LibWeb: Add basic support for <input type=checkbox>

This is implemented entirely inside LibWeb, there is no GUI::CheckBox
widget instantiated, unlike other input types. All input types should
be moved to this new style of implementation.

Libraries/LibWeb/CMakeLists.txt

@@ -133,6 +133,7 @@ set(SOURCES
     Layout/LayoutBox.cpp
     Layout/LayoutBreak.cpp
     Layout/LayoutCanvas.cpp
+    Layout/LayoutCheckBox.cpp
     Layout/LayoutDocument.cpp
     Layout/LayoutFrame.cpp
     Layout/LayoutImage.cpp

Libraries/LibWeb/HTML/HTMLInputElement.cpp

@@ -30,9 +30,10 @@
 #include <LibWeb/DOM/Event.h>
 #include <LibWeb/HTML/HTMLFormElement.h>
 #include <LibWeb/HTML/HTMLInputElement.h>
+#include <LibWeb/InProcessWebView.h>
+#include <LibWeb/Layout/LayoutCheckBox.h>
 #include <LibWeb/Layout/LayoutWidget.h>
 #include <LibWeb/Page/Frame.h>
-#include <LibWeb/InProcessWebView.h>
 
 namespace Web::HTML {
 
@@ -78,6 +79,8 @@ RefPtr<LayoutNode> HTMLInputElement::create_layout_node(const CSS::StyleProperti
             const_cast<HTMLInputElement*>(this)->dispatch_event(DOM::Event::create("click"));
         };
         widget = button;
+    } else if (type() == "checkbox") {
+        return adopt(*new LayoutCheckBox(document(), *this, move(style)));
     } else {
         auto& text_box = page_view.add<GUI::TextBox>();
         text_box.set_text(value());
@@ -99,4 +102,18 @@ RefPtr<LayoutNode> HTMLInputElement::create_layout_node(const CSS::StyleProperti
     return adopt(*new LayoutWidget(document(), *this, *widget));
 }
 
+void HTMLInputElement::set_checked(bool checked)
+{
+    if (m_checked == checked)
+        return;
+    m_checked = checked;
+    if (layout_node())
+        layout_node()->set_needs_display();
+}
+
+bool HTMLInputElement::enabled() const
+{
+    return !has_attribute(HTML::AttributeNames::disabled);
+}
+
 }

Libraries/LibWeb/HTML/HTMLInputElement.h

@@ -42,6 +42,14 @@ public:
     String type() const { return attribute(HTML::AttributeNames::type); }
     String value() const { return attribute(HTML::AttributeNames::value); }
     String name() const { return attribute(HTML::AttributeNames::name); }
+
+    bool checked() const { return m_checked; }
+    void set_checked(bool);
+
+    bool enabled() const;
+
+private:
+    bool m_checked { false };
 };
 
 }

Libraries/LibWeb/HTML/HTMLInputElement.idl

@@ -11,4 +11,5 @@ interface HTMLInputElement : HTMLElement {
     [Reflect=dirname] attribute DOMString dirName;
     [Reflect=value] attribute DOMString defaultValue;
 
