Taskbar: Start working on a taskbar app.

I originally thought I would do this inside WindowServer, but let's try to
make it as a standalone app that communicates with WindowServer instead.
That will allow us to use LibGUI. :^)

Applications/Taskbar/Makefile

@@ -0,0 +1,33 @@
+OBJS = \
+    TaskbarWindow.o \
+    TaskbarWidget.o \
+    main.o
+
+APP = Taskbar
+
+STANDARD_FLAGS = -std=c++17 -Wno-sized-deallocation
+WARNING_FLAGS = -Wextra -Wall -Wundef -Wcast-qual -Wwrite-strings -Wimplicit-fallthrough
+FLAVOR_FLAGS = -fno-exceptions -fno-rtti
+OPTIMIZATION_FLAGS = -Os
+INCLUDE_FLAGS = -I../.. -I. -I../../LibC
+
+DEFINES = -DSERENITY -DSANITIZE_PTRS -DUSERLAND
+
+CXXFLAGS = -MMD -MP $(WARNING_FLAGS) $(OPTIMIZATION_FLAGS) $(FLAVOR_FLAGS) $(STANDARD_FLAGS) $(INCLUDE_FLAGS) $(DEFINES)
+CXX = i686-pc-serenity-g++
+LD = i686-pc-serenity-g++
+LDFLAGS = -L../../LibC -L../../LibGUI
+
+all: $(APP)
+
+$(APP): $(OBJS)
+	$(LD) -o $(APP) $(LDFLAGS) $(OBJS) -lgui -lc
+
+.cpp.o:
+	@echo "CXX $<"; $(CXX) $(CXXFLAGS) -o $@ -c $<
+
+-include $(OBJS:%.o=%.d)
+
+clean:
+	@echo "CLEAN"; rm -f $(APPS) $(OBJS) *.d
+

Applications/Taskbar/TaskbarWidget.cpp

@@ -0,0 +1,31 @@
+#include "TaskbarWidget.h"
+#include <LibGUI/GLabel.h>
+#include <LibGUI/GButton.h>
+#include <LibGUI/GBoxLayout.h>
+#include <LibGUI/GPainter.h>
+#include <stdio.h>
+
+TaskbarWidget::TaskbarWidget(GWidget* parent)
+    : GFrame(parent)
+{
+    set_fill_with_background_color(true);
+    set_layout(make<GBoxLayout>(Orientation::Vertical));
+    layout()->set_margins({ 0, 8, 0, 8 });
+    layout()->set_spacing(8);
+
+    set_frame_thickness(1);
+    set_frame_shape(GFrame::Shape::Panel);
+    set_frame_shadow(GFrame::Shadow::Raised);
+}
+
+TaskbarWidget::~TaskbarWidget()
+{
+}
+
+void TaskbarWidget::paint_event(GPaintEvent& event)
+{
+    GFrame::paint_event(event);
+
+    GPainter painter(*this);
+    painter.add_clip_rect(event.rect());
+}

