Add "Transform" checkbox to slices and introduce moving slice content

data/strings/en.ini

@@ -578,6 +578,8 @@ all = All
 none = None
 select_slices = Select All Slices
 deselect_slices = Deselect Slices
+slice_transform = Transform
+slice_transform_tip = Transform pixels along slice modification
 slice_props = Slice Properties
 delete_slice = Delete Slice
 discard_brush = Discard Brush (Esc)

src/app/ui/context_bar.cpp

@@ -1650,6 +1650,7 @@ public:
     : m_doc(nullptr)
     , m_sel(2)
     , m_combobox(this)
+    , m_transform(Strings::context_bar_slice_transform())
     , m_action(2)
   {
     auto* theme = SkinTheme::get(this);
@@ -1665,6 +1666,14 @@ public:
     m_combobox.setExpansive(true);
     m_combobox.setMinSize(gfx::Size(256*guiscale(), 0));
 
+    if (auto* editor = Editor::activeEditor())
+      m_transform.setSelected(editor->slicesTransforms());
+    m_transform.Click.connect(
+      [this]() {
+        if (auto* editor = Editor::activeEditor())
+          editor->slicesTransforms(m_transform.isSelected());
+      });
+
     m_action.addItem(theme->parts.iconUserData(), theme->styles.buttonsetItemIconMono());
     m_action.addItem(theme->parts.iconClose(), theme->styles.buttonsetItemIconMono());
     m_action.ItemChange.connect(
@@ -1674,6 +1683,7 @@ public:
 
     addChild(&m_sel);
     addChild(&m_combobox);
+    addChild(&m_transform);
     addChild(&m_action);
 
     m_combobox.setVisible(false);
@@ -1685,6 +1695,8 @@ public:
       m_sel.at(0), Strings::context_bar_select_slices(), BOTTOM);
     tooltipManager->addTooltipFor(
       m_sel.at(1), Strings::context_bar_deselect_slices(), BOTTOM);
+    tooltipManager->addTooltipFor(
+      &m_transform, Strings::context_bar_slice_transform_tip(), BOTTOM);
     tooltipManager->addTooltipFor(
       m_action.at(0), Strings::context_bar_slice_props(), BOTTOM);
     tooltipManager->addTooltipFor(
@@ -1731,6 +1743,12 @@ public:
   }
 
 private:
+  void onInitTheme(InitThemeEvent& ev) override {
+    HBox::onInitTheme(ev);
+    auto* theme = SkinTheme::get(this);
+    m_transform.setStyle(theme->styles.miniCheckBox());
+  }
+
   void onVisible(bool visible) override {
     HBox::onVisible(visible);
     m_combobox.closeListBox();
@@ -1764,6 +1782,7 @@ private:
                            visible != m_action.isVisible());
 
     m_combobox.setVisible(visible);
+    m_transform.setVisible(visible);
     m_action.setVisible(visible);
 
     if (relayout)
@@ -1833,6 +1852,7 @@ private:
   Doc* m_doc;
   ButtonSet m_sel;
   Combo m_combobox;
+  CheckBox m_transform;
   ButtonSet m_action;
   bool m_changeFromEntry;
   std::string m_filter;

src/app/ui/editor/editor.h

@@ -314,6 +314,8 @@ namespace app {
     bool selectSliceBox(const gfx::Rect& box);
     void selectAllSlices();
     bool hasSelectedSlices() const { return !m_selectedSlices.empty(); }
+    void slicesTransforms(bool value) { m_slicesTransforms = value; }
+    bool slicesTransforms() const { return m_slicesTransforms; }
 
     // Called by DocView's InputChainElement::onCancel() impl when Esc
     // key is pressed to cancel the active selection.
@@ -490,6 +492,9 @@ namespace app {
 
     // For slices
     doc::SelectedObjects m_selectedSlices;
+    // When true, modifications to slices positions/sizes will transform the
+    // pixels inside their boundaries.
+    bool m_slicesTransforms = false;
 
     // Active sprite editor with the keyboard focus.
     static Editor* m_activeEditor;

src/app/ui/editor/moving_slice_state.cpp

@@ -18,6 +18,7 @@
 #include "app/ui/status_bar.h"
 #include "app/ui_context.h"
 #include "doc/slice.h"
+#include "gfx/point.h"
 #include "ui/message.h"
 
 #include <algorithm>
@@ -30,10 +31,12 @@ using namespace ui;
 MovingSliceState::MovingSliceState(Editor* editor,
                                    MouseMessage* msg,
                                    const EditorHit& hit,
-                                   const doc::SelectedObjects& selectedSlices)
+                                   const doc::SelectedObjects& selectedSlices,
+                                   PixelsMovementPtr pixelsMovement)
   : m_frame(editor->frame())
   , m_hit(hit)
   , m_items(std::max<std::size_t>(1, selectedSlices.size()))
+  , m_pixelsMovement(pixelsMovement)
 {
   m_mouseStart = editor->screenToEditor(msg->position());
 
@@ -48,11 +51,31 @@ MovingSliceState::MovingSliceState(Editor* editor,
     }
   }
 
