Browser: Add a basic GUI download feature

We now allow you to download files by right-clicking a link and then
choosing "Download".

All files are currently saved to the standard downloads location that
we get from Core::StandardPaths::downloads_directory().

In the future, we'll probably want to come up with a more restrictive
way of doing the "write to disk" portion of this.
We should also improve the ProtocolServer to allow streaming of data
instead of writing everything in one big go.

At the moment, I'm just pretty happy with this GUI. :^)

4 files changed, 299 insertions, 35 deletions

diff --git a/Applications/Browser/DownloadWidget.cpp b/Applications/Browser/DownloadWidget.cpp
new file mode 100644
index 0000000000..71b618656d
--- /dev/null
+++ b/Applications/Browser/DownloadWidget.cpp
@@ -0,0 +1,186 @@
+/*
+ * Copyright (c) 2020, 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 "DownloadWidget.h"
+#include <AK/NumberFormat.h>
+#include <AK/SharedBuffer.h>
+#include <AK/StringBuilder.h>
+#include <LibCore/File.h>
+#include <LibCore/StandardPaths.h>
+#include <LibGUI/BoxLayout.h>
+#include <LibGUI/MessageBox.h>
+#include <LibGUI/Button.h>
+#include <LibGUI/Label.h>
+#include <LibGUI/ProgressBar.h>
+#include <LibGUI/Window.h>
+#include <LibProtocol/Client.h>
+#include <LibWeb/ResourceLoader.h>
+#include <math.h>
+
+namespace Browser {
+
+DownloadWidget::DownloadWidget(const URL& url)
+    : m_url(url)
+{
+    {
+        StringBuilder builder;
+        builder.append(Core::StandardPaths::downloads_directory());
+        builder.append('/');
+        builder.append(m_url.basename());
+        m_destination_path = builder.to_string();
+    }
+
+    m_elapsed_timer.start();
+    m_download = Web::ResourceLoader::the().protocol_client().start_download(url.to_string());
+    ASSERT(m_download);
+    m_download->on_progress = [this](Optional<u32> total_size, u32 downloaded_size) {
+        did_progress(total_size.value(), downloaded_size);
+    };
+    m_download->on_finish = [this](bool success, const ByteBuffer& payload, RefPtr<SharedBuffer> payload_storage, const HashMap<String, String>& response_headers) {
+        did_finish(success, payload, payload_storage, response_headers);
+    };
+
+    set_fill_with_background_color(true);
+    auto& layout = set_layout<GUI::VerticalBoxLayout>();
+    layout.set_margins({ 4, 4, 4, 4 });
+
+    auto& animation_container = add<GUI::Widget>();
+    animation_container.set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
+    animation_container.set_preferred_size(0, 32);
+    auto& animation_layout = animation_container.set_layout<GUI::HorizontalBoxLayout>();
+    auto& browser_icon_label = animation_container.add<GUI::Label>();
+    browser_icon_label.set_icon(Gfx::Bitmap::load_from_file("/res/icons/32x32/app-browser.png"));
+    browser_icon_label.set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fixed);
+    browser_icon_label.set_preferred_size(32, 32);
+    animation_layout.add_spacer();
+    auto& folder_icon_label = animation_container.add<GUI::Label>();
+    folder_icon_label.set_icon(Gfx::Bitmap::load_from_file("/res/icons/32x32/filetype-folder.png"));
+    folder_icon_label.set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fixed);
+    folder_icon_label.set_preferred_size(32, 32);
+
+    auto& source_label = add<GUI::Label>(String::format("From: %s", url.to_string().characters()));
+    source_label.set_text_alignment(Gfx::TextAlignment::CenterLeft);
+    source_label.set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
+    source_label.set_preferred_size(0, 16);
+
+    m_progress_bar = add<GUI::ProgressBar>();
+    m_progress_bar->set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
+    m_progress_bar->set_preferred_size(0, 20);
+
+    m_progress_label = add<GUI::Label>();
+    m_progress_label->set_text_alignment(Gfx::TextAlignment::CenterLeft);
+    m_progress_label->set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
+    m_progress_label->set_preferred_size(0, 16);
+
+    auto& destination_label = add<GUI::Label>(String::format("To: %s", m_destination_path.characters()));
+    destination_label.set_text_alignment(Gfx::TextAlignment::CenterLeft);
+    destination_label.set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
+    destination_label.set_preferred_size(0, 16);
+
+    auto& button_container = add<GUI::Widget>();
+    auto& button_container_layout = button_container.set_layout<GUI::HorizontalBoxLayout>();
+    button_container_layout.add_spacer();
+    m_cancel_button = button_container.add<GUI::Button>("Cancel");
