PaintBrush: Add a "Move" tool for moving layers around :^)

Tool mouse event handlers now receive both a layer-relative mouse event
and the original event. This is needed for the move tool since it moves
the layer and thereby changes the origin of future events every time it
moves.

Applications/PaintBrush/BucketTool.cpp

@@ -78,7 +78,7 @@ static void flood_fill(Gfx::Bitmap& bitmap, const Gfx::Point& start_position, Co
     }
 }
 
-void BucketTool::on_mousedown(Layer& layer, GUI::MouseEvent& event)
+void BucketTool::on_mousedown(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (!layer.rect().contains(event.position()))
         return;

Applications/PaintBrush/BucketTool.h

@@ -35,7 +35,7 @@ public:
     BucketTool();
     virtual ~BucketTool() override;
 
-    virtual void on_mousedown(Layer&, GUI::MouseEvent&) override;
+    virtual void on_mousedown(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
 
 private:
     virtual const char* class_name() const override { return "BucketTool"; }

Applications/PaintBrush/EllipseTool.cpp

@@ -56,7 +56,7 @@ void EllipseTool::draw_using(GUI::Painter& painter)
     }
 }
 
-void EllipseTool::on_mousedown(Layer&, GUI::MouseEvent& event)
+void EllipseTool::on_mousedown(Layer&, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (event.button() != GUI::MouseButton::Left && event.button() != GUI::MouseButton::Right)
         return;
@@ -70,7 +70,7 @@ void EllipseTool::on_mousedown(Layer&, GUI::MouseEvent& event)
     m_editor->update();
 }
 
-void EllipseTool::on_mouseup(Layer& layer, GUI::MouseEvent& event)
+void EllipseTool::on_mouseup(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (event.button() == m_drawing_button) {
         GUI::Painter painter(layer.bitmap());
@@ -80,7 +80,7 @@ void EllipseTool::on_mouseup(Layer& layer, GUI::MouseEvent& event)
     }
 }
 
-void EllipseTool::on_mousemove(Layer& layer, GUI::MouseEvent& event)
+void EllipseTool::on_mousemove(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (m_drawing_button == GUI::MouseButton::None)
         return;

Applications/PaintBrush/EllipseTool.h

@@ -37,9 +37,9 @@ public:
     EllipseTool();
     virtual ~EllipseTool() override;
 
-    virtual void on_mousedown(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mousemove(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mouseup(Layer&, GUI::MouseEvent&) override;
+    virtual void on_mousedown(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mousemove(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mouseup(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
     virtual void on_contextmenu(GUI::ContextMenuEvent&) override;
     virtual void on_second_paint(GUI::PaintEvent&) override;
     virtual void on_keydown(GUI::KeyEvent&) override;

Applications/PaintBrush/EraseTool.cpp

@@ -53,7 +53,7 @@ Gfx::Rect EraseTool::build_rect(const Gfx::Point& pos, const Gfx::Rect& widget_r
     return Gfx::Rect(ex - eraser_radius, ey - eraser_radius, eraser_size, eraser_size).intersected(widget_rect);
 }
 
-void EraseTool::on_mousedown(Layer& layer, GUI::MouseEvent& event)
+void EraseTool::on_mousedown(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (event.button() != GUI::MouseButton::Left && event.button() != GUI::MouseButton::Right)
         return;
@@ -63,7 +63,7 @@ void EraseTool::on_mousedown(Layer& layer, GUI::MouseEvent& event)
     m_editor->update();
 }
 
-void EraseTool::on_mousemove(Layer& layer, GUI::MouseEvent& event)
+void EraseTool::on_mousemove(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (!m_editor->rect().contains(event.position()))
         return;

Applications/PaintBrush/EraseTool.h

@@ -38,8 +38,8 @@ public:
     EraseTool();
     virtual ~EraseTool() override;
 
-    virtual void on_mousedown(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mousemove(Layer&, GUI::MouseEvent&) override;
+    virtual void on_mousedown(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mousemove(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
     virtual void on_contextmenu(GUI::ContextMenuEvent&) override;
 
 private:

