From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sun, 8 Nov 2015 16:01:51 +0000 (+0100)
Subject: Do the UI changes always in the main thread.
X-Git-Tag: 1.0.0~152
X-Git-Url: https://git.sesse.net/?a=commitdiff_plain;h=7902286a0863f0ae655b14b5c830d81920c55e20;p=nageru

Do the UI changes always in the main thread.
---

diff --git a/mainwindow.cpp b/mainwindow.cpp
index 01baef5..d4e4d62 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -18,6 +18,7 @@
 #include "glwidget.h"
 #include "lrameter.h"
 #include "mixer.h"
+#include "post_to_main_thread.h"
 #include "ui_display.h"
 #include "ui_mainwindow.h"
 #include "vumeter.h"
@@ -91,21 +92,23 @@ void MainWindow::mixer_created(Mixer *mixer)
 	}
 
 	mixer->set_audio_level_callback([this](float level_lufs, float peak_db, float global_level_lufs, float range_low_lufs, float range_high_lufs, float auto_gain_staging_db){
-		ui->vu_meter->set_level(level_lufs);
-		ui->lra_meter->set_levels(global_level_lufs, range_low_lufs, range_high_lufs);
-
-		char buf[256];
-		snprintf(buf, sizeof(buf), "%.1f", peak_db);
-		ui->peak_display->setText(buf);
-		if (peak_db > -0.1f) {  // -0.1 dBFS is EBU peak limit.
-			ui->peak_display->setStyleSheet("QLabel { background-color: red; color: white; }");
-		} else {
-			ui->peak_display->setStyleSheet("");
-		}
-
-		ui->gainstaging_knob->setValue(lrintf(auto_gain_staging_db * 10.0f));
-		snprintf(buf, sizeof(buf), "%+.1f dB", auto_gain_staging_db);
-		ui->gainstaging_db_display->setText(buf);
+		post_to_main_thread([=]() {
+			ui->vu_meter->set_level(level_lufs);
+			ui->lra_meter->set_levels(global_level_lufs, range_low_lufs, range_high_lufs);
+
+			char buf[256];
+			snprintf(buf, sizeof(buf), "%.1f", peak_db);
+			ui->peak_display->setText(buf);
+			if (peak_db > -0.1f) {  // -0.1 dBFS is EBU peak limit.
+				ui->peak_display->setStyleSheet("QLabel { background-color: red; color: white; }");
+			} else {
+				ui->peak_display->setStyleSheet("");
+			}
+
+			ui->gainstaging_knob->setValue(lrintf(auto_gain_staging_db * 10.0f));
+			snprintf(buf, sizeof(buf), "%+.1f dB", auto_gain_staging_db);
+			ui->gainstaging_db_display->setText(buf);
+		});
 	});
 }
 
diff --git a/post_to_main_thread.h b/post_to_main_thread.h
new file mode 100644
index 0000000..0462c7b
--- /dev/null
+++ b/post_to_main_thread.h
@@ -0,0 +1,16 @@
+#ifndef _POST_TO_MAIN_THREAD_H
+#define _POST_TO_MAIN_THREAD_H 1
+
+#include <QApplication>
+#include <QObject>
+#include <memory>
+
+// http://stackoverflow.com/questions/21646467/how-to-execute-a-functor-in-a-given-thread-in-qt-gcd-style
+template<typename F>
+static inline void post_to_main_thread(F &&fun)
+{
+	QObject signalSource;
+	QObject::connect(&signalSource, &QObject::destroyed, qApp, std::move(fun));
+}
+
+#endif  // !defined(_POST_TO_MAIN_THREAD_H)