Implement flash

Fixes #5

src/flash.c

@@ -0,0 +1,141 @@
+#include "flash.h"
+
+#include "gtk/gtk.h"
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <inttypes.h>
+
+typedef enum {
+	FLASH_TYPE_LED,
+	FLASH_TYPE_DISPLAY,
+} FlashType;
+
+typedef struct {
+	char path[260];
+	int fd;
+} MPLEDFlash;
+
+typedef struct {
+	GtkWidget *window;
+} MPDisplayFlash;
+
+struct _MPFlash {
+	FlashType type;
+
+	union {
+		MPLEDFlash led;
+		MPDisplayFlash display;
+	};
+};
+
+MPFlash *
+mp_led_flash_from_path(const char * path)
+{
+	MPFlash *flash = malloc(sizeof(MPFlash));
+	flash->type = FLASH_TYPE_LED;
+
+	strncpy(flash->led.path, path, 259);
+
+	char mpath[275];
+	snprintf(mpath, 275, "%s/flash_strobe", path);
+	flash->led.fd = open(mpath, O_WRONLY);
+	if (flash->led.fd == -1) {
+		g_printerr("Failed to open %s\n", mpath);
+		free(flash);
+		return NULL;
+	}
+
+	return flash;
+}
+
+static bool create_display(MPFlash *flash)
+{
+	// Create a full screen full white window as a flash
+	GtkWidget *window = gtk_window_new();
+	// gtk_window_set_accept_focus(GTK_WINDOW(flash->display.window), FALSE);
+	gtk_window_set_decorated(GTK_WINDOW(window), FALSE);
+	gtk_window_fullscreen(GTK_WINDOW(window));
+
+	GtkStyleContext *context;
+	context = gtk_widget_get_style_context(window);
+	gtk_style_context_add_class(context, "flash");
+
+	flash->display.window = window;
+
+	return false;
+}
+
+MPFlash *
+mp_create_display_flash()
+{
+	MPFlash *flash = malloc(sizeof(MPFlash));
+	flash->type = FLASH_TYPE_DISPLAY;
+	flash->display.window = NULL;
+
+	// All GTK functions must be called on the main thread
+	g_main_context_invoke(NULL, (GSourceFunc)create_display, flash);
+
+	return flash;
+}
+
+static bool flash_free(MPFlash *flash)
+{
+	gtk_window_destroy(GTK_WINDOW(flash->display.window));
+	free(flash);
+	return false;
+}
+
+void
+mp_flash_free(MPFlash *flash)
+{
+	switch (flash->type) {
+		case FLASH_TYPE_LED:
+			close(flash->led.fd);
+			free(flash);
+			break;
+		case FLASH_TYPE_DISPLAY:
+			g_main_context_invoke(NULL, (GSourceFunc)flash_free, flash);
+			break;
+	}
+}
+
+static bool show_flash_window(MPFlash *flash)
+{
+	gtk_widget_show(flash->display.window);
+	return false;
+}
+
+void
+mp_flash_enable(MPFlash *flash)
+{
+	switch (flash->type) {
+		case FLASH_TYPE_LED:
+			lseek(flash->led.fd, 0, SEEK_SET);
+			dprintf(flash->led.fd, "1\n");
+			break;
+		case FLASH_TYPE_DISPLAY:
+			g_main_context_invoke(NULL, (GSourceFunc)show_flash_window, flash);
+			break;
+	}
+}
+
+static bool hide_flash_window(MPFlash *flash)
+{
+	gtk_widget_hide(flash->display.window);
+	return false;
+}
+
+void
+mp_flash_disable(MPFlash *flash)
+{
+	switch (flash->type) {
+		case FLASH_TYPE_LED:
+			// Flash gets reset automatically
+			break;
+		case FLASH_TYPE_DISPLAY:
+			g_main_context_invoke(NULL, (GSourceFunc)hide_flash_window, flash);
+			break;
+	}
+}
+