Applications/PaintBrush/ImageEditor.cpp

@@ -79,7 +79,7 @@ void ImageEditor::mousedown_event(GUI::MouseEvent& event)
     if (!m_active_layer || !m_active_tool)
         return;
     auto layer_event = event_adjusted_for_layer(event, *m_active_layer);
-    m_active_tool->on_mousedown(*m_active_layer, layer_event);
+    m_active_tool->on_mousedown(*m_active_layer, layer_event, event);
 }
 
 void ImageEditor::mousemove_event(GUI::MouseEvent& event)
@@ -87,7 +87,7 @@ void ImageEditor::mousemove_event(GUI::MouseEvent& event)
     if (!m_active_layer || !m_active_tool)
         return;
     auto layer_event = event_adjusted_for_layer(event, *m_active_layer);
-    m_active_tool->on_mousemove(*m_active_layer, layer_event);
+    m_active_tool->on_mousemove(*m_active_layer, layer_event, event);
 }
 
 void ImageEditor::mouseup_event(GUI::MouseEvent& event)
@@ -95,7 +95,7 @@ void ImageEditor::mouseup_event(GUI::MouseEvent& event)
     if (!m_active_layer || !m_active_tool)
         return;
     auto layer_event = event_adjusted_for_layer(event, *m_active_layer);
-    m_active_tool->on_mouseup(*m_active_layer, layer_event);
+    m_active_tool->on_mouseup(*m_active_layer, layer_event, event);
 }
 
 void ImageEditor::set_active_layer(Layer* layer)

Applications/PaintBrush/LineTool.cpp

@@ -56,7 +56,7 @@ LineTool::~LineTool()
 {
 }
 
-void LineTool::on_mousedown(Layer&, GUI::MouseEvent& event)
+void LineTool::on_mousedown(Layer&, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (event.button() != GUI::MouseButton::Left && event.button() != GUI::MouseButton::Right)
         return;
@@ -70,7 +70,7 @@ void LineTool::on_mousedown(Layer&, GUI::MouseEvent& event)
     m_editor->update();
 }
 
-void LineTool::on_mouseup(Layer& layer, GUI::MouseEvent& event)
+void LineTool::on_mouseup(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (event.button() == m_drawing_button) {
         GUI::Painter painter(layer.bitmap());
@@ -80,7 +80,7 @@ void LineTool::on_mouseup(Layer& layer, GUI::MouseEvent& event)
     }
 }
 
-void LineTool::on_mousemove(Layer&, GUI::MouseEvent& event)
+void LineTool::on_mousemove(Layer&, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (m_drawing_button == GUI::MouseButton::None)
         return;

Applications/PaintBrush/LineTool.h

@@ -37,9 +37,9 @@ public:
     LineTool();
     virtual ~LineTool() override;
 
-    virtual void on_mousedown(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mousemove(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mouseup(Layer&, GUI::MouseEvent&) override;
+    virtual void on_mousedown(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mousemove(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mouseup(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
     virtual void on_contextmenu(GUI::ContextMenuEvent&) override;
     virtual void on_second_paint(GUI::PaintEvent&) override;
     virtual void on_keydown(GUI::KeyEvent&) override;

Applications/PaintBrush/Makefile

@@ -7,6 +7,7 @@ OBJS = \
     Layer.o \
     LayerModel.o \
     LineTool.o \
+    MoveTool.o \
     PaintableWidget.o \
     PaletteWidget.o \
     PenTool.o \

Applications/PaintBrush/MoveTool.cpp

@@ -0,0 +1,70 @@
+/*
+ * 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 "MoveTool.h"
+#include "ImageEditor.h"
+#include "Layer.h"
+#include "PaintableWidget.h"
+#include <LibGfx/Bitmap.h>
+
+namespace PaintBrush {
+
+MoveTool::MoveTool()
+{
+}
+
+MoveTool::~MoveTool()
+{
+}
+
+void MoveTool::on_mousedown(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent& original_event)
+{
+    if (event.button() != GUI::MouseButton::Left)
+        return;
+    if (!layer.rect().contains(event.position()))
+        return;
+    m_layer_being_moved = layer;
+    m_event_origin = original_event.position();
+    m_layer_origin = layer.location();
+}
+
+void MoveTool::on_mousemove(Layer&, GUI::MouseEvent&, GUI::MouseEvent& original_event)
+{
+    if (!m_layer_being_moved)
+        return;
+    auto delta = original_event.position() - m_event_origin;
+    m_layer_being_moved->set_location(m_layer_origin.translated(delta));
+    m_editor->update();
+}
+
+void MoveTool::on_mouseup(Layer&, GUI::MouseEvent& event, GUI::MouseEvent&)
+{
+    if (event.button() != GUI::MouseButton::Left)
+        return;
+    m_layer_being_moved = nullptr;
+}
+
+}

