PixelPaint: Add a GUI for editing opacity and visibility of layers

Also, make the layer stack rendering respect opacity and visibility.

Applications/PixelPaint/CMakeLists.txt

@@ -7,6 +7,7 @@ set(SOURCES
     ImageEditor.cpp
     Layer.cpp
     LayerListWidget.cpp
+    LayerPropertiesWidget.cpp
     LineTool.cpp
     main.cpp
     MoveTool.cpp

Applications/PixelPaint/Image.cpp

@@ -54,9 +54,11 @@ void Image::paint_into(GUI::Painter& painter, const Gfx::IntRect& dest_rect)
     Gfx::PainterStateSaver saver(painter);
     painter.add_clip_rect(dest_rect);
     for (auto& layer : m_layers) {
+        if (!layer.is_visible())
+            continue;
         auto target = dest_rect.translated(layer.location().x() * scale, layer.location().y() * scale);
         target.set_size(layer.size().width() * scale, layer.size().height() * scale);
-        painter.draw_scaled_bitmap(target, layer.bitmap(), layer.rect());
+        painter.draw_scaled_bitmap(target, layer.bitmap(), layer.rect(), (float)layer.opacity_percent() / 100.0f);
     }
 }
 
@@ -174,6 +176,15 @@ void Image::layer_did_modify_bitmap(Badge<Layer>, const Layer& layer)
     did_change();
 }
 
+void Image::layer_did_modify_properties(Badge<Layer>, const Layer& layer)
+{
+    auto layer_index = index_of(layer);
+    for (auto* client : m_clients)
+        client->image_did_modify_layer(layer_index);
+
+    did_change();
+}
+
 void Image::did_change()
 {
     for (auto* client : m_clients)

Applications/PixelPaint/Image.h

@@ -75,6 +75,7 @@ public:
     void remove_client(ImageClient&);
 
     void layer_did_modify_bitmap(Badge<Layer>, const Layer&);
+    void layer_did_modify_properties(Badge<Layer>, const Layer&);
 
     size_t index_of(const Layer&) const;
 

Applications/PixelPaint/Layer.cpp

@@ -30,7 +30,7 @@
 
 namespace PixelPaint {
 
-RefPtr<Layer> Layer::create_with_size(const Gfx::IntSize& size, const String& name)
+RefPtr<Layer> Layer::create_with_size(Image& image, const Gfx::IntSize& size, const String& name)
 {
     if (size.is_empty())
         return nullptr;
@@ -38,11 +38,12 @@ RefPtr<Layer> Layer::create_with_size(const Gfx::IntSize& size, const String& na
     if (size.width() > 16384 || size.height() > 16384)
         return nullptr;
 
-    return adopt(*new Layer(size, name));
+    return adopt(*new Layer(image, size, name));
 }
 
-Layer::Layer(const Gfx::IntSize& size, const String& name)
-    : m_name(name)
+Layer::Layer(Image& image, const Gfx::IntSize& size, const String& name)
+    : m_image(image)
+    , m_name(name)
 {
     m_bitmap = Gfx::Bitmap::create(Gfx::BitmapFormat::RGBA32, size);
 }
@@ -52,4 +53,20 @@ void Layer::did_modify_bitmap(Image& image)
     image.layer_did_modify_bitmap({}, *this);
 }
 
+void Layer::set_visible(bool visible)
+{
+    if (m_visible == visible)
+        return;
+    m_visible = visible;
+    m_image.layer_did_modify_properties({}, *this);
+}
+
+void Layer::set_opacity_percent(int opacity_percent)
+{
+    if (m_opacity_percent == opacity_percent)
+        return;
+    m_opacity_percent = opacity_percent;
+    m_image.layer_did_modify_properties({}, *this);
+}
+
 }

Applications/PixelPaint/Layer.h

@@ -29,20 +29,24 @@
 #include <AK/Noncopyable.h>
 #include <AK/RefCounted.h>
 #include <AK/String.h>
+#include <AK/Weakable.h>
 #include <LibGfx/Bitmap.h>
 
 namespace PixelPaint {
 
 class Image;
 
-class Layer : public RefCounted<Layer> {
+class Layer
+    : public RefCounted<Layer>
+    , public Weakable<Layer> {
+
     AK_MAKE_NONCOPYABLE(Layer);
     AK_MAKE_NONMOVABLE(Layer);
 
 public:
-    static RefPtr<Layer> create_with_size(const Gfx::IntSize&, const String& name);
+    static RefPtr<Layer> create_with_size(Image&, const Gfx::IntSize&, const String& name);
 
-    ~Layer() {}
+    ~Layer() { }
 
     const Gfx::IntPoint& location() const { return m_location; }
     void set_location(const Gfx::IntPoint& location) { m_location = location; }
@@ -62,14 +66,25 @@ public:
     void set_selected(bool selected) { m_selected = selected; }
     bool is_selected() const { return m_selected; }
 
+    bool is_visible() const { return m_visible; }
+    void set_visible(bool visible);
+
+    int opacity_percent() const { return m_opacity_percent; }
+    void set_opacity_percent(int);
+
 private:
-    explicit Layer(const Gfx::IntSize&, const String& name);
+    explicit Layer(Image&, const Gfx::IntSize&, const String& name);
+
+    Image& m_image;
 
     String m_name;
     Gfx::IntPoint m_location;
     RefPtr<Gfx::Bitmap> m_bitmap;
 
     bool m_selected { false };
+    bool m_visible { true };
+
+    int m_opacity_percent { 100 };
 };
 