+    attribute boolean checked;
 }

Libraries/LibWeb/Layout/LayoutCheckBox.cpp

@@ -0,0 +1,105 @@
+/*
+ * 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 <LibGUI/Event.h>
+#include <LibGUI/Painter.h>
+#include <LibGfx/Font.h>
+#include <LibGfx/StylePainter.h>
+#include <LibWeb/Layout/LayoutCheckBox.h>
+#include <LibWeb/Page/Frame.h>
+
+namespace Web {
+
+LayoutCheckBox::LayoutCheckBox(DOM::Document& document, HTML::HTMLInputElement& element, NonnullRefPtr<CSS::StyleProperties> style)
+    : LayoutReplaced(document, element, move(style))
+{
+}
+
+LayoutCheckBox::~LayoutCheckBox()
+{
+}
+
+void LayoutCheckBox::layout(LayoutMode layout_mode)
+{
+    set_has_intrinsic_width(true);
+    set_has_intrinsic_height(true);
+    set_intrinsic_width(13);
+    set_intrinsic_height(13);
+    LayoutReplaced::layout(layout_mode);
+}
+
+void LayoutCheckBox::paint(PaintContext& context, PaintPhase phase)
+{
+    if (!is_visible())
+        return;
+
+    LayoutReplaced::paint(context, phase);
+
+    if (phase == PaintPhase::Foreground) {
+        Gfx::StylePainter::paint_check_box(context.painter(), enclosing_int_rect(absolute_rect()), context.palette(), node().enabled(), node().checked(), m_being_pressed);
+    }
+}
+
+void LayoutCheckBox::handle_mousedown(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned)
+{
+    if (button != GUI::MouseButton::Left)
+        return;
+
+    m_being_pressed = true;
+    set_needs_display();
+
+    m_tracking_mouse = true;
+    frame().event_handler().set_mouse_event_tracking_layout_node(this);
+}
+
+void LayoutCheckBox::handle_mouseup(Badge<EventHandler>, const Gfx::IntPoint& position, unsigned button, unsigned)
+{
+    if (!m_tracking_mouse || button != GUI::MouseButton::Left)
+        return;
+
+    bool is_inside = enclosing_int_rect(absolute_rect()).contains(position);
+    if (is_inside)
+        node().set_checked(!node().checked());
+
+    m_being_pressed = false;
+    m_tracking_mouse = false;
+    frame().event_handler().set_mouse_event_tracking_layout_node(nullptr);
+}
+
+void LayoutCheckBox::handle_mousemove(Badge<EventHandler>, const Gfx::IntPoint& position, unsigned, unsigned)
+{
+    if (!m_tracking_mouse)
+        return;
+
+    bool is_inside = enclosing_int_rect(absolute_rect()).contains(position);
+    if (m_being_pressed == is_inside)
+        return;
+
+    m_being_pressed = is_inside;
+    set_needs_display();
+}
+
+}

Libraries/LibWeb/Layout/LayoutCheckBox.h

@@ -0,0 +1,61 @@
+/*
+ * 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 <LibWeb/HTML/HTMLInputElement.h>
+#include <LibWeb/Layout/LayoutReplaced.h>
+
+namespace Web {
+
+class LayoutCheckBox : public LayoutReplaced {
+public:
+    LayoutCheckBox(DOM::Document&, HTML::HTMLInputElement&, NonnullRefPtr<CSS::StyleProperties>);
+    virtual ~LayoutCheckBox() override;
+
+    virtual void layout(LayoutMode = LayoutMode::Default) override;
+    virtual void paint(PaintContext&, PaintPhase) override;
+
+    const HTML::HTMLInputElement& node() const { return static_cast<const HTML::HTMLInputElement&>(LayoutReplaced::node()); }
+    HTML::HTMLInputElement& node() { return static_cast<HTML::HTMLInputElement&>(LayoutReplaced::node()); }
+
+private:
+    virtual const char* class_name() const override { return "LayoutCheckBox"; }
+    virtual bool is_check_box() const override { return true; }
+    virtual bool wants_mouse_events() const override { return true; }
+    virtual void handle_mousedown(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers) override;
+    virtual void handle_mouseup(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned modifiers) override;
+    virtual void handle_mousemove(Badge<EventHandler>, const Gfx::IntPoint&, unsigned buttons, unsigned modifiers) override;
+
+    bool m_being_pressed { false };
+    bool m_tracking_mouse { false };
+};
+
+}
+
+AK_BEGIN_TYPE_TRAITS(Web::LayoutCheckBox)
+static bool is_type(const Web::LayoutNode& layout_node) { return layout_node.is_check_box(); }
+AK_END_TYPE_TRAITS()

Libraries/LibWeb/Layout/LayoutNode.h

@@ -92,6 +92,7 @@ public:
     virtual bool is_table_cell() const { return false; }
     virtual bool is_table_row_group() const { return false; }
     virtual bool is_break() const { return false; }
+    virtual bool is_check_box() const { return false; }
     bool has_style() const { return m_has_style; }
 
     bool is_inline() const { return m_inline; }