LibWeb: Add a FrameLoader class and move PageView's loading logic there

Each Frame now has a FrameLoader which will be responsible for handling
loading inside that frame.

Libraries/LibWeb/Loader/FrameLoader.cpp

@@ -0,0 +1,276 @@
+/*
+ * 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 <AK/LexicalPath.h>
+#include <LibGemini/Document.h>
+#include <LibGfx/ImageDecoder.h>
+#include <LibMarkdown/Document.h>
+#include <LibWeb/DOM/ElementFactory.h>
+#include <LibWeb/DOM/Text.h>
+#include <LibWeb/Frame.h>
+#include <LibWeb/Loader/FrameLoader.h>
+#include <LibWeb/Loader/ResourceLoader.h>
+#include <LibWeb/Parser/HTMLDocumentParser.h>
+#include <LibWeb/Parser/HTMLParser.h>
+
+namespace Web {
+
+FrameLoader::FrameLoader(Frame& frame)
+    : m_frame(frame)
+{
+}
+
+FrameLoader::~FrameLoader()
+{
+}
+
+static RefPtr<Document> create_markdown_document(const ByteBuffer& data, const URL& url)
+{
+    auto markdown_document = Markdown::Document::parse(data);
+    if (!markdown_document)
+        return nullptr;
+
+    return parse_html_document(markdown_document->render_to_html(), url);
+}
+
+static RefPtr<Document> create_text_document(const ByteBuffer& data, const URL& url)
+{
+    auto document = adopt(*new Document(url));
+
+    auto html_element = document->create_element("html");
+    document->append_child(html_element);
+
+    auto head_element = document->create_element("head");
+    html_element->append_child(head_element);
+    auto title_element = document->create_element("title");
+    head_element->append_child(title_element);
+
+    auto title_text = document->create_text_node(url.basename());
+    title_element->append_child(title_text);
+
+    auto body_element = document->create_element("body");
+    html_element->append_child(body_element);
+
+    auto pre_element = create_element(document, "pre");
+    body_element->append_child(pre_element);
+
+    pre_element->append_child(document->create_text_node(String::copy(data)));
+    return document;
+}
+
+static RefPtr<Document> create_image_document(const ByteBuffer& data, const URL& url)
+{
+    auto document = adopt(*new Document(url));
+
+    auto image_decoder = Gfx::ImageDecoder::create(data.data(), data.size());
+    auto bitmap = image_decoder->bitmap();
+    ASSERT(bitmap);
+
+    auto html_element = create_element(document, "html");
+    document->append_child(html_element);
+
+    auto head_element = create_element(document, "head");
+    html_element->append_child(head_element);
+    auto title_element = create_element(document, "title");
+    head_element->append_child(title_element);
+
+    auto basename = LexicalPath(url.path()).basename();
+    auto title_text = adopt(*new Text(document, String::format("%s [%dx%d]", basename.characters(), bitmap->width(), bitmap->height())));
+    title_element->append_child(title_text);
+
+    auto body_element = create_element(document, "body");
+    html_element->append_child(body_element);
+
+    auto image_element = create_element(document, "img");
+    image_element->set_attribute(HTML::AttributeNames::src, url.to_string());
+    body_element->append_child(image_element);
+
+    return document;
+}
+
+static RefPtr<Document> create_gemini_document(const ByteBuffer& data, const URL& url)
+{
+    auto markdown_document = Gemini::Document::parse({ (const char*)data.data(), data.size() }, url);
+
+    return parse_html_document(markdown_document->render_to_html(), url);
+}
+
+String encoding_from_content_type(const String& content_type)
+{
+    auto offset = content_type.index_of("charset=");
+    if (offset.has_value())
+        return content_type.substring(offset.value() + 8, content_type.length() - offset.value() - 8).to_lowercase();
+
+    return "utf-8";
+}
+
+String mime_type_from_content_type(const String& content_type)
+{
+    auto offset = content_type.index_of(";");
+    if (offset.has_value())
+        return content_type.substring(0, offset.value()).to_lowercase();
+
+    return content_type;
+}
+
+static String guess_mime_type_based_on_filename(const URL& url)
+{
+    if (url.path().ends_with(".png"))
+        return "image/png";
+    if (url.path().ends_with(".gif"))
+        return "image/gif";
+    if (url.path().ends_with(".md"))
+        return "text/markdown";
+    if (url.path().ends_with(".html") || url.path().ends_with(".htm"))
+        return "text/html";
+    return "text/plain";
+}
+
+RefPtr<Document> FrameLoader::create_document_from_mime_type(const ByteBuffer& data, const URL& url, const String& mime_type, const String& encoding)
