Auto suggest scene and source names.

NameDialog can have placeholder text.
Localize scene number.
Pre-select scene and source text.

build/data/obs-studio/locale/en.txt

@@ -42,6 +42,9 @@ Basic.DisplayCapture="Display Capture"
 Basic.Main.AddSceneDlg.Title="Add Scene"
 Basic.Main.AddSceneDlg.Text="Please enter the name of the scene"
 
+# add scene suggested name
+Basic.Main.DefaultSceneName.Text="Scene %1"
+
 # add source dialog
 Basic.SourceSelect.CreateNew="Create new"
 Basic.SourceSelect.AddExisting="Add Existing"

obs/window-basic-main.cpp

@@ -958,10 +958,14 @@ void OBSBasic::on_scenes_customContextMenuRequested(const QPoint &pos)
 void OBSBasic::on_actionAddScene_triggered()
 {
 	string name;
+	QString format{QTStr("Basic.Main.DefaultSceneName.Text")};
+	QString placeHolderText = format.arg(ui->scenes->count() + 1);
+
 	bool accepted = NameDialog::AskForName(this,
 			QTStr("MainWindow.AddSceneDlg.Title"),
 			QTStr("MainWindow.AddSceneDlg.Text"),
-			name);
+			name,
+			placeHolderText);
 
 	if (accepted) {
 		if (name.empty()) {

obs/window-basic-source-select.cpp

@@ -18,6 +18,7 @@
 #include "window-basic-main.hpp"
 #include "window-basic-source-select.hpp"
 #include "qt-wrappers.hpp"
+#include "obs-app.hpp"
 
 bool OBSBasicSourceSelect::EnumSources(void *data, obs_source_t source)
 {
@@ -143,5 +144,13 @@ OBSBasicSourceSelect::OBSBasicSourceSelect(OBSBasic *parent, const char *type_)
 {
 	ui->setupUi(this);
 
+	const char *placeHolderText = obs_source_getdisplayname(
+		OBS_SOURCE_TYPE_INPUT,
+		type_, App()->GetLocale());
+
+	ui->sourceName->setText(QT_UTF8(placeHolderText));
+	ui->sourceName->setFocus();	//Fixes deselect of text.
+	ui->sourceName->selectAll();
+
 	obs_enum_sources(EnumSources, this);
 }

obs/window-namedialog.cpp

@@ -28,11 +28,13 @@ NameDialog::NameDialog(QWidget *parent)
 }
 
 bool NameDialog::AskForName(QWidget *parent, const QString &title,
-		const QString &text, string &str)
+		const QString &text, string &str, const QString &placeHolder)
 {
 	NameDialog dialog(parent);
 	dialog.setWindowTitle(title);
 	dialog.ui->label->setText(text);
+	dialog.ui->userText->setText(placeHolder);
+	dialog.ui->userText->selectAll();
 
 	bool accepted = (dialog.exec() == DialogCode::Accepted);
 	if (accepted)

obs/window-namedialog.hpp

@@ -33,5 +33,6 @@ public:
 	NameDialog(QWidget *parent);
 
 	static bool AskForName(QWidget *parent, const QString &title,
-			const QString &text, std::string &str);
+			const QString &text, std::string &str,
+			const QString &placeHolder = QString(""));
 };