 }

Applications/PixelPaint/LayerPropertiesWidget.cpp

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "LayerPropertiesWidget.h"
+#include "Layer.h"
+#include <LibGUI/BoxLayout.h>
+#include <LibGUI/CheckBox.h>
+#include <LibGUI/Label.h>
+#include <LibGUI/Slider.h>
+#include <LibGfx/Font.h>
+
+namespace PixelPaint {
+
+LayerPropertiesWidget::LayerPropertiesWidget()
+{
+    set_layout<GUI::VerticalBoxLayout>();
+    auto& label = add<GUI::Label>("Layer properties");
+    label.set_font(Gfx::Font::default_bold_font());
+
+    m_opacity_slider = add<GUI::HorizontalSlider>();
+    m_opacity_slider->set_range(0, 100);
+    m_opacity_slider->on_value_changed = [this](int value) {
+        if (m_layer)
+            m_layer->set_opacity_percent(value);
+    };
+
+    m_visibility_checkbox = add<GUI::CheckBox>("Visible");
+    m_visibility_checkbox->on_checked = [this](bool checked) {
+        if (m_layer)
+            m_layer->set_visible(checked);
+    };
+}
+
+LayerPropertiesWidget::~LayerPropertiesWidget()
+{
+}
+
+void LayerPropertiesWidget::set_layer(Layer* layer)
+{
+    if (m_layer == layer)
+        return;
+
+    if (layer) {
+        m_layer = layer->make_weak_ptr();
+        m_opacity_slider->set_value(layer->opacity_percent());
+        m_visibility_checkbox->set_checked(layer->is_visible());
+        set_enabled(true);
+    } else {
+        m_layer = nullptr;
+        set_enabled(false);
+    }
+}
+
+}

Applications/PixelPaint/LayerPropertiesWidget.h

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <LibGUI/Widget.h>
+
+namespace PixelPaint {
+
+class Layer;
+
+class LayerPropertiesWidget final : public GUI::Widget {
+    C_OBJECT(LayerPropertiesWidget);
+
+public:
+    virtual ~LayerPropertiesWidget() override;
+
+    void set_layer(Layer*);
+
+private:
+    LayerPropertiesWidget();
+
+    RefPtr<GUI::CheckBox> m_visibility_checkbox;
+    RefPtr<GUI::HorizontalSlider> m_opacity_slider;
+
+    WeakPtr<Layer> m_layer;
+};
+
+}

Applications/PixelPaint/main.cpp

@@ -32,6 +32,7 @@
 #include "PaletteWidget.h"
 #include "Tool.h"
 #include "ToolboxWidget.h"
+#include "LayerPropertiesWidget.h"
 #include <LibGUI/AboutDialog.h>
 #include <LibGUI/Action.h>
 #include <LibGUI/Application.h>
@@ -94,6 +95,8 @@ int main(int argc, char** argv)
 
     auto& layer_list_widget = right_panel.add<PixelPaint::LayerListWidget>();
 
+    auto& layer_properties_widget = right_panel.add<PixelPaint::LayerPropertiesWidget>();
+
     window->show();
 
     auto menubar = GUI::MenuBar::construct();
@@ -131,7 +134,7 @@ int main(int argc, char** argv)
         "Create new layer...", { Mod_Ctrl | Mod_Shift, Key_N }, [&](auto&) {
             auto dialog = PixelPaint::CreateNewLayerDialog::construct(image_editor.image()->size(), window);
             if (dialog->exec() == GUI::Dialog::ExecOK) {
-                auto layer = PixelPaint::Layer::create_with_size(dialog->layer_size(), dialog->layer_name());
+                auto layer = PixelPaint::Layer::create_with_size(*image_editor.image(), dialog->layer_size(), dialog->layer_name());
                 if (!layer) {
                     GUI::MessageBox::show_error(window, String::format("Unable to create layer with size %s", dialog->size().to_string().characters()));
                     return;
@@ -200,20 +203,21 @@ int main(int argc, char** argv)
 
     image_editor.on_active_layer_change = [&](auto* layer) {
         layer_list_widget.set_selected_layer(layer);
+        layer_properties_widget.set_layer(layer);
     };
 
     auto image = PixelPaint::Image::create_with_size({ 640, 480 });
 
-    auto bg_layer = PixelPaint::Layer::create_with_size({ 640, 480 }, "Background");
+    auto bg_layer = PixelPaint::Layer::create_with_size(*image, { 640, 480 }, "Background");
     image->add_layer(*bg_layer);
     bg_layer->bitmap().fill(Color::White);
 
-    auto fg_layer1 = PixelPaint::Layer::create_with_size({ 200, 200 }, "FG Layer 1");
+    auto fg_layer1 = PixelPaint::Layer::create_with_size(*image, { 200, 200 }, "FG Layer 1");
     fg_layer1->set_location({ 50, 50 });
     image->add_layer(*fg_layer1);
     fg_layer1->bitmap().fill(Color::Yellow);
 
-    auto fg_layer2 = PixelPaint::Layer::create_with_size({ 100, 100 }, "FG Layer 2");
+    auto fg_layer2 = PixelPaint::Layer::create_with_size(*image, { 100, 100 }, "FG Layer 2");
     fg_layer2->set_location({ 300, 300 });
     image->add_layer(*fg_layer2);
     fg_layer2->bitmap().fill(Color::Blue);