2 files changed, 82 insertions, 4 deletions

diff --git a/Userland/Applications/PixelPaint/RectangleSelectTool.cpp b/Userland/Applications/PixelPaint/RectangleSelectTool.cpp
index 194e5490e0..6a9dc62e69 100644
--- a/Userland/Applications/PixelPaint/RectangleSelectTool.cpp
+++ b/Userland/Applications/PixelPaint/RectangleSelectTool.cpp
@@ -5,31 +5,100 @@
  */
 
 #include "RectangleSelectTool.h"
+#include "Image.h"
+#include "ImageEditor.h"
+#include "Layer.h"
+#include <LibCore/Timer.h>
+#include <LibGUI/Painter.h>
 
 namespace PixelPaint {
 
+constexpr int marching_ant_length = 4;
+
 RectangleSelectTool::RectangleSelectTool()
 {
+    m_marching_ants_timer = Core::Timer::create_repeating(80, [this] {
+        if (!m_editor)
+            return;
+        ++m_marching_ants_offset;
+        m_marching_ants_offset %= marching_ant_length;
+        m_editor->update();
+    });
+    m_marching_ants_timer->start();
 }
 
 RectangleSelectTool::~RectangleSelectTool()
 {
 }
 
-void RectangleSelectTool::on_mousedown(Layer&, GUI::MouseEvent&, GUI::MouseEvent&)
+void RectangleSelectTool::on_mousedown(Layer&, GUI::MouseEvent&, GUI::MouseEvent& image_event)
 {
+    if (image_event.button() != GUI::MouseButton::Left)
+        return;
+
+    m_selecting = true;
+    m_selection_start = image_event.position();
+    m_selection_end = image_event.position();
+    m_editor->update();
 }
 
-void RectangleSelectTool::on_mousemove(Layer&, GUI::MouseEvent&, GUI::MouseEvent&)
+void RectangleSelectTool::on_mousemove(Layer&, GUI::MouseEvent&, GUI::MouseEvent& image_event)
 {
+    if (!m_selecting)
+        return;
+
+    m_selection_end = image_event.position();
+    m_editor->update();
 }
 
-void RectangleSelectTool::on_mouseup(Layer&, GUI::MouseEvent&, GUI::MouseEvent&)
+void RectangleSelectTool::on_mouseup(Layer&, GUI::MouseEvent&, GUI::MouseEvent& image_event)
 {
+    if (!m_selecting || image_event.button() != GUI::MouseButton::Left)
+        return;
+
+    m_selecting = false;
+    m_editor->update();
 }
 
-void RectangleSelectTool::on_second_paint(Layer const&, GUI::PaintEvent&)
+void RectangleSelectTool::draw_marching_ants(Gfx::Painter& painter, Gfx::IntRect const& rect) const
 {
+    int offset = m_marching_ants_offset;
+
+    auto draw_pixel = [&](int x, int y) {
+        if ((offset % marching_ant_length) != 0)
+            painter.set_pixel(x, y, Color::Black);
+        offset++;
+    };
+
+    // Top line
+    for (int x = rect.left(); x <= rect.right(); ++x)
+        draw_pixel(x, rect.top());
+
+    // Right line
+    for (int y = rect.top() + 1; y <= rect.bottom(); ++y)
+        draw_pixel(rect.right(), y);
+
+    // Bottom line
+    for (int x = rect.right() - 1; x >= rect.left(); --x)
+        draw_pixel(x, rect.bottom());
+
+    // Left line
+    for (int y = rect.bottom() - 1; y > rect.top(); --y)
+        draw_pixel(rect.left(), y);
+}
+
+void RectangleSelectTool::on_second_paint(Layer const&, GUI::PaintEvent& event)
+{
+    if (!m_selecting)
+        return;
+
+    GUI::Painter painter(*m_editor);
+    painter.add_clip_rect(event.rect());
+
+    auto rect_in_image = Gfx::IntRect::from_two_points(m_selection_start, m_selection_end);
+    auto rect_in_editor = m_editor->image_rect_to_editor_rect(rect_in_image);
+
+    draw_marching_ants(painter, rect_in_editor.to_type<int>());
 }
 
 }
diff --git a/Userland/Applications/PixelPaint/RectangleSelectTool.h b/Userland/Applications/PixelPaint/RectangleSelectTool.h
index dc14c985b4..6011d2f199 100644
--- a/Userland/Applications/PixelPaint/RectangleSelectTool.h
+++ b/Userland/Applications/PixelPaint/RectangleSelectTool.h
@@ -19,6 +19,15 @@ public:
     virtual void on_mousemove(Layer&, GUI::MouseEvent&, GUI::MouseEvent&) override;
     virtual void on_mouseup(Layer&, GUI::MouseEvent&, GUI::MouseEvent&) override;
     virtual void on_second_paint(Layer const&, GUI::PaintEvent&) override;
+
+private:
+    void draw_marching_ants(Gfx::Painter&, Gfx::IntRect const&) const;
+
+    bool m_selecting { false };
+    Gfx::IntPoint m_selection_start;
+    Gfx::IntPoint m_selection_end;
+    RefPtr<Core::Timer> m_marching_ants_timer;
+    int m_marching_ants_offset { 0 };
 };
 
 }