[file_selector] add GtkFileChooserDialog based implementation for Linux

packages/file_selector/file_selector_linux/.gitignore

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+.DS_Store
+.dart_tool/
+
+.packages
+.plugin_symlinks
+.pub/
+
+build/

packages/file_selector/file_selector_linux/.metadata

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+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 2783f8e2e14efec8b7e08f668dde61c40d128c24
+  channel: dev
+
+project_type: plugin

packages/file_selector/file_selector_linux/CHANGELOG.md

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+## 0.1.0
+
+* Initial GtkFileChooserDialog based implementation for Linux.

packages/file_selector/file_selector_linux/LICENSE

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+Copyright 2020 The Flutter Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+    * Neither the name of Google Inc. nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

packages/file_selector/file_selector_linux/README.md

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+# file_selector_linux
+
+The linux implementation of [`file_selector`].
+
+## Usage
+
+This package is already included as part of the `file_selector` package dependency, and will
+be included when using `file_selector` as normal. You will need to use version 1.6.10 or newer.

packages/file_selector/file_selector_linux/lib/file_selector_linux.dart

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+// The file_selector_platform_interface defaults to MethodChannelFileSelector
+// as its instance, which is all the Linux implementation needs. This file
+// is here to silence warnings when publishing to pub.

packages/file_selector/file_selector_linux/linux/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.10)
+set(PROJECT_NAME "file_selector_linux")
+project(${PROJECT_NAME} LANGUAGES CXX)
+
+# This value is used when generating builds using this plugin, so it must
+# not be changed
+set(PLUGIN_NAME "file_selector_linux_plugin")
+
+add_library(${PLUGIN_NAME} SHARED
+  "file_selector_linux_plugin.cc"
+)
+apply_standard_settings(${PLUGIN_NAME})
+set_target_properties(${PLUGIN_NAME} PROPERTIES
+  CXX_VISIBILITY_PRESET hidden)
+target_compile_definitions(${PLUGIN_NAME} PRIVATE FLUTTER_PLUGIN_IMPL)
+target_include_directories(${PLUGIN_NAME} INTERFACE
+  "${CMAKE_CURRENT_SOURCE_DIR}/include")
+target_link_libraries(${PLUGIN_NAME} PRIVATE flutter)
+target_link_libraries(${PLUGIN_NAME} PRIVATE PkgConfig::GTK)
+
+# List of absolute paths to libraries that should be bundled with the plugin
+set(file_selector_linux_bundled_libraries
+  ""
+  PARENT_SCOPE
+)