Applications/PaintBrush/MoveTool.h

@@ -0,0 +1,50 @@
+/*
+ * 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 "Tool.h"
+
+namespace PaintBrush {
+
+class MoveTool final : public Tool {
+public:
+    MoveTool();
+    virtual ~MoveTool() override;
+
+    virtual void on_mousedown(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mousemove(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mouseup(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+
+private:
+    virtual const char* class_name() const override { return "MoveTool"; }
+
+    RefPtr<Layer> m_layer_being_moved;
+    Gfx::Point m_event_origin;
+    Gfx::Point m_layer_origin;
+};
+
+}

Applications/PaintBrush/PenTool.cpp

@@ -42,7 +42,7 @@ PenTool::~PenTool()
 {
 }
 
-void PenTool::on_mousedown(Layer& layer, GUI::MouseEvent& event)
+void PenTool::on_mousedown(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (event.button() != GUI::MouseButton::Left && event.button() != GUI::MouseButton::Right)
         return;
@@ -53,13 +53,13 @@ void PenTool::on_mousedown(Layer& layer, GUI::MouseEvent& event)
     m_last_drawing_event_position = event.position();
 }
 
-void PenTool::on_mouseup(Layer&, GUI::MouseEvent& event)
+void PenTool::on_mouseup(Layer&, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (event.button() == GUI::MouseButton::Left || event.button() == GUI::MouseButton::Right)
         m_last_drawing_event_position = { -1, -1 };
 }
 
-void PenTool::on_mousemove(Layer& layer, GUI::MouseEvent& event)
+void PenTool::on_mousemove(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (!layer.rect().contains(event.position()))
         return;

Applications/PaintBrush/PenTool.h

@@ -37,9 +37,9 @@ public:
     PenTool();
     virtual ~PenTool() override;
 
-    virtual void on_mousedown(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mousemove(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mouseup(Layer&, GUI::MouseEvent&) override;
+    virtual void on_mousedown(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mousemove(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mouseup(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
     virtual void on_contextmenu(GUI::ContextMenuEvent&) override;
 
 private:

Applications/PaintBrush/PickerTool.cpp

@@ -39,7 +39,7 @@ PickerTool::~PickerTool()
 {
 }
 
-void PickerTool::on_mousedown(Layer& layer, GUI::MouseEvent& event)
+void PickerTool::on_mousedown(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (!layer.rect().contains(event.position()))
         return;

Applications/PaintBrush/PickerTool.h

@@ -35,7 +35,7 @@ public:
     PickerTool();
     virtual ~PickerTool() override;
 
-    virtual void on_mousedown(Layer&, GUI::MouseEvent&) override;
+    virtual void on_mousedown(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
 
 private:
     virtual const char* class_name() const override { return "PickerTool"; }

Applications/PaintBrush/RectangleTool.cpp

@@ -62,7 +62,7 @@ void RectangleTool::draw_using(GUI::Painter& painter)
     }
 }
 
-void RectangleTool::on_mousedown(Layer&, GUI::MouseEvent& event)
+void RectangleTool::on_mousedown(Layer&, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (event.button() != GUI::MouseButton::Left && event.button() != GUI::MouseButton::Right)
         return;
@@ -76,7 +76,7 @@ void RectangleTool::on_mousedown(Layer&, GUI::MouseEvent& event)
     m_editor->update();
 }
 
-void RectangleTool::on_mouseup(Layer& layer, GUI::MouseEvent& event)
+void RectangleTool::on_mouseup(Layer& layer, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (event.button() == m_drawing_button) {
         GUI::Painter painter(layer.bitmap());
@@ -86,7 +86,7 @@ void RectangleTool::on_mouseup(Layer& layer, GUI::MouseEvent& event)
     }
 }
 
