minor changes to selection widget

include/igl/opengl/glfw/imgui/SelectionPlugin.cpp

@@ -22,7 +22,7 @@ igl::opengl::glfw::imgui::SelectionPlugin usage:
 }
 IGL_INLINE bool SelectionPlugin::pre_draw()
 {
-  if(!visible){ return false; }
+  if(mode == OFF){ return false; }
   ImGuiMenu::pre_draw();
   return false;
 }
@@ -84,7 +84,7 @@ IGL_INLINE bool SelectionPlugin::post_draw()
 
 IGL_INLINE bool SelectionPlugin::mouse_down(int button, int modifier)
 {
-  if(mode == OFF){ return false;}
+  if(mode == OFF || (modifier & IGL_MOD_ALT) ){ return false;}
   is_down = true;
   has_moved_since_down = false;
   if(!is_drawing)
@@ -143,13 +143,11 @@ IGL_INLINE bool SelectionPlugin::mouse_move(int mouse_x, int mouse_y)
 
 IGL_INLINE bool SelectionPlugin::key_pressed(unsigned int key, int modifiers)
 {
-  const auto clear = [&]() { M.setZero(); L.clear(); is_drawing = false; is_down = false; };
+  Mode old = mode;
   if(OFF_KEY.find(char(key)) != std::string::npos)
   {
-      mode = OFF;
-      return true;
-  }
-  if(LASSO_KEY.find(char(key)) != std::string::npos)
+    mode = OFF;
+  }else if(LASSO_KEY.find(char(key)) != std::string::npos)
   {
     if(mode == LASSO)
     {
@@ -158,10 +156,7 @@ IGL_INLINE bool SelectionPlugin::key_pressed(unsigned int key, int modifiers)
     {
       mode = LASSO;
     }
-    clear();
-    return true;
-  }
-  if(MARQUEE_KEY.find(char(key)) != std::string::npos)
+  }else if(MARQUEE_KEY.find(char(key)) != std::string::npos)
   {
     if(mode == RECTANGULAR_MARQUEE)
     {
@@ -170,12 +165,24 @@ IGL_INLINE bool SelectionPlugin::key_pressed(unsigned int key, int modifiers)
     {
       mode = RECTANGULAR_MARQUEE;
     }
+  }
+  if(old != mode)
+  {
     clear();
+    if(callback_post_mode_change){ callback_post_mode_change(old); } 
     return true;
   }
   return false;
 }
 
+IGL_INLINE void SelectionPlugin::clear()
+{ 
+  M.setZero(); 
+  L.clear(); 
+  is_drawing = false; 
+  is_down = false; 
+};
+
 IGL_INLINE void SelectionPlugin::circle(const Eigen::Matrix<float,2,2> & M,  std::vector<Eigen::RowVector2f> & L)
 {
   L.clear();

include/igl/opengl/glfw/imgui/SelectionPlugin.h

@@ -13,25 +13,6 @@ namespace igl{ namespace opengl{ namespace glfw{ namespace imgui{
 class SelectionPlugin: public igl::opengl::glfw::imgui::ImGuiMenu
 {
 public:
-  // callback called when slection is completed (usually on mouse_up)
-  std::function<void(void)> callback;
-  // whether rotating, translating or scaling
-  ImGuizmo::OPERATION operation;
-  // stored transformation
-  Eigen::Matrix4f T;
-  // Initilize with rotate operation on an identity transform (at origin)
-  SelectionPlugin():operation(ImGuizmo::ROTATE),T(Eigen::Matrix4f::Identity()){};
-  IGL_INLINE virtual void init(igl::opengl::glfw::Viewer *_viewer) override;
-  IGL_INLINE virtual bool pre_draw() override;
-  IGL_INLINE virtual bool post_draw() override;
-  IGL_INLINE virtual bool mouse_down(int button, int modifier) override;
-  IGL_INLINE virtual bool mouse_up(int button, int modifier) override;
-  IGL_INLINE virtual bool mouse_move(int mouse_x, int mouse_y) override;
-  IGL_INLINE virtual bool key_pressed(unsigned int key, int modifiers) override;
-  // helpers
-  IGL_INLINE static void circle(const Eigen::Matrix<float,2,2> & M,  std::vector<Eigen::RowVector2f> & L);
-  IGL_INLINE static void rect(const Eigen::Matrix<float,2,2> & M,  std::vector<Eigen::RowVector2f> & L);
-  IGL_INLINE static Eigen::RowVector2f xy(const Viewer * v);
   // customizable hotkeys
   std::string MARQUEE_KEY = "Mm";
   // leave 'L' for show_lines in viewer
@@ -46,7 +27,6 @@ public:
     LASSO               = 4,
     NUM_MODES           = 5
   } mode = RECTANGULAR_MARQUEE;
-  bool visible = true;
   bool is_down = false;
   bool has_moved_since_down = false;
   bool is_drawing = false;
@@ -54,6 +34,30 @@ public:
   Eigen::Matrix<float,2,2> M = Eigen::Matrix<float,2,2>::Zero();
   // list of points of 2D lasso marquee
   std::vector<Eigen::RowVector2f> L;
+  // callback called when slection is completed (usually on mouse_up)
+  std::function<void(void)> callback;
+  // callback called after mode is changed 
+  std::function<void(Mode)> callback_post_mode_change;
+  // whether rotating, translating or scaling
+  ImGuizmo::OPERATION operation;
+  // stored transformation
+  Eigen::Matrix4f T;
+  // Initilize with rotate operation on an identity transform (at origin)
+  SelectionPlugin():operation(ImGuizmo::ROTATE),T(Eigen::Matrix4f::Identity()){};
+  IGL_INLINE virtual void init(igl::opengl::glfw::Viewer *_viewer) override;
+  IGL_INLINE virtual bool pre_draw() override;
+  IGL_INLINE virtual bool post_draw() override;
+  IGL_INLINE virtual bool mouse_down(int button, int modifier) override;
+  IGL_INLINE virtual bool mouse_up(int button, int modifier) override;
+  IGL_INLINE virtual bool mouse_move(int mouse_x, int mouse_y) override;
+  IGL_INLINE virtual bool key_pressed(unsigned int key, int modifiers) override;
+  IGL_INLINE void clear();
+  // helpers
+  IGL_INLINE static void circle(const Eigen::Matrix<float,2,2> & M,  std::vector<Eigen::RowVector2f> & L);
+  IGL_INLINE static void rect(const Eigen::Matrix<float,2,2> & M,  std::vector<Eigen::RowVector2f> & L);
+  IGL_INLINE static Eigen::RowVector2f xy(const Viewer * v);
+public:
+  EIGEN_MAKE_ALIGNED_OPERATOR_NEW
 };
 
 }}}}