LibWeb: Implement <input type=submit> without using LibGUI

Following in the footsteps of <input type=checkbox>, this patch adds LayoutButton which implements a basic push button using LibGfx styling primitives.
2025-05-23 19:05:08 +00:00 · 2020-09-12 17:56:11 +02:00 · 2020-09-12 17:56:11 +02:00 · cd5570670c
commit cd5570670c
parent 94c55d9e37
7 changed files with 220 additions and 40 deletions
--- a/Libraries/LibWeb/Layout/LayoutButton.cpp
+++ b/Libraries/LibWeb/Layout/LayoutButton.cpp
@ -0,0 +1,119 @@
+/*
+ * 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/DOM/Document.h>
+#include <LibWeb/Layout/LayoutButton.h>
+#include <LibWeb/Page/Frame.h>
+
+namespace Web {
+
+LayoutButton::LayoutButton(DOM::Document& document, HTML::HTMLInputElement& element, NonnullRefPtr<CSS::StyleProperties> style)
+    : LayoutReplaced(document, element, move(style))
+{
+}
+
+LayoutButton::~LayoutButton()
+{
+}
+
+void LayoutButton::layout(LayoutMode layout_mode)
+{
+    auto& font = specified_style().font();
+    set_intrinsic_width(font.width(node().value()) + 20);
+    set_has_intrinsic_width(true);
+
+    set_intrinsic_height(20);
+    set_has_intrinsic_height(true);
+    LayoutReplaced::layout(layout_mode);
+}
+
+void LayoutButton::paint(PaintContext& context, PaintPhase phase)
+{
+    if (!is_visible())
+        return;
+
+    LayoutReplaced::paint(context, phase);
+
+    if (phase == PaintPhase::Foreground) {
+        bool hovered = document().hovered_node() == &node();
+        Gfx::StylePainter::paint_button(context.painter(), enclosing_int_rect(absolute_rect()), context.palette(), Gfx::ButtonStyle::Normal, m_being_pressed, hovered, node().checked(), node().enabled());
+
+        auto text_rect = enclosing_int_rect(absolute_rect());
+        if (m_being_pressed)
+            text_rect.move_by(1, 1);
+        context.painter().draw_text(text_rect, node().value(), specified_style().font(), Gfx::TextAlignment::Center);
+    }
+}
+
+void LayoutButton::handle_mousedown(Badge<EventHandler>, const Gfx::IntPoint&, unsigned button, unsigned)
+{
+    if (button != GUI::MouseButton::Left || !node().enabled())
+        return;
+
+    m_being_pressed = true;
+    set_needs_display();
+
+    m_tracking_mouse = true;
+    frame().event_handler().set_mouse_event_tracking_layout_node(this);
+}
+
+void LayoutButton::handle_mouseup(Badge<EventHandler>, const Gfx::IntPoint& position, unsigned button, unsigned)
+{
+    if (!m_tracking_mouse || button != GUI::MouseButton::Left || !node().enabled())
+        return;
+
+    // NOTE: Handling the click may run arbitrary JS, which could disappear this node.
+    NonnullRefPtr protected_this = *this;
+    NonnullRefPtr protected_frame = frame();
+
+    bool is_inside = enclosing_int_rect(absolute_rect()).contains(position);
+    if (is_inside)
+        node().did_click_button({});
+
+    m_being_pressed = false;
+    m_tracking_mouse = false;
+
+    protected_frame->event_handler().set_mouse_event_tracking_layout_node(nullptr);
+}
+
+void LayoutButton::handle_mousemove(Badge<EventHandler>, const Gfx::IntPoint& position, unsigned, unsigned)
+{
+    if (!m_tracking_mouse || !node().enabled())
+        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();
+}
+
+}