add history to equirect import

src/canvas_actions.cpp

@@ -96,3 +96,51 @@ Action* ActionStroke::get_redo()
     action->clear_layer = false;
     return action;
 }
+
+//////////////////////////////////////////////////////////////////////////
+
+Action* ActionLayerClear::get_redo()
+{
+    auto a = new ActionLayerClear;
+    a->m_direction = reverse_direction();
+    a->m_snap = m_snap;
+    a->m_layer = m_layer;
+    a->m_color = m_color;
+    return a;
+}
+
+void ActionLayerClear::undo()
+{
+    if (m_direction == Direction::Undo)
+    {
+        m_layer->restore(*m_snap);
+    }
+    else
+    {
+        m_layer->clear(m_color);
+    }
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+Action* ActionImportEquirect::get_redo()
+{
+    auto a = new ActionImportEquirect;
+    a->m_direction = reverse_direction();
+    a->m_snap = m_snap;
+    a->m_layer = m_layer;
+    a->m_path = m_path;
+    return a;
+}
+
+void ActionImportEquirect::undo()
+{
+    if (m_direction == Direction::Undo)
+    {
+        m_layer->restore(*m_snap);
+    }
+    else
+    {
+        Canvas::I->import_equirectangular_thread(m_path, m_layer);
+    }
+}