[calamares] Tidying after fixing fit-text-in-sidepane

- Simplify delegate: unused m_parent, tidy up inheritance, then drop
   unnecessary custom constructor and extra Q_OBJECT macro.
 - Drop some unnecessary included headers
 - Drop single-use #define. APP was used in only one place; remove it
   (that would be stylistically correct, anyway).
 - Update copyright headers
 - Document new label-handling

CHANGES

@@ -14,6 +14,9 @@ This release contains contributions from (alphabetically by first name):
 
 ## Core ##
 
+ - The side-pane, which shows the list of steps that will be executed,
+   now tries to fit the text (name of each module) into the available space
+   by shrinking the font as needed. #1137
  - *libcalamares* (accidentally) linked with Qt's GUI libraries when
    PythonQt was found. This led to the odd situation where the non-GUI
    Calamares library depends on a bunch of GUI libraries.

src/calamares/CalamaresApplication.h

@@ -1,7 +1,7 @@
 /* === This file is part of Calamares - <https://github.com/calamares> ===
  *
  *   Copyright 2014-2015, Teo Mrnjavac <teo@kde.org>
- *   Copyright 2018, Adriaan de Groot <groot@kde.org>
+ *   Copyright 2018-2019, Adriaan de Groot <groot@kde.org>
  *
  *   Calamares is free software: you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -24,8 +24,6 @@
 
 #include <QApplication>
 
-#define APP CalamaresApplication::instance()
-
 class CalamaresWindow;
 
 namespace Calamares

src/calamares/progresstree/ProgressTreeDelegate.cpp

@@ -1,7 +1,7 @@
 /* === This file is part of Calamares - <https://github.com/calamares> ===
  *
  *   Copyright 2014-2015, Teo Mrnjavac <teo@kde.org>
- *   Copyright 2017, Adriaan de Groot <groot@kde.org>
+ *   Copyright 2017, 2019, Adriaan de Groot <groot@kde.org>
  *
  *   Calamares is free software: you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -18,29 +18,19 @@
  */
 
 #include "ProgressTreeDelegate.h"
+#include "ProgressTreeModel.h"
 
 #include "Branding.h"
 #include "CalamaresApplication.h"
 #include "CalamaresWindow.h"
-#include "ProgressTreeModel.h"
-#include "ViewManager.h"
-#include "ViewStepItem.h"
 
 #include "utils/CalamaresUtilsGui.h"
 
-#include <QAbstractItemView>
 #include <QPainter>
 
 static constexpr int const item_margin = 8;
 static inline int item_fontsize() { return CalamaresUtils::defaultFontSize() + 4; }
 
-ProgressTreeDelegate::ProgressTreeDelegate( QAbstractItemView* parent )
-    : QStyledItemDelegate( parent )
-    , m_parent( parent )
-{
-}
-
-
 QSize
 ProgressTreeDelegate::sizeHint( const QStyleOptionViewItem& option,
                                 const QModelIndex& index ) const
@@ -104,7 +94,7 @@ ProgressTreeDelegate::paintViewStep( QPainter* painter,
         QString textHighlight = Calamares::Branding::instance()->
                            styleString( Calamares::Branding::SidebarTextHighlight );
         if ( textHighlight.isEmpty() )
-            painter->setBrush( APP->mainWindow()->palette().background() );
+            painter->setBrush( CalamaresApplication::instance()->mainWindow()->palette().background() );
         else
             painter->setBrush( QColor( textHighlight ) );
     }

src/calamares/progresstree/ProgressTreeDelegate.h

@@ -1,6 +1,7 @@
 /* === This file is part of Calamares - <https://github.com/calamares> ===
  *
  *   Copyright 2014-2015, Teo Mrnjavac <teo@kde.org>
+ *   Copyright 2019, Adriaan de Groot <groot@kde.org>
  *
  *   Calamares is free software: you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -21,7 +22,6 @@
 
 #include <QStyledItemDelegate>
 
-
 /**
  * @brief The ProgressTreeDelegate class customizes the look and feel of the
  * ProgressTreeView elements.
@@ -29,9 +29,8 @@
  */
 class ProgressTreeDelegate : public QStyledItemDelegate
 {
-    Q_OBJECT
 public:
-    explicit ProgressTreeDelegate( QAbstractItemView* parent = nullptr );
+    using QStyledItemDelegate::QStyledItemDelegate;
 
 protected:
     QSize sizeHint( const QStyleOptionViewItem& option,
@@ -44,8 +43,6 @@ private:
     void paintViewStep( QPainter* painter,
                         const QStyleOptionViewItem& option,
                         const QModelIndex& index ) const;
-
-    QAbstractItemView* m_parent;
 };
 
 #endif // PROGRESSTREEDELEGATE_H