PixelPaint: Add copy action (copies the selection from active layer)

You can now select a part of a layer, copy it, and then paste it as
a new layer. Very cool :^)

Userland/Applications/PixelPaint/Layer.cpp

@@ -6,6 +6,7 @@
 
 #include "Layer.h"
 #include "Image.h"
+#include "Selection.h"
 #include <LibGfx/Bitmap.h>
 
 namespace PixelPaint {
@@ -89,4 +90,11 @@ void Layer::set_name(String name)
     m_image.layer_did_modify_properties({}, *this);
 }
 
+RefPtr<Gfx::Bitmap> Layer::try_copy_bitmap(Selection const& selection) const
+{
+    auto bounding_rect = selection.bounding_rect().translated(-m_location);
+    // FIXME: This needs to be smarter once we add more complex selections.
+    return m_bitmap->cropped(bounding_rect);
+}
+
 }

Userland/Applications/PixelPaint/Layer.h

@@ -15,6 +15,7 @@
 namespace PixelPaint {
 
 class Image;
+class Selection;
 
 class Layer
     : public RefCounted<Layer>
@@ -56,6 +57,8 @@ public:
     int opacity_percent() const { return m_opacity_percent; }
     void set_opacity_percent(int);
 
+    RefPtr<Gfx::Bitmap> try_copy_bitmap(Selection const&) const;
+
 private:
     Layer(Image&, NonnullRefPtr<Gfx::Bitmap>, String name);
 

Userland/Applications/PixelPaint/Selection.h

@@ -21,6 +21,7 @@ public:
     bool is_empty() const { return m_rect.is_empty(); }
     void clear() { m_rect = {}; }
     void set(Gfx::IntRect const& rect) { m_rect = rect; }
+    Gfx::IntRect bounding_rect() const { return m_rect; }
 
     void paint(Gfx::Painter&, ImageEditor const&);
 

Userland/Applications/PixelPaint/main.cpp

@@ -160,6 +160,21 @@ int main(int argc, char** argv)
     }));
 
     auto& edit_menu = menubar->add_menu("&Edit");
+
+    auto copy_action = GUI::CommonActions::make_copy_action([&](auto&) {
+        VERIFY(image_editor.image());
+        if (!image_editor.active_layer()) {
+            dbgln("Cannot copy with no active layer selected");
+            return;
+        }
+        auto bitmap = image_editor.active_layer()->try_copy_bitmap(image_editor.selection());
+        if (!bitmap) {
+            dbgln("try_copy() from Layer failed");
+            return;
+        }
+        GUI::Clipboard::the().set_bitmap(*bitmap);
+    });
+
     auto paste_action = GUI::CommonActions::make_paste_action([&](auto&) {
         VERIFY(image_editor.image());
         auto bitmap = GUI::Clipboard::the().bitmap();
@@ -175,6 +190,7 @@ int main(int argc, char** argv)
     };
     paste_action->set_enabled(GUI::Clipboard::the().mime_type() == "image/x-serenityos");
 
+    edit_menu.add_action(copy_action);
     edit_menu.add_action(paste_action);
 
     auto undo_action = GUI::CommonActions::make_undo_action([&](auto&) {
@@ -375,6 +391,7 @@ int main(int argc, char** argv)
     toolbar.add_action(open_image_action);
     toolbar.add_action(save_image_as_action);
     toolbar.add_separator();
+    toolbar.add_action(copy_action);
     toolbar.add_action(paste_action);
     toolbar.add_action(undo_action);
     toolbar.add_action(redo_action);