+    m_cancel_button->set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fixed);
+    m_cancel_button->set_preferred_size(100, 22);
+    m_cancel_button->on_click = [this] {
+        bool success = m_download->stop();
+        ASSERT(success);
+        window()->close();
+    };
+
+    m_close_button = button_container.add<GUI::Button>("OK");
+    m_close_button->set_enabled(false);
+    m_close_button->set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fixed);
+    m_close_button->set_preferred_size(100, 22);
+    m_close_button->on_click = [this] {
+        window()->close();
+    };
+}
+
+DownloadWidget::~DownloadWidget()
+{
+}
+
+void DownloadWidget::did_progress(Optional<u32> total_size, u32 downloaded_size)
+{
+    m_progress_bar->set_min(0);
+    if (total_size.has_value())
+        m_progress_bar->set_max(total_size.value());
+    else
+        m_progress_bar->set_max(0);
+    m_progress_bar->set_value(downloaded_size);
+
+    {
+        StringBuilder builder;
+        builder.append("Downloaded ");
+        builder.append(human_readable_size(downloaded_size));
+        builder.appendf(" in %d sec", m_elapsed_timer.elapsed() / 1000);
+        m_progress_label->set_text(builder.to_string());
+    }
+
+    {
+        StringBuilder builder;
+        if (total_size.has_value()) {
+            int percent = roundf(((float)downloaded_size / (float)total_size.value()) * 100);
+            builder.appendf("%d%%", percent);
+        } else {
+            builder.append(human_readable_size(downloaded_size));
+        }
+        builder.append(" of ");
+        builder.append(m_url.basename());
+        window()->set_title(builder.to_string());
+    }
+}
+
+void DownloadWidget::did_finish(bool success, const ByteBuffer& payload, RefPtr<SharedBuffer> payload_storage, const HashMap<String, String>& response_headers)
+{
+    (void)payload;
+    (void)payload_storage;
+    (void)response_headers;
+    dbg() << "did_finish, success=" << success;
+    m_cancel_button->set_enabled(false);
+    m_close_button->set_enabled(true);
+
+    if (!success) {
+        GUI::MessageBox::show(String::format("Download failed for some reason"), "Download failed", GUI::MessageBox::Type::Error, GUI::MessageBox::InputType::OK, window());
+        window()->close();
+        return;
+    }
+
+    auto file_or_error = Core::File::open(m_destination_path, Core::IODevice::WriteOnly);
+    if (file_or_error.is_error()) {
+        GUI::MessageBox::show(String::format("Cannot open %s for writing", m_destination_path.characters()), "Download failed", GUI::MessageBox::Type::Error, GUI::MessageBox::InputType::OK, window());
+        window()->close();
+        return;
+    }
+
+    auto& file = *file_or_error.value();
+    bool write_success = file.write(payload.data(), payload.size());
+    ASSERT(write_success);
+}
+
+}
diff --git a/Applications/Browser/DownloadWidget.h b/Applications/Browser/DownloadWidget.h
new file mode 100644
index 0000000000..9c632bbfc6
--- /dev/null
+++ b/Applications/Browser/DownloadWidget.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2020, 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 <AK/URL.h>
+#include <LibCore/ElapsedTimer.h>
+#include <LibGUI/ProgressBar.h>
+#include <LibGUI/Widget.h>
+#include <LibProtocol/Download.h>
+
+namespace Browser {
+
+class DownloadWidget final : public GUI::Widget {
+    C_OBJECT(DownloadWidget);
+
+public:
+    virtual ~DownloadWidget() override;
+
+private:
+    explicit DownloadWidget(const URL&);
+
+    void did_progress(Optional<u32> total_size, u32 downloaded_size);
+    void did_finish(bool success, const ByteBuffer& payload, RefPtr<SharedBuffer> payload_storage, const HashMap<String, String>& response_headers);
+
+    URL m_url;
+    String m_destination_path;
+    RefPtr<Protocol::Download> m_download;
+    RefPtr<GUI::ProgressBar> m_progress_bar;
+    RefPtr<GUI::Label> m_progress_label;
+    RefPtr<GUI::Button> m_cancel_button;
+    RefPtr<GUI::Button> m_close_button;
+    Core::ElapsedTimer m_elapsed_timer;
+};
+
+}
diff --git a/Applications/Browser/Makefile b/Applications/Browser/Makefile
index ac0182b6d5..354d07c7cb 100644
--- a/Applications/Browser/Makefile
+++ b/Applications/Browser/Makefile
@@ -1,5 +1,6 @@
 OBJS = \
     BookmarksBarWidget.o \
+    DownloadWidget.o \
     InspectorWidget.o \
     Tab.o \
     WindowActions.o \
diff --git a/Applications/Browser/Tab.cpp b/Applications/Browser/Tab.cpp
index 970386e038..7eafb09f6d 100644
--- a/Applications/Browser/Tab.cpp
+++ b/Applications/Browser/Tab.cpp
@@ -26,6 +26,7 @@
 
