PaintBrush: Allow editing palette colors by ctrl-clicking them.

Maybe the ColorDialog class could be fashioned into something generally
usable in LibGUI, but for now it lives in the PaintBrush app. :^)

Applications/PaintBrush/ColorDialog.cpp

@@ -0,0 +1,83 @@
+#include "ColorDialog.h"
+#include <LibGUI/GBoxLayout.h>
+#include <LibGUI/GButton.h>
+#include <LibGUI/GFrame.h>
+#include <LibGUI/GSpinBox.h>
+#include <LibGUI/GWidget.h>
+
+ColorDialog::ColorDialog(Color color, CObject* parent)
+    : GDialog(parent)
+    , m_color(color)
+{
+    set_title("Edit Color");
+    build();
+}
+
+ColorDialog::~ColorDialog()
+{
+}
+
+void ColorDialog::build()
+{
+    auto* horizontal_container = new GWidget;
+    horizontal_container->set_fill_with_background_color(true);
+    horizontal_container->set_layout(make<GBoxLayout>(Orientation::Horizontal));
+    horizontal_container->layout()->set_margins({ 4, 4, 4, 4 });
+    set_main_widget(horizontal_container);
+
+    auto* left_vertical_container = new GWidget(horizontal_container);
+    left_vertical_container->set_layout(make<GBoxLayout>(Orientation::Vertical));
+
+    auto* right_vertical_container = new GWidget(horizontal_container);
+    right_vertical_container->set_layout(make<GBoxLayout>(Orientation::Vertical));
+
+    enum RGBComponent {
+        Red, Green, Blue
+    };
+
+    auto* preview_widget = new GFrame(right_vertical_container);
+    preview_widget->set_background_color(m_color);
+    preview_widget->set_fill_with_background_color(true);
+    right_vertical_container->layout()->add_spacer();
+    auto* cancel_button = new GButton("Cancel", right_vertical_container);
+    cancel_button->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
+    cancel_button->set_preferred_size({ 0, 20 });
+    cancel_button->on_click = [&](auto&) {
+        done(GDialog::ExecCancel);
+    };
+    auto* ok_button = new GButton("Okay", right_vertical_container);
+    ok_button->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
+    ok_button->set_preferred_size({ 0, 20 });
+    ok_button->on_click = [&](auto&) {
+        done(GDialog::ExecOK);
+    };
+
+    auto make_spinbox = [&](RGBComponent component, int initial_value) {
+         auto* spinbox = new GSpinBox(left_vertical_container);
+         spinbox->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
+         spinbox->set_preferred_size({ 0, 20 });
+         spinbox->set_min(0);
+         spinbox->set_max(255);
+         spinbox->set_value(initial_value);
+
+         spinbox->on_change = [=](auto value) {
+             dbgprintf("on_change, component=%d, value=%d\n", component, value);
+             if (component == Red)
+                m_color.set_red(value);
+             if (component == Green)
+                m_color.set_green(value);
+             if (component == Blue)
+                m_color.set_blue(value);
+
+             dbgprintf("m_color is now: %s\n", m_color.to_string().characters());
+
+             preview_widget->set_background_color(m_color);
+             preview_widget->update();
+         };
+         return spinbox;
+    };
+
+    auto* red_spin = make_spinbox(Red, m_color.red());
+    auto* green_spin = make_spinbox(Green, m_color.green());
+    auto* blue_spin = make_spinbox(Blue, m_color.blue());
+}

Applications/PaintBrush/ColorDialog.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <LibGUI/GDialog.h>
+
+class ColorDialog final : public GDialog {
+public:
+    explicit ColorDialog(Color, CObject* parent = nullptr);
+    virtual ~ColorDialog() override;
+    virtual const char* class_name() const override { return "ColorDialog"; }
+
+    Color color() const { return m_color; }
+
+private:
+    void build();
+
+    Color m_color;
+};

Applications/PaintBrush/Makefile

@@ -7,6 +7,7 @@ OBJS = \
     Tool.o \
     PenTool.o \
     BucketTool.o \
+    ColorDialog.o \
     main.o
 
 APP = PaintBrush

Applications/PaintBrush/PaletteWidget.cpp

@@ -1,4 +1,5 @@
 #include "PaletteWidget.h"
+#include "ColorDialog.h"
 #include "PaintableWidget.h"
 #include <LibGUI/GBoxLayout.h>
 
@@ -20,6 +21,16 @@ public:
 
     virtual void mousedown_event(GMouseEvent& event) override
     {
+        if (event.modifiers() & KeyModifier::Mod_Ctrl && event.button() == GMouseButton::Left) {
+            ColorDialog dialog(m_color, window());
+            if (dialog.exec() == GDialog::ExecOK) {
+                m_color = dialog.color();
+                set_background_color(m_color);
+                update();
+            }
+            return;
+        }
+
         if (event.button() == GMouseButton::Left)
             m_palette_widget.set_primary_color(m_color);
         else if (event.button() == GMouseButton::Right)
@@ -75,7 +86,7 @@ PaletteWidget::PaletteWidget(PaintableWidget& paintable_widget, GWidget* parent)
     bottom_color_container->set_layout(make<GBoxLayout>(Orientation::Horizontal));
     bottom_color_container->layout()->set_spacing(1);
 
-    auto add_color_widget = [&] (GWidget* container, Color color) {
+    auto add_color_widget = [&](GWidget* container, Color color) {
         auto* color_widget = new ColorWidget(color, *this, container);
         color_widget->set_fill_with_background_color(true);
         color_widget->set_background_color(color);