libobs, UI: Implement item_locked event

Similar to item_visible, this event fires whenever a scene item is
locked or unlocked. This allows the UI and libobs to remain in sync
regarding scene elements' statuses.

UI/source-tree.cpp

@@ -130,6 +130,7 @@ void SourceTreeItem::DisconnectSignals()
 	itemRemoveSignal.Disconnect();
 	deselectSignal.Disconnect();
 	visibleSignal.Disconnect();
+	lockedSignal.Disconnect();
 	renameSignal.Disconnect();
 	removeSignal.Disconnect();
 }
@@ -177,6 +178,18 @@ void SourceTreeItem::ReconnectSignals()
 					Q_ARG(bool, visible));
 	};
 
+	auto itemLocked = [] (void *data, calldata_t *cd)
+	{
+		SourceTreeItem *this_ = reinterpret_cast<SourceTreeItem*>(data);
+		obs_sceneitem_t *curItem =
+			(obs_sceneitem_t*)calldata_ptr(cd, "item");
+		bool locked = calldata_bool(cd, "locked");
+
+		if (curItem == this_->sceneitem)
+			QMetaObject::invokeMethod(this_, "LockedChanged",
+					Q_ARG(bool, locked));
+	};
+
 	auto itemDeselect = [] (void *data, calldata_t *cd)
 	{
 		SourceTreeItem *this_ = reinterpret_cast<SourceTreeItem*>(data);
@@ -200,6 +213,7 @@ void SourceTreeItem::ReconnectSignals()
 	sceneRemoveSignal.Connect(signal, "remove", removeItem, this);
 	itemRemoveSignal.Connect(signal, "item_remove", removeItem, this);
 	visibleSignal.Connect(signal, "item_visible", itemVisible, this);
+	lockedSignal.Connect(signal, "item_locked", itemLocked, this);
 
 	if (obs_sceneitem_is_group(sceneitem)) {
 		obs_source_t *source = obs_sceneitem_get_source(sceneitem);
@@ -368,6 +382,11 @@ void SourceTreeItem::VisibilityChanged(bool visible)
 	vis->setChecked(visible);
 }
 
+void SourceTreeItem::LockedChanged(bool locked)
+{
+	lock->setChecked(locked);
+}
+
 void SourceTreeItem::Renamed(const QString &name)
 {
 	label->setText(name);

UI/source-tree.hpp

@@ -68,6 +68,7 @@ private:
 	OBSSignal groupReorderSignal;
 	OBSSignal deselectSignal;
 	OBSSignal visibleSignal;
+	OBSSignal lockedSignal;
 	OBSSignal renameSignal;
 	OBSSignal removeSignal;
 
@@ -80,6 +81,7 @@ private slots:
 	void ExitEditMode(bool save);
 
 	void VisibilityChanged(bool visible);
+	void LockedChanged(bool locked);
 	void Renamed(const QString &name);
 
 	void ExpandClicked(bool checked);

UI/visibility-item-widget.cpp

@@ -94,6 +94,8 @@ VisibilityItemWidget::VisibilityItemWidget(obs_sceneitem_t *item_)
 			this);
 	signal_handler_connect(signal, "item_visible", OBSSceneItemVisible,
 			this);
+	signal_handler_connect(signal, "item_locked", OBSSceneItemLocked,
+			this);
 
 	connect(vis, SIGNAL(clicked(bool)),
 			this, SLOT(VisibilityClicked(bool)));
@@ -121,6 +123,8 @@ void VisibilityItemWidget::DisconnectItemSignals()
 			this);
 	signal_handler_disconnect(signal, "item_visible", OBSSceneItemVisible,
 			this);
+	signal_handler_disconnect(signal, "item_locked", OBSSceneItemLocked,
+			this);
 
 	sceneRemoved = true;
 }

docs/sphinx/reference-scenes.rst

@@ -139,6 +139,10 @@ Scene Signals
 
    Called when a scene item's visibility state changes.
 
+**item_locked** (ptr scene, ptr item, bool locked)
+
+   Called when a scene item has been locked or unlocked.
+
 **item_select** (ptr scene, ptr item)
 **item_deselect** (ptr scene, ptr item)
 
@@ -406,6 +410,13 @@ Scene Item Functions
 
 ---------------------
 
+.. function:: bool obs_sceneitem_set_locked(obs_sceneitem_t *item, bool locked)
+              bool obs_sceneitem_locked(const obs_sceneitem_t *item)
+
+   Sets/gets the locked/unlocked state of the scene item.
+
+---------------------
+
 .. function:: void obs_sceneitem_set_crop(obs_sceneitem_t *item, const struct obs_sceneitem_crop *crop)
               void obs_sceneitem_get_crop(const obs_sceneitem_t *item, struct obs_sceneitem_crop *crop)
 

libobs/obs-scene.c

@@ -54,6 +54,7 @@ static const char *obs_scene_signals[] = {
 	"void item_select(ptr scene, ptr item)",
 	"void item_deselect(ptr scene, ptr item)",
 	"void item_transform(ptr scene, ptr item)",
+	"void item_locked(ptr scene, ptr item, bool locked)",
 	NULL
 };
 
@@ -2118,6 +2119,9 @@ bool obs_sceneitem_locked(const obs_sceneitem_t *item)
 
 bool obs_sceneitem_set_locked(obs_sceneitem_t *item, bool lock)
 {
+	struct calldata cd;
+	uint8_t stack[256];
+
 	if (!item)
 		return false;
 
@@ -2129,6 +2133,12 @@ bool obs_sceneitem_set_locked(obs_sceneitem_t *item, bool lock)
 
 	item->locked = lock;
 
+	calldata_init_fixed(&cd, stack, sizeof(stack));
+	calldata_set_ptr(&cd, "item", item);
+	calldata_set_bool(&cd, "locked", lock);
+
+	signal_parent(item->parent, "item_locked", &cd);
+
 	return true;
 }