From 86fb68f305ab41d27a0bd6980897826ea47cae54 Mon Sep 17 00:00:00 2001
From: Bill Somerville <bill@classdesign.com>
Date: Sun, 25 Nov 2018 21:55:19 +0000
Subject: [PATCH] Set foreign key item delegate references key values combo box
 size according to contents

---
 item_delegates/ForeignKeyDelegate.cpp | 22 +++++++++++++++++++++-
 item_delegates/ForeignKeyDelegate.hpp |  5 +++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/item_delegates/ForeignKeyDelegate.cpp b/item_delegates/ForeignKeyDelegate.cpp
index 09df6a731..204738163 100644
--- a/item_delegates/ForeignKeyDelegate.cpp
+++ b/item_delegates/ForeignKeyDelegate.cpp
@@ -1,7 +1,10 @@
 #include "ForeignKeyDelegate.hpp"
 
+#include <QApplication>
 #include <QComboBox>
-
+#include <QFontMetrics>
+#include <QSize>
+#include <QStyleOptionViewItem>
 #include "CandidateKeyFilter.hpp"
 
 ForeignKeyDelegate::ForeignKeyDelegate (QAbstractItemModel const * referenced_model
@@ -40,3 +43,20 @@ QWidget * ForeignKeyDelegate::createEditor (QWidget * parent
   editor->setSizeAdjustPolicy (QComboBox::AdjustToContents);
   return editor;
 }
+
+QSize ForeignKeyDelegate::sizeHint (QStyleOptionViewItem const& option, QModelIndex const& index) const
+{
+  auto size_hint = QStyledItemDelegate::sizeHint (option, index);
+  QFontMetrics metrics {option.font};
+  QStyleOptionComboBox combo_box_option;
+  combo_box_option.rect = option.rect;
+  combo_box_option.state = option.state | QStyle::State_Enabled;
+  for (auto row = 0; row < candidate_key_filter_->rowCount (); ++row)
+    {
+      size_hint = size_hint.expandedTo (qApp->style ()->sizeFromContents (QStyle::CT_ComboBox
+                                                                          , &combo_box_option
+                                                                          , {metrics.width (candidate_key_filter_->data (candidate_key_filter_->index (row, 0)).toString ())
+                                                                              , metrics.height ()}));
+    }
+  return size_hint;
+}
diff --git a/item_delegates/ForeignKeyDelegate.hpp b/item_delegates/ForeignKeyDelegate.hpp
index 01b03ee5b..4f58f4608 100644
--- a/item_delegates/ForeignKeyDelegate.hpp
+++ b/item_delegates/ForeignKeyDelegate.hpp
@@ -33,9 +33,10 @@ public:
                                , int referencing_key_role = Qt::EditRole);
   ~ForeignKeyDelegate ();
 
-  QWidget * createEditor (QWidget * parent, QStyleOptionViewItem const&, QModelIndex const&) const override;
-
 private:
+  QWidget * createEditor (QWidget * parent, QStyleOptionViewItem const&, QModelIndex const&) const override;
+  QSize sizeHint (QStyleOptionViewItem const&, QModelIndex const&) const override;
+
   QScopedPointer<CandidateKeyFilter> candidate_key_filter_;
 };