packages/file_selector/file_selector_linux/linux/file_selector_linux_plugin.cc

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+#include "include/file_selector_linux/file_selector_linux_plugin.h"
+
+#include <flutter_linux/flutter_linux.h>
+#include <glib.h>
+#include <glib/gi18n.h>
+#include <glib/gprintf.h>
+#include <gtk/gtk.h>
+
+#define FILE_SELECTOR_LINUX_PLUGIN(obj)                                     \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj), file_selector_linux_plugin_get_type(), \
+                              FileSelectorLinuxPlugin))
+
+struct _FileSelectorLinuxPlugin {
+  GObject parent_instance;
+  FlView* view;
+};
+
+G_DEFINE_TYPE(FileSelectorLinuxPlugin, file_selector_linux_plugin,
+              g_object_get_type())
+
+static bool fl_value_is_valid(FlValue* value, FlValueType type) {
+  return value && fl_value_get_type(value) == type;
+}
+
+static void fl_value_list_for_each(FlValue* list, GFunc func,
+                                   gpointer user_data) {
+  g_return_if_fail(func != nullptr);
+  if (!list || fl_value_get_type(list) != FL_VALUE_TYPE_LIST) {
+    return;
+  }
+
+  size_t length = fl_value_get_length(list);
+  for (size_t j = 0; j < length; ++j) {
+    FlValue* value = fl_value_get_list_value(list, j);
+    func(value, user_data);
+  }
+}
+
+static FlValue* file_chooser_get_filename(GtkFileChooser* chooser) {
+  gchar* filename = gtk_file_chooser_get_filename(chooser);
+  FlValue* value = fl_value_new_string(filename);
+  g_free(filename);
+  return value;
+}
+
+static FlValue* file_chooser_get_filenames(GtkFileChooser* chooser) {
+  FlValue* value = fl_value_new_list();
+  GSList* filenames = gtk_file_chooser_get_filenames(chooser);
+  while (filenames) {
+    const gchar* filename = static_cast<const gchar*>(filenames->data);
+    fl_value_append_take(value, fl_value_new_string(filename));
+    filenames = filenames->next;
+  }
+  g_slist_free(filenames);
+  return value;
+}
+
+static void file_filter_add_pattern(gpointer data, gpointer user_data) {
+  FlValue* value = static_cast<FlValue*>(data);
+  if (fl_value_is_valid(value, FL_VALUE_TYPE_STRING)) {
+    gchar* pattern = g_strdup_printf("*.%s", fl_value_get_string(value));
+    gtk_file_filter_add_pattern(GTK_FILE_FILTER(user_data), pattern);
+    g_free(pattern);
+  }
+}
+
+static void file_filter_add_mime_type(gpointer data, gpointer user_data) {
+  FlValue* value = static_cast<FlValue*>(data);
+  if (fl_value_is_valid(value, FL_VALUE_TYPE_STRING)) {
+    gtk_file_filter_add_mime_type(GTK_FILE_FILTER(user_data),
+                                  fl_value_get_string(value));
+  }
+}
+
+static void file_chooser_add_filter(gpointer data, gpointer user_data) {
+  FlValue* type = static_cast<FlValue*>(data);
+  if (fl_value_is_valid(type, FL_VALUE_TYPE_MAP)) {
+    GtkFileFilter* filter = gtk_file_filter_new();
+
+    FlValue* label = fl_value_lookup_string(type, "label");
+    if (fl_value_is_valid(label, FL_VALUE_TYPE_STRING)) {
+      gtk_file_filter_set_name(filter, fl_value_get_string(label));
+    }
+
+    FlValue* extensions = fl_value_lookup_string(type, "extensions");
+    fl_value_list_for_each(extensions, file_filter_add_pattern, filter);
+
+    FlValue* mime_types = fl_value_lookup_string(type, "mimeTypes");
+    fl_value_list_for_each(mime_types, file_filter_add_mime_type, filter);
+
+    gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(user_data), filter);
+  }
+}
+
+static FlMethodResponse* file_chooser_show(GtkFileChooserAction action,
+                                           FlValue* args, FlView* view) {
+  FlMethodResponse* response = nullptr;
+
+  const gchar* accept_label = _("_Open");
+  FlValue* confirm = fl_value_lookup_string(args, "confirmButtonText");
+  if (fl_value_is_valid(confirm, FL_VALUE_TYPE_STRING)) {
+    accept_label = fl_value_get_string(confirm);
+  }
+
+  GtkWidget* parent_window = gtk_widget_get_toplevel(GTK_WIDGET(view));
+  GtkWidget* dialog = gtk_file_chooser_dialog_new(
+      NULL, GTK_WINDOW(parent_window), action, _("_Cancel"),
+      GTK_RESPONSE_CANCEL, accept_label, GTK_RESPONSE_ACCEPT, NULL);
+
+  GtkFileChooser* chooser = GTK_FILE_CHOOSER(dialog);
+
+  FlValue* types = fl_value_lookup_string(args, "acceptedTypeGroups");
+  fl_value_list_for_each(types, file_chooser_add_filter, chooser);
+
+  FlValue* dir = fl_value_lookup_string(args, "initialDirectory");
+  if (fl_value_is_valid(dir, FL_VALUE_TYPE_STRING)) {
+    gtk_file_chooser_set_current_folder(chooser, fl_value_get_string(dir));
+  }
+
+  FlValue* multiple = fl_value_lookup_string(args, "multiple");
+  if (fl_value_is_valid(multiple, FL_VALUE_TYPE_BOOL)) {
+    gtk_file_chooser_set_select_multiple(chooser, fl_value_get_bool(multiple));
+  }
+
+  FlValue* name = fl_value_lookup_string(args, "suggestedName");
+  if (fl_value_is_valid(name, FL_VALUE_TYPE_STRING)) {
+    gtk_file_chooser_set_current_name(chooser, fl_value_get_string(name));
+  }
+
+  gint res = gtk_dialog_run(GTK_DIALOG(dialog));
+  if (res == GTK_RESPONSE_ACCEPT) {
+    if (action == GTK_FILE_CHOOSER_ACTION_OPEN) {
+      FlValue* filenames = file_chooser_get_filenames(chooser);
+      response = FL_METHOD_RESPONSE(fl_method_success_response_new(filenames));
+    } else {
+      FlValue* filename = file_chooser_get_filename(chooser);
+      response = FL_METHOD_RESPONSE(fl_method_success_response_new(filename));
+    }
+  } else {
+    response = FL_METHOD_RESPONSE(fl_method_success_response_new(nullptr));
+  }
+
+  gtk_widget_destroy(dialog);
+  return response;
+}
+
+static void file_selector_linux_plugin_handle_method_call(
+    FileSelectorLinuxPlugin* self, FlMethodCall* method_call) {
+  g_autoptr(FlMethodResponse) response = nullptr;
+
+  static const GtkFileChooserAction none = GtkFileChooserAction(-1);
+  GtkFileChooserAction action = none;
+  const gchar* method = fl_method_call_get_name(method_call);
+
+  if (strcmp(method, "openFile") == 0 || strcmp(method, "openFiles") == 0) {
+    action = GTK_FILE_CHOOSER_ACTION_OPEN;
+  } else if (strcmp(method, "getSavePath") == 0) {
+    action = GTK_FILE_CHOOSER_ACTION_SAVE;
+  } else if (strcmp(method, "getDirectoryPath") == 0) {
+    action = GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER;
+  }
+
+  if (action != none) {
+    FlValue* args = fl_method_call_get_args(method_call);
+    response = file_chooser_show(action, args, self->view);
+  } else {
+    response = FL_METHOD_RESPONSE(fl_method_not_implemented_response_new());
+  }
+
+  fl_method_call_respond(method_call, response, nullptr);
+}
+
+static void file_selector_linux_plugin_dispose(GObject* object) {
+  G_OBJECT_CLASS(file_selector_linux_plugin_parent_class)->dispose(object);
+}
+
+static void file_selector_linux_plugin_class_init(
+    FileSelectorLinuxPluginClass* klass) {
+  G_OBJECT_CLASS(klass)->dispose = file_selector_linux_plugin_dispose;
+}
+
+static void file_selector_linux_plugin_init(FileSelectorLinuxPlugin* self) {}
+
+static void method_call_cb(FlMethodChannel* channel, FlMethodCall* method_call,
+                           gpointer user_data) {
+  FileSelectorLinuxPlugin* plugin = FILE_SELECTOR_LINUX_PLUGIN(user_data);
+  file_selector_linux_plugin_handle_method_call(plugin, method_call);
+}
+
+void file_selector_linux_plugin_register_with_registrar(
+    FlPluginRegistrar* registrar) {
+  FileSelectorLinuxPlugin* plugin = FILE_SELECTOR_LINUX_PLUGIN(
+      g_object_new(file_selector_linux_plugin_get_type(), nullptr));
+  plugin->view = fl_plugin_registrar_get_view(registrar);
+
+  g_autoptr(FlStandardMethodCodec) codec = fl_standard_method_codec_new();
+  g_autoptr(FlMethodChannel) channel = fl_method_channel_new(
+      fl_plugin_registrar_get_messenger(registrar),
+      "plugins.flutter.io/file_selector", FL_METHOD_CODEC(codec));
+  fl_method_channel_set_method_call_handler(
+      channel, method_call_cb, g_object_ref(plugin), g_object_unref);
+
+  g_object_unref(plugin);
+}

