add drop bindings.

Dockerfile

@@ -8,7 +8,7 @@ WORKDIR /src
 # install dependencies
 ENV DEBIAN_FRONTEND=noninteractive
 RUN set -eux; apt-get update; \
-    apt-get install -y --no-install-recommends git cmake make libx11-dev libxrandr-dev libxtst-dev \
+    apt-get install -y --no-install-recommends git cmake make libx11-dev libxrandr-dev libxtst-dev libgtk-3-dev \
     libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly; \
     #
     # install libclipboard

internal/desktop/drop/drop.c

@@ -0,0 +1,100 @@
+#include "drop.h"
+
+static void drag_data_get(
+  GtkWidget *widget,
+  GdkDragContext *context,
+  GtkSelectionData *data,
+  guint target_type,
+  guint time,
+  gpointer user_data
+) {
+  gchar **uris = (gchar **) user_data;
+
+  if (target_type == TARGET_TYPE_URI) {
+    gtk_selection_data_set_uris(data, uris);
+    return;
+  }
+
+  if (target_type == TARGET_TYPE_TEXT) {
+    gtk_selection_data_set_text(data, uris[0], -1);
+    return;
+  }
+}
+
+static void drag_end(
+  GtkWidget *widget,
+  GdkDragContext *context,
+  gpointer user_data
+) {
+  gboolean succeeded = gdk_drag_drop_succeeded(context);
+  GdkDragAction action = gdk_drag_context_get_selected_action(context);
+
+  char* action_str;
+  switch (action) {
+    case GDK_ACTION_COPY:
+      action_str = "COPY"; break;
+    case GDK_ACTION_MOVE:
+      action_str = "MOVE"; break;
+    case GDK_ACTION_LINK:
+      action_str = "LINK"; break;
+    case GDK_ACTION_ASK:
+      action_str = "ASK"; break;
+    default:
+      action_str = malloc(sizeof(char) * 20);
+      snprintf(action_str, 20, "invalid (%d)", action);
+      break;
+  }
+
+  fprintf(stderr, "Selected drop action: %s; Succeeded: %d\n", action_str, succeeded);
+  if (action_str[0] == 'i') {
+    free(action_str);
+  }
+
+  gtk_widget_destroy(widget);
+}
+
+void drag_window(char **uris) {
+  gtk_init(NULL, NULL);
+
+  GtkWidget *widget = gtk_window_new(GTK_WINDOW_TOPLEVEL);
+  GtkWindow *window = GTK_WINDOW(widget);
+
+  gtk_window_move(window, 0, 0);
+  gtk_window_set_title(window, "neko-drop");
+  gtk_window_set_decorated(window, FALSE);
+  gtk_window_set_keep_above(window, TRUE);
+  gtk_window_set_default_size(window, 100, 100);
+  gtk_widget_set_opacity(widget, 0);
+
+  GtkTargetList* target_list = gtk_target_list_new(NULL, 0);
+  gtk_target_list_add_uri_targets(target_list, TARGET_TYPE_URI);
+  gtk_target_list_add_text_targets(target_list, TARGET_TYPE_TEXT);
+
+  gtk_drag_source_set(widget, GDK_BUTTON1_MASK, NULL, 0, GDK_ACTION_COPY | GDK_ACTION_LINK | GDK_ACTION_ASK);
+  gtk_drag_source_set_target_list(widget, target_list);
+
+  g_signal_connect(widget, "drag-data-get", G_CALLBACK(drag_data_get), uris);
+  g_signal_connect(widget, "drag-end", G_CALLBACK(drag_end), NULL);
+  g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
+
+  gtk_widget_show_all(widget);
+  gtk_main();
+}
+
+char **uris_make(int size) {
+  return calloc(size + 1, sizeof(char *));
+}
+
+void uris_set(char **uris, char *filename, int n) {
+  GFile *file = g_file_new_for_path(filename);
+  uris[n] = g_file_get_uri(file);
+}
+
+void uris_free(char **uris, int size) {
+  int i;
+  for (i = 0; i < size; i++) {
+    free(uris[i]);
+  }
+
+  free(uris);
+}

internal/desktop/drop/drop.go

@@ -0,0 +1,30 @@
+package drop
+
+/*
+#cgo linux CFLAGS: -I/usr/src -I/usr/local/include/
+#cgo pkg-config: gdk-3.0 gtk+-3.0
+
+#include "drop.h"
+*/
+import "C"
+
+import (
+	"sync"
+)
+
+var mu = sync.Mutex{}
+
+func FileDrop(x int, y int, uris []string) {
+	mu.Lock()
+	defer mu.Unlock()
+
+	size := C.int(len(uris))
+	urisUnsafe := C.uris_make(size);
+	defer C.uris_free(urisUnsafe, size)
+
+	for i, uri := range uris {
+		C.uris_set(urisUnsafe, C.CString(uri), C.int(i))
+	}
+
+	C.drag_window(urisUnsafe)
+}

internal/desktop/drop/drop.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <gtk/gtk.h>
+
+enum {
+  TARGET_TYPE_TEXT,
+  TARGET_TYPE_URI
+};
+
+static void drag_data_get(
+    GtkWidget *widget,
+    GdkDragContext *context,
+    GtkSelectionData *data,
+    guint target_type,
+    guint time,
+    gpointer user_data
+);
+
+static void drag_end(
+    GtkWidget *widget,
+    GdkDragContext *context,
+    gpointer user_data
+);
+
+void drag_window(char **uris);
+
+char **uris_make(int size);
+void uris_set(char **uris, char *filename, int n);
+void uris_free(char **uris, int size);