PixelPaint: Extract common scope code into a generic ScopeWidget

When we add more scopes, this will facilitate code sharing.

Userland/Applications/PixelPaint/CMakeLists.txt

@@ -52,6 +52,7 @@ set(SOURCES
     ProjectLoader.cpp
     ResizeImageDialog.cpp
     ResizeImageDialogGML.h
+    ScopeWidget.cpp
     Selection.cpp
     ToolPropertiesWidget.cpp
     ToolboxWidget.cpp

Userland/Applications/PixelPaint/HistogramWidget.cpp

@@ -16,25 +16,6 @@ REGISTER_WIDGET(PixelPaint, HistogramWidget);
 
 namespace PixelPaint {
 
-HistogramWidget::~HistogramWidget()
-{
-    if (m_image)
-        m_image->remove_client(*this);
-}
-
-void HistogramWidget::set_image(Image* image)
-{
-    if (m_image == image)
-        return;
-    if (m_image)
-        m_image->remove_client(*this);
-    m_image = image;
-    if (m_image)
-        m_image->add_client(*this);
-
-    (void)rebuild_histogram_data();
-}
-
 ErrorOr<void> HistogramWidget::rebuild_histogram_data()
 {
     if (!m_image)
@@ -81,16 +62,15 @@ ErrorOr<void> HistogramWidget::rebuild_histogram_data()
     }
 
     // Scale the frequency values to fit the widgets height.
-    m_widget_height = height();
+    auto widget_height = height();
 
     for (int i = 0; i < 256; i++) {
-        m_data.red[i] = m_data.red[i] != 0 ? (static_cast<float>(m_data.red[i]) / max_color_frequency) * m_widget_height : 0;
+        m_data.red[i] = m_data.red[i] != 0 ? (static_cast<float>(m_data.red[i]) / max_color_frequency) * widget_height : 0;
-        m_data.green[i] = m_data.green[i] != 0 ? (static_cast<float>(m_data.green[i]) / max_color_frequency) * m_widget_height : 0;
+        m_data.green[i] = m_data.green[i] != 0 ? (static_cast<float>(m_data.green[i]) / max_color_frequency) * widget_height : 0;
-        m_data.blue[i] = m_data.blue[i] != 0 ? (static_cast<float>(m_data.blue[i]) / max_color_frequency) * m_widget_height : 0;
+        m_data.blue[i] = m_data.blue[i] != 0 ? (static_cast<float>(m_data.blue[i]) / max_color_frequency) * widget_height : 0;
-        m_data.brightness[i] = m_data.brightness[i] != 0 ? (static_cast<float>(m_data.brightness[i]) / max_brightness_frequency) * m_widget_height : 0;
+        m_data.brightness[i] = m_data.brightness[i] != 0 ? (static_cast<float>(m_data.brightness[i]) / max_brightness_frequency) * widget_height : 0;
     }
 
-    update();
     return {};
 }
 
@@ -102,7 +82,7 @@ void HistogramWidget::paint_event(GUI::PaintEvent& event)
     if (!m_image)
         return;
 
-    int bottom_line = m_widget_height - 1;
+    int bottom_line = height() - 1;
     float step_width = static_cast<float>(width()) / 256;
 
     Gfx::Path brightness_path;
@@ -153,14 +133,6 @@ void HistogramWidget::paint_event(GUI::PaintEvent& event)
 void HistogramWidget::image_changed()
 {
     (void)rebuild_histogram_data();
-}
-
-void HistogramWidget::set_color_at_mouseposition(Color color)
-{
-    if (m_color_at_mouseposition == color)
-        return;
-
-    m_color_at_mouseposition = color;
     update();
 }
 

Userland/Applications/PixelPaint/HistogramWidget.h

@@ -7,21 +7,17 @@
 #pragma once
 
 #include "Image.h"
-#include <LibGUI/AbstractScrollableWidget.h>
+#include "ScopeWidget.h"
 
 namespace PixelPaint {
 
 class HistogramWidget final
-    : public GUI::Frame
+    : public ScopeWidget {
-    , ImageClient {
     C_OBJECT(HistogramWidget);
 
 public:
-    virtual ~HistogramWidget() override;
+    virtual ~HistogramWidget() = default;
-
+    virtual void image_changed() override;
-    void set_image(Image*);
-    void image_changed();
-    void set_color_at_mouseposition(Color);
 
 private:
     HistogramWidget() = default;
@@ -29,9 +25,6 @@ private:
     virtual void paint_event(GUI::PaintEvent&) override;
 
     ErrorOr<void> rebuild_histogram_data();
-    int m_widget_height = 0;
-    Color m_color_at_mouseposition = Color::Transparent;
-    RefPtr<Image> m_image;
 
     struct HistogramData {
         Vector<int> red;

Userland/Applications/PixelPaint/ScopeWidget.cpp

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2022, kleines Filmröllchen <filmroellchen@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "ScopeWidget.h"
+#include "Layer.h"
+
+namespace PixelPaint {
+
+ScopeWidget::~ScopeWidget()
+{
+    if (m_image)
+        m_image->remove_client(*this);
+}
+
+void ScopeWidget::set_image(Image* image)
+{
+    if (m_image == image)
+        return;
+    if (m_image)
+        m_image->remove_client(*this);
+    m_image = image;
+    if (m_image)
+        m_image->add_client(*this);
+
+    image_changed();
+    update();
+}
+
+void ScopeWidget::set_color_at_mouseposition(Color color)
+{
+    if (m_color_at_mouseposition == color)
+        return;
+
+    m_color_at_mouseposition = color;
+    update();
+}
+
+}

Userland/Applications/PixelPaint/ScopeWidget.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2022, kleines Filmröllchen <filmroellchen@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include "Image.h"
+#include <LibCore/Object.h>
+#include <LibGUI/Frame.h>
+
+namespace PixelPaint {
+
+class ScopeWidget
+    : public GUI::Frame
+    , public ImageClient {
+    C_OBJECT_ABSTRACT(ScopeWidget);
+
+public:
+    virtual ~ScopeWidget() override;
+
+    void set_image(Image*);
+    virtual void image_changed() = 0;
+    void set_color_at_mouseposition(Color);
+
+protected:
+    virtual void paint_event(GUI::PaintEvent&) override = 0;
+
+    Color m_color_at_mouseposition = Color::Transparent;
+    RefPtr<Image> m_image;
+};
+
+}