From 642c82fbff7ebc6fbe5d4c29dec1c5d33859e5ac Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Mon, 10 Jun 2019 19:35:24 +0200
Subject: [PATCH] PaintBrush: Use draw_line() when drawing continuously.

---
 Applications/PaintBrush/PaintableWidget.cpp | 17 ++++++++++++++---
 Applications/PaintBrush/PaintableWidget.h   |  1 +
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/Applications/PaintBrush/PaintableWidget.cpp b/Applications/PaintBrush/PaintableWidget.cpp
index bac84d85de..767aac222d 100644
--- a/Applications/PaintBrush/PaintableWidget.cpp
+++ b/Applications/PaintBrush/PaintableWidget.cpp
@@ -30,10 +30,13 @@ void PaintableWidget::mousedown_event(GMouseEvent& event)
     GPainter painter(*m_bitmap);
     painter.set_pixel(event.position(), Color::Black);
     update({ event.position(), { 1, 1 } });
+    m_last_drawing_event_position = event.position();
 }
 
-void PaintableWidget::mouseup_event(GMouseEvent&)
+void PaintableWidget::mouseup_event(GMouseEvent& event)
 {
+    if (event.button() == GMouseButton::Left)
+        m_last_drawing_event_position = { -1, -1 };
 }
 
 void PaintableWidget::mousemove_event(GMouseEvent& event)
@@ -43,7 +46,15 @@ void PaintableWidget::mousemove_event(GMouseEvent& event)
 
     if (event.buttons() & GMouseButton::Left) {
         GPainter painter(*m_bitmap);
-        painter.set_pixel(event.position(), Color::Black);
-        update({ event.position(), { 1, 1 } });
+
+        if (m_last_drawing_event_position != Point(-1, -1)) {
+            painter.draw_line(m_last_drawing_event_position, event.position(), Color::Black);
+            update();
+        } else {
+            painter.set_pixel(event.position(), Color::Black);
+            update({ event.position(), { 1, 1 } });
+        }
+
+        m_last_drawing_event_position = event.position();
     }
 }
diff --git a/Applications/PaintBrush/PaintableWidget.h b/Applications/PaintBrush/PaintableWidget.h
index 11d25e9a8b..3714492c6d 100644
--- a/Applications/PaintBrush/PaintableWidget.h
+++ b/Applications/PaintBrush/PaintableWidget.h
@@ -15,5 +15,6 @@ private:
     virtual void mouseup_event(GMouseEvent&) override;
     virtual void mousemove_event(GMouseEvent&) override;
 
+    Point m_last_drawing_event_position { -1, -1 };
     RetainPtr<GraphicsBitmap> m_bitmap;
 };