LibWeb: Split out image loading logic from HTMLImageElement

Since more DOM nodes are going to want to load images (<object>, ...)
this patch splits out the image loading logic into an ImageLoader class
and then HTMLImageElement simply has an ImageLoader.

LayoutImage is then given a const ImageLoader& at construction and can
then provide layout and rendering for many kinds of DOM nodes.

2 files changed, 160 insertions, 0 deletions

diff --git a/Libraries/LibWeb/Loader/ImageLoader.cpp b/Libraries/LibWeb/Loader/ImageLoader.cpp
new file mode 100644
index 0000000000..df992e5483
--- /dev/null
+++ b/Libraries/LibWeb/Loader/ImageLoader.cpp
@@ -0,0 +1,101 @@
+/*
+ * 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 <LibGfx/Bitmap.h>
+#include <LibGfx/ImageDecoder.h>
+#include <LibWeb/Loader/ImageLoader.h>
+#include <LibWeb/Loader/ResourceLoader.h>
+
+namespace Web {
+
+ImageLoader::ImageLoader()
+{
+}
+
+void ImageLoader::load(const URL& url)
+{
+    LoadRequest request;
+    request.set_url(url);
+    set_resource(ResourceLoader::the().load_resource(Resource::Type::Image, request));
+}
+
+void ImageLoader::set_visible_in_viewport(bool visible_in_viewport)
+{
+    if (m_visible_in_viewport == visible_in_viewport)
+        return;
+    m_visible_in_viewport = visible_in_viewport;
+
+    // FIXME: Don't update volatility every time. If we're here, we're probably scanning through
+    //        the whole document, updating "is visible in viewport" flags, and this could lead
+    //        to the same bitmap being marked volatile back and forth unnecessarily.
+    if (resource())
+        resource()->update_volatility();
+}
+
+void ImageLoader::resource_did_load()
+{
+    ASSERT(resource());
+
+    if (!resource()->mime_type().starts_with("image/")) {
+        if (on_fail)
+            on_fail();
+        return;
+    }
+
+    if (!resource()->has_encoded_data()) {
+        dbg() << "ImageLoader: Resource did load, no encoded data. URL: " << resource()->url();
+    } else {
+        dbg() << "ImageLoader: Resource did load, has encoded data. URL: " << resource()->url();
+    }
+    m_decoder = resource()->ensure_decoder();
+
+    if (on_load)
+        on_load();
+}
+
+void ImageLoader::resource_did_fail()
+{
+    dbg() << "ImageLoader: Resource did fail. URL: " << resource()->url();
+    if (on_fail)
+        on_fail();
+}
+
+void ImageLoader::resource_did_replace_decoder()
+{
+    m_decoder = resource()->ensure_decoder();
+}
+
+const Gfx::Bitmap* ImageLoader::bitmap() const
+{
+    return m_decoder ? m_decoder->bitmap() : nullptr;
+}
+
+const Gfx::ImageDecoder* ImageLoader::image_decoder() const
+{
+    return m_decoder;
+}
+
+}
diff --git a/Libraries/LibWeb/Loader/ImageLoader.h b/Libraries/LibWeb/Loader/ImageLoader.h
new file mode 100644
index 0000000000..4b0e15ab59
--- /dev/null
+++ b/Libraries/LibWeb/Loader/ImageLoader.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/Function.h>
+#include <LibWeb/Loader/ImageResource.h>
+
+namespace Web {
+
+class ImageLoader : public ImageResourceClient {
+public:
+    ImageLoader();
+
+    void load(const URL&);
+
+    const Gfx::Bitmap* bitmap() const;
+    const Gfx::ImageDecoder* image_decoder() const;
+
+    void set_visible_in_viewport(bool);
+
+    Function<void()> on_load;
+    Function<void()> on_fail;
+
+private:
+    // ^ImageResourceClient
+    virtual void resource_did_load() override;
+    virtual void resource_did_fail() override;
+    virtual void resource_did_replace_decoder() override;
+    virtual bool is_visible_in_viewport() const override { return m_visible_in_viewport; }
+
+    RefPtr<Gfx::ImageDecoder> m_decoder;
+    bool m_visible_in_viewport { false };
+};
+
+}