FileManager: Use FileOperation to perform drag&drop copy out-of-process

And display the progress of the copy operation in a separate window. :^)

Note that this patch only updates the drag&drop code path to use the new
mechanism. We still have to go through FileManager and make use of this
everywhere.

We also need to support additional operations, like Move, Delete, etc.

Still, this is quite cool! :^)

5 files changed, 292 insertions, 6 deletions

diff --git a/Userland/Applications/FileManager/CMakeLists.txt b/Userland/Applications/FileManager/CMakeLists.txt
index 39149a23b9..2ee5c116ba 100644
--- a/Userland/Applications/FileManager/CMakeLists.txt
+++ b/Userland/Applications/FileManager/CMakeLists.txt
@@ -1,9 +1,12 @@
 compile_gml(FileManagerWindow.gml FileManagerWindowGML.h file_manager_window_gml)
+compile_gml(FileOperationProgress.gml FileOperationProgressGML.h file_operation_progress_gml)
 
 set(SOURCES
     DesktopWidget.cpp
     DirectoryView.cpp
     FileManagerWindowGML.h
+    FileOperationProgress.gml
+    FileOperationProgressWidget.cpp
     FileUtils.cpp
     main.cpp
     PropertiesWindow.cpp
diff --git a/Userland/Applications/FileManager/DirectoryView.cpp b/Userland/Applications/FileManager/DirectoryView.cpp
index b6544fc63a..a13e268847 100644
--- a/Userland/Applications/FileManager/DirectoryView.cpp
+++ b/Userland/Applications/FileManager/DirectoryView.cpp
@@ -25,6 +25,7 @@
  */
 
 #include "DirectoryView.h"
+#include "FileOperationProgressWidget.h"
 #include "FileUtils.h"
 #include <AK/LexicalPath.h>
 #include <AK/NumberFormat.h>
@@ -45,6 +46,29 @@
 
 namespace FileManager {
 
+enum class FileOperation {
+    Copy,
+};
+
+static HashTable<RefPtr<GUI::Window>> file_operation_windows;
+
+static void run_file_operation([[maybe_unused]] FileOperation operation, const String& source, const String& destination, GUI::Window* parent_window)
+{
+    // FIXME: Don't use popen() like this, very string injection friendly..
+    FILE* helper_pipe = popen(String::formatted("/bin/FileOperation Copy {} {}", source, LexicalPath(destination).dirname()).characters(), "r");
+    VERIFY(helper_pipe);
+
+    auto window = GUI::Window::construct();
+    file_operation_windows.set(window);
+
+    window->set_title("Copying Files...");
+    window->set_main_widget<FileOperationProgressWidget>(helper_pipe);
+    window->resize(320, 200);
+    if (parent_window)
+        window->center_within(*parent_window);
+    window->show();
+}
+
 NonnullRefPtr<GUI::Action> LauncherHandler::create_launch_action(Function<void(const LauncherHandler&)> launch_handler)
 {
     auto icon = GUI::FileIconProvider::icon_for_executable(details().executable).bitmap_for_size(16);
@@ -578,12 +602,8 @@ void DirectoryView::handle_drop(const GUI::ModelIndex& index, const GUI::DropEve
         if (url_to_copy.path() == new_path)
             continue;
 
