preferences: support a pre-defined list of date formats

Add a combo-box in place of the single line text field and
support some pre-defined date formats, such as:
MM/dd/yyyy

Each long format has a corresponding short variant stored in the
QMap dateFormatShortMap and it's updated automatically once
the user selects a combo box item for the long format.

The regex for dates is slighly modified:
[^dMy/\\s:;\\.,\\-]

The user is still allowed to enter custom long / short date foramats.

Fixes #276

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>

3 files changed, 46 insertions, 26 deletions

diff --git a/desktop-widgets/preferences/preferences_language.cpp b/desktop-widgets/preferences/preferences_language.cpp
index ff0429721..4d200d82f 100644
--- a/desktop-widgets/preferences/preferences_language.cpp
+++ b/desktop-widgets/preferences/preferences_language.cpp
@@ -22,6 +22,14 @@ PreferencesLanguage::PreferencesLanguage() : AbstractPreferencesWidget(tr("Langu
 	filterModel->sort(0);
 	connect(ui->languageFilter, &QLineEdit::textChanged,
 			filterModel, &QSortFilterProxyModel::setFilterFixedString);
+
+	dateFormatShortMap.insert("MM/dd/yyyy", "M/d/yy");
+	dateFormatShortMap.insert("dd.MM.yyyy", "d.M.yy");
+	dateFormatShortMap.insert("yyyy-MM-dd", "yy-M-d");
+	foreach (QString format, dateFormatShortMap.keys())
+		ui->dateFormatEntry->addItem(format);
+	connect(ui->dateFormatEntry, SIGNAL(currentIndexChanged(const QString&)),
+		this, SLOT(dateFormatChanged(const QString&)));
 }
 
 PreferencesLanguage::~PreferencesLanguage()
@@ -29,13 +37,18 @@ PreferencesLanguage::~PreferencesLanguage()
 	delete ui;
 }
 
+void PreferencesLanguage::dateFormatChanged(const QString &text)
+{
+	ui->shortDateFormatEntry->setText(dateFormatShortMap.value(text));
+}
+
 void PreferencesLanguage::refreshSettings()
 {
 	ui->languageSystemDefault->setChecked(prefs.locale.use_system_language);
 	ui->timeFormatSystemDefault->setChecked(!prefs.time_format_override);
 	ui->dateFormatSystemDefault->setChecked(!prefs.date_format_override);
 	ui->timeFormatEntry->setText(prefs.time_format);
-	ui->dateFormatEntry->setText(prefs.date_format);
+	ui->dateFormatEntry->setCurrentText(prefs.date_format);
 	ui->shortDateFormatEntry->setText(prefs.date_format_short);
 	QAbstractItemModel *m = ui->languageDropdown->model();
 	QModelIndexList languages = m->match(m->index(0, 0), Qt::UserRole, QString(prefs.locale.lang_locale).replace("-", "_"));
@@ -72,7 +85,7 @@ void PreferencesLanguage::syncSettings()
 	lang->setTimeFormatOverride(!ui->timeFormatSystemDefault->isChecked());
 	lang->setDateFormatOverride(!ui->dateFormatSystemDefault->isChecked());
 	lang->setTimeFormat(ui->timeFormatEntry->text());
-	lang->setDateFormat(ui->dateFormatEntry->text());
+	lang->setDateFormat(ui->dateFormatEntry->currentText());
 	lang->setDateFormatShort(ui->shortDateFormatEntry->text());
 	uiLanguage(NULL);
 
@@ -81,8 +94,8 @@ void PreferencesLanguage::syncSettings()
 		QMessageBox::warning(this, tr("Literal characters"),
 			tr("Non-special character(s) in time format.\nThese will be used as is. This might not be what you intended.\nSee http://doc.qt.io/qt-5/qdatetime.html#toString"));
 
-	QRegExp dfillegalchars("[^dMy/\\s:;\\.,]");
-	if (dfillegalchars.indexIn(ui->dateFormatEntry->text()) >= 0 ||
+	QRegExp dfillegalchars("[^dMy/\\s:;\\.,\\-]");
+	if (dfillegalchars.indexIn(ui->dateFormatEntry->currentText()) >= 0 ||
 	    dfillegalchars.indexIn(ui->shortDateFormatEntry->text()) >= 0)
 		QMessageBox::warning(this, tr("Literal characters"),
 				     tr("Non-special character(s) in time format.\nThese will be used as is. This might not be what you intended.\nSee http://doc.qt.io/qt-5/qdatetime.html#toString"));
diff --git a/desktop-widgets/preferences/preferences_language.h b/desktop-widgets/preferences/preferences_language.h
index aaff67eed..4ff268b87 100644
--- a/desktop-widgets/preferences/preferences_language.h
+++ b/desktop-widgets/preferences/preferences_language.h
@@ -2,6 +2,7 @@
 #ifndef PREFERENCES_LANGUAGE_H
 #define PREFERENCES_LANGUAGE_H
 
