From e97ce527b0c73db98fa471c6877a048505f32c9e Mon Sep 17 00:00:00 2001
From: Martijn Braam <martijn@brixit.nl>
Date: Thu, 20 Jul 2023 18:27:17 +0200
Subject: [PATCH] Pause frame processing when window is not active

---
 src/io_pipeline.c | 6 ++++++
 src/main.c        | 9 ++++++++-
 src/main.h        | 2 ++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/io_pipeline.c b/src/io_pipeline.c
index 78db658..3cd6729 100644
--- a/src/io_pipeline.c
+++ b/src/io_pipeline.c
@@ -2,6 +2,7 @@
 
 #include "camera.h"
 #include "flash.h"
+#include "main.h"
 #include "pipeline.h"
 #include "process_pipeline.h"
 #include "state.h"
@@ -240,6 +241,11 @@ update_controls()
 static void
 on_frame(MPBuffer buffer, void *_data)
 {
+        // Don't process frame when the window is not active
+        if (!check_window_active()) {
+                return;
+        }
+        
         // Only update controls right after a frame was captured
         update_controls();
 
diff --git a/src/main.c b/src/main.c
index d9dd2c7..9d67181 100644
--- a/src/main.c
+++ b/src/main.c
@@ -55,6 +55,7 @@ static char last_path[260] = "";
 static MPZBarScanResult *zbar_result = NULL;
 
 // Widgets
+GtkWidget *window;
 GtkWidget *preview;
 GtkWidget *main_stack;
 GtkWidget *open_last_stack;
@@ -90,6 +91,12 @@ remap(int value, int input_min, int input_max, int output_min, int output_max)
         return (int)result;
 }
 
+bool
+check_window_active()
+{
+        return gtk_window_is_active(GTK_WINDOW(window));
+}
+
 static void
 update_io_pipeline()
 {
@@ -1126,7 +1133,7 @@ activate(GtkApplication *app, gpointer data)
         GtkBuilder *builder = gtk_builder_new_from_resource(
                 "/org/postmarketos/Megapixels/camera.ui");
 
-        GtkWidget *window = GTK_WIDGET(gtk_builder_get_object(builder, "window"));
+        window = GTK_WIDGET(gtk_builder_get_object(builder, "window"));
         iso_button =
                 GTK_WIDGET(gtk_builder_get_object(builder, "iso-controls-button"));
         shutter_button = GTK_WIDGET(
diff --git a/src/main.h b/src/main.h
index 27f1a6c..f6730f6 100644
--- a/src/main.h
+++ b/src/main.h
@@ -31,3 +31,5 @@ void mp_main_capture_completed(GdkTexture *thumb, const char *fname);
 void mp_main_set_zbar_result(MPZBarScanResult *result);
 
 int remap(int value, int input_min, int input_max, int output_min, int output_max);
+
+bool check_window_active();
\ No newline at end of file