+  if (m_pixelsMovement) {
+    const gfx::Rect totalBounds = selectedSlicesBounds();
+    if (m_hit.border() == (CENTER | MIDDLE)) {
+      m_pixelsMovement->catchImage(gfx::PointF(totalBounds.origin()),
+                                  HandleType::MovePixelsHandle);
+    }
+    m_pixelsMovement->cutMask();
+  }
+
   editor->captureMouse();
 }
 
+EditorState::LeaveAction MovingSliceState::onLeaveState(Editor *editor, EditorState *newState)
+{
+  editor->document()->resetTransformation();
+  return StandbyState::onLeaveState(editor, newState);
+}
+
 bool MovingSliceState::onMouseUp(Editor* editor, MouseMessage* msg)
 {
+  if (m_pixelsMovement) {
+    m_pixelsMovement->dropImage();
+    m_pixelsMovement.reset();
+  }
+
   {
     ContextWriter writer(UIContext::instance(), 1000);
     Tx tx(writer, "Slice Movement", ModifyDocument);
@@ -67,6 +90,7 @@ bool MovingSliceState::onMouseUp(Editor* editor, MouseMessage* msg)
 
   editor->backToPreviousState();
   editor->releaseMouse();
+  editor->invalidate();
   return true;
 }
 
@@ -91,6 +115,12 @@ bool MovingSliceState::onMouseMove(Editor* editor, MouseMessage* msg)
     if (m_hit.border() == (CENTER | MIDDLE)) {
       rc.x += delta.x;
       rc.y += delta.y;
+
+      if (m_pixelsMovement) {
+        m_pixelsMovement->moveImage(gfx::PointF(totalBounds.origin()+delta),
+                                    PixelsMovement::MoveModifier::NormalMovement);
+        m_pixelsMovement->dropImageTemporarily();
+      }
     }
     // Move/resize 9-slices center
     else if (m_hit.type() == EditorHit::SliceCenter) {

src/app/ui/editor/moving_slice_state.h

@@ -11,6 +11,7 @@
 
 #include "app/ui/editor/editor_hit.h"
 #include "app/ui/editor/standby_state.h"
+#include "app/ui/editor/pixels_movement.h"
 #include "doc/frame.h"
 #include "doc/selected_objects.h"
 #include "doc/slice.h"
@@ -23,8 +24,10 @@ namespace app {
     MovingSliceState(Editor* editor,
                      ui::MouseMessage* msg,
                      const EditorHit& hit,
-                     const doc::SelectedObjects& selectedSlices);
+                     const doc::SelectedObjects& selectedSlices,
+                     PixelsMovementPtr pixelsMovement);
 
+    LeaveAction onLeaveState(Editor *editor, EditorState *newState) override;
     bool onMouseUp(Editor* editor, ui::MouseMessage* msg) override;
     bool onMouseMove(Editor* editor, ui::MouseMessage* msg) override;
     bool onSetCursor(Editor* editor, const gfx::Point& mouseScreenPos) override;
@@ -45,6 +48,8 @@ namespace app {
     EditorHit m_hit;
     gfx::Point m_mouseStart;
     std::vector<Item> m_items;
+    // Helper member to move/translate the pixels under the slices.
+    PixelsMovementPtr m_pixelsMovement;
   };
 
 } // namespace app

src/app/ui/editor/standby_state.cpp

@@ -246,8 +246,50 @@ bool StandbyState::onMouseDown(Editor* editor, MouseMessage* msg)
             editor->getSite(&site);
           }
 
+          PixelsMovementPtr pixelsMovement = nullptr;
+          if (editor->slicesTransforms() && !site.selectedSlices().empty()) {
+            site = Site();
+            editor->getSite(&site);
+            ImageRef tmpImage;
+
+            auto& slices = site.selectedSlices();
+            Mask newMask;
+            for (const auto& s : slices.iterateAs<Slice>()) {
+              newMask.add(s->getByFrame(site.frame())->bounds());
+            }
+
+            if (site.layer() &&
+                site.layer()->isTilemap() &&
+                site.tilemapMode() == TilemapMode::Tiles) {
+              tmpImage.reset(new_tilemap_from_mask(site, &newMask));
+            }
+            else {
+              tmpImage.reset(new_image_from_mask(site, &newMask,
+                                                    Preferences::instance().experimental.newBlend()));
+            }
+
+            ASSERT(tmpImage);
+            if (!tmpImage) {
+              // We've received a bug report with this case, we're not sure
+              // yet how to reproduce it. Probably new_tilemap_from_mask() can
+              // return nullptr (e.g. when site.cel() is nullptr?)
+              return true;
+            }
+
+            // Clear brush preview, as the extra cel will be replaced with the
+            // transformed image.
+            editor->brushPreview().hide();
+
+            pixelsMovement = PixelsMovementPtr(
+                              new PixelsMovement(UIContext::instance(),
+                                site,
+                                tmpImage.get(),
+                                &newMask,
+                                "Transformation"));
+          }
+
           MovingSliceState* newState = new MovingSliceState(
-            editor, msg, hit, site.selectedSlices());
+            editor, msg, hit, site.selectedSlices(), pixelsMovement);
           editor->setState(EditorStatePtr(newState));
         }
         else {