From 90873781c1d2bbe5334dd6f732b6010843956c56 Mon Sep 17 00:00:00 2001
From: Elliot Maisl <elliot.maisl@gmail.com>
Date: Thu, 17 Jun 2021 00:00:23 +0200
Subject: [PATCH] PixelPaint: Add new selection moving modes

If you press "spacebar" while moving a selection, it will now move the
origin point of the selection; and if you press "control" it will move
it relatively to the center.
---
 .../PixelPaint/RectangleSelectTool.cpp        | 24 +++++++++++++++++++
 .../PixelPaint/RectangleSelectTool.h          |  9 +++++++
 2 files changed, 33 insertions(+)

diff --git a/Userland/Applications/PixelPaint/RectangleSelectTool.cpp b/Userland/Applications/PixelPaint/RectangleSelectTool.cpp
index a7a52e0bb2..66b541405f 100644
--- a/Userland/Applications/PixelPaint/RectangleSelectTool.cpp
+++ b/Userland/Applications/PixelPaint/RectangleSelectTool.cpp
@@ -37,6 +37,14 @@ void RectangleSelectTool::on_mousemove(Layer&, GUI::MouseEvent&, GUI::MouseEvent
     if (!m_selecting)
         return;
 
+    if (m_moving_mode != MovingMode::None) {
+        auto delta = m_selection_end - image_event.position();
+        if (m_moving_mode == MovingMode::MovingOrigin)
+            m_selection_start -= delta;
+        else if (m_moving_mode == MovingMode::AroundCenter)
+            m_selection_start += delta;
+    }
+
     m_selection_end = image_event.position();
     m_editor->update();
 }
@@ -55,6 +63,22 @@ void RectangleSelectTool::on_mouseup(Layer&, GUI::MouseEvent&, GUI::MouseEvent&
     m_editor->selection().set(rect_in_image);
 }
 
+void RectangleSelectTool::on_keydown(GUI::KeyEvent& key_event)
+{
+    if (key_event.key() == KeyCode::Key_Space)
+        m_moving_mode = MovingMode::MovingOrigin;
+    else if (key_event.key() == KeyCode::Key_Control)
+        m_moving_mode = MovingMode::AroundCenter;
+}
+
+void RectangleSelectTool::on_keyup(GUI::KeyEvent& key_event)
+{
+    if (key_event.key() == KeyCode::Key_Space && m_moving_mode == MovingMode::MovingOrigin)
+        m_moving_mode = MovingMode::None;
+    else if (key_event.key() == KeyCode::Key_Control && m_moving_mode == MovingMode::AroundCenter)
+        m_moving_mode = MovingMode::None;
+}
+
 void RectangleSelectTool::on_second_paint(Layer const&, GUI::PaintEvent& event)
 {
     if (!m_selecting)
diff --git a/Userland/Applications/PixelPaint/RectangleSelectTool.h b/Userland/Applications/PixelPaint/RectangleSelectTool.h
index 2bfe4324b9..a47fd35ee8 100644
--- a/Userland/Applications/PixelPaint/RectangleSelectTool.h
+++ b/Userland/Applications/PixelPaint/RectangleSelectTool.h
@@ -18,10 +18,19 @@ public:
     virtual void on_mousedown(Layer&, GUI::MouseEvent&, GUI::MouseEvent&) override;
     virtual void on_mousemove(Layer&, GUI::MouseEvent&, GUI::MouseEvent&) override;
     virtual void on_mouseup(Layer&, GUI::MouseEvent&, GUI::MouseEvent&) override;
+    virtual void on_keydown(GUI::KeyEvent&) override;
+    virtual void on_keyup(GUI::KeyEvent&) override;
     virtual void on_second_paint(Layer const&, GUI::PaintEvent&) override;
 
 private:
+    enum class MovingMode {
+        MovingOrigin,
+        AroundCenter,
+        None,
+    };
+
     bool m_selecting { false };
+    MovingMode m_moving_mode { MovingMode::None };
     Gfx::IntPoint m_selection_start;
     Gfx::IntPoint m_selection_end;
 };