-        if (auto result = Core::File::copy_file_or_directory(new_path, url_to_copy.path()); result.is_error()) {
-            auto error_message = String::formatted("Could not copy {} into {}: {}", url_to_copy.to_string(), new_path, result.error().error_code);
-            GUI::MessageBox::show(window(), error_message, "File Manager", GUI::MessageBox::Type::Error);
-        } else {
-            had_accepted_drop = true;
-        }
+        run_file_operation(FileOperation::Copy, url_to_copy.path(), new_path, window());
+        had_accepted_drop = true;
     }
     if (had_accepted_drop && on_accepted_drop)
         on_accepted_drop();
diff --git a/Userland/Applications/FileManager/FileOperationProgress.gml b/Userland/Applications/FileManager/FileOperationProgress.gml
new file mode 100644
index 0000000000..039845a0c4
--- /dev/null
+++ b/Userland/Applications/FileManager/FileOperationProgress.gml
@@ -0,0 +1,89 @@
+@GUI::Widget {
+    fill_with_background_color: true
+
+    layout: @GUI::VerticalBoxLayout {
+        margins: [4, 4, 4, 4]
+    }
+
+    @GUI::Label {
+        text: "Copying files..."
+        text_alignment: "CenterLeft"
+        font_weight: "Bold"
+        fixed_height: 32
+    }
+
+    @GUI::HorizontalSeparator {
+        fixed_height: 2
+    }
+
+    @GUI::Widget {
+        fixed_height: 32
+
+        layout: @GUI::HorizontalBoxLayout {
+        }
+
+        @GUI::Label {
+            text: "Copying: "
+            font_weight: "Bold"
+            text_alignment: "CenterLeft"
+            fixed_width: 80
+        }
+
+        @GUI::Label {
+            name: "current_file_label"
+            text: "Placeholder"
+            text_alignment: "CenterLeft"
+        }
+    }
+
+    @GUI::ProgressBar {
+        fixed_height: 22
+        name: "current_file_progress_bar"
+        min: 0
+    }
+
+    @GUI::Widget {
+        fixed_height: 32
+
+        layout: @GUI::HorizontalBoxLayout {
+        }
+
+        @GUI::Label {
+            text: "Overall progress: "
+            font_weight: "Bold"
+            text_alignment: "CenterLeft"
+            fixed_width: 120
+        }
+
+        @GUI::Label {
+            name: "overall_progress_label"
+            text: "Placeholder"
+            text_alignment: "CenterLeft"
+        }
+    }
+
+    @GUI::ProgressBar {
+        fixed_height: 22
+        name: "overall_progress_bar"
+        min: 0
+    }
+
+    @GUI::Widget {
+        fixed_height: 2
+    }
+
+    @GUI::Widget {
+        shrink_to_fit: true
+        layout: @GUI::HorizontalBoxLayout {
+        }
+
+        @GUI::Widget {
+        }
+
+        @GUI::Button {
+            text: "Cancel"
+            name: "button"
+            fixed_width: 80
+        }
+    }
+}
diff --git a/Userland/Applications/FileManager/FileOperationProgressWidget.cpp b/Userland/Applications/FileManager/FileOperationProgressWidget.cpp
new file mode 100644
index 0000000000..25b758a88c
--- /dev/null
+++ b/Userland/Applications/FileManager/FileOperationProgressWidget.cpp
@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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.
+ */
+
+#include "FileOperationProgressWidget.h"
+#include <Applications/FileManager/FileOperationProgressGML.h>
+#include <LibCore/Notifier.h>
+#include <LibGUI/Button.h>
+#include <LibGUI/Label.h>
+#include <LibGUI/MessageBox.h>
+#include <LibGUI/ProgressBar.h>
+#include <LibGUI/Window.h>
+
+namespace FileManager {
+
+FileOperationProgressWidget::FileOperationProgressWidget(FILE* helper_pipe)
+    : m_helper_pipe(helper_pipe)
+{
+    load_from_gml(file_operation_progress_gml);
+
+    auto& button = *find_descendant_of_type_named<GUI::Button>("button");
+
+    button.on_click = [this] {
+        close_pipe();
+        window()->close();
+    };
+
+    m_notifier = Core::Notifier::construct(fileno(m_helper_pipe), Core::Notifier::Read);
+    m_notifier->on_ready_to_read = [this] {
+        char buffer[8192];
+        if (!fgets(buffer, sizeof(buffer), m_helper_pipe)) {
+            did_error();
+            return;
+        }
+        auto parts = StringView(buffer).split_view(' ');
+        VERIFY(!parts.is_empty());
+
+        if (parts[0] == "FINISH\n"sv) {
+            did_finish();
+            return;
+        }
+
+        if (parts[0] == "PROGRESS"sv) {
+            VERIFY(parts.size() >= 6);
+            did_progress(
+                parts[3].to_uint().value_or(0),
+                parts[4].to_uint().value_or(0),
+                parts[1].to_uint().value_or(0),
+                parts[2].to_uint().value_or(0),
+                parts[5]);
+        }
+    };
+}
+
+FileOperationProgressWidget::~FileOperationProgressWidget()
+{
+    close_pipe();
+}
+
+void FileOperationProgressWidget::did_finish()
+{
+    close_pipe();
+    window()->close();
+}
+
+void FileOperationProgressWidget::did_error()
+{
+    // FIXME: Communicate more with the user about errors.
+    close_pipe();
+    GUI::MessageBox::show(window(), "An error occurred", "Error", GUI::MessageBox::Type::Error, GUI::MessageBox::InputType::OK);
+    window()->close();
+}
+
+void FileOperationProgressWidget::did_progress(off_t bytes_done, off_t total_byte_count, size_t files_done, size_t total_file_count, const StringView& current_file_name)
+{
+    auto& current_file_label = *find_descendant_of_type_named<GUI::Label>("current_file_label");
+    auto& current_file_progress_bar = *find_descendant_of_type_named<GUI::ProgressBar>("current_file_progress_bar");
+    auto& overall_progress_label = *find_descendant_of_type_named<GUI::Label>("overall_progress_label");
+    auto& overall_progress_bar = *find_descendant_of_type_named<GUI::ProgressBar>("overall_progress_bar");
+
+    current_file_label.set_text(current_file_name);
+    current_file_progress_bar.set_max(total_byte_count);
+    current_file_progress_bar.set_value(bytes_done);
+
+    overall_progress_label.set_text(String::formatted("{} of {}", files_done, total_file_count));
+    overall_progress_bar.set_max(total_file_count);
+    overall_progress_bar.set_value(files_done);
+}
+
+void FileOperationProgressWidget::close_pipe()
+{
+    if (!m_helper_pipe)
+        return;
+    pclose(m_helper_pipe);
+    m_helper_pipe = nullptr;
+    if (m_notifier)
+        m_notifier->on_ready_to_read = nullptr;
+    m_notifier = nullptr;
+}
+
+}
diff --git a/Userland/Applications/FileManager/FileOperationProgressWidget.h b/Userland/Applications/FileManager/FileOperationProgressWidget.h
new file mode 100644
index 0000000000..1bd9b5d2c1
--- /dev/null
+++ b/Userland/Applications/FileManager/FileOperationProgressWidget.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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.
+ */
+
+#pragma once
+
+#include <LibGUI/Widget.h>
+
+namespace FileManager {
+
+class FileOperationProgressWidget : public GUI::Widget {
+    C_OBJECT(FileOperationProgressWidget);
+
+public:
+    virtual ~FileOperationProgressWidget() override;
+
+private:
+    explicit FileOperationProgressWidget(FILE* helper_pipe);
+
+    void did_finish();
+    void did_error();
+    void did_progress(off_t bytes_done, off_t total_byte_count, size_t files_done, size_t total_file_count, const StringView& current_file_name);
+
+    void close_pipe();
+
+    RefPtr<Core::Notifier> m_notifier;
+    FILE* m_helper_pipe { nullptr };
+};
+}