Applications/Taskbar/TaskbarWidget.d

@@ -0,0 +1,133 @@
+TaskbarWidget.o: TaskbarWidget.cpp TaskbarWidget.h ../../LibGUI/GFrame.h \
+ ../../LibGUI/GWidget.h ../../LibGUI/GElapsedTimer.h ../../LibC/time.h \
+ ../../LibC/sys/cdefs.h ../../LibC/sys/types.h ../../LibC/stdint.h \
+ ../../LibGUI/GEvent.h ../../SharedGraphics/Point.h ../../AK/AKString.h \
+ ../../AK/ByteBuffer.h ../../AK/Types.h ../../AK/StdLibExtras.h \
+ ../../LibC/stdlib.h ../../LibC/stddef.h ../../LibC/string.h \
+ ../../AK/Retainable.h ../../AK/Assertions.h ../../LibC/assert.h \
+ ../../AK/RetainPtr.h ../../AK/Retained.h ../../AK/kmalloc.h \
+ ../../AK/StringImpl.h ../../AK/Traits.h ../../AK/kstdio.h \
+ ../../Kernel/kstdio.h ../../Kernel/kprintf.h ../../AK/HashFunctions.h \
+ ../../AK/Vector.h ../../AK/OwnPtr.h ../../SharedGraphics/Rect.h \
+ ../../SharedGraphics/Size.h ../../AK/WeakPtr.h ../../AK/Weakable.h \
+ ../../Kernel/KeyCode.h ../../LibGUI/GObject.h \
+ ../../SharedGraphics/Color.h ../../SharedGraphics/Font.h \
+ ../../AK/MappedFile.h ../../AK/Badge.h ../../LibGUI/GLabel.h \
+ ../../SharedGraphics/TextAlignment.h ../../LibGUI/GButton.h \
+ ../../SharedGraphics/StylePainter.h ../../AK/Function.h \
+ ../../SharedGraphics/GraphicsBitmap.h ../../LibC/SharedBuffer.h \
+ ../../LibGUI/GBoxLayout.h ../../LibGUI/GLayout.h ../../LibGUI/GMargins.h \
+ ../../LibGUI/GPainter.h ../../SharedGraphics/Painter.h \
+ ../../LibC/stdio.h ../../LibC/stdarg.h ../../LibC/limits.h
+
+TaskbarWidget.h:
+
+../../LibGUI/GFrame.h:
+
+../../LibGUI/GWidget.h:
+
+../../LibGUI/GElapsedTimer.h:
+
+../../LibC/time.h:
+
+../../LibC/sys/cdefs.h:
+
+../../LibC/sys/types.h:
+
+../../LibC/stdint.h:
+
+../../LibGUI/GEvent.h:
+
+../../SharedGraphics/Point.h:
+
+../../AK/AKString.h:
+
+../../AK/ByteBuffer.h:
+
+../../AK/Types.h:
+
+../../AK/StdLibExtras.h:
+
+../../LibC/stdlib.h:
+
+../../LibC/stddef.h:
+
+../../LibC/string.h:
+
+../../AK/Retainable.h:
+
+../../AK/Assertions.h:
+
+../../LibC/assert.h:
+
+../../AK/RetainPtr.h:
+
+../../AK/Retained.h:
+
+../../AK/kmalloc.h:
+
+../../AK/StringImpl.h:
+
+../../AK/Traits.h:
+
+../../AK/kstdio.h:
+
+../../Kernel/kstdio.h:
+
+../../Kernel/kprintf.h:
+
+../../AK/HashFunctions.h:
+
+../../AK/Vector.h:
+
+../../AK/OwnPtr.h:
+
+../../SharedGraphics/Rect.h:
+
+../../SharedGraphics/Size.h:
+
+../../AK/WeakPtr.h:
+
+../../AK/Weakable.h:
+
+../../Kernel/KeyCode.h:
+
+../../LibGUI/GObject.h:
+
+../../SharedGraphics/Color.h:
+
+../../SharedGraphics/Font.h:
+
+../../AK/MappedFile.h:
+
+../../AK/Badge.h:
+
+../../LibGUI/GLabel.h:
+
+../../SharedGraphics/TextAlignment.h:
+
+../../LibGUI/GButton.h:
+
+../../SharedGraphics/StylePainter.h:
+
+../../AK/Function.h:
+
+../../SharedGraphics/GraphicsBitmap.h:
+
+../../LibC/SharedBuffer.h:
+
+../../LibGUI/GBoxLayout.h:
+
+../../LibGUI/GLayout.h:
+
+../../LibGUI/GMargins.h:
+
+../../LibGUI/GPainter.h:
+
+../../SharedGraphics/Painter.h:
+
+../../LibC/stdio.h:
+
+../../LibC/stdarg.h:
+
+../../LibC/limits.h:

Applications/Taskbar/TaskbarWidget.h

@@ -0,0 +1,13 @@
+#include <LibGUI/GFrame.h>
+
+class TaskbarWidget final : public GFrame {
+public:
+    TaskbarWidget(GWidget* parent = nullptr);
+    virtual ~TaskbarWidget() override;
+
+    virtual const char* class_name() const override { return "TaskbarWidget"; }
+
+private:
+    virtual void paint_event(GPaintEvent&) override;
+
+};

Applications/Taskbar/TaskbarWindow.cpp

@@ -0,0 +1,29 @@
+#include "TaskbarWindow.h"
+#include "TaskbarWidget.h"
+#include <LibGUI/GWindow.h>
+#include <LibGUI/GDesktop.h>
+#include <stdio.h>
+
+TaskbarWindow::TaskbarWindow()
+{
+    set_window_type(GWindowType::Taskbar);
+    set_title("Taskbar");
+    set_should_exit_event_loop_on_close(true);
+
+    on_screen_rect_change(GDesktop::the().rect());
+
+    GDesktop::the().on_rect_change = [this] (const Rect& rect) { on_screen_rect_change(rect); };
+
+    auto* widget = new TaskbarWidget;
+    set_main_widget(widget);
+}
+
+TaskbarWindow::~TaskbarWindow()
+{
+}
+
+void TaskbarWindow::on_screen_rect_change(const Rect& rect)
+{
+    Rect new_rect { rect.x(), rect.bottom() - taskbar_height() + 1, rect.width(), taskbar_height() };
+    set_rect(new_rect);
+}