 #include "Tab.h"
 #include "BookmarksBarWidget.h"
+#include "DownloadWidget.h"
 #include "History.h"
 #include "InspectorWidget.h"
 #include "WindowActions.h"
@@ -143,6 +144,17 @@ Tab::Tab()
     m_link_context_menu->add_action(GUI::Action::create("Open in new tab", [this](auto&) {
         m_html_widget->on_link_click(m_link_context_menu_href, "_blank", 0);
     }));
+    m_link_context_menu->add_separator();
+    m_link_context_menu->add_action(GUI::Action::create("Download", [this](auto&) {
+        auto window = GUI::Window::construct();
+        window->set_rect(300, 300, 300, 150);
+        auto url = m_html_widget->document()->complete_url(m_link_context_menu_href);
+        window->set_title(String::format("0% of %s", url.basename().characters()));
+        window->set_resizable(false);
+        window->set_main_widget<DownloadWidget>(url);
+        window->show();
+        (void)window.leak_ref();
+    }));
 
     m_html_widget->on_link_context_menu_request = [this](auto& href, auto& screen_position) {
         m_link_context_menu_href = href;
@@ -165,10 +177,12 @@ Tab::Tab()
             on_favicon_change(icon);
     };
 
-    auto focus_location_box_action = GUI::Action::create("Focus location box", { Mod_Ctrl, Key_L }, [this](auto&) {
-        m_location_box->select_all();
-        m_location_box->set_focus(true);
-    }, this);
+    auto focus_location_box_action = GUI::Action::create(
+        "Focus location box", { Mod_Ctrl, Key_L }, [this](auto&) {
+            m_location_box->select_all();
+            m_location_box->set_focus(true);
+        },
+        this);
 
     m_statusbar = widget.add<GUI::StatusBar>();
 
@@ -198,37 +212,41 @@ Tab::Tab()
     }));
 
     auto& inspect_menu = m_menubar->add_menu("Inspect");
-    inspect_menu.add_action(GUI::Action::create("View source", { Mod_Ctrl, Key_U }, [this](auto&) {
-        String filename_to_open;
-        char tmp_filename[] = "/tmp/view-source.XXXXXX";
-        ASSERT(m_html_widget->document());
-        if (m_html_widget->document()->url().protocol() == "file") {
-            filename_to_open = m_html_widget->document()->url().path();
-        } else {
-            int fd = mkstemp(tmp_filename);
-            ASSERT(fd >= 0);
-            auto source = m_html_widget->document()->source();
-            write(fd, source.characters(), source.length());
-            close(fd);
-            filename_to_open = tmp_filename;
-        }
-        if (fork() == 0) {
-            execl("/bin/TextEditor", "TextEditor", filename_to_open.characters(), nullptr);
-            ASSERT_NOT_REACHED();
-        }
-    }, this));
-    inspect_menu.add_action(GUI::Action::create("Inspect DOM tree", { Mod_None, Key_F12 }, [this](auto&) {
-        if (!m_dom_inspector_window) {
-            m_dom_inspector_window = GUI::Window::construct();
-            m_dom_inspector_window->set_rect(100, 100, 300, 500);
-            m_dom_inspector_window->set_title("DOM inspector");
-            m_dom_inspector_window->set_main_widget<InspectorWidget>();
-        }
-        auto* inspector_widget = static_cast<InspectorWidget*>(m_dom_inspector_window->main_widget());
-        inspector_widget->set_document(m_html_widget->document());
-        m_dom_inspector_window->show();
-        m_dom_inspector_window->move_to_front();
-    }, this));
+    inspect_menu.add_action(GUI::Action::create(
+        "View source", { Mod_Ctrl, Key_U }, [this](auto&) {
+            String filename_to_open;
+            char tmp_filename[] = "/tmp/view-source.XXXXXX";
+            ASSERT(m_html_widget->document());
+            if (m_html_widget->document()->url().protocol() == "file") {
+                filename_to_open = m_html_widget->document()->url().path();
+            } else {
+                int fd = mkstemp(tmp_filename);
+                ASSERT(fd >= 0);
+                auto source = m_html_widget->document()->source();
+                write(fd, source.characters(), source.length());
+                close(fd);
+                filename_to_open = tmp_filename;
+            }
+            if (fork() == 0) {
+                execl("/bin/TextEditor", "TextEditor", filename_to_open.characters(), nullptr);
+                ASSERT_NOT_REACHED();
+            }
+        },
+        this));
+    inspect_menu.add_action(GUI::Action::create(
+        "Inspect DOM tree", { Mod_None, Key_F12 }, [this](auto&) {
+            if (!m_dom_inspector_window) {
+                m_dom_inspector_window = GUI::Window::construct();
+                m_dom_inspector_window->set_rect(100, 100, 300, 500);
+                m_dom_inspector_window->set_title("DOM inspector");
+                m_dom_inspector_window->set_main_widget<InspectorWidget>();
+            }
+            auto* inspector_widget = static_cast<InspectorWidget*>(m_dom_inspector_window->main_widget());
+            inspector_widget->set_document(m_html_widget->document());
+            m_dom_inspector_window->show();
+            m_dom_inspector_window->move_to_front();
+        },
+        this));
 
     auto& debug_menu = m_menubar->add_menu("Debug");
     debug_menu.add_action(GUI::Action::create(