+{
+    if (mime_type.starts_with("image/"))
+        return create_image_document(data, url);
+    if (mime_type == "text/plain")
+        return create_text_document(data, url);
+    if (mime_type == "text/markdown")
+        return create_markdown_document(data, url);
+    if (mime_type == "text/gemini")
+        return create_gemini_document(data, url);
+    if (mime_type == "text/html") {
+        if (m_use_old_parser)
+            return parse_html_document(data, url, encoding);
+        HTMLDocumentParser parser(data, encoding);
+        parser.run(url);
+        return parser.document();
+    }
+    return nullptr;
+}
+
+bool FrameLoader::load(const URL& url)
+{
+    dbg() << "FrameLoader::load: " << url;
+
+    if (!url.is_valid()) {
+        load_error_page(url, "Invalid URL");
+        return false;
+    }
+
+    ResourceLoader::the().load(
+        url,
+        [this, url](auto data, auto& response_headers) {
+            // FIXME: Also check HTTP status code before redirecting
+            auto location = response_headers.get("Location");
+            if (location.has_value()) {
+                load(location.value());
+                return;
+            }
+
+            if (data.is_null()) {
+                load_error_page(url, "No data");
+                return;
+            }
+
+            String encoding = "utf-8";
+            String mime_type;
+
+            auto content_type = response_headers.get("Content-Type");
+            if (content_type.has_value()) {
+                dbg() << "Content-Type header: _" << content_type.value() << "_";
+                encoding = encoding_from_content_type(content_type.value());
+                mime_type = mime_type_from_content_type(content_type.value());
+            } else {
+                dbg() << "No Content-Type header to go on! Guessing based on filename...";
+                mime_type = guess_mime_type_based_on_filename(url);
+            }
+
+            dbg() << "I believe this content has MIME type '" << mime_type << "', encoding '" << encoding << "'";
+            auto document = create_document_from_mime_type(data, url, mime_type, encoding);
+            ASSERT(document);
+            frame().set_document(document);
+
+            if (!url.fragment().is_empty())
+                frame().scroll_to_anchor(url.fragment());
+
+            if (frame().on_title_change)
+                frame().on_title_change(document->title());
+        },
+        [this, url](auto error) {
+            load_error_page(url, error);
+        });
+
+    if (frame().on_load_start)
+        frame().on_load_start(url);
+
+    if (url.protocol() != "file" && url.protocol() != "about") {
+        URL favicon_url;
+        favicon_url.set_protocol(url.protocol());
+        favicon_url.set_host(url.host());
+        favicon_url.set_port(url.port());
+        favicon_url.set_path("/favicon.ico");
+
+        ResourceLoader::the().load(
+            favicon_url,
+            [this, favicon_url](auto data, auto&) {
+                dbg() << "Favicon downloaded, " << data.size() << " bytes from " << favicon_url;
+                auto decoder = Gfx::ImageDecoder::create(data.data(), data.size());
+                auto bitmap = decoder->bitmap();
+                if (!bitmap) {
+                    dbg() << "Could not decode favicon " << favicon_url;
+                    return;
+                }
+                dbg() << "Decoded favicon, " << bitmap->size();
+                if (frame().on_favicon_change)
+                    frame().on_favicon_change(*bitmap);
+            });
+    }
+
+    return true;
+}
+
+void FrameLoader::load_error_page(const URL& failed_url, const String& error)
+{
+    auto error_page_url = "file:///res/html/error.html";
+    ResourceLoader::the().load(
+        error_page_url,
+        [this, failed_url, error](auto data, auto&) {
+            ASSERT(!data.is_null());
+            auto html = String::format(
+                String::copy(data).characters(),
+                escape_html_entities(failed_url.to_string()).characters(),
+                escape_html_entities(error).characters());
+            auto document = parse_html_document(html, failed_url);
+            ASSERT(document);
+            frame().set_document(document);
+            if (frame().on_title_change)
+                frame().on_title_change(document->title());
+        },
+        [](auto error) {
+            dbg() << "Failed to load error page: " << error;
+            ASSERT_NOT_REACHED();
+        });
+}
+
+}