Applications/Taskbar/TaskbarWindow.d

@@ -0,0 +1,118 @@
+TaskbarWindow.o: TaskbarWindow.cpp TaskbarWindow.h ../../LibGUI/GWindow.h \
+ ../../LibGUI/GObject.h ../../AK/Vector.h ../../AK/Assertions.h \
+ ../../LibC/assert.h ../../LibC/sys/cdefs.h ../../AK/OwnPtr.h \
+ ../../AK/StdLibExtras.h ../../LibC/stdlib.h ../../LibC/sys/types.h \
+ ../../LibC/stdint.h ../../LibC/stddef.h ../../LibC/string.h \
+ ../../AK/Types.h ../../AK/Traits.h ../../AK/kstdio.h \
+ ../../Kernel/kstdio.h ../../Kernel/kprintf.h ../../AK/HashFunctions.h \
+ ../../AK/kmalloc.h ../../AK/Weakable.h ../../AK/Retainable.h \
+ ../../AK/RetainPtr.h ../../AK/Retained.h ../../SharedGraphics/Rect.h \
+ ../../SharedGraphics/Point.h ../../AK/AKString.h ../../AK/ByteBuffer.h \
+ ../../AK/StringImpl.h ../../SharedGraphics/Size.h \
+ ../../SharedGraphics/GraphicsBitmap.h ../../SharedGraphics/Color.h \
+ ../../AK/MappedFile.h ../../LibC/SharedBuffer.h ../../AK/WeakPtr.h \
+ ../../LibGUI/GWidget.h ../../LibGUI/GElapsedTimer.h ../../LibC/time.h \
+ ../../LibGUI/GEvent.h ../../Kernel/KeyCode.h ../../SharedGraphics/Font.h \
+ ../../AK/Badge.h TaskbarWidget.h ../../LibGUI/GFrame.h \
+ ../../LibGUI/GDesktop.h ../../AK/Function.h ../../LibC/stdio.h \
+ ../../LibC/stdarg.h ../../LibC/limits.h
+
+TaskbarWindow.h:
+
+../../LibGUI/GWindow.h:
+
+../../LibGUI/GObject.h:
+
+../../AK/Vector.h:
+
+../../AK/Assertions.h:
+
+../../LibC/assert.h:
+
+../../LibC/sys/cdefs.h:
+
+../../AK/OwnPtr.h:
+
+../../AK/StdLibExtras.h:
+
+../../LibC/stdlib.h:
+
+../../LibC/sys/types.h:
+
+../../LibC/stdint.h:
+
+../../LibC/stddef.h:
+
+../../LibC/string.h:
+
+../../AK/Types.h:
+
+../../AK/Traits.h:
+
+../../AK/kstdio.h:
+
+../../Kernel/kstdio.h:
+
+../../Kernel/kprintf.h:
+
+../../AK/HashFunctions.h:
+
+../../AK/kmalloc.h:
+
+../../AK/Weakable.h:
+
+../../AK/Retainable.h:
+
+../../AK/RetainPtr.h:
+
+../../AK/Retained.h:
+
+../../SharedGraphics/Rect.h:
+
+../../SharedGraphics/Point.h:
+
+../../AK/AKString.h:
+
+../../AK/ByteBuffer.h:
+
+../../AK/StringImpl.h:
+
+../../SharedGraphics/Size.h:
+
+../../SharedGraphics/GraphicsBitmap.h:
+
+../../SharedGraphics/Color.h:
+
+../../AK/MappedFile.h:
+
+../../LibC/SharedBuffer.h:
+
+../../AK/WeakPtr.h:
+
+../../LibGUI/GWidget.h:
+
+../../LibGUI/GElapsedTimer.h:
+
+../../LibC/time.h:
+
+../../LibGUI/GEvent.h:
+
+../../Kernel/KeyCode.h:
+
+../../SharedGraphics/Font.h:
+
+../../AK/Badge.h:
+
+TaskbarWidget.h:
+
+../../LibGUI/GFrame.h:
+
+../../LibGUI/GDesktop.h:
+
+../../AK/Function.h:
+
+../../LibC/stdio.h:
+
+../../LibC/stdarg.h:
+
+../../LibC/limits.h:

Applications/Taskbar/TaskbarWindow.h

@@ -0,0 +1,16 @@
+#include <LibGUI/GWindow.h>
+#include <LibGUI/GWidget.h>
+
+class TaskbarWindow final : public GWindow {
+public:
+    TaskbarWindow();
+    virtual ~TaskbarWindow() override;
+
+    int taskbar_height() const { return 20; }
+
+    virtual const char* class_name() const override { return "TaskbarWindow"; }
+
+private:
+    void on_screen_rect_change(const Rect&);
+
+};

