UI: Add Start Streaming settings check on start

When we use the server error to respond to user's failing to start a
stream it is slow to return an error and unclear to the user what went
wrong. This diff introduces a simple settings check before attempting
to stream and catch and explain specific URL/key issues to the user.

In the case of preset services we check there is a Stream Key before
attempting to start a stream.

In the case of "custom" we only verify there is a URL since for some
services that's all that is required or the user may use user/password
authentication.

UI/data/locale/en-US.ini

@@ -679,6 +679,11 @@ Basic.Settings.Stream.TTVAddon.None="None"
 Basic.Settings.Stream.TTVAddon.BTTV="BetterTTV"
 Basic.Settings.Stream.TTVAddon.FFZ="FrankerFaceZ"
 Basic.Settings.Stream.TTVAddon.Both="BetterTTV and FrankerFaceZ"
+Basic.Settings.Stream.MissingSettingAlert="Missing Stream Setup"
+Basic.Settings.Stream.StreamSettingsWarning="Open Settings"
+Basic.Settings.Stream.MissingUrlAndApiKey="URL and Stream Key are missing.\n\nOpen settings to enter the URL and Stream Key in the 'stream' tab."
+Basic.Settings.Stream.MissingUrl="Stream URL is missing.\n\nOpen settings to enter the URL in the 'Stream' tab."
+Basic.Settings.Stream.MissingStreamKey="Stream key is missing.\n\nOpen settings to enter the stream key in the 'Stream' tab."
 
 # basic mode 'output' settings
 Basic.Settings.Output="Output"

UI/ui-validation.cpp

@@ -6,6 +6,7 @@
 #include <QPushButton>
 
 #include <obs-app.hpp>
+#include <obs-service.h>
 
 static int CountVideoSources()
 {
@@ -54,3 +55,65 @@ bool UIValidation::NoSourcesConfirmation(QWidget *parent)
 	else
 		return true;
 }
+
+StreamSettingsAction
+UIValidation::StreamSettingsConfirmation(QWidget *parent, OBSService service)
+{
+	// Custom services can user API key in URL or user/pass combo.
+	// So only check there is a URL
+	char const *serviceType = obs_service_get_type(service);
+	bool isCustomUrlService = (strcmp(serviceType, "rtmp_custom") == 0);
+
+	char const *streamUrl = obs_service_get_url(service);
+	char const *streamKey = obs_service_get_key(service);
+
+	bool hasStreamUrl = (streamUrl != NULL && streamUrl[0] != '\0');
+	bool hasStreamKey = ((streamKey != NULL && streamKey[0] != '\0') ||
+			     isCustomUrlService);
+
+	if (hasStreamUrl && hasStreamKey)
+		return StreamSettingsAction::ContinueStream;
+
+	QString msg;
+
+	if (!hasStreamUrl && !hasStreamKey) {
+		msg = QTStr("Basic.Settings.Stream.MissingUrlAndApiKey");
+	} else if (!hasStreamKey) {
+		msg = QTStr("Basic.Settings.Stream.MissingStreamKey");
+	} else {
+		msg = QTStr("Basic.Settings.Stream.MissingUrl");
+	}
+
+	QMessageBox messageBox(parent);
+	messageBox.setWindowTitle(
+		QTStr("Basic.Settings.Stream.MissingSettingAlert"));
+	messageBox.setText(msg);
+
+	QPushButton *cancel;
+	QPushButton *settings;
+
+#ifdef __APPLE__
+#define ACCEPT_BUTTON QMessageBox::AcceptRole
+#define REJECT_BUTTON QMessageBox::ResetRole
+#else
+#define ACCEPT_BUTTON QMessageBox::NoRole
+#define REJECT_BUTTON QMessageBox::NoRole
+#endif
+	settings = messageBox.addButton(
+		QTStr("Basic.Settings.Stream.StreamSettingsWarning"),
+		ACCEPT_BUTTON);
+	cancel = messageBox.addButton(QTStr("Cancel"), REJECT_BUTTON);
+
+	messageBox.setDefaultButton(settings);
+	messageBox.setEscapeButton(cancel);
+
+	messageBox.setIcon(QMessageBox::Warning);
+	messageBox.exec();
+
+	if (messageBox.clickedButton() == settings)
+		return StreamSettingsAction::OpenSettings;
+	if (messageBox.clickedButton() == cancel)
+		return StreamSettingsAction::Cancel;
+
+	return StreamSettingsAction::ContinueStream;
+}

UI/ui-validation.hpp

@@ -3,13 +3,28 @@
 #include <QObject>
 #include <QWidget>
 
+#include <obs.hpp>
+
+enum class StreamSettingsAction {
+	OpenSettings,
+	Cancel,
+	ContinueStream,
+};
+
 class UIValidation : public QObject {
 	Q_OBJECT
 
 public:
-	// Shows alert box notifying there are no video sources
-	// Returns true if user clicks "Yes"
-	// Returns false if user clicks "No"
-	// Blocks UI
+	/* Confirm video about to record or stream has sources.  Shows alert
+	 * box notifying there are no video sources Returns true if user clicks
+	 * "Yes" Returns false if user clicks "No" */
 	static bool NoSourcesConfirmation(QWidget *parent);
+
+	/* Check streaming requirements, shows warning with options to open
+	 * settings, cancel stream, or attempt connection anyways.  If setup
+	 * basics is missing in stream, explain missing fields and offer to
+	 * open settings, cancel, or continue.  Returns Continue if all
+	 * settings are valid. */
+	static StreamSettingsAction
+	StreamSettingsConfirmation(QWidget *parent, OBSService service);
 };

UI/window-basic-main.cpp

@@ -5754,6 +5754,20 @@ void OBSBasic::on_streamButton_clicked()
 			return;
 		}
 
+		auto action =
+			UIValidation::StreamSettingsConfirmation(this, service);
+		switch (action) {
+		case StreamSettingsAction::ContinueStream:
+			break;
+		case StreamSettingsAction::OpenSettings:
+			on_action_Settings_triggered();
+			ui->streamButton->setChecked(false);
+			return;
+		case StreamSettingsAction::Cancel:
+			ui->streamButton->setChecked(false);
+			return;
+		}
+
 		bool confirm = config_get_bool(GetGlobalConfig(), "BasicWindow",
 					       "WarnBeforeStartingStream");