From d59954489011c32c74a3ed3dea7edda8e14e852c Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Mon, 10 Jun 2019 19:29:33 +0200
Subject: [PATCH] PaintBrush: Start working on a simple painting application.

---
 Applications/PaintBrush/.gitignore          |  3 ++
 Applications/PaintBrush/Makefile            | 23 ++++++++++
 Applications/PaintBrush/PaintableWidget.cpp | 49 +++++++++++++++++++++
 Applications/PaintBrush/PaintableWidget.h   | 19 ++++++++
 Applications/PaintBrush/main.cpp            | 18 ++++++++
 Kernel/build-root-filesystem.sh             |  2 +
 6 files changed, 114 insertions(+)
 create mode 100644 Applications/PaintBrush/.gitignore
 create mode 100644 Applications/PaintBrush/Makefile
 create mode 100644 Applications/PaintBrush/PaintableWidget.cpp
 create mode 100644 Applications/PaintBrush/PaintableWidget.h
 create mode 100644 Applications/PaintBrush/main.cpp

diff --git a/Applications/PaintBrush/.gitignore b/Applications/PaintBrush/.gitignore
new file mode 100644
index 0000000000..30424a7dff
--- /dev/null
+++ b/Applications/PaintBrush/.gitignore
@@ -0,0 +1,3 @@
+*.o
+*.d
+PaintBrush
diff --git a/Applications/PaintBrush/Makefile b/Applications/PaintBrush/Makefile
new file mode 100644
index 0000000000..0a10066fb6
--- /dev/null
+++ b/Applications/PaintBrush/Makefile
@@ -0,0 +1,23 @@
+include ../../Makefile.common
+
+OBJS = \
+    PaintableWidget.o \
+    main.o
+
+APP = PaintBrush
+
+DEFINES += -DUSERLAND
+
+all: $(APP)
+
+$(APP): $(OBJS)
+	$(LD) -o $(APP) $(LDFLAGS) $(OBJS) -lgui -lcore -lc
+
+.cpp.o:
+	@echo "CXX $<"; $(CXX) $(CXXFLAGS) -o $@ -c $<
+
+-include $(OBJS:%.o=%.d)
+
+clean:
+	@echo "CLEAN"; rm -f $(APP) $(OBJS) *.d
+
diff --git a/Applications/PaintBrush/PaintableWidget.cpp b/Applications/PaintBrush/PaintableWidget.cpp
new file mode 100644
index 0000000000..bac84d85de
--- /dev/null
+++ b/Applications/PaintBrush/PaintableWidget.cpp
@@ -0,0 +1,49 @@
+#include "PaintableWidget.h"
+#include <LibGUI/GPainter.h>
+#include <SharedGraphics/GraphicsBitmap.h>
+
+PaintableWidget::PaintableWidget(GWidget* parent)
+    : GWidget(parent)
+{
+    set_fill_with_background_color(true);
+    set_background_color(Color::LightGray);
+    m_bitmap = GraphicsBitmap::create(GraphicsBitmap::Format::RGB32, { 600, 400 });
+    m_bitmap->fill(Color::White);
+}
+
+PaintableWidget::~PaintableWidget()
+{
+}
+
+void PaintableWidget::paint_event(GPaintEvent& event)
+{
+    GPainter painter(*this);
+    painter.add_clip_rect(event.rect());
+    painter.blit({ 0, 0 }, *m_bitmap, m_bitmap->rect());
+}
+
+void PaintableWidget::mousedown_event(GMouseEvent& event)
+{
+    if (event.button() != GMouseButton::Left)
+        return;
+
+    GPainter painter(*m_bitmap);
+    painter.set_pixel(event.position(), Color::Black);
+    update({ event.position(), { 1, 1 } });
+}
+
+void PaintableWidget::mouseup_event(GMouseEvent&)
+{
+}
+
+void PaintableWidget::mousemove_event(GMouseEvent& event)
+{
+    if (!rect().contains(event.position()))
+        return;
+
+    if (event.buttons() & GMouseButton::Left) {
+        GPainter painter(*m_bitmap);
+        painter.set_pixel(event.position(), Color::Black);
+        update({ event.position(), { 1, 1 } });
+    }
+}
diff --git a/Applications/PaintBrush/PaintableWidget.h b/Applications/PaintBrush/PaintableWidget.h
new file mode 100644
index 0000000000..11d25e9a8b
--- /dev/null
+++ b/Applications/PaintBrush/PaintableWidget.h
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <LibGUI/GWidget.h>
+
+class PaintableWidget final : public GWidget {
+public:
+    explicit PaintableWidget(GWidget* parent);
+    virtual ~PaintableWidget() override;
+
+    virtual const char* class_name() const override { return "PaintableWidget"; }
+
+private:
+    virtual void paint_event(GPaintEvent&) override;
+    virtual void mousedown_event(GMouseEvent&) override;
+    virtual void mouseup_event(GMouseEvent&) override;
+    virtual void mousemove_event(GMouseEvent&) override;
+
+    RetainPtr<GraphicsBitmap> m_bitmap;
+};
diff --git a/Applications/PaintBrush/main.cpp b/Applications/PaintBrush/main.cpp
new file mode 100644
index 0000000000..b2057f75fd
--- /dev/null
+++ b/Applications/PaintBrush/main.cpp
@@ -0,0 +1,18 @@
+#include "PaintableWidget.h"
+#include <LibGUI/GApplication.h>
+#include <LibGUI/GWindow.h>
+
+int main(int argc, char** argv)
+{
+    GApplication app(argc, argv);
+
+    auto* window = new GWindow;
+    window->set_title("PaintBrush");
+    window->set_rect(100, 100, 600, 400);
+
+    auto* paintable_widget = new PaintableWidget(nullptr);
+    window->set_main_widget(paintable_widget);
+
+    window->show();
+    return app.exec();
+}
diff --git a/Kernel/build-root-filesystem.sh b/Kernel/build-root-filesystem.sh
index 2e2870b9d3..15cd36d86e 100755
--- a/Kernel/build-root-filesystem.sh
+++ b/Kernel/build-root-filesystem.sh
@@ -71,6 +71,7 @@ cp ../Applications/ProcessManager/ProcessManager mnt/bin/ProcessManager
 cp ../Applications/Taskbar/Taskbar mnt/bin/Taskbar
 cp ../Applications/Terminal/Terminal mnt/bin/Terminal
 cp ../Applications/TextEditor/TextEditor mnt/bin/TextEditor
+cp ../Applications/PaintBrush/PaintBrush mnt/bin/PaintBrush
 cp ../Demos/HelloWorld/HelloWorld mnt/bin/HelloWorld
 cp ../Demos/RetroFetch/RetroFetch mnt/bin/RetroFetch
 cp ../Demos/WidgetGallery/WidgetGallery mnt/bin/WidgetGallery
@@ -95,6 +96,7 @@ ln -s Taskbar mnt/bin/tb
 ln -s VisualBuilder mnt/bin/vb
 ln -s WidgetGallery mnt/bin/wg
 ln -s TextEditor mnt/bin/te
+ln -s PaintBrush mnt/bin/pb
 echo "done"
 
 # Run local sync script, if it exists