT Break : public LayoutItem
+    {
+    public:
+        Break();
+    };
+
+    class QTCREATOR_UTILS_EXPORT Title : public LayoutBuilder::LayoutItem
+    {
+    public:
+        explicit Title(const QString &title);
+    };
+
 private:
     void flushPendingFormItems();
     void init(QWidget *parent, LayoutType layoutType);
@@ -175,9 +191,19 @@ public:
     {}
 };
 
+class QTCREATOR_UTILS_EXPORT Form : public Box
+{
+public:
+    Form(std::initializer_list<LayoutItem> items)
+        : Box(FormLayout, items)
+    {}
+};
+
+using Item = LayoutBuilder::LayoutItem;
 using Stretch = LayoutBuilder::Stretch;
 using Space = LayoutBuilder::Space;
 using Break = LayoutBuilder::Break;
+using Title = LayoutBuilder::Title;
 
 }
 } // namespace Utils