+#include <QMap>
 #include "abstractpreferenceswidget.h"
 
 namespace Ui {
@@ -17,6 +18,9 @@ public:
 	virtual void syncSettings();
 private:
 	Ui::PreferencesLanguage *ui;
+	QMap<QString, QString> dateFormatShortMap;
+public slots:
+	void dateFormatChanged(const QString&);
 };
 
 #endif
diff --git a/desktop-widgets/preferences/prefs_language.ui b/desktop-widgets/preferences/prefs_language.ui
index af3a0ad87..470e8b6d1 100644
--- a/desktop-widgets/preferences/prefs_language.ui
+++ b/desktop-widgets/preferences/prefs_language.ui
@@ -74,13 +74,6 @@
       <string>Date format</string>
      </property>
      <layout class="QGridLayout" name="gridLayout">
-      <item row="0" column="1">
-       <widget class="QLineEdit" name="dateFormatEntry">
-        <property name="toolTip">
-         <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Preferred date format. Commonly used fields are&lt;/p&gt;&lt;p&gt;d (day of month)&lt;/p&gt;&lt;p&gt;ddd (abbr. day name)&lt;/p&gt;&lt;p&gt;M (month number)&lt;/p&gt;&lt;p&gt;MMM (abbr. month name)&lt;/p&gt;&lt;p&gt;yy/yyyy (2/4 digit year)&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
-        </property>
-       </widget>
-      </item>
       <item row="0" column="0">
        <widget class="QCheckBox" name="dateFormatSystemDefault">
         <property name="text">
@@ -114,6 +107,16 @@
         </property>
        </spacer>
       </item>
+      <item row="0" column="1">
+       <widget class="QComboBox" name="dateFormatEntry">
+        <property name="toolTip">
+         <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Preferred date format. Commonly used fields are&lt;/p&gt;&lt;p&gt;d (day of month)&lt;/p&gt;&lt;p&gt;ddd (abbr. day name)&lt;/p&gt;&lt;p&gt;M (month number)&lt;/p&gt;&lt;p&gt;MMM (abbr. month name)&lt;/p&gt;&lt;p&gt;yy/yyyy (2/4 digit year)&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+        </property>
+        <property name="editable">
+         <bool>true</bool>
+        </property>
+       </widget>
+      </item>
      </layout>
     </widget>
    </item>
@@ -209,50 +212,50 @@
    </hints>
   </connection>
   <connection>
-   <sender>dateFormatSystemDefault</sender>
+   <sender>timeFormatSystemDefault</sender>
    <signal>toggled(bool)</signal>
-   <receiver>dateFormatEntry</receiver>
+   <receiver>timeFormatEntry</receiver>
    <slot>setDisabled(bool)</slot>
    <hints>
     <hint type="sourcelabel">
      <x>79</x>
-     <y>132</y>
+     <y>210</y>
     </hint>
     <hint type="destinationlabel">
      <x>264</x>
-     <y>132</y>
+     <y>210</y>
     </hint>
    </hints>
   </connection>
   <connection>
-   <sender>timeFormatSystemDefault</sender>
+   <sender>dateFormatSystemDefault</sender>
    <signal>toggled(bool)</signal>
-   <receiver>timeFormatEntry</receiver>
+   <receiver>shortDateFormatEntry</receiver>
    <slot>setDisabled(bool)</slot>
    <hints>
     <hint type="sourcelabel">
-     <x>79</x>
-     <y>210</y>
+     <x>99</x>
+     <y>132</y>
     </hint>
     <hint type="destinationlabel">
-     <x>264</x>
-     <y>210</y>
+     <x>293</x>
+     <y>169</y>
     </hint>
    </hints>
   </connection>
   <connection>
    <sender>dateFormatSystemDefault</sender>
    <signal>toggled(bool)</signal>
-   <receiver>shortDateFormatEntry</receiver>
+   <receiver>dateFormatEntry</receiver>
    <slot>setDisabled(bool)</slot>
    <hints>
     <hint type="sourcelabel">
-     <x>99</x>
-     <y>132</y>
+     <x>89</x>
+     <y>103</y>
     </hint>
     <hint type="destinationlabel">
-     <x>293</x>
-     <y>169</y>
+     <x>273</x>
+     <y>103</y>
     </hint>
    </hints>
   </connection>