Show temperature units in the label when editing dive

Currently when user wants to add a new dive information,
the ways to know what unit system is being used are

 - Through preferences panel.
 - Save the dive information, which displays units in
   the text field.

This patch provides an option to the user to show current
unit system by displaying the unit on the side of the label
when the user is editing the fields.

This feature can be enabled or disabled by using the new
checkbox option i.e. `Show units in text labels` included
in `preferences->units` section.

Signed-off-by: Lakshman Anumolu <acrlakshman@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

pref.h

@@ -40,6 +40,7 @@ struct preferences {
 	short show_sac;
 	bool display_unused_tanks;
 	bool zoomed_plot;
+	bool text_label_with_units;
 };
 enum unit_system_values {
 	METRIC,

qt-ui/maintab.cpp

@@ -201,6 +201,7 @@ void MainTab::hideMessage()
 	ui.diveEquipmentMessage->animatedHide();
 	ui.diveInfoMessage->animatedHide();
 	ui.diveStatisticsMessage->animatedHide();
+	updateTextLabels();
 }
 
 void MainTab::closeMessage()
@@ -222,6 +223,18 @@ void MainTab::displayMessage(QString str)
 	ui.diveInfoMessage->animatedShow();
 	ui.diveStatisticsMessage->setText(str);
 	ui.diveStatisticsMessage->animatedShow();
+	updateTextLabels(true);
+}
+
+void MainTab::updateTextLabels(bool showUnits)
+{
+	if (showUnits && prefs.text_label_with_units) {
+		ui.airTempLabel->setText(QApplication::translate("MainTab", "Air temp [%1]").arg(get_temp_unit()));
+		ui.waterTempLabel->setText(QApplication::translate("MainTab", "Water temp [%1]").arg(get_temp_unit()));
+	} else {
+		ui.airTempLabel->setText(QApplication::translate("MainTab", "Air temp", 0, QApplication::UnicodeUTF8));
+		ui.waterTempLabel->setText(QApplication::translate("MainTab", "Water temp", 0, QApplication::UnicodeUTF8));
+	}
 }
 
 void MainTab::enableEdition(EditMode newEditMode)

qt-ui/maintab.h

@@ -94,6 +94,7 @@ slots:
 	void displayMessage(QString str);
 	void enableEdition(EditMode newEditMode = NONE);
 	void toggleTriggeredColumn();
+	void updateTextLabels(bool showUnits = false);
 
 private:
 	Ui::MainTab ui;

qt-ui/preferences.cpp

@@ -75,6 +75,7 @@ void PreferencesDialog::setUiFromPrefs()
 	ui.cuft->setChecked(prefs.units.volume == units::CUFT);
 	ui.kg->setChecked(prefs.units.weight == units::KG);
 	ui.lbs->setChecked(prefs.units.weight == units::LBS);
+	ui.text_label_with_units->setChecked(prefs.text_label_with_units);
 
 	ui.font->setCurrentFont(QString(prefs.divelist_font));
 	ui.fontsize->setValue(prefs.font_size);
@@ -190,6 +191,7 @@ void PreferencesDialog::syncSettings()
 	s.setValue("volume", ui.cuft->isChecked() ? units::CUFT : units::LITER);
 	s.setValue("weight", ui.lbs->isChecked() ? units::LBS : units::KG);
 	s.setValue("vertical_speed_time", ui.vertical_speed_minutes->isChecked() ? units::MINUTES : units::SECONDS);
+	SB("text_label_with_units", ui.text_label_with_units);
 	s.endGroup();
 	// Defaults
 	s.beginGroup("GeneralSettings");
@@ -244,6 +246,7 @@ void PreferencesDialog::loadSettings()
 		GET_UNIT("weight", weight, units::LBS, units::KG);
 	}
 	GET_UNIT("vertical_speed_time", vertical_speed_time, units::MINUTES, units::SECONDS);
+	GET_BOOL("text_label_with_units", text_label_with_units);
 	s.endGroup();
 	s.beginGroup("TecDetails");
 	GET_BOOL("po2graph", pp_graphs.po2);

qt-ui/preferences.ui

@@ -478,7 +478,21 @@
             </widget>
            </item>
           </layout>
-         </item>
+	 </item>
+	 <item>
+	  <layout class="QHBoxLayout" name="text_label_with_units_hbox">
+	   <item>
+	    <widget class="QCheckBox" name="text_label_with_units">
+	     <property name="enabled">
+	      <bool>true</bool>
+	     </property>
+	     <property name="text">
+	      <string>Show units in text labels</string>
+	     </property>
+	    </widget>
+	   </item>
+	  </layout>
+	 </item>
          <item>
           <spacer name="verticalSpacer">
            <property name="orientation">

subsurfacestartup.c

@@ -29,7 +29,8 @@ struct preferences default_prefs = {
 	.font_size = -1,
 	.display_invalid_dives = false,
 	.show_sac = false,
-	.display_unused_tanks = false
+	.display_unused_tanks = false,
+	.text_label_with_units = false
 };
 
 struct units *get_units()