eg-sampler: Improve UI show/hide handling

Ensures that gtk_init() is only called once, and that the idle callback does
not block the UI thread.

1 files changed, 43 insertions, 4 deletions

diff --git a/plugins/eg-sampler.lv2/sampler_ui.c b/plugins/eg-sampler.lv2/sampler_ui.c
index 1cb7553..0140e24 100644
--- a/plugins/eg-sampler.lv2/sampler_ui.c
+++ b/plugins/eg-sampler.lv2/sampler_ui.c
@@ -63,13 +63,16 @@ typedef struct {
 	GtkWidget* request_file_button;
 	GtkWidget* button_box;
 	GtkWidget* canvas;
-	GtkWidget* window;  /* For optional show interface. */
 
 	uint32_t width;
 	uint32_t requested_n_peaks;
 	char*    filename;
 
 	uint8_t forge_buf[1024];
+
+	// Optional show/hide interface
+	GtkWidget* window;
+	bool       did_init;
 } SamplerUI;
 
 static void
@@ -211,6 +214,18 @@ on_canvas_expose(GtkWidget* widget, GdkEventExpose* event, gpointer data)
 	return TRUE;
 }
 
+static gboolean
+on_window_closed(GtkWidget* widget, GdkEvent* event, gpointer data)
+{
+	SamplerUI* ui = (SamplerUI*)data;
+
+	// Remove widget so Gtk doesn't delete it when the window is closed
+	gtk_container_remove(GTK_CONTAINER(ui->window), ui->box);
+	ui->window = NULL;
+
+	return FALSE;
+}
+
 static LV2UI_Handle
 instantiate(const LV2UI_Descriptor*   descriptor,
             const char*               plugin_uri,
@@ -229,6 +244,8 @@ instantiate(const LV2UI_Descriptor*   descriptor,
 	ui->controller = controller;
 	ui->width      = MIN_CANVAS_W;
 	*widget        = NULL;
+	ui->window     = NULL;
+	ui->did_init   = false;
 
 	// Get host features
 	const char* missing = lv2_features_query(
@@ -350,11 +367,25 @@ ui_show(LV2UI_Handle handle)
 {
 	SamplerUI* ui = (SamplerUI*)handle;
 
-	int argc = 0;
-	gtk_init(&argc, NULL);
+	if (ui->window) {
+		return 0;
+	}
+
+	if (!ui->did_init) {
+		int argc = 0;
+		gtk_init_check(&argc, NULL);
+		g_object_ref(ui->box);
+		ui->did_init = true;
+	}
 
 	ui->window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
 	gtk_container_add(GTK_CONTAINER(ui->window), ui->box);
+
+	g_signal_connect(G_OBJECT(ui->window),
+	                 "delete-event",
+	                 G_CALLBACK(on_window_closed),
+	                 handle);
+
 	gtk_widget_show_all(ui->window);
 	gtk_window_present(GTK_WINDOW(ui->window));
 
@@ -365,6 +396,14 @@ ui_show(LV2UI_Handle handle)
 static int
 ui_hide(LV2UI_Handle handle)
 {
+	SamplerUI* ui = (SamplerUI*)handle;
+
+	if (ui->window) {
+		gtk_container_remove(GTK_CONTAINER(ui->window), ui->box);
+		gtk_widget_destroy(ui->window);
+		ui->window = NULL;
+	}
+
 	return 0;
 }
 
@@ -374,7 +413,7 @@ ui_idle(LV2UI_Handle handle)
 {
 	SamplerUI* ui = (SamplerUI*)handle;
 	if (ui->window) {
-		gtk_main_iteration();
+		gtk_main_iteration_do(false);
 	}
 	return 0;
 }