PaintBrush: Allow canceling a line by pressing the Escape key

Sometimes you change your mind mid-line, and just want to get out of
the situation. You can now do that :^)

Applications/PaintBrush/LineTool.cpp

@@ -58,6 +58,15 @@ void LineTool::on_second_paint(GPaintEvent& event)
     painter.draw_line(m_line_start_position, m_line_end_position, m_widget->color_for(m_drawing_button), m_thickness);
 }
 
+void LineTool::on_keydown(GKeyEvent& event)
+{
+    if (event.key() == Key_Escape && m_drawing_button != GMouseButton::None) {
+        m_drawing_button = GMouseButton::None;
+        m_widget->update();
+        event.accept();
+    }
+}
+
 void LineTool::on_contextmenu(GContextMenuEvent& event)
 {
     if (!m_context_menu) {

Applications/PaintBrush/LineTool.h

@@ -15,6 +15,7 @@ public:
     virtual void on_mouseup(GMouseEvent&) override;
     virtual void on_contextmenu(GContextMenuEvent&) override;
     virtual void on_second_paint(GPaintEvent&) override;
+    virtual void on_keydown(GKeyEvent&) override;
 
 private:
     virtual const char* class_name() const override { return "LineTool"; }

Applications/PaintBrush/PaintableWidget.cpp

@@ -96,6 +96,13 @@ void PaintableWidget::second_paint_event(GPaintEvent& event)
     GWidget::second_paint_event(event);
 }
 
+void PaintableWidget::keydown_event(GKeyEvent& event)
+{
+    if (m_tool)
+        m_tool->on_keydown(event);
+    GWidget::keydown_event(event);
+}
+
 void PaintableWidget::set_primary_color(Color color)
 {
     if (m_primary_color == color)

Applications/PaintBrush/PaintableWidget.h

@@ -32,11 +32,13 @@ public:
     Function<void(Color)> on_secondary_color_change;
 
 private:
+    virtual bool accepts_focus() const override { return true; }
     virtual void paint_event(GPaintEvent&) override;
     virtual void second_paint_event(GPaintEvent&) override;
     virtual void mousedown_event(GMouseEvent&) override;
     virtual void mouseup_event(GMouseEvent&) override;
     virtual void mousemove_event(GMouseEvent&) override;
+    virtual void keydown_event(GKeyEvent&) override;
 
     RefPtr<GraphicsBitmap> m_bitmap;
 

Applications/PaintBrush/Tool.h

@@ -1,7 +1,6 @@
 #pragma once
 
 #include "PaintableWidget.h"
-class GMouseEvent;
 
 class Tool {
 public:
@@ -14,6 +13,7 @@ public:
     virtual void on_mouseup(GMouseEvent&) {}
     virtual void on_contextmenu(GContextMenuEvent&) {}
     virtual void on_second_paint(GPaintEvent&) {}
+    virtual void on_keydown(GKeyEvent&) {}
 
     void clear() { m_widget = nullptr; }
     void setup(PaintableWidget& widget) { m_widget = widget.make_weak_ptr(); }

Applications/PaintBrush/main.cpp

@@ -33,6 +33,7 @@ int main(int argc, char** argv)
     vertical_container->layout()->set_spacing(0);
 
     auto paintable_widget = PaintableWidget::construct(vertical_container);
+    paintable_widget->set_focus(true);
     PaletteWidget::construct(*paintable_widget, vertical_container);
 
     window->show();