Applications/Taskbar/main.cpp

@@ -0,0 +1,10 @@
+#include <LibGUI/GApplication.h>
+#include "TaskbarWindow.h"
+
+int main(int argc, char** argv)
+{
+    GApplication app(argc, argv);
+    TaskbarWindow window;
+    window.show();
+    return app.exec();
+}

Applications/Taskbar/main.d

@@ -0,0 +1,114 @@
+main.o: main.cpp ../../LibGUI/GApplication.h ../../AK/Badge.h \
+ ../../AK/OwnPtr.h ../../AK/StdLibExtras.h ../../LibC/stdlib.h \
+ ../../LibC/sys/cdefs.h ../../LibC/sys/types.h ../../LibC/stdint.h \
+ ../../LibC/stddef.h ../../LibC/string.h ../../AK/Types.h \
+ ../../AK/Traits.h ../../AK/kstdio.h ../../Kernel/kstdio.h \
+ ../../Kernel/kprintf.h ../../AK/HashFunctions.h ../../AK/HashMap.h \
+ ../../AK/HashTable.h ../../AK/Assertions.h ../../LibC/assert.h \
+ ../../AK/DoublyLinkedList.h ../../LibGUI/GShortcut.h \
+ ../../Kernel/KeyCode.h ../../AK/AKString.h ../../AK/ByteBuffer.h \
+ ../../AK/Retainable.h ../../AK/RetainPtr.h ../../AK/Retained.h \
+ ../../AK/kmalloc.h ../../AK/StringImpl.h ../../AK/Vector.h \
+ TaskbarWindow.h ../../LibGUI/GWindow.h ../../LibGUI/GObject.h \
+ ../../AK/Weakable.h ../../SharedGraphics/Rect.h \
+ ../../SharedGraphics/Point.h ../../SharedGraphics/Size.h \
+ ../../SharedGraphics/GraphicsBitmap.h ../../SharedGraphics/Color.h \
+ ../../AK/MappedFile.h ../../LibC/SharedBuffer.h ../../AK/WeakPtr.h \
+ ../../LibGUI/GWidget.h ../../LibGUI/GElapsedTimer.h ../../LibC/time.h \
+ ../../LibGUI/GEvent.h ../../SharedGraphics/Font.h
+
+../../LibGUI/GApplication.h:
+
+../../AK/Badge.h:
+
+../../AK/OwnPtr.h:
+
+../../AK/StdLibExtras.h:
+
+../../LibC/stdlib.h:
+
+../../LibC/sys/cdefs.h:
+
+../../LibC/sys/types.h:
+
+../../LibC/stdint.h:
+
+../../LibC/stddef.h:
+
+../../LibC/string.h:
+
+../../AK/Types.h:
+
+../../AK/Traits.h:
+
+../../AK/kstdio.h:
+
+../../Kernel/kstdio.h:
+
+../../Kernel/kprintf.h:
+
+../../AK/HashFunctions.h:
+
+../../AK/HashMap.h:
+
+../../AK/HashTable.h:
+
+../../AK/Assertions.h:
+
+../../LibC/assert.h:
+
+../../AK/DoublyLinkedList.h:
+
+../../LibGUI/GShortcut.h:
+
+../../Kernel/KeyCode.h:
+
+../../AK/AKString.h:
+
+../../AK/ByteBuffer.h:
+
+../../AK/Retainable.h:
+
+../../AK/RetainPtr.h:
+
+../../AK/Retained.h:
+
+../../AK/kmalloc.h:
+
+../../AK/StringImpl.h:
+
+../../AK/Vector.h:
+
+TaskbarWindow.h:
+
+../../LibGUI/GWindow.h:
+
+../../LibGUI/GObject.h:
+
+../../AK/Weakable.h:
+
+../../SharedGraphics/Rect.h:
+
+../../SharedGraphics/Point.h:
+
+../../SharedGraphics/Size.h:
+
+../../SharedGraphics/GraphicsBitmap.h:
+
+../../SharedGraphics/Color.h:
+
+../../AK/MappedFile.h:
+
+../../LibC/SharedBuffer.h:
+
+../../AK/WeakPtr.h:
+
+../../LibGUI/GWidget.h:
+
+../../LibGUI/GElapsedTimer.h:
+
+../../LibC/time.h:
+
+../../LibGUI/GEvent.h:
+
+../../SharedGraphics/Font.h: