Groups UI: Ensure the selected group's page is displayed

Including when using keybinds to switch groups

src/droid.cpp

@@ -1871,7 +1871,12 @@ void assignDroidsToGroup(UDWORD	playerNumber, UDWORD groupNumber, bool clearGrou
 	}
 	if (bAtLeastOne || numCleared > 0)
 	{
-		intGroupsChanged();
+		optional<UBYTE> newSelectedGroup;
+		if (bAtLeastOne)
+		{
+			newSelectedGroup = groupNumber;
+		}
+		intGroupsChanged(newSelectedGroup);
 	}
 }
 
@@ -1961,7 +1966,7 @@ bool activateGroupAndMove(UDWORD playerNumber, UDWORD groupNumber)
 
 	if (selected || numDeselected > 0)
 	{
-		intGroupsChanged(true);
+		intGroupsChanged((selected) ? groupNumber : UBYTE_MAX);
 	}
 
 	return selected;
@@ -1998,7 +2003,7 @@ bool activateNoGroup(UDWORD playerNumber, const SELECTIONTYPE selectionType, con
 			psFlagPos->selected = false;
 		}
 	}
-	intGroupsChanged(true);
+	intGroupsChanged(UBYTE_MAX);
 	CONPRINTF(ngettext("%u unit selected", "%u units selected", selectionCount), selectionCount);
 	return selected;
 }
@@ -2044,7 +2049,7 @@ bool activateGroup(UDWORD playerNumber, UDWORD groupNumber)
 	}
 	if (selected || numDeselected > 0)
 	{
-		intGroupsChanged(true);
+		intGroupsChanged((selected) ? groupNumber : UBYTE_MAX);
 	}
 	return selected;
 }

src/hci.cpp

@@ -2030,11 +2030,15 @@ void intAlliedResearchChanged()
 	}
 }
 
-void intGroupsChanged(bool selectionOnly)
+void intGroupsChanged(optional<UBYTE> selectedGroup)
 {
 	if (getGroupButtonEnabled())
 	{
 		intRefreshGroupsUI();
+		if (selectedGroup.has_value() && selectedGroup.value() != UBYTE_MAX)
+		{
+			groupsUI->updateSelectedGroup(selectedGroup.value());
+		}
 	}
 }
 

src/hci.h

@@ -34,6 +34,10 @@ typedef std::function<void (const int)> playerCallbackFunc; // callback function
 
 #include "message.h"
 
+#include <nonstd/optional.hpp>
+using nonstd::optional;
+using nonstd::nullopt;
+
 class MultipleChoiceButton;
 class WIDGET;
 struct DROID;
@@ -305,7 +309,7 @@ void intResearchFinished(STRUCTURE *psBuilding);
 void intAlliedResearchChanged();
 
 /* Tell the interface that groups have changed */
-void intGroupsChanged(bool selectionOnly = false);
+void intGroupsChanged(optional<UBYTE> selectedGroup = nullopt);
 void intGroupDamaged(UBYTE group, uint64_t additionalDamage, bool unitKilled);
 
 /* Sync the interface to an object */

src/hci/groups.cpp

@@ -286,6 +286,17 @@ void GroupsForum::updateData()
 	groupsUIController->updateData();
 }
 
+void GroupsForum::updateSelectedGroup(size_t group)
+{
+	size_t groupButtonIdx = (group > 0) ? group - 1 : 9;
+	if (groupButtonIdx >= groupsList->childrenSize())
+	{
+		return;
+	}
+	// ensure that the page that contains this group is displayed
+	groupsList->goToChildPage(groupButtonIdx);
+}
+
 void GroupsForum::addGroupDamageForCurrentTick(size_t group, uint64_t additionalDamage, bool unitKilled)
 {
 	groupsUIController->addGroupDamageForCurrentTick(group, additionalDamage, unitKilled);

src/hci/groups.h

@@ -52,6 +52,7 @@ class GroupsForum: public IntFormAnimated
 		return widget;
 	}
 	void updateData();
+	void updateSelectedGroup(size_t group);
 	void addGroupDamageForCurrentTick(size_t group, uint64_t additionalDamage, bool unitKilled);
 private:
 	std::shared_ptr<GroupButton> makeGroupButton(size_t groupNumber);

src/keybind.cpp

@@ -1106,7 +1106,7 @@ void kf_SelectGrouping(UDWORD groupNumber)
 	{
 		Selected = activateGroup(selectedPlayer, groupNumber);
 	}
-	intGroupsChanged(true);
+	intGroupsChanged(groupNumber);
 
 	/* play group audio but only if they weren't already selected - AM */
 	if (Selected && !bAlreadySelected)