packages/file_selector/file_selector_linux/linux/include/file_selector_linux/file_selector_linux_plugin.h

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+#ifndef FLUTTER_PLUGIN_FILE_SELECTOR_LINUX_PLUGIN_H_
+#define FLUTTER_PLUGIN_FILE_SELECTOR_LINUX_PLUGIN_H_
+
+#include <flutter_linux/flutter_linux.h>
+
+G_BEGIN_DECLS
+
+#ifdef FLUTTER_PLUGIN_IMPL
+#define FLUTTER_PLUGIN_EXPORT __attribute__((visibility("default")))
+#else
+#define FLUTTER_PLUGIN_EXPORT
+#endif
+
+typedef struct _FileSelectorLinuxPlugin FileSelectorLinuxPlugin;
+typedef struct {
+  GObjectClass parent_class;
+} FileSelectorLinuxPluginClass;
+
+FLUTTER_PLUGIN_EXPORT GType file_selector_linux_plugin_get_type();
+
+FLUTTER_PLUGIN_EXPORT void file_selector_linux_plugin_register_with_registrar(
+    FlPluginRegistrar* registrar);
+
+G_END_DECLS
+
+#endif  // FLUTTER_PLUGIN_FILE_SELECTOR_LINUX_PLUGIN_H_

packages/file_selector/file_selector_linux/pubspec.yaml

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+name: file_selector_linux
+description: A Linux implementation of the file_selector plugin.
+homepage: https://github.com/flutter/plugins/tree/master/packages/file_selector/file_selector_linux
+# NOTE: We strongly prefer non-breaking changes, even at the expense of a
+# less-clean API. See https://flutter.dev/go/platform-interface-breaking-changes
+version: 0.1.0
+
+dependencies:
+  file_selector_platform_interface: ^1.0.0
+  flutter:
+    sdk: flutter
+
+environment:
+  sdk: ">=2.1.0 <3.0.0"
+  flutter: ">=1.12.8 <2.0.0"
+
+flutter:
+  plugin:
+    platforms:
+      linux:
+        pluginClass: FileSelectorLinuxPlugin