-void RectangleTool::on_mousemove(Layer&, GUI::MouseEvent& event)
+void RectangleTool::on_mousemove(Layer&, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (m_drawing_button == GUI::MouseButton::None)
         return;

Applications/PaintBrush/RectangleTool.h

@@ -37,9 +37,9 @@ public:
     RectangleTool();
     virtual ~RectangleTool() override;
 
-    virtual void on_mousedown(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mousemove(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mouseup(Layer&, GUI::MouseEvent&) override;
+    virtual void on_mousedown(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mousemove(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mouseup(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
     virtual void on_contextmenu(GUI::ContextMenuEvent&) override;
     virtual void on_second_paint(GUI::PaintEvent&) override;
     virtual void on_keydown(GUI::KeyEvent&) override;

Applications/PaintBrush/SprayTool.cpp

@@ -82,7 +82,7 @@ void SprayTool::paint_it()
     }
 }
 
-void SprayTool::on_mousedown(Layer&, GUI::MouseEvent& event)
+void SprayTool::on_mousedown(Layer&, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     if (!m_editor->rect().contains(event.position()))
         return;
@@ -93,7 +93,7 @@ void SprayTool::on_mousedown(Layer&, GUI::MouseEvent& event)
     paint_it();
 }
 
-void SprayTool::on_mousemove(Layer&, GUI::MouseEvent& event)
+void SprayTool::on_mousemove(Layer&, GUI::MouseEvent& event, GUI::MouseEvent&)
 {
     m_last_pos = event.position();
     if (m_timer->is_active()) {
@@ -102,7 +102,7 @@ void SprayTool::on_mousemove(Layer&, GUI::MouseEvent& event)
     }
 }
 
-void SprayTool::on_mouseup(Layer&, GUI::MouseEvent&)
+void SprayTool::on_mouseup(Layer&, GUI::MouseEvent&, GUI::MouseEvent&)
 {
     m_timer->stop();
 }

Applications/PaintBrush/SprayTool.h

@@ -38,9 +38,9 @@ public:
     SprayTool();
     virtual ~SprayTool() override;
 
-    virtual void on_mousedown(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mouseup(Layer&, GUI::MouseEvent&) override;
-    virtual void on_mousemove(Layer&, GUI::MouseEvent&) override;
+    virtual void on_mousedown(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mouseup(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
+    virtual void on_mousemove(Layer&, GUI::MouseEvent& layer_event, GUI::MouseEvent& original_event) override;
     virtual void on_contextmenu(GUI::ContextMenuEvent&) override;
 
 private:

Applications/PaintBrush/Tool.h

@@ -39,9 +39,9 @@ public:
 
     virtual const char* class_name() const = 0;
 
-    virtual void on_mousedown(Layer&, GUI::MouseEvent&) {}
-    virtual void on_mousemove(Layer&, GUI::MouseEvent&) {}
-    virtual void on_mouseup(Layer&, GUI::MouseEvent&) {}
+    virtual void on_mousedown(Layer&, GUI::MouseEvent&, GUI::MouseEvent&) {}
+    virtual void on_mousemove(Layer&, GUI::MouseEvent&, GUI::MouseEvent&) {}
+    virtual void on_mouseup(Layer&, GUI::MouseEvent&, GUI::MouseEvent&) {}
     virtual void on_contextmenu(GUI::ContextMenuEvent&) {}
     virtual void on_second_paint(GUI::PaintEvent&) {}
     virtual void on_keydown(GUI::KeyEvent&) {}

Applications/PaintBrush/ToolboxWidget.cpp

@@ -29,6 +29,7 @@
 #include "EllipseTool.h"
 #include "EraseTool.h"
 #include "LineTool.h"
+#include "MoveTool.h"
 #include "PaintableWidget.h"
 #include "PenTool.h"
 #include "PickerTool.h"
@@ -92,6 +93,7 @@ ToolboxWidget::ToolboxWidget()
         };
     };
 
+    add_tool("Move", "move", make<MoveTool>());
     add_tool("Pen", "pen", make<PenTool>());
     add_tool("Bucket Fill", "bucket", make<BucketTool>());
     add_tool("Spray", "spray", make<SprayTool>());