From 77dc08725080cc04fa0b34c677f3fa1079335bf4 Mon Sep 17 00:00:00 2001
From: hjk <hjk@qt.io>
Date: Mon, 22 Mar 2021 17:40:44 +0100
Subject: [PATCH] Utils: Allow aspects to modify values for loading and saving

In some cases it is useful when the persistent value is not the
internally used actual value, e.g.  Having the displayed string
of a SelectionAspect instead of a numerical index makes
the settings more readable for a human.

Change-Id: I11ecb8e75ab041ace2358cc45972ce9ee965b24d
Reviewed-by: David Schulz <david.schulz@qt.io>
---
 src/libs/utils/aspects.cpp | 62 +++++++++++++++++++++++++++++++++++---
 src/libs/utils/aspects.h   | 10 ++++++
 2 files changed, 68 insertions(+), 4 deletions(-)

diff --git a/src/libs/utils/aspects.cpp b/src/libs/utils/aspects.cpp
index 7826baa00d6..bb3668e1a7d 100644
--- a/src/libs/utils/aspects.cpp
+++ b/src/libs/utils/aspects.cpp
@@ -60,6 +60,8 @@ public:
     Utils::Id m_id;
     QVariant m_value;
     QVariant m_defaultValue;
+    std::function<QVariant(const QVariant &)> m_toSettings;
+    std::function<QVariant(const QVariant &)> m_fromSettings;
 
     QString m_displayName;
     QString m_settingsKey; // Name of data in settings.
@@ -488,7 +490,8 @@ void BaseAspect::saveToMap(QVariantMap &data, const QVariant &value,
 */
 void BaseAspect::fromMap(const QVariantMap &map)
 {
-    setValue(map.value(settingsKey(), defaultValue()));
+    const QVariant val = map.value(settingsKey(), toSettingsValue(defaultValue()));
+    setValue(fromSettingsValue(val));
 }
 
 /*!
@@ -496,21 +499,45 @@ void BaseAspect::fromMap(const QVariantMap &map)
 */
 void BaseAspect::toMap(QVariantMap &map) const
 {
-    saveToMap(map, d->m_value, d->m_defaultValue, settingsKey());
+    saveToMap(map, toSettingsValue(d->m_value), toSettingsValue(d->m_defaultValue), settingsKey());
 }
 
 void BaseAspect::readSettings(const QSettings *settings)
 {
     if (settingsKey().isEmpty())
         return;
-    setValue(settings->value(settingsKey(), defaultValue()));
+    const QVariant val = settings->value(settingsKey(), toSettingsValue(defaultValue()));
+    setValue(fromSettingsValue(val));
 }
 
 void BaseAspect::writeSettings(QSettings *settings) const
 {
     if (settingsKey().isEmpty())
         return;
-    QtcSettings::setValueWithDefault(settings, settingsKey(), value(), defaultValue());
+    QtcSettings::setValueWithDefault(settings,
+                                     settingsKey(),
+                                     toSettingsValue(value()),
+                                     toSettingsValue(defaultValue()));
+}
+
+void BaseAspect::setFromSettingsTransformation(const SavedValueTransformation &transform)
+{
+    d->m_fromSettings = transform;
+}
+
+void BaseAspect::setToSettingsTransformation(const SavedValueTransformation &transform)
+{
+    d->m_toSettings = transform;
+}
+
+QVariant BaseAspect::toSettingsValue(const QVariant &val) const
+{
+    return d->m_toSettings ? d->m_toSettings(val) : val;
+}
+
+QVariant BaseAspect::fromSettingsValue(const QVariant &val) const
+{
+    return d->m_fromSettings ? d->m_fromSettings(val) : val;
 }
 
 /*!
@@ -1436,11 +1463,24 @@ void SelectionAspect::setValue(int value)
     }
 }
 
+void SelectionAspect::setStringValue(const QString &val)
+{
+    const int index = indexForDisplay(val);
+    QTC_ASSERT(index >= 0, return);
+    setValue(index);
+}
+
 void SelectionAspect::setDefaultValue(int val)
 {
     BaseAspect::setDefaultValue(val);
 }
 
+// Note: This needs to be set after all options are added.
+void SelectionAspect::setDefaultValue(const QString &val)
+{
+    BaseAspect::setDefaultValue(indexForDisplay(val));
+}
+
 QString SelectionAspect::stringValue() const
 {
     return d->m_options.at(value()).displayName;
@@ -1451,6 +1491,20 @@ void SelectionAspect::addOption(const QString &displayName, const QString &toolT
     d->m_options.append({displayName, toolTip});
 }
 
+int SelectionAspect::indexForDisplay(const QString &displayName) const
+{
+    for (int i = 0, n = d->m_options.size(); i < n; ++i) {
+        if (d->m_options.at(i).displayName == displayName)
+            return i;
+    }
+    return -1;
+}
+
+QString SelectionAspect::displayForIndex(int index) const
+{
+    return d->m_options.at(index).displayName;
+}
+
 /*!
     \class Utils::MultiSelectionAspect
     \inmodule QtCreator
diff --git a/src/libs/utils/aspects.h b/src/libs/utils/aspects.h
index d4a57def07f..f2c7d7d9c17 100644
--- a/src/libs/utils/aspects.h
+++ b/src/libs/utils/aspects.h
@@ -120,6 +120,12 @@ public:
     virtual void readSettings(const QSettings *settings);
     virtual void writeSettings(QSettings *settings) const;
 
+    using SavedValueTransformation = std::function<QVariant(const QVariant &)>;
+    void setFromSettingsTransformation(const SavedValueTransformation &transform);
+    void setToSettingsTransformation(const SavedValueTransformation &transform);
+    QVariant toSettingsValue(const QVariant &val) const;
+    QVariant fromSettingsValue(const QVariant &val) const;
+
     virtual void apply();
     virtual void cancel();
     virtual void finish();
@@ -242,7 +248,9 @@ public:
 
     int value() const;
     void setValue(int val);
+    void setStringValue(const QString &val);
     void setDefaultValue(int val);
+    void setDefaultValue(const QString &val);
 
     QString stringValue() const;
 
@@ -250,6 +258,8 @@ public:
     void setDisplayStyle(DisplayStyle style);
 
     void addOption(const QString &displayName, const QString &toolTip = {});
+    int indexForDisplay(const QString &displayName) const;
+    QString displayForIndex(int index) const;
 
 private:
     std::unique_ptr<Internal::SelectionAspectPrivate> d;